src/Unix/video_x.cpp

/*
 *  video_x.cpp - Video/graphics emulation, X11 specific stuff
 *
 *  SheepShaver (C) 1997-2005 Marc Hellwig and Christian Bauer
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "sysdeps.h"

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/keysym.h>
#include <X11/extensions/XShm.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <errno.h>
#include <pthread.h>

#include <algorithm>

#ifdef ENABLE_XF86_DGA
# include <X11/extensions/xf86dga.h>
#endif

#ifdef ENABLE_XF86_VIDMODE
# include <X11/extensions/xf86vmode.h>
#endif

#include "main.h"
#include "adb.h"
#include "prefs.h"
#include "user_strings.h"
#include "about_window.h"
#include "video.h"
#include "video_defs.h"
#include "video_blit.h"

#define DEBUG 0
#include "debug.h"

#ifndef NO_STD_NAMESPACE
using std::sort;
#endif


// Constants
const char KEYCODE_FILE_NAME[] = DATADIR "/keycodes";
static const bool hw_mac_cursor_accl = true;    // Flag: Enable MacOS to X11 copy of cursor?

// Global variables
static int32 frame_skip;
static int16 mouse_wheel_mode;
static int16 mouse_wheel_lines;
static bool redraw_thread_active = false;       // Flag: Redraw thread installed
static pthread_attr_t redraw_thread_attr;       // Redraw thread attributes
static volatile bool redraw_thread_cancel;      // Flag: Cancel Redraw thread
static pthread_t redraw_thread;                         // Redraw thread

static bool local_X11;                                          // Flag: X server running on local machine?
static volatile bool thread_stop_req = false;
static volatile bool thread_stop_ack = false;   // Acknowledge for thread_stop_req

static bool has_dga = false;                            // Flag: Video DGA capable
static bool has_vidmode = false;                        // Flag: VidMode extension available

#ifdef ENABLE_VOSF
static bool use_vosf = true;                            // Flag: VOSF enabled
#else
static const bool use_vosf = false;                     // VOSF not possible
#endif

static bool palette_changed = false;            // Flag: Palette changed, redraw thread must update palette
static bool ctrl_down = false;                          // Flag: Ctrl key pressed
static bool caps_on = false;                            // Flag: Caps Lock on
static bool quit_full_screen = false;           // Flag: DGA close requested from redraw thread
static volatile bool quit_full_screen_ack = false;      // Acknowledge for quit_full_screen
static bool emerg_quit = false;                         // Flag: Ctrl-Esc pressed, emergency quit requested from MacOS thread

static bool emul_suspended = false;                     // Flag: emulator suspended
static Window suspend_win;                                      // "Suspend" window
static void *fb_save = NULL;                            // Saved frame buffer for suspend
static bool use_keycodes = false;                       // Flag: Use keycodes rather than keysyms
static int keycode_table[256];                          // X keycode -> Mac keycode translation table

// X11 variables
static int screen;                                                      // Screen number
static int xdepth;                                                      // Depth of X screen
static int depth;                                                       // Depth of Mac frame buffer
static Window rootwin, the_win;                         // Root window and our window
static int num_depths = 0;                                      // Number of available X depths
static int *avail_depths = NULL;                        // List of available X depths
static VisualFormat visualFormat;
static XVisualInfo visualInfo;
static Visual *vis;
static int color_class;
static int rshift, rloss, gshift, gloss, bshift, bloss; // Pixel format of DirectColor/TrueColor modes
static Colormap cmap[2];                                        // Two colormaps (DGA) for 8-bit mode
static XColor x_palette[256];                           // Color palette to be used as CLUT and gamma table

static XColor black, white;
static unsigned long black_pixel, white_pixel;
static int eventmask;
static const int win_eventmask = KeyPressMask | KeyReleaseMask | ButtonPressMask | ButtonReleaseMask | PointerMotionMask | EnterWindowMask | ExposureMask | StructureNotifyMask;
static const int dga_eventmask = KeyPressMask | KeyReleaseMask | ButtonPressMask | ButtonReleaseMask | PointerMotionMask | StructureNotifyMask;

// Variables for window mode
static GC the_gc;
static XImage *img = NULL;
static XShmSegmentInfo shminfo;
static XImage *cursor_image, *cursor_mask_image;
static Pixmap cursor_map, cursor_mask_map;
static Cursor mac_cursor;
static GC cursor_gc, cursor_mask_gc;
static bool cursor_changed = false;                     // Flag: Cursor changed, window_func must update cursor
static bool have_shm = false;                           // Flag: SHM present and usable
static uint8 *the_buffer = NULL;                        // Pointer to Mac frame buffer
static uint8 *the_buffer_copy = NULL;           // Copy of Mac frame buffer
static uint32 the_buffer_size;                          // Size of allocated the_buffer

// Variables for DGA mode
static int current_dga_cmap;

#ifdef ENABLE_XF86_VIDMODE
// Variables for XF86 VidMode support
static XF86VidModeModeInfo **x_video_modes;             // Array of all available modes
static int num_x_video_modes;
#endif

// Mutex to protect palette
#ifdef HAVE_SPINLOCKS
static spinlock_t x_palette_lock = SPIN_LOCK_UNLOCKED;
#define LOCK_PALETTE spin_lock(&x_palette_lock)
#define UNLOCK_PALETTE spin_unlock(&x_palette_lock)
#elif defined(HAVE_PTHREADS)
static pthread_mutex_t x_palette_lock = PTHREAD_MUTEX_INITIALIZER;
#define LOCK_PALETTE pthread_mutex_lock(&x_palette_lock)
#define UNLOCK_PALETTE pthread_mutex_unlock(&x_palette_lock)
#else
#define LOCK_PALETTE
#define UNLOCK_PALETTE
#endif


// Prototypes
static void *redraw_func(void *arg);


// From main_unix.cpp
extern char *x_display_name;
extern Display *x_display;

// From sys_unix.cpp
extern void SysMountFirstFloppy(void);

// From clip_unix.cpp
extern void ClipboardSelectionClear(XSelectionClearEvent *);
extern void ClipboardSelectionRequest(XSelectionRequestEvent *);


// Video acceleration through SIGSEGV
#ifdef ENABLE_VOSF
# include "video_vosf.h"
#endif


/*
 *  Utility functions
 */

// Get current video mode
static inline int get_current_mode(void)
{
        return VModes[cur_mode].viAppleMode;
}

// Find palette size for given color depth
static int palette_size(int mode)
{
        switch (mode) {
        case APPLE_1_BIT: return 2;
        case APPLE_2_BIT: return 4;
        case APPLE_4_BIT: return 16;
        case APPLE_8_BIT: return 256;
        case APPLE_16_BIT: return 32;
        case APPLE_32_BIT: return 256;
        default: return 0;
        }
}

// Return bits per pixel for requested depth
static inline int bytes_per_pixel(int depth)
{
        int bpp;
        switch (depth) {
        case 8:
                bpp = 1;
                break;
        case 15: case 16:
                bpp = 2;
                break;
        case 24: case 32:
                bpp = 4;
                break;
        default:
                abort();
        }
        return bpp;
}

// Map video_mode depth ID to numerical depth value
static inline int depth_of_video_mode(int mode)
{
        int depth;
        switch (mode) {
        case APPLE_1_BIT:
                depth = 1;
                break;
        case APPLE_2_BIT:
                depth = 2;
                break;
        case APPLE_4_BIT:
                depth = 4;
                break;
        case APPLE_8_BIT:
                depth = 8;
                break;
        case APPLE_16_BIT:
                depth = 16;
                break;
        case APPLE_32_BIT:
                depth = 32;
                break;
        default:
                abort();
        }
        return depth;
}

// Map RGB color to pixel value (this only works in TrueColor/DirectColor visuals)
static inline uint32 map_rgb(uint8 red, uint8 green, uint8 blue)
{
        return ((red >> rloss) << rshift) | ((green >> gloss) << gshift) | ((blue >> bloss) << bshift);
}


// Do we have a visual for handling the specified Mac depth? If so, set the
// global variables "xdepth", "visualInfo", "vis" and "color_class".
static bool find_visual_for_depth(int depth)
{
        D(bug("have_visual_for_depth(%d)\n", depth_of_video_mode(depth)));

        // 1-bit works always and uses default visual
        if (depth == APPLE_1_BIT) {
                vis = DefaultVisual(x_display, screen);
                visualInfo.visualid = XVisualIDFromVisual(vis);
                int num = 0;
                XVisualInfo *vi = XGetVisualInfo(x_display, VisualIDMask, &visualInfo, &num);
                visualInfo = vi[0];
                XFree(vi);
                xdepth = visualInfo.depth;
                color_class = visualInfo.c_class;
                D(bug(" found visual ID 0x%02x, depth %d\n", visualInfo.visualid, xdepth));
                return true;
        }

        // Calculate minimum and maximum supported X depth
        int min_depth = 1, max_depth = 32;
        switch (depth) {
#ifdef ENABLE_VOSF
                case APPLE_2_BIT:
                case APPLE_4_BIT:       // VOSF blitters can convert 2/4/8-bit -> 8/16/32-bit
                case APPLE_8_BIT:
                        min_depth = 8;
                        max_depth = 32;
                        break;
#else
                case APPLE_2_BIT:
                case APPLE_4_BIT:       // 2/4-bit requires VOSF blitters
                        return false;
                case APPLE_8_BIT:       // 8-bit without VOSF requires an 8-bit visual
                        min_depth = 8;
                        max_depth = 8;
                        break;
#endif
                case APPLE_16_BIT:      // 16-bit requires a 15/16-bit visual
                        min_depth = 15;
                        max_depth = 16;
                        break;
                case APPLE_32_BIT:      // 32-bit requires a 24/32-bit visual
                        min_depth = 24;
                        max_depth = 32;
                        break;
        }
        D(bug(" minimum required X depth is %d, maximum supported X depth is %d\n", min_depth, max_depth));

        // Try to find a visual for one of the color depths
        bool visual_found = false;
        for (int i=0; i<num_depths && !visual_found; i++) {

                xdepth = avail_depths[i];
                D(bug(" trying to find visual for depth %d\n", xdepth));
                if (xdepth < min_depth || xdepth > max_depth)
                        continue;

                // Determine best color class for this depth
                switch (xdepth) {
                        case 1: // Try StaticGray or StaticColor
                                if (XMatchVisualInfo(x_display, screen, xdepth, StaticGray, &visualInfo)
                                 || XMatchVisualInfo(x_display, screen, xdepth, StaticColor, &visualInfo))
                                        visual_found = true;
                                break;
                        case 8: // Need PseudoColor
                                if (XMatchVisualInfo(x_display, screen, xdepth, PseudoColor, &visualInfo))
                                        visual_found = true;
                                break;
                        case 15:
                        case 16:
                        case 24:
                        case 32: // Try DirectColor first, as this will allow gamma correction
                                if (XMatchVisualInfo(x_display, screen, xdepth, DirectColor, &visualInfo)
                                 || XMatchVisualInfo(x_display, screen, xdepth, TrueColor, &visualInfo))
                                        visual_found = true;
                                break;
                        default:
                                D(bug("  not a supported depth\n"));
                                break;
                }
        }
        if (!visual_found)
                return false;

        // Visual was found
        vis = visualInfo.visual;
        color_class = visualInfo.c_class;
        D(bug(" found visual ID 0x%02x, depth %d, class ", visualInfo.visualid, xdepth));
#if DEBUG
        switch (color_class) {
                case StaticGray: D(bug("StaticGray\n")); break;
                case GrayScale: D(bug("GrayScale\n")); break;
                case StaticColor: D(bug("StaticColor\n")); break;
                case PseudoColor: D(bug("PseudoColor\n")); break;
                case TrueColor: D(bug("TrueColor\n")); break;
                case DirectColor: D(bug("DirectColor\n")); break;
        }
#endif
        return true;
}


/*
 *  Open display (window or fullscreen)
 */

// Set WM_DELETE_WINDOW protocol on window (preventing it from being destroyed by the WM when clicking on the "close" widget)
static Atom WM_DELETE_WINDOW = (Atom)0;
static void set_window_delete_protocol(Window w)
{
        WM_DELETE_WINDOW = XInternAtom(x_display, "WM_DELETE_WINDOW", false);
        XSetWMProtocols(x_display, w, &WM_DELETE_WINDOW, 1);
}

// Wait until window is mapped/unmapped
static void wait_mapped(Window w)
{
        XEvent e;
        do {
                XMaskEvent(x_display, StructureNotifyMask, &e);
        } while ((e.type != MapNotify) || (e.xmap.event != w));
}

static void wait_unmapped(Window w)
{
        XEvent e;
        do {
                XMaskEvent(x_display, StructureNotifyMask, &e);
        } while ((e.type != UnmapNotify) || (e.xmap.event != w));
}

// Trap SHM errors
static bool shm_error = false;
static int (*old_error_handler)(Display *, XErrorEvent *);

static int error_handler(Display *d, XErrorEvent *e)
{
        if (e->error_code == BadAccess) {
                shm_error = true;
                return 0;
        } else
                return old_error_handler(d, e);
}

// Open window
static bool open_window(int width, int height)
{
        int aligned_width = (width + 15) & ~15;
        int aligned_height = (height + 15) & ~15;

        // Set absolute mouse mode
        ADBSetRelMouseMode(false);

        // Create window
        XSetWindowAttributes wattr;
        wattr.event_mask = eventmask = win_eventmask;
        wattr.background_pixel = (vis == DefaultVisual(x_display, screen) ? black_pixel : 0);
        wattr.border_pixel = 0;
        wattr.backing_store = NotUseful;
        wattr.colormap = (depth == 1 ? DefaultColormap(x_display, screen) : cmap[0]);
        the_win = XCreateWindow(x_display, rootwin, 0, 0, width, height, 0, xdepth,
                InputOutput, vis, CWEventMask | CWBackPixel | CWBorderPixel | CWBackingStore | CWColormap, &wattr);

        // Set window name
        XStoreName(x_display, the_win, GetString(STR_WINDOW_TITLE));

        // Set delete protocol property
        set_window_delete_protocol(the_win);

        // Make window unresizable
        XSizeHints *hints;
        if ((hints = XAllocSizeHints()) != NULL) {
                hints->min_width = width;
                hints->max_width = width;
                hints->min_height = height;
                hints->max_height = height;
                hints->flags = PMinSize | PMaxSize;
                XSetWMNormalHints(x_display, the_win, hints);
                XFree((char *)hints);
        }

        // Show window
        XMapWindow(x_display, the_win);
        wait_mapped(the_win);

        // 1-bit mode is big-endian; if the X server is little-endian, we can't
        // use SHM because that doesn't allow changing the image byte order
        bool need_msb_image = (depth == 1 && XImageByteOrder(x_display) == LSBFirst);

        // Try to create and attach SHM image
        have_shm = false;
        if (local_X11 && !need_msb_image && XShmQueryExtension(x_display)) {

                // Create SHM image ("height + 2" for safety)
                img = XShmCreateImage(x_display, vis, depth == 1 ? 1 : xdepth, depth == 1 ? XYBitmap : ZPixmap, 0, &shminfo, width, height);
                shminfo.shmid = shmget(IPC_PRIVATE, (aligned_height + 2) * img->bytes_per_line, IPC_CREAT | 0777);
                D(bug(" shm image created\n"));
                the_buffer_copy = (uint8 *)shmat(shminfo.shmid, 0, 0);
                shminfo.shmaddr = img->data = (char *)the_buffer_copy;
                shminfo.readOnly = False;

                // Try to attach SHM image, catching errors
                shm_error = false;
                old_error_handler = XSetErrorHandler(error_handler);
                XShmAttach(x_display, &shminfo);
                XSync(x_display, false);
                XSetErrorHandler(old_error_handler);
                if (shm_error) {
                        shmdt(shminfo.shmaddr);
                        XDestroyImage(img);
                        shminfo.shmid = -1;
                } else {
                        have_shm = true;
                        shmctl(shminfo.shmid, IPC_RMID, 0);
                }
                D(bug(" shm image attached\n"));
        }

        // Create normal X image if SHM doesn't work ("height + 2" for safety)
        if (!have_shm) {
                int bytes_per_row = depth == 1 ? aligned_width/8 : TrivialBytesPerRow(aligned_width, DepthModeForPixelDepth(xdepth));
                the_buffer_copy = (uint8 *)malloc((aligned_height + 2) * bytes_per_row);
                img = XCreateImage(x_display, vis, depth == 1 ? 1 : xdepth, depth == 1 ? XYBitmap : ZPixmap, 0, (char *)the_buffer_copy, aligned_width, aligned_height, 32, bytes_per_row);
                D(bug(" X image created\n"));
        }

        // 1-Bit mode is big-endian
    if (need_msb_image) {
        img->byte_order = MSBFirst;
        img->bitmap_bit_order = MSBFirst;
    }

#ifdef ENABLE_VOSF
        use_vosf = true;
        // Allocate memory for frame buffer (SIZE is extended to page-boundary)
        the_host_buffer = the_buffer_copy;
        the_buffer_size = page_extend((aligned_height + 2) * img->bytes_per_line);
        the_buffer = (uint8 *)vm_acquire(the_buffer_size);
        the_buffer_copy = (uint8 *)malloc(the_buffer_size);
        D(bug("the_buffer = %p, the_buffer_copy = %p, the_host_buffer = %p\n", the_buffer, the_buffer_copy, the_host_buffer));
#else
        // Allocate memory for frame buffer
        the_buffer = (uint8 *)malloc((aligned_height + 2) * img->bytes_per_line);
        D(bug("the_buffer = %p, the_buffer_copy = %p\n", the_buffer, the_buffer_copy));
#endif
        screen_base = Host2MacAddr(the_buffer);

        // Create GC
        the_gc = XCreateGC(x_display, the_win, 0, 0);
        XSetState(x_display, the_gc, black_pixel, white_pixel, GXcopy, AllPlanes);

        // Create cursor
        if (hw_mac_cursor_accl) {
                cursor_image = XCreateImage(x_display, vis, 1, XYPixmap, 0, (char *)MacCursor + 4, 16, 16, 16, 2);
                cursor_image->byte_order = MSBFirst;
                cursor_image->bitmap_bit_order = MSBFirst;
                cursor_mask_image = XCreateImage(x_display, vis, 1, XYPixmap, 0, (char *)MacCursor + 36, 16, 16, 16, 2);
                cursor_mask_image->byte_order = MSBFirst;
                cursor_mask_image->bitmap_bit_order = MSBFirst;
                cursor_map = XCreatePixmap(x_display, the_win, 16, 16, 1);
                cursor_mask_map = XCreatePixmap(x_display, the_win, 16, 16, 1);
                cursor_gc = XCreateGC(x_display, cursor_map, 0, 0);
                cursor_mask_gc = XCreateGC(x_display, cursor_mask_map, 0, 0);
                mac_cursor = XCreatePixmapCursor(x_display, cursor_map, cursor_mask_map, &black, &white, 0, 0);
                cursor_changed = false;
        }

        // Create no_cursor
        else {
                mac_cursor = XCreatePixmapCursor(x_display,
                        XCreatePixmap(x_display, the_win, 1, 1, 1),
                        XCreatePixmap(x_display, the_win, 1, 1, 1),
                        &black, &white, 0, 0);
                XDefineCursor(x_display, the_win, mac_cursor);
        }

        // Init blitting routines
        bool native_byte_order;
#ifdef WORDS_BIGENDIAN
        native_byte_order = (XImageByteOrder(x_display) == MSBFirst);
#else
        native_byte_order = (XImageByteOrder(x_display) == LSBFirst);
#endif
#ifdef ENABLE_VOSF
        Screen_blitter_init(visualFormat, native_byte_order, depth);
#endif

        // Set bytes per row
        XSync(x_display, false);
        return true;
}

// Open DGA display (!! should use X11 VidMode extensions to set mode)
static bool open_dga(int width, int height)
{
#ifdef ENABLE_XF86_DGA
        // Set relative mouse mode
        ADBSetRelMouseMode(true);

        // Create window
        XSetWindowAttributes wattr;
        wattr.event_mask = eventmask = dga_eventmask;
        wattr.override_redirect = True;
        wattr.colormap = (depth == 1 ? DefaultColormap(x_display, screen) : cmap[0]);
        the_win = XCreateWindow(x_display, rootwin, 0, 0, width, height, 0, xdepth,
                InputOutput, vis, CWEventMask | CWOverrideRedirect |
                (color_class == DirectColor ? CWColormap : 0), &wattr);

        // Show window
        XMapRaised(x_display, the_win);
        wait_mapped(the_win);

#ifdef ENABLE_XF86_VIDMODE
        // Switch to best mode
        if (has_vidmode) {
                int best = 0;
                for (int i=1; i<num_x_video_modes; i++) {
                        if (x_video_modes[i]->hdisplay >= width && x_video_modes[i]->vdisplay >= height &&
                                x_video_modes[i]->hdisplay <= x_video_modes[best]->hdisplay && x_video_modes[i]->vdisplay <= x_video_modes[best]->vdisplay) {
                                best = i;
                        }
                }
                XF86VidModeSwitchToMode(x_display, screen, x_video_modes[best]);
                XF86VidModeSetViewPort(x_display, screen, 0, 0);
        }
#endif

        // Establish direct screen connection
        XMoveResizeWindow(x_display, the_win, 0, 0, width, height);
        XWarpPointer(x_display, None, rootwin, 0, 0, 0, 0, 0, 0);
        XGrabKeyboard(x_display, rootwin, True, GrabModeAsync, GrabModeAsync, CurrentTime);
        XGrabPointer(x_display, rootwin, True, PointerMotionMask | ButtonPressMask | ButtonReleaseMask, GrabModeAsync, GrabModeAsync, None, None, CurrentTime);

        int v_width, v_bank, v_size;
        XF86DGAGetVideo(x_display, screen, (char **)&the_buffer, &v_width, &v_bank, &v_size);
        XF86DGADirectVideo(x_display, screen, XF86DGADirectGraphics | XF86DGADirectKeyb | XF86DGADirectMouse);
        XF86DGASetViewPort(x_display, screen, 0, 0);
        XF86DGASetVidPage(x_display, screen, 0);

        // Set colormap
        if (!IsDirectMode(get_current_mode())) {
                XSetWindowColormap(x_display, the_win, cmap[current_dga_cmap = 0]);
                XF86DGAInstallColormap(x_display, screen, cmap[current_dga_cmap]);
        }
        XSync(x_display, false);

        // Init blitting routines
        int bytes_per_row = TrivialBytesPerRow((v_width + 7) & ~7, DepthModeForPixelDepth(depth));
#if ENABLE_VOSF
        bool native_byte_order;
#ifdef WORDS_BIGENDIAN
        native_byte_order = (XImageByteOrder(x_display) == MSBFirst);
#else
        native_byte_order = (XImageByteOrder(x_display) == LSBFirst);
#endif
#if REAL_ADDRESSING || DIRECT_ADDRESSING
        // Screen_blitter_init() returns TRUE if VOSF is mandatory
        // i.e. the framebuffer update function is not Blit_Copy_Raw
        use_vosf = Screen_blitter_init(visualFormat, native_byte_order, depth);
        
        if (use_vosf) {
          // Allocate memory for frame buffer (SIZE is extended to page-boundary)
          the_host_buffer = the_buffer;
          the_buffer_size = page_extend((height + 2) * bytes_per_row);
          the_buffer_copy = (uint8 *)malloc(the_buffer_size);
          the_buffer = (uint8 *)vm_acquire(the_buffer_size);
          D(bug("the_buffer = %p, the_buffer_copy = %p, the_host_buffer = %p\n", the_buffer, the_buffer_copy, the_host_buffer));
        }
#else
        use_vosf = false;
#endif
#endif

        // Set frame buffer base
        D(bug("the_buffer = %p, use_vosf = %d\n", the_buffer, use_vosf));
        screen_base = Host2MacAddr(the_buffer);
        VModes[cur_mode].viRowBytes = bytes_per_row;
        return true;
#else
        ErrorAlert("SheepShaver has been compiled with DGA support disabled.");
        return false;
#endif
}

static bool open_display(void)
{
        D(bug("open_display()\n"));
        const VideoInfo &mode = VModes[cur_mode];

        // Find best available X visual
        if (!find_visual_for_depth(mode.viAppleMode)) {
                ErrorAlert(GetString(STR_NO_XVISUAL_ERR));
                return false;
        }

        // Build up visualFormat structure
        visualFormat.depth = visualInfo.depth;
        visualFormat.Rmask = visualInfo.red_mask;
        visualFormat.Gmask = visualInfo.green_mask;
        visualFormat.Bmask = visualInfo.blue_mask;

        // Create color maps
        if (color_class == PseudoColor || color_class == DirectColor) {
                cmap[0] = XCreateColormap(x_display, rootwin, vis, AllocAll);
                cmap[1] = XCreateColormap(x_display, rootwin, vis, AllocAll);
        } else {
                cmap[0] = XCreateColormap(x_display, rootwin, vis, AllocNone);
                cmap[1] = XCreateColormap(x_display, rootwin, vis, AllocNone);
        }

        // Find pixel format of direct modes
        if (color_class == DirectColor || color_class == TrueColor) {
                rshift = gshift = bshift = 0;
                rloss = gloss = bloss = 8;
                uint32 mask;
                for (mask=vis->red_mask; !(mask&1); mask>>=1)
                        ++rshift;
                for (; mask&1; mask>>=1)
                        --rloss;
                for (mask=vis->green_mask; !(mask&1); mask>>=1)
                        ++gshift;
                for (; mask&1; mask>>=1)
                        --gloss;
                for (mask=vis->blue_mask; !(mask&1); mask>>=1)
                        ++bshift;
                for (; mask&1; mask>>=1)
                        --bloss;
        }

        // Preset palette pixel values for CLUT or gamma table
        if (color_class == DirectColor) {
                int num = vis->map_entries;
                for (int i=0; i<num; i++) {
                        int c = (i * 256) / num;
                        x_palette[i].pixel = map_rgb(c, c, c);
                        x_palette[i].flags = DoRed | DoGreen | DoBlue;
                }
        } else if (color_class == PseudoColor) {
                for (int i=0; i<256; i++) {
                        x_palette[i].pixel = i;
                        x_palette[i].flags = DoRed | DoGreen | DoBlue;
                }
        }

        // Load gray ramp to color map
        int num = (color_class == DirectColor ? vis->map_entries : 256);
        for (int i=0; i<num; i++) {
                int c = (i * 256) / num;
                x_palette[i].red = c * 0x0101;
                x_palette[i].green = c * 0x0101;
                x_palette[i].blue = c * 0x0101;
        }
        if (color_class == PseudoColor || color_class == DirectColor) {
                XStoreColors(x_display, cmap[0], x_palette, num);
                XStoreColors(x_display, cmap[1], x_palette, num);
        }

#ifdef ENABLE_VOSF
        // Load gray ramp to 8->16/32 expand map
        if (!IsDirectMode(get_current_mode()) && xdepth > 8)
                for (int i=0; i<256; i++)
                        ExpandMap[i] = map_rgb(i, i, i);
#endif

        // Create display of requested type
        display_type = mode.viType;
        depth = depth_of_video_mode(mode.viAppleMode);

        bool display_open = false;
        if (display_type == DIS_SCREEN)
                display_open = open_dga(VModes[cur_mode].viXsize, VModes[cur_mode].viYsize);
        else if (display_type == DIS_WINDOW)
                display_open = open_window(VModes[cur_mode].viXsize, VModes[cur_mode].viYsize);

#ifdef ENABLE_VOSF
        if (use_vosf) {
                // Initialize the VOSF system
                if (!video_vosf_init()) {
                        ErrorAlert(GetString(STR_VOSF_INIT_ERR));
                        return false;
                }
        }
#endif
        
        return display_open;
}


/*
 *  Close display
 */

// Close window
static void close_window(void)
{
        if (have_shm) {
                XShmDetach(x_display, &shminfo);
#ifdef ENABLE_VOSF
                the_host_buffer = NULL; // don't free() in driver_base dtor
#else
                the_buffer_copy = NULL; // don't free() in driver_base dtor
#endif
        }
        if (img) {
                if (!have_shm)
                        img->data = NULL;
                XDestroyImage(img);
        }
        if (have_shm) {
                shmdt(shminfo.shmaddr);
                shmctl(shminfo.shmid, IPC_RMID, 0);
        }
        if (the_gc)
                XFreeGC(x_display, the_gc);

        XFlush(x_display);
        XSync(x_display, false);
}

// Close DGA mode
static void close_dga(void)
{
#ifdef ENABLE_XF86_DGA
        XF86DGADirectVideo(x_display, screen, 0);
        XUngrabPointer(x_display, CurrentTime);
        XUngrabKeyboard(x_display, CurrentTime);
#endif

#ifdef ENABLE_XF86_VIDMODE
        if (has_vidmode)
                XF86VidModeSwitchToMode(x_display, screen, x_video_modes[0]);
#endif

        if (!use_vosf) {
                // don't free() the screen buffer in driver_base dtor
                the_buffer = NULL;
        }
#ifdef ENABLE_VOSF
        else {
                // don't free() the screen buffer in driver_base dtor
                the_host_buffer = NULL;
        }
#endif
}

static void close_display(void)
{
        if (display_type == DIS_SCREEN)
                close_dga();
        else if (display_type == DIS_WINDOW)
                close_window();

        // Close window
        if (the_win) {
                XUnmapWindow(x_display, the_win);
                wait_unmapped(the_win);
                XDestroyWindow(x_display, the_win);
        }

        // Free colormaps
        if (cmap[0]) {
                XFreeColormap(x_display, cmap[0]);
                cmap[0] = 0;
        }
        if (cmap[1]) {
                XFreeColormap(x_display, cmap[1]);
                cmap[1] = 0;
        }

#ifdef ENABLE_VOSF
        if (use_vosf) {
                // Deinitialize VOSF
                video_vosf_exit();
        }
#endif

        // Free frame buffer(s)
        if (!use_vosf) {
                if (the_buffer_copy) {
                        free(the_buffer_copy);
                        the_buffer_copy = NULL;
                }
        }
#ifdef ENABLE_VOSF
        else {
                // the_buffer shall always be mapped through vm_acquire() so that we can vm_protect() it at will
                if (the_buffer != VM_MAP_FAILED) {
                        D(bug(" releasing the_buffer at %p (%d bytes)\n", the_buffer, the_buffer_size));
                        vm_release(the_buffer, the_buffer_size);
                        the_buffer = NULL;
                }
                if (the_host_buffer) {
                        D(bug(" freeing the_host_buffer at %p\n", the_host_buffer));
                        free(the_host_buffer);
                        the_host_buffer = NULL;
                }
                if (the_buffer_copy) {
                        D(bug(" freeing the_buffer_copy at %p\n", the_buffer_copy));
                        free(the_buffer_copy);
                        the_buffer_copy = NULL;
                }
        }
#endif
}


/*
 *  Initialization
 */

// Init keycode translation table
static void keycode_init(void)
{
        bool use_kc = PrefsFindBool("keycodes");
        if (use_kc) {

                // Get keycode file path from preferences
                const char *kc_path = PrefsFindString("keycodefile");

                // Open keycode table
                FILE *f = fopen(kc_path ? kc_path : KEYCODE_FILE_NAME, "r");
                if (f == NULL) {
                        char str[256];
                        sprintf(str, GetString(STR_KEYCODE_FILE_WARN), kc_path ? kc_path : KEYCODE_FILE_NAME, strerror(errno));
                        WarningAlert(str);
                        return;
                }

                // Default translation table
                for (int i=0; i<256; i++)
                        keycode_table[i] = -1;

                // Search for server vendor string, then read keycodes
                const char *vendor = ServerVendor(x_display);
                // Force use of MacX mappings on MacOS X with Apple's X server
                int dummy;
                if (XQueryExtension(x_display, "Apple-DRI", &dummy, &dummy, &dummy))
                        vendor = "MacX";
                bool vendor_found = false;
                char line[256];
                while (fgets(line, 255, f)) {
                        // Read line
                        int len = strlen(line);
                        if (len == 0)
                                continue;
                        line[len-1] = 0;

                        // Comments begin with "#" or ";"
                        if (line[0] == '#' || line[0] == ';' || line[0] == 0)
                                continue;

                        if (vendor_found) {
                                // Read keycode
                                int x_code, mac_code;
                                if (sscanf(line, "%d %d", &x_code, &mac_code) == 2)
                                        keycode_table[x_code & 0xff] = mac_code;
                                else
                                        break;
                        } else {
                                // Search for vendor string
                                if (strstr(vendor, line) == vendor)
                                        vendor_found = true;
                        }
                }

                // Keycode file completely read
                fclose(f);
                use_keycodes = vendor_found;

                // Vendor not found? Then display warning
                if (!vendor_found) {
                        char str[256];
                        sprintf(str, GetString(STR_KEYCODE_VENDOR_WARN), vendor, kc_path ? kc_path : KEYCODE_FILE_NAME);
                        WarningAlert(str);
                        return;
                }
        }
}

// Find Apple mode matching best specified dimensions
static int find_apple_resolution(int xsize, int ysize)
{
        int apple_id;
        if (xsize < 800)
                apple_id = APPLE_640x480;
        else if (xsize < 1024)
                apple_id = APPLE_800x600;
        else if (xsize < 1152)
                apple_id = APPLE_1024x768;
        else if (xsize < 1280) {
                if (ysize < 900)
                        apple_id = APPLE_1152x768;
                else
                        apple_id = APPLE_1152x900;
        }
        else if (xsize < 1600)
                apple_id = APPLE_1280x1024;
        else
                apple_id = APPLE_1600x1200;
        return apple_id;
}

// Find mode in list of supported modes
static int find_mode(int apple_mode, int apple_id, int type)
{
        for (VideoInfo *p = VModes; p->viType != DIS_INVALID; p++) {
                if (p->viType == type && p->viAppleID == apple_id && p->viAppleMode == apple_mode)
                        return p - VModes;
        }
        return -1;
}

// Add custom video mode
static void add_custom_mode(VideoInfo *&p, int type, uint32 x, uint32 y, int apple_mode, int apple_id)
{
        p->viType = type;
        p->viXsize = x;
        p->viYsize = y;
        p->viRowBytes = TrivialBytesPerRow(p->viXsize, apple_mode);
        p->viAppleMode = apple_mode;
        p->viAppleID = apple_id;
        p++;
}

// Add mode to list of supported modes
static void add_mode(VideoInfo *&p, uint32 allow, uint32 test, int apple_mode, int apple_id, int type)
{
        if (allow & test) {
                uint32 x = 0, y = 0;
                switch (apple_id) {
                        case APPLE_W_640x480:
                        case APPLE_640x480:
                                x = 640;
                                y = 480;
                                break;
                        case APPLE_W_800x600:
                        case APPLE_800x600:
                                x = 800;
                                y = 600;
                                break;
                        case APPLE_1024x768:
                                x = 1024;
                                y = 768;
                                break;
                        case APPLE_1152x768:
                                x = 1152;
                                y = 768;
                                break;
                        case APPLE_1152x900:
                                x = 1152;
                                y = 900;
                                break;
                        case APPLE_1280x1024:
                                x = 1280;
                                y = 1024;
                                break;
                        case APPLE_1600x1200:
                                x = 1600;
                                y = 1200;
                                break;
                }
                add_custom_mode(p, type, x, y, apple_mode, apple_id);
        }
}

// Add standard list of windowed modes for given color depth
static void add_window_modes(VideoInfo *&p, int window_modes, int mode)
{
        add_mode(p, window_modes, 1, mode, APPLE_W_640x480, DIS_WINDOW);
        add_mode(p, window_modes, 2, mode, APPLE_W_800x600, DIS_WINDOW);
}

static bool has_mode(int x, int y)
{
#ifdef ENABLE_XF86_VIDMODE
        for (int i=0; i<num_x_video_modes; i++)
                if (x_video_modes[i]->hdisplay >= x && x_video_modes[i]->vdisplay >= y)
                        return true;
        return false;
#else
        return DisplayWidth(x_display, screen) >= x && DisplayHeight(x_display, screen) >= y;
#endif
}

bool VideoInit(void)
{
#ifdef ENABLE_VOSF
        // Zero the mainBuffer structure
        mainBuffer.dirtyPages = NULL;
        mainBuffer.pageInfo = NULL;
#endif
        
        // Check if X server runs on local machine
        local_X11 = (strncmp(XDisplayName(x_display_name), ":", 1) == 0)
                 || (strncmp(XDisplayName(x_display_name), "unix:", 5) == 0);
    
        // Init keycode translation
        keycode_init();

        // Read frame skip prefs
        frame_skip = PrefsFindInt32("frameskip");
        if (frame_skip == 0)
                frame_skip = 1;

        // Read mouse wheel prefs
        mouse_wheel_mode = PrefsFindInt32("mousewheelmode");
        mouse_wheel_lines = PrefsFindInt32("mousewheellines");

        // Init variables
        private_data = NULL;
        video_activated = true;

        // Find screen and root window
        screen = XDefaultScreen(x_display);
        rootwin = XRootWindow(x_display, screen);

        // Get sorted list of available depths
        avail_depths = XListDepths(x_display, screen, &num_depths);
        if (avail_depths == NULL) {
                ErrorAlert(GetString(STR_UNSUPP_DEPTH_ERR));
                return false;
        }
        sort(avail_depths, avail_depths + num_depths);
        
        // Get screen depth
        xdepth = DefaultDepth(x_display, screen);

#ifdef ENABLE_XF86_DGA
        // DGA available?
    int event_base, error_base;
    if (local_X11 && XF86DGAQueryExtension(x_display, &event_base, &error_base)) {
                int dga_flags = 0;
                XF86DGAQueryDirectVideo(x_display, screen, &dga_flags);
                has_dga = dga_flags & XF86DGADirectPresent;
        } else
                has_dga = false;
#endif

#ifdef ENABLE_XF86_VIDMODE
        // VidMode available?
        int vm_event_base, vm_error_base;
        has_vidmode = XF86VidModeQueryExtension(x_display, &vm_event_base, &vm_error_base);
        if (has_vidmode)
                XF86VidModeGetAllModeLines(x_display, screen, &num_x_video_modes, &x_video_modes);
#endif

        // Find black and white colors
        XParseColor(x_display, DefaultColormap(x_display, screen), "rgb:00/00/00", &black);
        XAllocColor(x_display, DefaultColormap(x_display, screen), &black);
        XParseColor(x_display, DefaultColormap(x_display, screen), "rgb:ff/ff/ff", &white);
        XAllocColor(x_display, DefaultColormap(x_display, screen), &white);
        black_pixel = BlackPixel(x_display, screen);
        white_pixel = WhitePixel(x_display, screen);

        // Mac screen depth follows X depth (for now)
        int default_mode = APPLE_8_BIT;
        switch (DefaultDepth(x_display, screen)) {
        case 1:
                default_mode = APPLE_1_BIT;
                break;
        case 8:
                default_mode = APPLE_8_BIT;
                break;
        case 15: case 16:
                default_mode = APPLE_16_BIT;
                break;
        case 24: case 32:
                default_mode = APPLE_32_BIT;
                break;
        }

        // Get screen mode from preferences
        const char *mode_str = PrefsFindString("screen");
        int default_width = 640, default_height = 480;
        if (mode_str) {
                display_type = DIS_INVALID;
                if (sscanf(mode_str, "win/%d/%d", &default_width, &default_height) == 2)
                        display_type = DIS_WINDOW;
#ifdef ENABLE_XF86_DGA
                else if (has_dga && sscanf(mode_str, "dga/%d/%d", &default_width, &default_height) == 2)
                        display_type = DIS_SCREEN;
#endif
                if (display_type == DIS_INVALID) {
                        D(bug("Invalid screen mode specified, defaulting to old modes selection\n"));
                        mode_str = NULL;
                }
                else {
                        if (default_width <= 0)
                                default_width = DisplayWidth(x_display, screen);
                        else if (default_width > DisplayWidth(x_display, screen))
                                default_width = DisplayWidth(x_display, screen);
                        if (default_height <= 0)
                                default_height = DisplayHeight(x_display, screen);
                        else if (default_height > DisplayHeight(x_display, screen))
                                default_height = DisplayHeight(x_display, screen);
                }
        }

        // Construct video mode table
        uint32 window_modes = PrefsFindInt32("windowmodes");
        uint32 screen_modes = PrefsFindInt32("screenmodes");
        if (!has_dga)
                screen_modes = 0;
        if (mode_str)
                window_modes = screen_modes = 0;
        else if (window_modes == 0 && screen_modes == 0)
                window_modes |= 3;      // Allow at least 640x480 and 800x600 window modes

        VideoInfo *p = VModes;
        if (mode_str) {
                if (display_type == DIS_WINDOW) {
                        for (unsigned int d = APPLE_1_BIT; d <= APPLE_32_BIT; d++) {
                                if (find_visual_for_depth(d)) {
                                        if (default_width > 640 && default_height > 480)
                                                add_mode(p, 3, 1, d, APPLE_W_640x480, DIS_WINDOW);
                                        if (default_width > 800 && default_height > 600)
                                                add_mode(p, 3, 2, d, APPLE_W_800x600, DIS_WINDOW);
                                        add_custom_mode(p, display_type, default_width, default_height, d, APPLE_CUSTOM);
                                }
                        }
                } else
                        add_custom_mode(p, display_type, default_width, default_height, default_mode, APPLE_CUSTOM);
        } else if (window_modes) {
                for (unsigned int d = APPLE_1_BIT; d <= APPLE_32_BIT; d++)
                        if (find_visual_for_depth(d))
                                add_window_modes(p, window_modes, d);
        } else if (has_vidmode) {
                if (has_mode(640, 480))
                        add_mode(p, screen_modes, 1, default_mode, APPLE_640x480, DIS_SCREEN);
                if (has_mode(800, 600))
                        add_mode(p, screen_modes, 2, default_mode, APPLE_800x600, DIS_SCREEN);
                if (has_mode(1024, 768))
                        add_mode(p, screen_modes, 4, default_mode, APPLE_1024x768, DIS_SCREEN);
                if (has_mode(1152, 768))
                        add_mode(p, screen_modes, 64, default_mode, APPLE_1152x768, DIS_SCREEN);
                if (has_mode(1152, 900))
                        add_mode(p, screen_modes, 8, default_mode, APPLE_1152x900, DIS_SCREEN);
                if (has_mode(1280, 1024))
                        add_mode(p, screen_modes, 16, default_mode, APPLE_1280x1024, DIS_SCREEN);
                if (has_mode(1600, 1200))
                        add_mode(p, screen_modes, 32, default_mode, APPLE_1600x1200, DIS_SCREEN);
        } else if (screen_modes) {
                int xsize = DisplayWidth(x_display, screen);
                int ysize = DisplayHeight(x_display, screen);
                int apple_id = find_apple_resolution(xsize, ysize);
                p->viType = DIS_SCREEN;
                p->viRowBytes = 0;
                p->viXsize = xsize;
                p->viYsize = ysize;
                p->viAppleMode = default_mode;
                p->viAppleID = apple_id;
                p++;
        }
        p->viType = DIS_INVALID;        // End marker
        p->viRowBytes = 0;
        p->viXsize = p->viYsize = 0;
        p->viAppleMode = 0;
        p->viAppleID = 0;

        // Find default mode (window 640x480)
        cur_mode = -1;
        if (has_dga && screen_modes) {
                int screen_width = DisplayWidth(x_display, screen);
                int screen_height = DisplayHeight(x_display, screen);
                int apple_id = find_apple_resolution(screen_width, screen_height);
                if (apple_id != -1)
                        cur_mode = find_mode(default_mode, apple_id, DIS_SCREEN);
        } else if (has_dga && mode_str)
                cur_mode = find_mode(default_mode, APPLE_CUSTOM, DIS_SCREEN);

        if (cur_mode == -1) {
                // pick up first windowed mode available
                for (VideoInfo *p = VModes; p->viType != DIS_INVALID; p++) {
                        if (p->viType == DIS_WINDOW && p->viAppleMode == default_mode) {
                                cur_mode = p - VModes;
                                break;
                        }
                }
        }
        assert(cur_mode != -1);

#if DEBUG
        D(bug("Available video modes:\n"));
        for (p = VModes; p->viType != DIS_INVALID; p++) {
                int bits = depth_of_video_mode(p->viAppleMode);
                D(bug(" %dx%d (ID %02x), %d colors\n", p->viXsize, p->viYsize, p->viAppleID, 1 << bits));
        }
#endif

        // Open window/screen
        if (!open_display())
                return false;

#if 0
        // Ignore errors from now on
        XSetErrorHandler(ignore_errors);
#endif

        // Start periodic thread
        XSync(x_display, false);
        Set_pthread_attr(&redraw_thread_attr, 0);
        redraw_thread_cancel = false;
        redraw_thread_active = (pthread_create(&redraw_thread, &redraw_thread_attr, redraw_func, NULL) == 0);
        D(bug("Redraw thread installed (%ld)\n", redraw_thread));
        return true;
}


/*
 *  Deinitialization
 */

void VideoExit(void)
{
        // Stop redraw thread
        if (redraw_thread_active) {
                redraw_thread_cancel = true;
                pthread_cancel(redraw_thread);
                pthread_join(redraw_thread, NULL);
                redraw_thread_active = false;
        }

#ifdef ENABLE_VOSF
        if (use_vosf) {
                // Deinitialize VOSF
                video_vosf_exit();
        }
#endif

        // Close window and server connection
        if (x_display != NULL) {
                XSync(x_display, false);
                close_display();
                XFlush(x_display);
                XSync(x_display, false);
        }
}


/*
 *  Suspend/resume emulator
 */

extern void PauseEmulator(void);
extern void ResumeEmulator(void);

static void suspend_emul(void)
{
        if (display_type == DIS_SCREEN) {
                // Release ctrl key
                ADBKeyUp(0x36);
                ctrl_down = false;

                // Pause MacOS thread
                PauseEmulator();
                emul_suspended = true;

                // Save frame buffer
                fb_save = malloc(VModes[cur_mode].viYsize * VModes[cur_mode].viRowBytes);
                if (fb_save)
                        Mac2Host_memcpy(fb_save, screen_base, VModes[cur_mode].viYsize * VModes[cur_mode].viRowBytes);

                // Close full screen display
#ifdef ENABLE_XF86_DGA
                XF86DGADirectVideo(x_display, screen, 0);
                XUngrabPointer(x_display, CurrentTime);
                XUngrabKeyboard(x_display, CurrentTime);
#endif
                XSync(x_display, false);

                // Open "suspend" window
                XSetWindowAttributes wattr;
                wattr.event_mask = KeyPressMask;
                wattr.background_pixel = black_pixel;
                wattr.border_pixel = black_pixel;
                wattr.backing_store = Always;
                wattr.backing_planes = xdepth;
                wattr.colormap = DefaultColormap(x_display, screen);
                XSync(x_display, false);
                suspend_win = XCreateWindow(x_display, rootwin, 0, 0, 512, 1, 0, xdepth,
                        InputOutput, vis, CWEventMask | CWBackPixel | CWBorderPixel |
                        CWBackingStore | CWBackingPlanes | (xdepth == 8 ? CWColormap : 0), &wattr);
                XSync(x_display, false);
                XStoreName(x_display, suspend_win, GetString(STR_SUSPEND_WINDOW_TITLE));
                XMapRaised(x_display, suspend_win);
                XSync(x_display, false);
        }
}

static void resume_emul(void)
{
        // Close "suspend" window
        XDestroyWindow(x_display, suspend_win);
        XSync(x_display, false);

        // Reopen full screen display
        XGrabKeyboard(x_display, rootwin, 1, GrabModeAsync, GrabModeAsync, CurrentTime);
        XGrabPointer(x_display, rootwin, 1, PointerMotionMask | ButtonPressMask | ButtonReleaseMask, GrabModeAsync, GrabModeAsync, None, None, CurrentTime);
#ifdef ENABLE_XF86_DGA
        XF86DGADirectVideo(x_display, screen, XF86DGADirectGraphics | XF86DGADirectKeyb | XF86DGADirectMouse);
        XF86DGASetViewPort(x_display, screen, 0, 0);
#endif
        XSync(x_display, false);

        // the_buffer already contains the data to restore. i.e. since a temporary
        // frame buffer is used when VOSF is actually used, fb_save is therefore
        // not necessary.
#ifdef ENABLE_VOSF
        if (use_vosf) {
                LOCK_VOSF;
                PFLAG_SET_ALL;
                UNLOCK_VOSF;
                memset(the_buffer_copy, 0, VModes[cur_mode].viRowBytes * VModes[cur_mode].viYsize);
        }
#endif
        
        // Restore frame buffer
        if (fb_save) {
#ifdef ENABLE_VOSF
                // Don't copy fb_save to the temporary frame buffer in VOSF mode
                if (!use_vosf)
#endif
                Host2Mac_memcpy(screen_base, fb_save, VModes[cur_mode].viYsize * VModes[cur_mode].viRowBytes);
                free(fb_save);
                fb_save = NULL;
        }
        if (depth == 8)
                palette_changed = true;

        // Resume MacOS thread
        emul_suspended = false;
        ResumeEmulator();
}


/*
 *  Close screen in full-screen mode
 */

void VideoQuitFullScreen(void)
{
        D(bug("VideoQuitFullScreen()\n"));
        if (display_type == DIS_SCREEN) {
                quit_full_screen = true;
                while (!quit_full_screen_ack) ;
        }
}


/*
 *  X11 event handling
 */

// Translate key event to Mac keycode
static int kc_decode(KeySym ks)
{
        switch (ks) {
                case XK_A: case XK_a: return 0x00;
                case XK_B: case XK_b: return 0x0b;
                case XK_C: case XK_c: return 0x08;
                case XK_D: case XK_d: return 0x02;
                case XK_E: case XK_e: return 0x0e;
                case XK_F: case XK_f: return 0x03;
                case XK_G: case XK_g: return 0x05;
                case XK_H: case XK_h: return 0x04;
                case XK_I: case XK_i: return 0x22;
                case XK_J: case XK_j: return 0x26;
                case XK_K: case XK_k: return 0x28;
                case XK_L: case XK_l: return 0x25;
                case XK_M: case XK_m: return 0x2e;
                case XK_N: case XK_n: return 0x2d;
                case XK_O: case XK_o: return 0x1f;
                case XK_P: case XK_p: return 0x23;
                case XK_Q: case XK_q: return 0x0c;
                case XK_R: case XK_r: return 0x0f;
                case XK_S: case XK_s: return 0x01;
                case XK_T: case XK_t: return 0x11;
                case XK_U: case XK_u: return 0x20;
                case XK_V: case XK_v: return 0x09;
                case XK_W: case XK_w: return 0x0d;
                case XK_X: case XK_x: return 0x07;
                case XK_Y: case XK_y: return 0x10;
                case XK_Z: case XK_z: return 0x06;

                case XK_1: case XK_exclam: return 0x12;
                case XK_2: case XK_at: return 0x13;
                case XK_3: case XK_numbersign: return 0x14;
                case XK_4: case XK_dollar: return 0x15;
                case XK_5: case XK_percent: return 0x17;
                case XK_6: return 0x16;
                case XK_7: return 0x1a;
                case XK_8: return 0x1c;
                case XK_9: return 0x19;
                case XK_0: return 0x1d;

                case XK_grave: case XK_asciitilde: return 0x0a;
                case XK_minus: case XK_underscore: return 0x1b;
                case XK_equal: case XK_plus: return 0x18;
                case XK_bracketleft: case XK_braceleft: return 0x21;
                case XK_bracketright: case XK_braceright: return 0x1e;
                case XK_backslash: case XK_bar: return 0x2a;
                case XK_semicolon: case XK_colon: return 0x29;
                case XK_apostrophe: case XK_quotedbl: return 0x27;
                case XK_comma: case XK_less: return 0x2b;
                case XK_period: case XK_greater: return 0x2f;
                case XK_slash: case XK_question: return 0x2c;

                case XK_Tab: if (ctrl_down) {suspend_emul(); return -1;} else return 0x30;
                case XK_Return: return 0x24;
                case XK_space: return 0x31;
                case XK_BackSpace: return 0x33;

                case XK_Delete: return 0x75;
                case XK_Insert: return 0x72;
                case XK_Home: case XK_Help: return 0x73;
                case XK_End: return 0x77;
#ifdef __hpux
                case XK_Prior: return 0x74;
                case XK_Next: return 0x79;
#else
                case XK_Page_Up: return 0x74;
                case XK_Page_Down: return 0x79;
#endif

                case XK_Control_L: return 0x36;
                case XK_Control_R: return 0x36;
                case XK_Shift_L: return 0x38;
                case XK_Shift_R: return 0x38;
                case XK_Alt_L: return 0x37;
                case XK_Alt_R: return 0x37;
                case XK_Meta_L: return 0x3a;
                case XK_Meta_R: return 0x3a;
                case XK_Menu: return 0x32;
                case XK_Caps_Lock: return 0x39;
                case XK_Num_Lock: return 0x47;

                case XK_Up: return 0x3e;
                case XK_Down: return 0x3d;
                case XK_Left: return 0x3b;
                case XK_Right: return 0x3c;

                case XK_Escape: if (ctrl_down) {quit_full_screen = true; emerg_quit = true; return -1;} else return 0x35;

                case XK_F1: if (ctrl_down) {SysMountFirstFloppy(); return -1;} else return 0x7a;
                case XK_F2: return 0x78;
                case XK_F3: return 0x63;
                case XK_F4: return 0x76;
                case XK_F5: return 0x60;
                case XK_F6: return 0x61;
                case XK_F7: return 0x62;
                case XK_F8: return 0x64;
                case XK_F9: return 0x65;
                case XK_F10: return 0x6d;
                case XK_F11: return 0x67;
                case XK_F12: return 0x6f;

                case XK_Print: return 0x69;
                case XK_Scroll_Lock: return 0x6b;
                case XK_Pause: return 0x71;

#if defined(XK_KP_Prior) && defined(XK_KP_Left) && defined(XK_KP_Insert) && defined (XK_KP_End)
                case XK_KP_0: case XK_KP_Insert: return 0x52;
                case XK_KP_1: case XK_KP_End: return 0x53;
                case XK_KP_2: case XK_KP_Down: return 0x54;
                case XK_KP_3: case XK_KP_Next: return 0x55;
                case XK_KP_4: case XK_KP_Left: return 0x56;
                case XK_KP_5: case XK_KP_Begin: return 0x57;
                case XK_KP_6: case XK_KP_Right: return 0x58;
                case XK_KP_7: case XK_KP_Home: return 0x59;
                case XK_KP_8: case XK_KP_Up: return 0x5b;
                case XK_KP_9: case XK_KP_Prior: return 0x5c;
                case XK_KP_Decimal: case XK_KP_Delete: return 0x41;
#else
                case XK_KP_0: return 0x52;
                case XK_KP_1: return 0x53;
                case XK_KP_2: return 0x54;
                case XK_KP_3: return 0x55;
                case XK_KP_4: return 0x56;
                case XK_KP_5: return 0x57;
                case XK_KP_6: return 0x58;
                case XK_KP_7: return 0x59;
                case XK_KP_8: return 0x5b;
                case XK_KP_9: return 0x5c;
                case XK_KP_Decimal: return 0x41;
#endif
                case XK_KP_Add: return 0x45;
                case XK_KP_Subtract: return 0x4e;
                case XK_KP_Multiply: return 0x43;
                case XK_KP_Divide: return 0x4b;
                case XK_KP_Enter: return 0x4c;
                case XK_KP_Equal: return 0x51;
        }
        return -1;
}

static int event2keycode(XKeyEvent &ev, bool key_down)
{
        KeySym ks;
        int i = 0;

        do {
                ks = XLookupKeysym(&ev, i++);
                int as = kc_decode(ks);
                if (as >= 0)
                        return as;
                if (as == -2)
                        return as;
        } while (ks != NoSymbol);

        return -1;
}

static void handle_events(void)
{
        // Handle events
        for (;;) {
                XEvent event;

                XDisplayLock();
                if (!XCheckMaskEvent(x_display, eventmask, &event)) {
                        // Handle clipboard events
                        if (XCheckTypedEvent(x_display, SelectionRequest, &event))
                                ClipboardSelectionRequest(&event.xselectionrequest);
                        else if (XCheckTypedEvent(x_display, SelectionClear, &event))
                                ClipboardSelectionClear(&event.xselectionclear);

                        // Window "close" widget clicked
                        else if (XCheckTypedEvent(x_display, ClientMessage, &event)) {
                                if (event.xclient.format == 32 && event.xclient.data.l[0] == WM_DELETE_WINDOW) {
                                        ADBKeyDown(0x7f);       // Power key
                                        ADBKeyUp(0x7f);
                                }
                        }

                        XDisplayUnlock();
                        break;
                }
                XDisplayUnlock();

                switch (event.type) {
                        // Mouse button
                        case ButtonPress: {
                                unsigned int button = ((XButtonEvent *)&event)->button;
                                if (button < 4)
                                        ADBMouseDown(button - 1);
                                else if (button < 6) {  // Wheel mouse
                                        if (mouse_wheel_mode == 0) {
                                                int key = (button == 5) ? 0x79 : 0x74;  // Page up/down
                                                ADBKeyDown(key);
                                                ADBKeyUp(key);
                                        } else {
                                                int key = (button == 5) ? 0x3d : 0x3e;  // Cursor up/down
                                                for(int i=0; i<mouse_wheel_lines; i++) {
                                                        ADBKeyDown(key);
                                                        ADBKeyUp(key);
                                                }
                                        }
                                }
                                break;
                        }
                        case ButtonRelease: {
                                unsigned int button = ((XButtonEvent *)&event)->button;
                                if (button < 4)
                                        ADBMouseUp(button - 1);
                                break;
                        }

                        // Mouse entered window
                        case EnterNotify:
                                if (event.xcrossing.mode != NotifyGrab && event.xcrossing.mode != NotifyUngrab)
                                        ADBMouseMoved(event.xmotion.x, event.xmotion.y);
                                break;

                        // Mouse moved
                        case MotionNotify:
                                ADBMouseMoved(event.xmotion.x, event.xmotion.y);
                                break;

                        // Keyboard
                        case KeyPress: {
                                int code = -1;
                                if (use_keycodes) {
                                        if (event2keycode(event.xkey, true) != -2)      // This is called to process the hotkeys
                                                code = keycode_table[event.xkey.keycode & 0xff];
                                } else
                                        code = event2keycode(event.xkey, true);
                                if (code >= 0) {
                                        if (!emul_suspended) {
                                                if (code == 0x39) {     // Caps Lock pressed
                                                        if (caps_on) {
                                                                ADBKeyUp(code);
                                                                caps_on = false;
                                                        } else {
                                                                ADBKeyDown(code);
                                                                caps_on = true;
                                                        }
                                                } else
                                                        ADBKeyDown(code);
                                                if (code == 0x36)
                                                        ctrl_down = true;
                                        } else {
                                                if (code == 0x31)
                                                        resume_emul();  // Space wakes us up
                                        }
                                }
                                break;
                        }
                        case KeyRelease: {
                                int code = -1;
                                if (use_keycodes) {
                                        if (event2keycode(event.xkey, false) != -2)     // This is called to process the hotkeys
                                                code = keycode_table[event.xkey.keycode & 0xff];
                                } else
                                        code = event2keycode(event.xkey, false);
                                if (code >= 0 && code != 0x39) {        // Don't propagate Caps Lock releases
                                        ADBKeyUp(code);
                                        if (code == 0x36)
                                                ctrl_down = false;
                                }
                                break;
                        }

                        // Hidden parts exposed, force complete refresh
                        case Expose:
#ifdef ENABLE_VOSF
                                if (use_vosf) {                 // VOSF refresh
                                        LOCK_VOSF;
                                        PFLAG_SET_ALL;
                                        UNLOCK_VOSF;
                                }
#endif
                                memset(the_buffer_copy, 0, VModes[cur_mode].viRowBytes * VModes[cur_mode].viYsize);
                                break;
                }
        }
}


/*
 *  Execute video VBL routine
 */

void VideoVBL(void)
{
        if (emerg_quit)
                QuitEmulator();

        // Execute video VBL
        if (private_data != NULL && private_data->interruptsEnabled)
                VSLDoInterruptService(private_data->vslServiceID);
}


/*
 *  Change video mode
 */

int16 video_mode_change(VidLocals *csSave, uint32 ParamPtr)
{
        /* return if no mode change */
        if ((csSave->saveData == ReadMacInt32(ParamPtr + csData)) &&
            (csSave->saveMode == ReadMacInt16(ParamPtr + csMode))) return noErr;

        /* first find video mode in table */
        for (int i=0; VModes[i].viType != DIS_INVALID; i++) {
                if ((ReadMacInt16(ParamPtr + csMode) == VModes[i].viAppleMode) &&
                    (ReadMacInt32(ParamPtr + csData) == VModes[i].viAppleID)) {
                        csSave->saveMode = ReadMacInt16(ParamPtr + csMode);
                        csSave->saveData = ReadMacInt32(ParamPtr + csData);
                        csSave->savePage = ReadMacInt16(ParamPtr + csPage);

                        // Disable interrupts and pause redraw thread
                        DisableInterrupt();
                        thread_stop_ack = false;
                        thread_stop_req = true;
                        while (!thread_stop_ack) ;

                        /* close old display */
                        close_display();

                        /* open new display */
                        cur_mode = i;
                        bool ok = open_display();

                        /* opening the screen failed? Then bail out */
                        if (!ok) {
                                ErrorAlert(GetString(STR_FULL_SCREEN_ERR));
                                QuitEmulator();
                        }

                        WriteMacInt32(ParamPtr + csBaseAddr, screen_base);
                        csSave->saveBaseAddr=screen_base;
                        csSave->saveData=VModes[cur_mode].viAppleID;/* First mode ... */
                        csSave->saveMode=VModes[cur_mode].viAppleMode;

                        // Enable interrupts and resume redraw thread
                        thread_stop_req = false;
                        EnableInterrupt();
                        return noErr;
                }
        }
        return paramErr;
}


/*
 *  Set color palette
 */

void video_set_palette(void)
{
        LOCK_PALETTE;

        // Convert colors to XColor array
        int mode = get_current_mode();
        int num_in = palette_size(mode);
        int num_out = 256;
        bool stretch = false;
        if (IsDirectMode(mode)) {
                // If X is in 565 mode we have to stretch the gamma table from 32 to 64 entries
                num_out = vis->map_entries;
                stretch = true;
        }
        XColor *p = x_palette;
        for (int i=0; i<num_out; i++) {
                int c = (stretch ? (i * num_in) / num_out : i);
                p->red = mac_pal[c].red * 0x0101;
                p->green = mac_pal[c].green * 0x0101;
                p->blue = mac_pal[c].blue * 0x0101;
                p++;
        }

#ifdef ENABLE_VOSF
        // Recalculate pixel color expansion map
        if (!IsDirectMode(mode) && xdepth > 8) {
                for (int i=0; i<256; i++) {
                        int c = i & (num_in-1); // If there are less than 256 colors, we repeat the first entries (this makes color expansion easier)
                        ExpandMap[i] = map_rgb(mac_pal[c].red, mac_pal[c].green, mac_pal[c].blue);
                }

                // We have to redraw everything because the interpretation of pixel values changed
                LOCK_VOSF;
                PFLAG_SET_ALL;
                UNLOCK_VOSF;
                memset(the_buffer_copy, 0, VModes[cur_mode].viRowBytes * VModes[cur_mode].viYsize);
        }
#endif

        // Tell redraw thread to change palette
        palette_changed = true;

        UNLOCK_PALETTE;
}


/*
 *  Can we set the MacOS cursor image into the window?
 */

bool video_can_change_cursor(void)
{
        return hw_mac_cursor_accl && (display_type != DIS_SCREEN);
}


/*
 *  Set cursor image for window
 */

void video_set_cursor(void)
{
        cursor_changed = true;
}


/*
 *  Thread for window refresh, event handling and other periodic actions
 */

static void update_display(void)
{
        // Incremental update code
        int wide = 0, high = 0, x1, x2, y1, y2, i, j;
        int bytes_per_row = VModes[cur_mode].viRowBytes;
        int bytes_per_pixel = VModes[cur_mode].viRowBytes / VModes[cur_mode].viXsize;
        uint8 *p, *p2;

        // Check for first line from top and first line from bottom that have changed
        y1 = 0;
        for (j=0; j<VModes[cur_mode].viYsize; j++) {
                if (memcmp(&the_buffer[j * bytes_per_row], &the_buffer_copy[j * bytes_per_row], bytes_per_row)) {
                        y1 = j;
                        break;
                }
        }
        y2 = y1 - 1;
        for (j=VModes[cur_mode].viYsize-1; j>=y1; j--) {
                if (memcmp(&the_buffer[j * bytes_per_row], &the_buffer_copy[j * bytes_per_row], bytes_per_row)) {
                        y2 = j;
                        break;
                }
        }
        high = y2 - y1 + 1;

        // Check for first column from left and first column from right that have changed
        if (high) {
                if (depth == 1) {
                        x1 = VModes[cur_mode].viXsize;
                        for (j=y1; j<=y2; j++) {
                                p = &the_buffer[j * bytes_per_row];
                                p2 = &the_buffer_copy[j * bytes_per_row];
                                for (i=0; i<(x1>>3); i++) {
                                        if (*p != *p2) {
                                                x1 = i << 3;
                                                break;
                                        }
                                        p++;
                                        p2++;
                                }
                        }
                        x2 = x1;
                        for (j=y1; j<=y2; j++) {
                                p = &the_buffer[j * bytes_per_row];
                                p2 = &the_buffer_copy[j * bytes_per_row];
                                p += bytes_per_row;
                                p2 += bytes_per_row;
                                for (i=(VModes[cur_mode].viXsize>>3); i>(x2>>3); i--) {
                                        p--;
                                        p2--;
                                        if (*p != *p2) {
                                                x2 = i << 3;
                                                break;
                                        }
                                }
                        }
                        wide = x2 - x1;

                        // Update copy of the_buffer
                        if (high && wide) {
                                for (j=y1; j<=y2; j++) {
                                        i = j * bytes_per_row + (x1 >> 3);
                                        memcpy(&the_buffer_copy[i], &the_buffer[i], wide >> 3);
                                }
                        }

                } else {
                        x1 = VModes[cur_mode].viXsize;
                        for (j=y1; j<=y2; j++) {
                                p = &the_buffer[j * bytes_per_row];
                                p2 = &the_buffer_copy[j * bytes_per_row];
                                for (i=0; i<x1; i++) {
                                        if (memcmp(p, p2, bytes_per_pixel)) {
                                                x1 = i;
                                                break;
                                        }
                                        p += bytes_per_pixel;
                                        p2 += bytes_per_pixel;
                                }
                        }
                        x2 = x1;
                        for (j=y1; j<=y2; j++) {
                                p = &the_buffer[j * bytes_per_row];
                                p2 = &the_buffer_copy[j * bytes_per_row];
                                p += bytes_per_row;
                                p2 += bytes_per_row;
                                for (i=VModes[cur_mode].viXsize; i>x2; i--) {
                                        p -= bytes_per_pixel;
                                        p2 -= bytes_per_pixel;
                                        if (memcmp(p, p2, bytes_per_pixel)) {
                                                x2 = i;
                                                break;
                                        }
                                }
                        }
                        wide = x2 - x1;

                        // Update copy of the_buffer
                        if (high && wide) {
                                for (j=y1; j<=y2; j++) {
                                        i = j * bytes_per_row + x1 * bytes_per_pixel;
                                        memcpy(&the_buffer_copy[i], &the_buffer[i], bytes_per_pixel * wide);
                                }
                        }
                }
        }

        // Refresh display
        if (high && wide) {
                XDisplayLock();
                if (have_shm)
                        XShmPutImage(x_display, the_win, the_gc, img, x1, y1, x1, y1, wide, high, 0);
                else
                        XPutImage(x_display, the_win, the_gc, img, x1, y1, x1, y1, wide, high);
                XDisplayUnlock();
        }
}

const int VIDEO_REFRESH_HZ = 60;
const int VIDEO_REFRESH_DELAY = 1000000 / VIDEO_REFRESH_HZ;

static void handle_palette_changes(void)
{
        LOCK_PALETTE;

        if (palette_changed && !emul_suspended) {
                palette_changed = false;

                int mode = get_current_mode();
                if (color_class == PseudoColor || color_class == DirectColor) {
                        int num = vis->map_entries;
                        bool set_clut = true;
                        if (!IsDirectMode(mode) && color_class == DirectColor) {
                                if (display_type == DIS_WINDOW)
                                        set_clut = false; // Indexed mode on true color screen, don't set CLUT
                        }

                        if (set_clut) {
                                XDisplayLock();
                                XStoreColors(x_display, cmap[0], x_palette, num);
                                XStoreColors(x_display, cmap[1], x_palette, num);
                                XSync(x_display, false);
                                XDisplayUnlock();
                        }
                }

#ifdef ENABLE_XF86_DGA
                if (display_type == DIS_SCREEN) {
                        current_dga_cmap ^= 1;
                        if (!IsDirectMode(mode) && cmap[current_dga_cmap])
                                XF86DGAInstallColormap(x_display, screen, cmap[current_dga_cmap]);
                }
#endif
        }

        UNLOCK_PALETTE;
}

static void *redraw_func(void *arg)
{
        int fd = ConnectionNumber(x_display);

        uint64 start = GetTicks_usec();
        int64 ticks = 0;
        uint64 next = GetTicks_usec() + VIDEO_REFRESH_DELAY;

        while (!redraw_thread_cancel) {

                // Pause if requested (during video mode switches)
                while (thread_stop_req)
                        thread_stop_ack = true;

                int64 delay = next - GetTicks_usec();
                if (delay < -VIDEO_REFRESH_DELAY) {

                        // We are lagging far behind, so we reset the delay mechanism
                        next = GetTicks_usec();

                } else if (delay <= 0) {

                        // Delay expired, refresh display
                        next += VIDEO_REFRESH_DELAY;
                        ticks++;

                        // Handle X11 events
                        handle_events();

                        // Quit DGA mode if requested
                        if (quit_full_screen) {
                                quit_full_screen = false;
                                if (display_type == DIS_SCREEN) {
                                        XDisplayLock();
#ifdef ENABLE_XF86_DGA
                                        XF86DGADirectVideo(x_display, screen, 0);
                                        XUngrabPointer(x_display, CurrentTime);
                                        XUngrabKeyboard(x_display, CurrentTime);
                                        XUnmapWindow(x_display, the_win);
                                        wait_unmapped(the_win);
                                        XDestroyWindow(x_display, the_win);
#endif
                                        XSync(x_display, false);
                                        XDisplayUnlock();
                                        quit_full_screen_ack = true;
                                        return NULL;
                                }
                        }

                        // Refresh display and set cursor image in window mode
                        static int tick_counter = 0;
                        if (display_type == DIS_WINDOW) {
                                tick_counter++;
                                if (tick_counter >= frame_skip) {
                                        tick_counter = 0;

                                        // Update display
#ifdef ENABLE_VOSF
                                        if (use_vosf) {
                                                XDisplayLock();
                                                if (mainBuffer.dirty) {
                                                        LOCK_VOSF;
                                                        update_display_window_vosf();
                                                        UNLOCK_VOSF;
                                                        XSync(x_display, false); // Let the server catch up
                                                }
                                                XDisplayUnlock();
                                        }
                                        else
#endif
                                                update_display();

                                        // Set new cursor image if it was changed
                                        if (hw_mac_cursor_accl && cursor_changed) {
                                                cursor_changed = false;
                                                uint8 *x_data = (uint8 *)cursor_image->data;
                                                uint8 *x_mask = (uint8 *)cursor_mask_image->data;
                                                for (int i = 0; i < 32; i++) {
                                                        x_mask[i] = MacCursor[4 + i] | MacCursor[36 + i];
                                                        x_data[i] = MacCursor[4 + i];
                                                }
                                                XDisplayLock();
                                                XFreeCursor(x_display, mac_cursor);
                                                XPutImage(x_display, cursor_map, cursor_gc, cursor_image, 0, 0, 0, 0, 16, 16);
                                                XPutImage(x_display, cursor_mask_map, cursor_mask_gc, cursor_mask_image, 0, 0, 0, 0, 16, 16);
                                                mac_cursor = XCreatePixmapCursor(x_display, cursor_map, cursor_mask_map, &black, &white, MacCursor[2], MacCursor[3]);
                                                XDefineCursor(x_display, the_win, mac_cursor);
                                                XDisplayUnlock();
                                        }
                                }
                        }
#ifdef ENABLE_VOSF
                        else if (use_vosf) {
                                // Update display (VOSF variant)
                                if (++tick_counter >= frame_skip) {
                                        tick_counter = 0;
                                        if (mainBuffer.dirty) {
                                                LOCK_VOSF;
                                                update_display_dga_vosf();
                                                UNLOCK_VOSF;
                                        }
                                }
                        }
#endif

                        // Set new palette if it was changed
                        handle_palette_changes();

                } else {

                        // No display refresh pending, check for X events
                        fd_set readfds;
                        FD_ZERO(&readfds);
                        FD_SET(fd, &readfds);
                        struct timeval timeout;
                        timeout.tv_sec = 0;
                        timeout.tv_usec = delay;
                        if (select(fd+1, &readfds, NULL, NULL, &timeout) > 0)
                                handle_events();
                }
        }
        return NULL;
}
Revision:	1.37
Committed:	2005-03-27T14:53:04Z (19 years, 2 months ago) by gbeauche
Branch:	MAIN
Changes since 1.36:	+51 -7 lines
Log Message:	Implement screen win/WIDTH/HEIGHT prefs item that overrides any other value for windowmodes and screenmodes. Necessary for arbitrary full screen mode sizes.