src/devices/dev_fb.c

/*
 *  Copyright (C) 2003-2005  Anders Gavare.  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright  
 *     notice, this list of conditions and the following disclaimer in the 
 *     documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 *  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE   
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 *  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 *  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 *  SUCH DAMAGE.
 *   
 *
 *  $Id: dev_fb.c,v 1.107 2005/09/18 19:54:15 debug Exp $
 *  
 *  Generic framebuffer device.
 *
 *      DECstation VFB01 monochrome framebuffer, 1024x864
 *      DECstation VFB02 8-bit color framebuffer, 1024x864
 *      DECstation Maxine, 1024x768 8-bit color
 *      HPCmips framebuffer
 *      Playstation 2 (24-bit color)
 *      generic (any resolution, several bit depths possible)
 *
 *
 *  TODO:  There is still a bug when redrawing the cursor. The underlying
 *         image is moved 1 pixel (?), or something like that.
 *
 *  TODO:  This should actually be independant of X11, but that
 *         might be too hard to do right now.
 *
 *  TODO:  playstation 2 pixels are stored in another format, actually
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "console.h"
#include "cpu.h"
#include "devices.h"
#include "machine.h"
#include "memory.h"
#include "misc.h"
#include "x11.h"

#ifdef WITH_X11
#include <X11/Xlib.h>
#include <X11/Xos.h>
#include <X11/Xutil.h>
#endif


#define FB_TICK_SHIFT           19


/*  #define FB_DEBUG  */

/*
 *  set_grayscale_palette():
 *
 *  Fill d->rgb_palette with grayscale values. ncolors should
 *  be something like 2, 4, 16, or 256.
 */
void set_grayscale_palette(struct vfb_data *d, int ncolors)
{
        int i, gray;

        for (i=0; i<256; i++) {
                gray = 255*i/(ncolors-1);
                d->rgb_palette[i*3 + 0] = gray;
                d->rgb_palette[i*3 + 1] = gray;
                d->rgb_palette[i*3 + 2] = gray;
        }
}


/*
 *  set_blackwhite_palette():
 *
 *  Set color 0 = black, all others to white.
 */
void set_blackwhite_palette(struct vfb_data *d, int ncolors)
{
        int i, gray;

        for (i=0; i<256; i++) {
                gray = i==0? 0 : 255;
                d->rgb_palette[i*3 + 0] = gray;
                d->rgb_palette[i*3 + 1] = gray;
                d->rgb_palette[i*3 + 2] = gray;
        }
}


/*
 *  dev_fb_resize():
 *
 *  Resize a framebuffer window. (This functionality is probably a bit buggy,
 *  because I didn't think of including it from the start.)
 */
void dev_fb_resize(struct vfb_data *d, int new_xsize, int new_ysize)
{
        unsigned char *new_framebuffer;
        int y, new_bytes_per_line;
        size_t size;

        if (d == NULL) {
                fatal("dev_fb_resize(): d == NULL\n");
                return;
        }

        new_bytes_per_line = new_xsize * d->bit_depth / 8;
        size = new_ysize * new_bytes_per_line;

        new_framebuffer = malloc(size);
        if (new_framebuffer == NULL) {
                fprintf(stderr, "dev_fb_resize(): out of memory\n");
                exit(1);
        }

        /*  Copy the old framebuffer to the new:  */
        if (d->framebuffer != NULL) {
                for (y=0; y<new_ysize; y++) {
                        size_t fromofs = d->bytes_per_line * y;
                        size_t toofs = new_bytes_per_line * y;
                        size_t len_to_copy = d->bytes_per_line <
                            new_bytes_per_line? d->bytes_per_line       
                            : new_bytes_per_line;
                        memset(new_framebuffer + toofs, 0, new_bytes_per_line);
                        if (y < d->x11_ysize)
                                memmove(new_framebuffer + toofs,
                                    d->framebuffer + fromofs, len_to_copy);
                }

                free(d->framebuffer);
        }

        d->framebuffer = new_framebuffer;
        d->framebuffer_size = size;

        if (new_xsize > d->x11_xsize || new_ysize > d->x11_ysize) {
                d->update_x1 = d->update_y1 = 0;
                d->update_x2 = new_xsize - 1;
                d->update_y2 = new_ysize - 1;
        }

        d->bytes_per_line = new_bytes_per_line;
        d->x11_xsize = d->visible_xsize = new_xsize;
        d->x11_ysize = d->visible_ysize = new_ysize;

#ifdef WITH_X11
        if (d->fb_window != NULL)
                x11_fb_resize(d->fb_window, new_xsize, new_ysize);
#endif
}


/*
 *  dev_fb_setcursor():
 */
void dev_fb_setcursor(struct vfb_data *d, int cursor_x, int cursor_y, int on,
        int cursor_xsize, int cursor_ysize)
{
        if (cursor_x < 0)
                cursor_x = 0;
        if (cursor_y < 0)
                cursor_y = 0;
        if (cursor_x + cursor_xsize >= d->xsize)
                cursor_x = d->xsize - cursor_xsize;
        if (cursor_y + cursor_ysize >= d->ysize)
                cursor_y = d->ysize - cursor_ysize;

#ifdef WITH_X11
        if (d->fb_window != NULL) {
                d->fb_window->cursor_x      = cursor_x;
                d->fb_window->cursor_y      = cursor_y;
                d->fb_window->cursor_on     = on;
                d->fb_window->cursor_xsize  = cursor_xsize;
                d->fb_window->cursor_ysize  = cursor_ysize;
        }
#endif

        if (d->fb_window != NULL)
                console_set_framebuffer_mouse(cursor_x, cursor_y,
                    d->fb_window->fb_number);

        /*  debug("dev_fb_setcursor(%i,%i, size %i,%i, on=%i)\n",
            cursor_x, cursor_y, cursor_xsize, cursor_ysize, on);  */
}


/*
 *  framebuffer_blockcopyfill():
 *
 *  This function should be used by devices that are capable of doing
 *  block copy/fill.
 *
 *  If fillflag is non-zero, then fill_[rgb] should contain the color
 *  with which to fill.
 *
 *  If fillflag is zero, copy mode is used, and from_[xy] should contain
 *  the offset on the framebuffer where we should copy from.
 *
 *  NOTE:  Overlapping copies are undefined!
 */
void framebuffer_blockcopyfill(struct vfb_data *d, int fillflag, int fill_r,
        int fill_g, int fill_b, int x1, int y1, int x2, int y2,
        int from_x, int from_y)
{
        int y;
        long from_ofs, dest_ofs, linelen;

        if (fillflag)
                debug("framebuffer_blockcopyfill(FILL, %i,%i, %i,%i, "
                    "color %i,%i,%i)\n", x1,y1, x2,y2, fill_r, fill_g, fill_b);
        else
                debug("framebuffer_blockcopyfill(COPY, %i,%i, %i,%i, from "
                    "%i,%i)\n", x1,y1, x2,y2, from_x,from_y);

        /*  Clip x:  */
        if (x1 < 0)             x1 = 0;
        if (x1 >= d->xsize)     x1 = d->xsize-1;
        if (x2 < 0)             x2 = 0;
        if (x2 >= d->xsize)     x2 = d->xsize-1;

        dest_ofs = d->bytes_per_line * y1 + (d->bit_depth/8) * x1;
        linelen = (x2-x1 + 1) * (d->bit_depth/8);
        /*  NOTE: linelen is nr of bytes, not pixels  */

        if (fillflag) {
                for (y=y1; y<=y2; y++) {
                        if (y>=0 && y<d->ysize) {
                                int x;
                                char buf[8192 * 3];
                                if (d->bit_depth == 24)
                                        for (x=0; x<linelen; x+=3) {
                                                buf[x] = fill_r;
                                                buf[x+1] = fill_g;
                                                buf[x+2] = fill_b;
                                        }
                                else
                                        printf("TODO: fill for non-24-bit"
                                            " modes\n");

                                memmove(d->framebuffer + dest_ofs, buf,
                                    linelen);
                        }

                        dest_ofs += d->bytes_per_line;
                }
        } else {
                from_ofs = d->bytes_per_line * from_y +
                    (d->bit_depth/8) * from_x;

                for (y=y1; y<=y2; y++) {
                        if (y>=0 && y<d->ysize)
                                memmove(d->framebuffer + dest_ofs,
                                    d->framebuffer + from_ofs, linelen);

                        from_ofs += d->bytes_per_line;
                        dest_ofs += d->bytes_per_line;
                }
        }

        if (x1 < d->update_x1 || d->update_x1 == -1)    d->update_x1 = x1;
        if (x1 > d->update_x2 || d->update_x2 == -1)    d->update_x2 = x1;
        if (x2 < d->update_x1 || d->update_x1 == -1)    d->update_x1 = x2;
        if (x2 > d->update_x2 || d->update_x2 == -1)    d->update_x2 = x2;

        if (y1 < d->update_y1 || d->update_y1 == -1)    d->update_y1 = y1;
        if (y1 > d->update_y2 || d->update_y2 == -1)    d->update_y2 = y1;
        if (y2 < d->update_y1 || d->update_y1 == -1)    d->update_y1 = y2;
        if (y2 > d->update_y2 || d->update_y2 == -1)    d->update_y2 = y2;
}


#ifdef WITH_X11
#define macro_put_pixel() {     \
        /*  Combine the color into an X11 long and display it:  */      \
        /*  TODO:  construct color in a more portable way:  */          \
        switch (d->fb_window->x11_screen_depth) {                       \
        case 24:                                                        \
                if (d->fb_window->fb_ximage->byte_order)                \
                        color = (b << 16) + (g << 8) + r;               \
                else                                                    \
                        color = (r << 16) + (g << 8) + b;               \
                break;                                                  \
        case 16:                                                        \
                r >>= 3; g >>= 2; b >>= 3;                              \
                if (d->fb_window->fb_ximage->byte_order) {              \
                        /*  Big endian 16-bit X server:  */             \
                        static int first = 1;                           \
                        if (first) {                                    \
                                fprintf(stderr, "\n*** Please report "  \
                                    "to the author whether 16-bit X11 " \
                                    "colors are rendered correctly or " \
                                    "not!\n\n");                        \
                                first = 0;                              \
                        }                                               \
                        color = (b << 11) + (g << 5) + r;               \
                } else {                                                \
                        /*  Little endian (eg PC) X servers:  */        \
                        color = (r << 11) + (g << 5) + b;               \
                }                                                       \
                break;                                                  \
        case 15:                                                        \
                r >>= 3; g >>= 3; b >>= 3;                              \
                if (d->fb_window->fb_ximage->byte_order) {              \
                        /*  Big endian 15-bit X server:  */             \
                        static int first = 1;                           \
                        if (first) {                                    \
                                fprintf(stderr, "\n*** Please report "  \
                                    "to the author whether 15-bit X11 " \
                                    "colors are rendered correctly or " \
                                    "not!\n\n");                        \
                                first = 0;                              \
                        }                                               \
                        color = (b << 10) + (g << 5) + r;               \
                } else {                                                \
                        /*  Little endian (eg PC) X servers:  */        \
                        color = (r << 10) + (g << 5) + b;               \
                }                                                       \
                break;                                                  \
        default:                                                        \
                color = d->fb_window->x11_graycolor[15 * (r + g + b)    \
                    / (255 * 3)].pixel;                                 \
        }                                                               \
        if (x>=0 && x<d->x11_xsize && y>=0 && y<d->x11_ysize)           \
                XPutPixel(d->fb_window->fb_ximage, x, y, color);        \
    }
#else
/*  If not WITH_X11:  */
#define macro_put_pixel() { }
#endif


/*
 *  update_framebuffer():
 *
 *  The framebuffer memory has been updated. This function tries to make
 *  sure that the XImage is also updated (1 or more pixels).
 */
void update_framebuffer(struct vfb_data *d, int addr, int len)
{
        int x, y, pixel, npixels;
        long color_r, color_g, color_b;
#ifdef WITH_X11
        long color;
#endif
        int scaledown = d->vfb_scaledown;
        int scaledownXscaledown = 1;

        if (scaledown == 1) {
                /*  Which framebuffer pixel does addr correspond to?  */
                pixel = addr * 8 / d->bit_depth;
                y = pixel / d->xsize;
                x = pixel % d->xsize;

                /*  How many framebuffer pixels?  */
                npixels = len * 8 / d->bit_depth;
                if (npixels == 0)
                        npixels = 1;

                if (d->bit_depth < 8) {
                        for (pixel=0; pixel<npixels; pixel++) {
                                int fb_addr, c, r, g, b;
                                color_r = color_g = color_b = 0;

                                fb_addr = (y * d->xsize + x) * d->bit_depth;
                                /*  fb_addr is now which _bit_ in
                                    the framebuffer  */

                                c = d->framebuffer[fb_addr >> 3];
                                fb_addr &= 7;

                                /*  HPCmips is reverse:  */
                                if (d->vfb_type == VFB_HPCMIPS)
                                        fb_addr = 8 - d->bit_depth - fb_addr;

                                c = (c >> fb_addr) & ((1<<d->bit_depth) - 1);
                                /*  c <<= (8 - d->bit_depth);  */

                                r = d->rgb_palette[c*3 + 0];
                                g = d->rgb_palette[c*3 + 1];
                                b = d->rgb_palette[c*3 + 2];

                                macro_put_pixel();
                                x++;
                        }
                } else if (d->bit_depth == 8) {
                        for (pixel=0; pixel<npixels; pixel++) {
                                int fb_addr, c, r, g, b;
                                color_r = color_g = color_b = 0;

                                fb_addr = y * d->xsize + x;
                                /*  fb_addr is now which byte in framebuffer  */
                                c = d->framebuffer[fb_addr];
                                r = d->rgb_palette[c*3 + 0];
                                g = d->rgb_palette[c*3 + 1];
                                b = d->rgb_palette[c*3 + 2];

                                macro_put_pixel();
                                x++;
                        }
                } else {        /*  d->bit_depth > 8  */
                        for (pixel=0; pixel<npixels; pixel++) {
                                int fb_addr, r, g, b;
                                color_r = color_g = color_b = 0;

                                fb_addr = (y * d->xsize + x) * d->bit_depth;
                                /*  fb_addr is now which byte in framebuffer  */

                                /*  > 8 bits color.  */
                                fb_addr >>= 3;
                                switch (d->bit_depth) {
                                case 24:
                                        r = d->framebuffer[fb_addr];
                                        g = d->framebuffer[fb_addr + 1];
                                        b = d->framebuffer[fb_addr + 2];
                                        break;
                                /*  TODO: copy to the scaledown code below  */
                                case 16:
                                        if (d->vfb_type == VFB_HPCMIPS) {
                                                b = d->framebuffer[fb_addr] +
                                                    (d->framebuffer[fb_addr+1]
                                                    << 8);

                                                if (d->color32k) {
                                                        r = b >> 11;
                                                        g = b >> 5;
                                                        r = r & 31;
                                                        g = (g & 31) * 2;
                                                        b = b & 31;
                                                } else if (d->psp_15bit) {
                                                        int tmp;
                                                        r = (b >> 10) & 0x1f;
                                                        g = (b >>  5) & 0x1f;
                                                        b = b & 0x1f;
                                                        g <<= 1;
                                                        tmp = r; r = b; b = tmp;
                                                } else {
                                                        r = (b >> 11) & 0x1f;
                                                        g = (b >>  5) & 0x3f;
                                                        b = b & 0x1f;
                                                }
                                        } else {
                                            r = d->framebuffer[fb_addr] >> 3;
                                            g = (d->framebuffer[fb_addr] << 5) +
                                              (d->framebuffer[fb_addr + 1] >>5);
                                            b = d->framebuffer[fb_addr + 1]&31;
                                        }

                                        r *= 8;
                                        g *= 4;
                                        b *= 8;
                                        break;
                                default:
                                        r = g = b = random() & 255;
                                }

                                macro_put_pixel();
                                x++;
                        }
                }

                return;
        }

        /*  scaledown > 1:  */

        scaledown = d->vfb_scaledown;
        scaledownXscaledown = scaledown * scaledown;

        /*  Which framebuffer pixel does addr correspond to?  */
        pixel = addr * 8 / d->bit_depth;
        y = pixel / d->xsize;
        x = pixel % d->xsize;

        /*  How many framebuffer pixels?  */
        npixels = len * 8 / d->bit_depth;

        /*  Which x11 pixel?  */
        x /= scaledown;
        y /= scaledown;

        /*  How many x11 pixels:  */
        npixels /= scaledown;
        if (npixels == 0)
                npixels = 1;

        if (d->bit_depth < 8) {
                for (pixel=0; pixel<npixels; pixel++) {
                        int subx, suby, r, g, b;
                        color_r = color_g = color_b = 0;
                        for (suby=0; suby<scaledown; suby++)
                            for (subx=0; subx<scaledown; subx++) {
                                int fb_x, fb_y, fb_addr, c;

                                fb_x = x * scaledown + subx;
                                fb_y = y * scaledown + suby;
                                fb_addr = fb_y * d->xsize + fb_x;
                                fb_addr = fb_addr * d->bit_depth;
                                /*  fb_addr is now which _bit_ in
                                    the framebuffer  */

                                c = d->framebuffer[fb_addr >> 3];
                                fb_addr &= 7;

                                /*  HPCmips is reverse:  */
                                if (d->vfb_type == VFB_HPCMIPS)
                                        fb_addr = 8 - d->bit_depth - fb_addr;

                                c = (c >> fb_addr) & ((1<<d->bit_depth) - 1);
                                /*  c <<= (8 - d->bit_depth);  */

                                r = d->rgb_palette[c*3 + 0];
                                g = d->rgb_palette[c*3 + 1];
                                b = d->rgb_palette[c*3 + 2];

                                color_r += r;
                                color_g += g;
                                color_b += b;
                            }

                        r = color_r / scaledownXscaledown;
                        g = color_g / scaledownXscaledown;
                        b = color_b / scaledownXscaledown;
                        macro_put_pixel();
                        x++;
                }
        } else if (d->bit_depth == 8) {
                for (pixel=0; pixel<npixels; pixel++) {
                        int subx, suby, r, g, b;
                        color_r = color_g = color_b = 0;
                        for (suby=0; suby<scaledown; suby++)
                            for (subx=0; subx<scaledown; subx++) {
                                int fb_x, fb_y, fb_addr, c;

                                fb_x = x * scaledown + subx;
                                fb_y = y * scaledown + suby;
                                fb_addr = fb_y * d->xsize + fb_x;
                                /*  fb_addr is which _byte_ in framebuffer  */
                                c = d->framebuffer[fb_addr] * 3;
                                r = d->rgb_palette[c + 0];
                                g = d->rgb_palette[c + 1];
                                b = d->rgb_palette[c + 2];
                                color_r += r;
                                color_g += g;
                                color_b += b;
                            }

                        r = color_r / scaledownXscaledown;
                        g = color_g / scaledownXscaledown;
                        b = color_b / scaledownXscaledown;
                        macro_put_pixel();
                        x++;
                }
        } else {
                /*  Generic > 8 bit bit-depth:  */
                for (pixel=0; pixel<npixels; pixel++) {
                        int subx, suby, r, g, b;
                        color_r = color_g = color_b = 0;
                        for (suby=0; suby<scaledown; suby++)
                            for (subx=0; subx<scaledown; subx++) {
                                int fb_x, fb_y, fb_addr;

                                fb_x = x * scaledown + subx;
                                fb_y = y * scaledown + suby;
                                fb_addr = fb_y * d->xsize + fb_x;
                                fb_addr = (fb_addr * d->bit_depth) >> 3;
                                /*  fb_addr is which _byte_ in framebuffer  */

                                /*  > 8 bits color.  */
                                switch (d->bit_depth) {
                                case 24:
                                        r = d->framebuffer[fb_addr];
                                        g = d->framebuffer[fb_addr + 1];
                                        b = d->framebuffer[fb_addr + 2];
                                        break;
                                default:
                                        r = g = b = random() & 255;
                                }
                                color_r += r;
                                color_g += g;
                                color_b += b;
                            }
                        r = color_r / scaledownXscaledown;
                        g = color_g / scaledownXscaledown;
                        b = color_b / scaledownXscaledown;
                        macro_put_pixel();
                        x++;
                }
        }
}


/*
 *  dev_fb_tick():
 *
 */
void dev_fb_tick(struct cpu *cpu, void *extra)
{
        struct vfb_data *d = extra;
#ifdef WITH_X11
        int need_to_flush_x11 = 0;
        int need_to_redraw_cursor = 0;
#endif

        if (!cpu->machine->use_x11)
                return;

        do {
                uint64_t high, low = (uint64_t)(int64_t) -1;
                int x, y;

                memory_device_dyntrans_access(cpu, cpu->mem,
                    extra, &low, &high);
                if ((int64_t)low == -1)
                        break;

                /*  printf("low=%016llx high=%016llx\n",
                    (long long)low, (long long)high);  */

                x = (low % d->bytes_per_line) * 8 / d->bit_depth;
                y = low / d->bytes_per_line;
                if (x < d->update_x1 || d->update_x1 == -1)
                        d->update_x1 = x;
                if (x > d->update_x2 || d->update_x2 == -1)
                        d->update_x2 = x;
                if (y < d->update_y1 || d->update_y1 == -1)
                        d->update_y1 = y;
                if (y > d->update_y2 || d->update_y2 == -1)
                        d->update_y2 = y;

                x = ((low+7) % d->bytes_per_line) * 8 / d->bit_depth;
                y = (low+7) / d->bytes_per_line;
                if (x < d->update_x1 || d->update_x1 == -1)
                        d->update_x1 = x;
                if (x > d->update_x2 || d->update_x2 == -1)
                        d->update_x2 = x;
                if (y < d->update_y1 || d->update_y1 == -1)
                        d->update_y1 = y;
                if (y > d->update_y2 || d->update_y2 == -1)
                        d->update_y2 = y;

                x = (high % d->bytes_per_line) * 8 / d->bit_depth;
                y = high / d->bytes_per_line;
                if (x < d->update_x1 || d->update_x1 == -1)
                        d->update_x1 = x;
                if (x > d->update_x2 || d->update_x2 == -1)
                        d->update_x2 = x;
                if (y < d->update_y1 || d->update_y1 == -1)
                        d->update_y1 = y;
                if (y > d->update_y2 || d->update_y2 == -1)
                        d->update_y2 = y;

                x = ((high+7) % d->bytes_per_line) * 8 / d->bit_depth;
                y = (high+7) / d->bytes_per_line;
                if (x < d->update_x1 || d->update_x1 == -1)
                        d->update_x1 = x;
                if (x > d->update_x2 || d->update_x2 == -1)
                        d->update_x2 = x;
                if (y < d->update_y1 || d->update_y1 == -1)
                        d->update_y1 = y;
                if (y > d->update_y2 || d->update_y2 == -1)
                        d->update_y2 = y;

                /*
                 *  An update covering more than one line will automatically
                 *  force an update of all the affected lines:
                 */
                if (d->update_y1 != d->update_y2) {
                        d->update_x1 = 0;
                        d->update_x2 = d->xsize-1;
                }
        } while (0);

#ifdef WITH_X11
        /*  Do we need to redraw the cursor?  */
        if (d->fb_window->cursor_on != d->fb_window->OLD_cursor_on ||
            d->fb_window->cursor_x != d->fb_window->OLD_cursor_x ||
            d->fb_window->cursor_y != d->fb_window->OLD_cursor_y ||
            d->fb_window->cursor_xsize != d->fb_window->OLD_cursor_xsize ||
            d->fb_window->cursor_ysize != d->fb_window->OLD_cursor_ysize)
                need_to_redraw_cursor = 1;

        if (d->update_x2 != -1) {
                if (((d->update_x1 >= d->fb_window->OLD_cursor_x &&
                      d->update_x1 < (d->fb_window->OLD_cursor_x +
                      d->fb_window->OLD_cursor_xsize)) ||
                     (d->update_x2 >= d->fb_window->OLD_cursor_x &&
                      d->update_x2 < (d->fb_window->OLD_cursor_x +
                      d->fb_window->OLD_cursor_xsize)) ||
                     (d->update_x1 <  d->fb_window->OLD_cursor_x &&
                      d->update_x2 >= (d->fb_window->OLD_cursor_x +
                      d->fb_window->OLD_cursor_xsize)) ) &&
                   ( (d->update_y1 >= d->fb_window->OLD_cursor_y &&
                      d->update_y1 < (d->fb_window->OLD_cursor_y +
                      d->fb_window->OLD_cursor_ysize)) ||
                     (d->update_y2 >= d->fb_window->OLD_cursor_y &&
                      d->update_y2 < (d->fb_window->OLD_cursor_y +
                      d->fb_window->OLD_cursor_ysize)) ||
                     (d->update_y1 <  d->fb_window->OLD_cursor_y &&
                      d->update_y2 >= (d->fb_window->OLD_cursor_y +
                     d->fb_window->OLD_cursor_ysize)) ) )
                        need_to_redraw_cursor = 1;
        }

        if (need_to_redraw_cursor) {
                /*  Remove old cursor, if any:  */
                if (d->fb_window->OLD_cursor_on) {
                        XPutImage(d->fb_window->x11_display,
                            d->fb_window->x11_fb_window,
                            d->fb_window->x11_fb_gc, d->fb_window->fb_ximage,
                            d->fb_window->OLD_cursor_x/d->vfb_scaledown,
                            d->fb_window->OLD_cursor_y/d->vfb_scaledown,
                            d->fb_window->OLD_cursor_x/d->vfb_scaledown,
                            d->fb_window->OLD_cursor_y/d->vfb_scaledown,
                            d->fb_window->OLD_cursor_xsize/d->vfb_scaledown + 1,
                            d->fb_window->OLD_cursor_ysize/d->vfb_scaledown +1);
                }
        }
#endif

        if (d->update_x2 != -1) {
                int y, addr, addr2, q = d->vfb_scaledown;

                if (d->update_x1 >= d->visible_xsize)
                        d->update_x1 = d->visible_xsize - 1;
                if (d->update_x2 >= d->visible_xsize)
                        d->update_x2 = d->visible_xsize - 1;
                if (d->update_y1 >= d->visible_ysize)
                        d->update_y1 = d->visible_ysize - 1;
                if (d->update_y2 >= d->visible_ysize)
                        d->update_y2 = d->visible_ysize - 1;

                /*  Without these, we might miss the rightmost/bottom pixel:  */
                d->update_x2 += (q - 1);
                d->update_y2 += (q - 1);

                d->update_x1 = d->update_x1 / q * q;
                d->update_x2 = d->update_x2 / q * q;
                d->update_y1 = d->update_y1 / q * q;
                d->update_y2 = d->update_y2 / q * q;

                addr  = d->update_y1 * d->bytes_per_line +
                    d->update_x1 * d->bit_depth / 8;
                addr2 = d->update_y1 * d->bytes_per_line +
                    d->update_x2 * d->bit_depth / 8;

                for (y=d->update_y1; y<=d->update_y2; y+=q) {
                        update_framebuffer(d, addr, addr2 - addr);
                        addr  += d->bytes_per_line * q;
                        addr2 += d->bytes_per_line * q;
                }

#ifdef WITH_X11
                XPutImage(d->fb_window->x11_display, d->fb_window->
                    x11_fb_window, d->fb_window->x11_fb_gc, d->fb_window->
                    fb_ximage, d->update_x1/d->vfb_scaledown, d->update_y1/
                    d->vfb_scaledown, d->update_x1/d->vfb_scaledown,
                    d->update_y1/d->vfb_scaledown,
                    (d->update_x2 - d->update_x1)/d->vfb_scaledown + 1,
                    (d->update_y2 - d->update_y1)/d->vfb_scaledown + 1);

                need_to_flush_x11 = 1;
#endif

                d->update_x1 = d->update_y1 = 99999;
                d->update_x2 = d->update_y2 = -1;
        }

#ifdef WITH_X11
        if (need_to_redraw_cursor) {
                /*  Paint new cursor:  */
                if (d->fb_window->cursor_on) {
                        x11_redraw_cursor(cpu->machine,
                            d->fb_window->fb_number);
                        d->fb_window->OLD_cursor_on = d->fb_window->cursor_on;
                        d->fb_window->OLD_cursor_x = d->fb_window->cursor_x;
                        d->fb_window->OLD_cursor_y = d->fb_window->cursor_y;
                        d->fb_window->OLD_cursor_xsize = d->fb_window->
                            cursor_xsize;
                        d->fb_window->OLD_cursor_ysize = d->fb_window->
                            cursor_ysize;
                }
        }
#endif

#ifdef WITH_X11
        if (need_to_flush_x11)
                XFlush(d->fb_window->x11_display);
#endif
}


/*
 *  dev_fb_access():
 */
int dev_fb_access(struct cpu *cpu, struct memory *mem,
        uint64_t relative_addr, unsigned char *data, size_t len,
        int writeflag, void *extra)
{
        struct vfb_data *d = extra;
        int i;

#ifdef FB_DEBUG
        if (writeflag == MEM_WRITE) { if (data[0]) {
                fatal("[ dev_fb: write  to addr=%08lx, data = ",
                    (long)relative_addr);
                for (i=0; i<len; i++)
                        fatal("%02x ", data[i]);
                fatal("]\n");
        } else {
                fatal("[ dev_fb: read from addr=%08lx, data = ",
                    (long)relative_addr);
                for (i=0; i<len; i++)
                        fatal("%02x ", d->framebuffer[relative_addr + i]);
                fatal("]\n");
        }
#endif

        if (relative_addr >= d->framebuffer_size)
                return 0;

        /*  See if a write actually modifies the framebuffer contents:  */
        if (writeflag == MEM_WRITE) {
                for (i=0; i<len; i++) {
                        if (data[i] != d->framebuffer[relative_addr + i])
                                break;

                        /*  If all bytes are equal to what is already stored
                            in the framebuffer, then simply return:  */
                        if (i==len-1)
                                return 1;
                }
        }

        /*
         *  If the framebuffer is modified, then we should keep a track
         *  of which area(s) we modify, so that the display isn't updated
         *  unnecessarily.
         */
        if (writeflag == MEM_WRITE && cpu->machine->use_x11) {
                int x, y, x2,y2;

                x = (relative_addr % d->bytes_per_line) * 8 / d->bit_depth;
                y = relative_addr / d->bytes_per_line;
                x2 = ((relative_addr + len) % d->bytes_per_line)
                    * 8 / d->bit_depth;
                y2 = (relative_addr + len) / d->bytes_per_line;

                if (x < d->update_x1 || d->update_x1 == -1)
                        d->update_x1 = x;
                if (x > d->update_x2 || d->update_x2 == -1)
                        d->update_x2 = x;

                if (y < d->update_y1 || d->update_y1 == -1)
                        d->update_y1 = y;
                if (y > d->update_y2 || d->update_y2 == -1)
                        d->update_y2 = y;

                if (x2 < d->update_x1 || d->update_x1 == -1)
                        d->update_x1 = x2;
                if (x2 > d->update_x2 || d->update_x2 == -1)
                        d->update_x2 = x2;

                if (y2 < d->update_y1 || d->update_y1 == -1)
                        d->update_y1 = y2;
                if (y2 > d->update_y2 || d->update_y2 == -1)
                        d->update_y2 = y2;

                /*
                 *  An update covering more than one line will automatically
                 *  force an update of all the affected lines:
                 */
                if (y != y2) {
                        d->update_x1 = 0;
                        d->update_x2 = d->xsize-1;
                }
        }

        /*
         *  Read from/write to the framebuffer:
         *  (TODO: take the color_plane_mask into account)
         *
         *  Calling memcpy() is probably overkill, as it usually is just one
         *  or a few bytes that are read/written at a time.
         */
        if (writeflag == MEM_WRITE) {
                if (len > 8)
                        memcpy(d->framebuffer + relative_addr, data, len);
                else
                        for (i=0; i<len; i++)
                                d->framebuffer[relative_addr + i] = data[i];
        } else {
                if (len > 8)
                        memcpy(data, d->framebuffer + relative_addr, len);
                else
                        for (i=0; i<len; i++)
                                data[i] = d->framebuffer[relative_addr + i];
        }

        return 1;
}


/*
 *  dev_fb_init():
 *
 *  This function is big and ugly, but the point is to initialize a framebuffer
 *  device. :-)
 *
 *  visible_xsize and visible_ysize are the sizes of the visible display area.
 *  xsize and ysize tell how much memory is actually allocated (for example
 *  visible_xsize could be 640, but xsize could be 1024, for better alignment).
 *
 *  vfb_type is useful for selecting special features.
 *
 *  type = VFB_GENERIC is the most useful type, especially when bit_depth = 24.
 *
 *  VFB_DEC_VFB01, _VFB02, and VFB_DEC_MAXINE are DECstation specific.
 *
 *  If type is VFB_HPCMIPS, then color encoding differs from the generic case.
 *
 *  If bit_depth = -15 (note the minus sign), then a special hack is used for
 *  the Playstation Portable's 5-bit R, 5-bit G, 5-bit B.
 */
struct vfb_data *dev_fb_init(struct machine *machine, struct memory *mem,
        uint64_t baseaddr, int vfb_type, int visible_xsize, int visible_ysize,
        int xsize, int ysize, int bit_depth, char *name)
{
        struct vfb_data *d;
        size_t size, nlen;
        int flags;
        char title[400];
        char *name2;

        d = malloc(sizeof(struct vfb_data));
        if (d == NULL) {
                fprintf(stderr, "out of memory\n");
                exit(1);
        }
        memset(d, 0, sizeof(struct vfb_data));

        d->vfb_type = vfb_type;

        /*  Defaults:  */
        d->xsize = xsize;  d->visible_xsize = visible_xsize;
        d->ysize = ysize;  d->visible_ysize = visible_ysize;

        d->bit_depth = bit_depth;

        if (bit_depth == 15) {
                d->color32k = 1;
                bit_depth = d->bit_depth = 16;
        } else if (bit_depth == -15) {
                d->psp_15bit = 1;
                bit_depth = d->bit_depth = 16;
        }

        /*  Specific types:  */
        switch (vfb_type) {
        case VFB_DEC_VFB01:
                /*  DECstation VFB01 (monochrome)  */
                d->xsize = 2048;  d->visible_xsize = 1024;
                d->ysize = 1024;  d->visible_ysize = 864;
                d->bit_depth = 1;
                break;
        case VFB_DEC_VFB02:
                /*  DECstation VFB02 (color)  */
                d->xsize = 1024;  d->visible_xsize = 1024;
                d->ysize = 1024;  d->visible_ysize = 864;
                d->bit_depth = 8;
                break;
        case VFB_DEC_MAXINE:
                /*  DECstation Maxine (1024x768x8)  */
                d->xsize = 1024; d->visible_xsize = d->xsize;
                d->ysize = 768;  d->visible_ysize = d->ysize;
                d->bit_depth = 8;
                break;
        case VFB_PLAYSTATION2:
                /*  Playstation 2  */
                d->xsize = xsize;  d->visible_xsize = d->xsize;
                d->ysize = ysize;  d->visible_ysize = d->ysize;
                d->bit_depth = 24;
                break;
        default:
                ;
        }

        if (d->bit_depth == 2 || d->bit_depth == 4)
                set_grayscale_palette(d, 1 << d->bit_depth);
        else if (d->bit_depth == 8 || d->bit_depth == 1)
                set_blackwhite_palette(d, 1 << d->bit_depth);

        d->vfb_scaledown = machine->x11_scaledown;

        d->bytes_per_line = d->xsize * d->bit_depth / 8;
        size = d->ysize * d->bytes_per_line;

        d->framebuffer = malloc(size);
        if (d->framebuffer == NULL) {
                fprintf(stderr, "out of memory\n");
                exit(1);
        }

        /*  Clear the framebuffer (all black pixels):  */
        d->framebuffer_size = size;
        memset(d->framebuffer, 0, size);

        d->x11_xsize = d->visible_xsize / d->vfb_scaledown;
        d->x11_ysize = d->visible_ysize / d->vfb_scaledown;

        d->update_x1 = d->update_y1 = 99999;
        d->update_x2 = d->update_y2 = -1;


        /*  Don't set the title to include the size of the framebuffer for
            VGA, since then the resolution might change during runtime.  */
        if (strcmp(name, "VGA") == 0)
                snprintf(title, sizeof(title),"GXemul: %s framebuffer", name);
        else
                snprintf(title, sizeof(title),"GXemul: %ix%ix%i %s framebuffer",
                    d->visible_xsize, d->visible_ysize, d->bit_depth, name);
        title[sizeof(title)-1] = '\0';

#ifdef WITH_X11
        if (machine->use_x11)
                d->fb_window = x11_fb_init(d->x11_xsize, d->x11_ysize,
                    title, machine->x11_scaledown, machine);
        else
#endif
                d->fb_window = NULL;

        nlen = strlen(name) + 10;
        name2 = malloc(nlen);
        if (name2 == NULL) {
                fprintf(stderr, "out of memory in dev_fb_init()\n");
                exit(1);
        }
        snprintf(name2, nlen, "fb [%s]", name);

        flags = MEM_DEFAULT;
        if ((baseaddr & 0xfff) == 0)
                flags = MEM_DYNTRANS_OK | MEM_DYNTRANS_WRITE_OK;

        flags |= MEM_READING_HAS_NO_SIDE_EFFECTS;

        memory_device_register(mem, name2, baseaddr, size, dev_fb_access,
            d, flags, d->framebuffer);

        machine_add_tickfunction(machine, dev_fb_tick, d, FB_TICK_SHIFT);
        return d;
}
