/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* DGA 2.0 based SDL video driver implementation.
*/

#include <stdio.h>

#include <X11/Xlib.h>
#include "../Xext/extensions/xf86dga.h"

#include "SDL_video.h"
#include "SDL_mouse.h"
#include "../SDL_sysvideo.h"
#include "../SDL_pixels_c.h"
#include "../../events/SDL_events_c.h"
#include "SDL_dgavideo.h"
#include "SDL_dgamouse_c.h"
#include "SDL_dgaevents_c.h"

/* get function pointers... */
#include "../x11/SDL_x11dyn.h"

/*#define DGA_DEBUG*/

/* Heheh we're using X11 event code */
extern void X11_SaveScreenSaver(Display * display, int *saved_timeout,
                                BOOL * dpms);
extern void X11_DisableScreenSaver(Display * display);
extern void X11_RestoreScreenSaver(Display * display, int saved_timeout,
                                   BOOL dpms);

/* Initialization/Query functions */
static int DGA_VideoInit(_THIS, SDL_PixelFormat * vformat);
static SDL_Rect **DGA_ListModes(_THIS, SDL_PixelFormat * format,
                                Uint32 flags);
static SDL_Surface *DGA_SetVideoMode(_THIS, SDL_Surface * current, int width,
                                     int height, int bpp, Uint32 flags);
static int DGA_SetColors(_THIS, int firstcolor, int ncolors,
                         SDL_Color * colors);
static int DGA_SetGammaRamp(_THIS, Uint16 * ramp);
static void DGA_VideoQuit(_THIS);

/* Hardware surface functions */
static int DGA_InitHWSurfaces(_THIS, SDL_Surface * screen, Uint8 * base,
                              int size);
static void DGA_FreeHWSurfaces(_THIS);
static int DGA_AllocHWSurface(_THIS, SDL_Surface * surface);
static int DGA_FillHWRect(_THIS, SDL_Surface * dst, SDL_Rect * rect,
                          Uint32 color);
static int DGA_CheckHWBlit(_THIS, SDL_Surface * src, SDL_Surface * dst);
static int DGA_LockHWSurface(_THIS, SDL_Surface * surface);
static void DGA_UnlockHWSurface(_THIS, SDL_Surface * surface);
static void DGA_FreeHWSurface(_THIS, SDL_Surface * surface);
static int DGA_FlipHWSurface(_THIS, SDL_Surface * surface);

/* DGA driver bootstrap functions */

static int
DGA_Available(void)
{
    const char *display = NULL;
    Display *dpy = NULL;
    int available = 0;

    /* The driver is available is available if the display is local
       and the DGA 2.0+ extension is available, and we can map mem.
     */
    if (SDL_X11_LoadSymbols()) {
        if ((SDL_strncmp(XDisplayName(display), ":", 1) == 0) ||
            (SDL_strncmp(XDisplayName(display), "unix:", 5) == 0)) {
            dpy = XOpenDisplay(display);
            if (dpy) {
                int events, errors, major, minor;

                if (SDL_NAME(XDGAQueryExtension)
                    (dpy, &events, &errors)
                    && SDL_NAME(XDGAQueryVersion) (dpy, &major, &minor)) {
                    int screen;

                    screen = DefaultScreen(dpy);
                    if ((major >= 2) &&
                        SDL_NAME(XDGAOpenFramebuffer) (dpy, screen)) {
                        available = 1;
                        SDL_NAME(XDGACloseFramebuffer) (dpy, screen);
                    }
                }
                XCloseDisplay(dpy);
            }
        }
        SDL_X11_UnloadSymbols();
    }
    return (available);
}

static void
DGA_DeleteDevice(SDL_VideoDevice * device)
{
    if (device != NULL) {
        SDL_free(device->hidden);
        SDL_free(device);
        SDL_X11_UnloadSymbols();
    }
}

static SDL_VideoDevice *
DGA_CreateDevice(int devindex)
{
    SDL_VideoDevice *device = NULL;

    /* Initialize all variables that we clean on shutdown */
    if (SDL_X11_LoadSymbols()) {
        device = (SDL_VideoDevice *) SDL_malloc(sizeof(SDL_VideoDevice));
        if (device) {
            SDL_memset(device, 0, (sizeof *device));
            device->hidden = (struct SDL_PrivateVideoData *)
                SDL_malloc((sizeof *device->hidden));
        }
        if ((device == NULL) || (device->hidden == NULL)) {
            SDL_OutOfMemory();
            if (device) {
                SDL_free(device);
            }
            SDL_X11_UnloadSymbols();
            return (0);
        }
        SDL_memset(device->hidden, 0, (sizeof *device->hidden));

        /* Set the function pointers */
        device->VideoInit = DGA_VideoInit;
        device->ListModes = DGA_ListModes;
        device->SetVideoMode = DGA_SetVideoMode;
        device->SetColors = DGA_SetColors;
        device->UpdateRects = NULL;
        device->VideoQuit = DGA_VideoQuit;
        device->AllocHWSurface = DGA_AllocHWSurface;
        device->CheckHWBlit = DGA_CheckHWBlit;
        device->FillHWRect = DGA_FillHWRect;
        device->SetHWColorKey = NULL;
        device->SetHWAlpha = NULL;
        device->LockHWSurface = DGA_LockHWSurface;
        device->UnlockHWSurface = DGA_UnlockHWSurface;
        device->FlipHWSurface = DGA_FlipHWSurface;
        device->FreeHWSurface = DGA_FreeHWSurface;
        device->SetGammaRamp = DGA_SetGammaRamp;
        device->GetGammaRamp = NULL;
        device->SetCaption = NULL;
        device->SetIcon = NULL;
        device->IconifyWindow = NULL;
        device->GrabInput = NULL;
        device->GetWMInfo = NULL;
        device->InitOSKeymap = DGA_InitOSKeymap;
        device->PumpEvents = DGA_PumpEvents;

        device->free = DGA_DeleteDevice;
    }

    return device;
}

VideoBootStrap DGA_bootstrap = {
    "dga", "XFree86 DGA 2.0",
    DGA_Available, DGA_CreateDevice
};

static int
DGA_AddMode(_THIS, int bpp, int w, int h)
{
    SDL_Rect *mode;
    int index;
    int next_mode;

    /* Check to see if we already have this mode */
    if (bpp < 8) {              /* Not supported */
        return (0);
    }
    index = ((bpp + 7) / 8) - 1;
    if (SDL_nummodes[index] > 0) {
        mode = SDL_modelist[index][SDL_nummodes[index] - 1];
        if ((mode->w == w) && (mode->h == h)) {
            return (0);
        }
    }

    /* Set up the new video mode rectangle */
    mode = (SDL_Rect *) SDL_malloc(sizeof *mode);
    if (mode == NULL) {
        SDL_OutOfMemory();
        return (-1);
    }
    mode->x = 0;
    mode->y = 0;
    mode->w = w;
    mode->h = h;

    /* Allocate the new list of modes, and fill in the new mode */
    next_mode = SDL_nummodes[index];
    SDL_modelist[index] = (SDL_Rect **)
        SDL_realloc(SDL_modelist[index],
                    (1 + next_mode + 1) * sizeof(SDL_Rect *));
    if (SDL_modelist[index] == NULL) {
        SDL_OutOfMemory();
        SDL_nummodes[index] = 0;
        SDL_free(mode);
        return (-1);
    }
    SDL_modelist[index][next_mode] = mode;
    SDL_modelist[index][next_mode + 1] = NULL;
    SDL_nummodes[index]++;

    return (0);
}

/* This whole function is a hack. :) */
static Uint32
get_video_size(_THIS)
{
    /* This is a non-exported function from libXxf86dga.a */
    extern unsigned char *SDL_NAME(XDGAGetMappedMemory) (int screen);
    FILE *proc;
    unsigned long mem;
    unsigned start, stop;
    char line[BUFSIZ];
    Uint32 size;

    mem = (unsigned long) SDL_NAME(XDGAGetMappedMemory) (DGA_Screen);
    size = 0;
    proc = fopen("/proc/self/maps", "r");
    if (proc) {
        while (fgets(line, sizeof(line) - 1, proc)) {
            SDL_sscanf(line, "%x-%x", &start, &stop);
            if (start == mem) {
                size = (Uint32) ((stop - start) / 1024);
                break;
            }
        }
        fclose(proc);
    }
    return (size);
}

#ifdef DGA_DEBUG
static void
PrintMode(SDL_NAME(XDGAMode) * mode)
{
    printf("Mode: %s (%dx%d) at %d bpp (%f refresh, %d pitch) num: %d\n",
           mode->name,
           mode->viewportWidth, mode->viewportHeight,
           mode->depth == 24 ? mode->bitsPerPixel : mode->depth,
           mode->verticalRefresh, mode->bytesPerScanline, mode->num);
    printf("\tRGB: 0x%8.8x 0x%8.8x 0x%8.8x (%d - %s)\n",
           mode->redMask, mode->greenMask, mode->blueMask,
           mode->visualClass,
           mode->visualClass == TrueColor ? "truecolor" :
           mode->visualClass == DirectColor ? "directcolor" :
           mode->visualClass == PseudoColor ? "pseudocolor" : "unknown");
    printf("\tFlags: ");
    if (mode->flags & XDGAConcurrentAccess)
        printf(" XDGAConcurrentAccess");
    if (mode->flags & XDGASolidFillRect)
        printf(" XDGASolidFillRect");
    if (mode->flags & XDGABlitRect)
        printf(" XDGABlitRect");
    if (mode->flags & XDGABlitTransRect)
        printf(" XDGABlitTransRect");
    if (mode->flags & XDGAPixmap)
        printf(" XDGAPixmap");
    if (mode->flags & XDGAInterlaced)
        printf(" XDGAInterlaced");
    if (mode->flags & XDGADoublescan)
        printf(" XDGADoublescan");
    if (mode->viewportFlags & XDGAFlipRetrace)
        printf(" XDGAFlipRetrace");
    if (mode->viewportFlags & XDGAFlipImmediate)
        printf(" XDGAFlipImmediate");
    printf("\n");
}
#endif /* DGA_DEBUG */

static int
cmpmodes(const void *va, const void *vb)
{
    const SDL_NAME(XDGAMode) * a = (const SDL_NAME(XDGAMode) *) va;
    const SDL_NAME(XDGAMode) * b = (const SDL_NAME(XDGAMode) *) vb;

    if ((a->viewportWidth == b->viewportWidth) &&
        (b->viewportHeight == a->viewportHeight)) {
        /* Prefer 32 bpp over 24 bpp, 16 bpp over 15 bpp */
        int a_bpp = a->depth == 24 ? a->bitsPerPixel : a->depth;
        int b_bpp = b->depth == 24 ? b->bitsPerPixel : b->depth;
        if (a_bpp != b_bpp) {
            return b_bpp - a_bpp;
        }
        /* Prefer DirectColor visuals, for gamma support */
        if (a->visualClass == DirectColor && b->visualClass != DirectColor)
            return -1;
        if (b->visualClass == DirectColor && a->visualClass != DirectColor)
            return 1;
        /* Maintain server refresh rate sorting */
        return a->num - b->num;
    } else if (a->viewportWidth == b->viewportWidth) {
        return b->viewportHeight - a->viewportHeight;
    } else {
        return b->viewportWidth - a->viewportWidth;
    }
}
static void
UpdateHWInfo(_THIS, SDL_NAME(XDGAMode) * mode)
{
    this->info.wm_available = 0;
    this->info.hw_available = 1;
    if (mode->flags & XDGABlitRect) {
        this->info.blit_hw = 1;
    } else {
        this->info.blit_hw = 0;
    }
    if (mode->flags & XDGABlitTransRect) {
        this->info.blit_hw_CC = 1;
    } else {
        this->info.blit_hw_CC = 0;
    }
    if (mode->flags & XDGASolidFillRect) {
        this->info.blit_fill = 1;
    } else {
        this->info.blit_fill = 0;
    }
    this->info.video_mem = get_video_size(this);
}

static int
DGA_VideoInit(_THIS, SDL_PixelFormat * vformat)
{
    const char *display;
    int event_base, error_base;
    int major_version, minor_version;
    Visual *visual;
    SDL_NAME(XDGAMode) * modes;
    int i, num_modes;

    /* Open the X11 display */
    display = NULL;             /* Get it from DISPLAY environment variable */

    DGA_Display = XOpenDisplay(display);
    if (DGA_Display == NULL) {
        SDL_SetError("Couldn't open X11 display");
        return (-1);
    }

    /* Check for the DGA extension */
    if (!SDL_NAME(XDGAQueryExtension) (DGA_Display, &event_base, &error_base)
        || !SDL_NAME(XDGAQueryVersion) (DGA_Display, &major_version,
                                        &minor_version)) {
        SDL_SetError("DGA extension not available");
        XCloseDisplay(DGA_Display);
        return (-1);
    }
    if (major_version < 2) {
        SDL_SetError("DGA driver requires DGA 2.0 or newer");
        XCloseDisplay(DGA_Display);
        return (-1);
    }
    DGA_event_base = event_base;

    /* Determine the current screen size */
    this->info.current_w = DisplayWidth(DGA_Display, DGA_Screen);
    this->info.current_h = DisplayHeight(DGA_Display, DGA_Screen);

    /* Determine the current screen depth */
    visual = DefaultVisual(DGA_Display, DGA_Screen);
    {
        XPixmapFormatValues *pix_format;
        int i, num_formats;

        vformat->BitsPerPixel = DefaultDepth(DGA_Display, DGA_Screen);
        pix_format = XListPixmapFormats(DGA_Display, &num_formats);
        if (pix_format == NULL) {
            SDL_SetError("Couldn't determine screen formats");
            XCloseDisplay(DGA_Display);
            return (-1);
        }
        for (i = 0; i < num_formats; ++i) {
            if (vformat->BitsPerPixel == pix_format[i].depth)
                break;
        }
        if (i != num_formats)
            vformat->BitsPerPixel = pix_format[i].bits_per_pixel;
        XFree((char *) pix_format);
    }
    if (vformat->BitsPerPixel > 8) {
        vformat->Rmask = visual->red_mask;
        vformat->Gmask = visual->green_mask;
        vformat->Bmask = visual->blue_mask;
    }

    /* Open access to the framebuffer */
    if (!SDL_NAME(XDGAOpenFramebuffer) (DGA_Display, DGA_Screen)) {
        SDL_SetError("Unable to map the video memory");
        XCloseDisplay(DGA_Display);
        return (-1);
    }

    /* Save DPMS and screensaver settings */
    X11_SaveScreenSaver(DGA_Display, &screensaver_timeout, &dpms_enabled);
    X11_DisableScreenSaver(DGA_Display);

    /* Query for the list of available video modes */
    modes = SDL_NAME(XDGAQueryModes) (DGA_Display, DGA_Screen, &num_modes);
    SDL_qsort(modes, num_modes, sizeof *modes, cmpmodes);
    for (i = 0; i < num_modes; ++i) {
        if (((modes[i].visualClass == PseudoColor) ||
             (modes[i].visualClass == DirectColor) ||
             (modes[i].visualClass == TrueColor)) &&
            !(modes[i].flags & (XDGAInterlaced | XDGADoublescan))) {
#ifdef DGA_DEBUG
            PrintMode(&modes[i]);
#endif
            DGA_AddMode(this, modes[i].bitsPerPixel,
                        modes[i].viewportWidth, modes[i].viewportHeight);
        }
    }
    UpdateHWInfo(this, modes);
    XFree(modes);

    /* Create the hardware surface lock mutex */
    hw_lock = SDL_CreateMutex();
    if (hw_lock == NULL) {
        SDL_SetError("Unable to create lock mutex");
        DGA_VideoQuit(this);
        return (-1);
    }
#ifdef LOCK_DGA_DISPLAY
    /* Create the event lock so we're thread-safe.. :-/ */
    event_lock = SDL_CreateMutex();
#endif /* LOCK_DGA_DISPLAY */

    /* We're done! */
    return (0);
}

SDL_Rect **
DGA_ListModes(_THIS, SDL_PixelFormat * format, Uint32 flags)
{
    return (SDL_modelist[((format->BitsPerPixel + 7) / 8) - 1]);
}

/* Various screen update functions available */
static void DGA_DirectUpdate(_THIS, int numrects, SDL_Rect * rects);

SDL_Surface *
DGA_SetVideoMode(_THIS, SDL_Surface * current,
                 int width, int height, int bpp, Uint32 flags)
{
    SDL_NAME(XDGAMode) * modes;
    int i, num_modes;
    SDL_NAME(XDGADevice) * mode;
    int screen_len;
    Uint8 *surfaces_mem;
    int surfaces_len;

    /* Free any previous colormap */
    if (DGA_colormap) {
        XFreeColormap(DGA_Display, DGA_colormap);
        DGA_colormap = 0;
    }

    /* Search for a matching video mode */
    modes = SDL_NAME(XDGAQueryModes) (DGA_Display, DGA_Screen, &num_modes);
    SDL_qsort(modes, num_modes, sizeof *modes, cmpmodes);
    for (i = 0; i < num_modes; ++i) {
        int depth;

        depth = modes[i].depth;
        if (depth == 24) {      /* Distinguish between 24 and 32 bpp */
            depth = modes[i].bitsPerPixel;
        }
        if ((depth == bpp) &&
            (modes[i].viewportWidth == width) &&
            (modes[i].viewportHeight == height) &&
            ((modes[i].visualClass == PseudoColor) ||
             (modes[i].visualClass == DirectColor) ||
             (modes[i].visualClass == TrueColor)) &&
            !(modes[i].flags & (XDGAInterlaced | XDGADoublescan))) {
            break;
        }
    }
    if (i == num_modes) {
        SDL_SetError("No matching video mode found");
        return (NULL);
    }
#ifdef DGA_DEBUG
    PrintMode(&modes[i]);
#endif

    /* Set the video mode */
    mode = SDL_NAME(XDGASetMode) (DGA_Display, DGA_Screen, modes[i].num);
    XFree(modes);
    if (mode == NULL) {
        SDL_SetError("Unable to switch to requested mode");
        return (NULL);
    }
    DGA_visualClass = mode->mode.visualClass;
    memory_base = (Uint8 *) mode->data;
    memory_pitch = mode->mode.bytesPerScanline;

    /* Set up the new mode framebuffer */
    current->flags = (SDL_FULLSCREEN | SDL_HWSURFACE);
    current->w = mode->mode.viewportWidth;
    current->h = mode->mode.viewportHeight;
    current->pitch = memory_pitch;
    current->pixels = memory_base;
    if (!SDL_ReallocFormat(current, mode->mode.bitsPerPixel,
                           mode->mode.redMask,
                           mode->mode.greenMask, mode->mode.blueMask, 0)) {
        return (NULL);
    }
    screen_len = current->h * current->pitch;

    /* Create a colormap if necessary */
    if ((DGA_visualClass == PseudoColor) || (DGA_visualClass == DirectColor)) {
        DGA_colormap =
            SDL_NAME(XDGACreateColormap) (DGA_Display, DGA_Screen, mode,
                                          AllocAll);
        if (DGA_visualClass == PseudoColor) {
            current->flags |= SDL_HWPALETTE;
        } else {
            /* Initialize the colormap to the identity mapping */
            SDL_GetGammaRamp(0, 0, 0);
            this->screen = current;
            DGA_SetGammaRamp(this, this->gamma);
            this->screen = NULL;
        }
    } else {
        DGA_colormap =
            SDL_NAME(XDGACreateColormap) (DGA_Display, DGA_Screen, mode,
                                          AllocNone);
    }
    SDL_NAME(XDGAInstallColormap) (DGA_Display, DGA_Screen, DGA_colormap);

    /* Update the hardware capabilities */
    UpdateHWInfo(this, &mode->mode);

    /* Set up the information for hardware surfaces */
    surfaces_mem = (Uint8 *) current->pixels + screen_len;
    surfaces_len = (mode->mode.imageHeight * current->pitch - screen_len);

    /* Update for double-buffering, if we can */
    SDL_NAME(XDGASetViewport) (DGA_Display, DGA_Screen, 0, 0,
                               XDGAFlipRetrace);
    if (flags & SDL_DOUBLEBUF) {
        if (mode->mode.imageHeight >= (current->h * 2)) {
            current->flags |= SDL_DOUBLEBUF;
            flip_page = 0;
            flip_yoffset[0] = 0;
            flip_yoffset[1] = current->h;
            flip_address[0] = memory_base;
            flip_address[1] = memory_base + screen_len;
            surfaces_mem += screen_len;
            surfaces_len -= screen_len;
        }
    }

    /* Allocate memory tracking for hardware surfaces */
    DGA_FreeHWSurfaces(this);
    if (surfaces_len < 0) {
        surfaces_len = 0;
    }
    DGA_InitHWSurfaces(this, current, surfaces_mem, surfaces_len);

    /* Expose the back buffer as surface memory */
    if (current->flags & SDL_DOUBLEBUF) {
        this->screen = current;
        DGA_FlipHWSurface(this, current);
        this->screen = NULL;
    }

    /* Set the update rectangle function */
    this->UpdateRects = DGA_DirectUpdate;

    /* Enable mouse and keyboard support */
    {
        long input_mask;
        input_mask = (KeyPressMask | KeyReleaseMask);
        input_mask |= (ButtonPressMask | ButtonReleaseMask);
        input_mask |= PointerMotionMask;
        SDL_NAME(XDGASelectInput) (DGA_Display, DGA_Screen, input_mask);
    }

    /* We're done */
    return (current);
}

#ifdef DGA_DEBUG
static void
DGA_DumpHWSurfaces(_THIS)
{
    vidmem_bucket *bucket;

    printf("Memory left: %d (%d total)\n", surfaces_memleft,
           surfaces_memtotal);
    printf("\n");
    printf("         Base  Size\n");
    for (bucket = &surfaces; bucket; bucket = bucket->next) {
        printf("Bucket:  %p, %d (%s)\n", bucket->base, bucket->size,
               bucket->used ? "used" : "free");
        if (bucket->prev) {
            if (bucket->base != bucket->prev->base + bucket->prev->size) {
                printf("Warning, corrupt bucket list! (prev)\n");
            }
        } else {
            if (bucket != &surfaces) {
                printf("Warning, corrupt bucket list! (!prev)\n");
            }
        }
        if (bucket->next) {
            if (bucket->next->base != bucket->base + bucket->size) {
                printf("Warning, corrupt bucket list! (next)\n");
            }
        }
    }
    printf("\n");
}
#endif

static int
DGA_InitHWSurfaces(_THIS, SDL_Surface * screen, Uint8 * base, int size)
{
    vidmem_bucket *bucket;

    surfaces_memtotal = size;
    surfaces_memleft = size;

    if (surfaces_memleft > 0) {
        bucket = (vidmem_bucket *) SDL_malloc(sizeof(*bucket));
        if (bucket == NULL) {
            SDL_OutOfMemory();
            return (-1);
        }
        bucket->prev = &surfaces;
        bucket->used = 0;
        bucket->dirty = 0;
        bucket->base = base;
        bucket->size = size;
        bucket->next = NULL;
    } else {
        bucket = NULL;
    }

    surfaces.prev = NULL;
    surfaces.used = 1;
    surfaces.dirty = 0;
    surfaces.base = screen->pixels;
    surfaces.size = (unsigned int) ((long) base - (long) surfaces.base);
    surfaces.next = bucket;
    screen->hwdata = (struct private_hwdata *) &surfaces;
    return (0);
}
static void
DGA_FreeHWSurfaces(_THIS)
{
    vidmem_bucket *bucket, *freeable;

    bucket = surfaces.next;
    while (bucket) {
        freeable = bucket;
        bucket = bucket->next;
        SDL_free(freeable);
    }
    surfaces.next = NULL;
}

static __inline__ void
DGA_AddBusySurface(SDL_Surface * surface)
{
    ((vidmem_bucket *) surface->hwdata)->dirty = 1;
}

static __inline__ int
DGA_IsSurfaceBusy(SDL_Surface * surface)
{
    return ((vidmem_bucket *) surface->hwdata)->dirty;
}

static __inline__ void
DGA_WaitBusySurfaces(_THIS)
{
    vidmem_bucket *bucket;

    /* Wait for graphic operations to complete */
    SDL_NAME(XDGASync) (DGA_Display, DGA_Screen);

    /* Clear all surface dirty bits */
    for (bucket = &surfaces; bucket; bucket = bucket->next) {
        bucket->dirty = 0;
    }
}

static int
DGA_AllocHWSurface(_THIS, SDL_Surface * surface)
{
    vidmem_bucket *bucket;
    int size;
    int extra;
    int retval = 0;

/* Temporarily, we only allow surfaces the same width as display.
   Some blitters require the pitch between two hardware surfaces
   to be the same.  Others have interesting alignment restrictions.
*/
    if (surface->pitch > SDL_VideoSurface->pitch) {
        SDL_SetError("Surface requested wider than screen");
        return (-1);
    }
    surface->pitch = SDL_VideoSurface->pitch;
    size = surface->h * surface->pitch;
#ifdef DGA_DEBUG
    fprintf(stderr, "Allocating bucket of %d bytes\n", size);
#endif
    LOCK_DISPLAY();

    /* Quick check for available mem */
    if (size > surfaces_memleft) {
        SDL_SetError("Not enough video memory");
        retval = -1;
        goto done;
    }

    /* Search for an empty bucket big enough */
    for (bucket = &surfaces; bucket; bucket = bucket->next) {
        if (!bucket->used && (size <= bucket->size)) {
            break;
        }
    }
    if (bucket == NULL) {
        SDL_SetError("Video memory too fragmented");
        retval = -1;
        goto done;
    }

    /* Create a new bucket for left-over memory */
    extra = (bucket->size - size);
    if (extra) {
        vidmem_bucket *newbucket;

#ifdef DGA_DEBUG
        fprintf(stderr, "Adding new free bucket of %d bytes\n", extra);
#endif
        newbucket = (vidmem_bucket *) SDL_malloc(sizeof(*newbucket));
        if (newbucket == NULL) {
            SDL_OutOfMemory();
            retval = -1;
            goto done;
        }
        newbucket->prev = bucket;
        newbucket->used = 0;
        newbucket->base = bucket->base + size;
        newbucket->size = extra;
        newbucket->next = bucket->next;
        if (bucket->next) {
            bucket->next->prev = newbucket;
        }
        bucket->next = newbucket;
    }

    /* Set the current bucket values and return it! */
    bucket->used = 1;
    bucket->size = size;
    bucket->dirty = 0;
#ifdef DGA_DEBUG
    fprintf(stderr, "Allocated %d bytes at %p\n", bucket->size, bucket->base);
#endif
    surfaces_memleft -= size;
    surface->flags |= SDL_HWSURFACE;
    surface->pixels = bucket->base;
    surface->hwdata = (struct private_hwdata *) bucket;
  done:
    UNLOCK_DISPLAY();
    return (retval);
}
static void
DGA_FreeHWSurface(_THIS, SDL_Surface * surface)
{
    vidmem_bucket *bucket, *freeable;

    /* Wait for any pending operations involving this surface */
    if (DGA_IsSurfaceBusy(surface)) {
        LOCK_DISPLAY();
        DGA_WaitBusySurfaces(this);
        UNLOCK_DISPLAY();
    }

    /* Look for the bucket in the current list */
    for (bucket = &surfaces; bucket; bucket = bucket->next) {
        if (bucket == (vidmem_bucket *) surface->hwdata) {
            break;
        }
    }
    if (bucket && bucket->used) {
        /* Add the memory back to the total */
#ifdef DGA_DEBUG
        printf("Freeing bucket of %d bytes\n", bucket->size);
#endif
        surfaces_memleft += bucket->size;

        /* Can we merge the space with surrounding buckets? */
        bucket->used = 0;
        if (bucket->next && !bucket->next->used) {
#ifdef DGA_DEBUG
            printf("Merging with next bucket, for %d total bytes\n",
                   bucket->size + bucket->next->size);
#endif
            freeable = bucket->next;
            bucket->size += bucket->next->size;
            bucket->next = bucket->next->next;
            if (bucket->next) {
                bucket->next->prev = bucket;
            }
            SDL_free(freeable);
        }
        if (bucket->prev && !bucket->prev->used) {
#ifdef DGA_DEBUG
            printf("Merging with previous bucket, for %d total bytes\n",
                   bucket->prev->size + bucket->size);
#endif
            freeable = bucket;
            bucket->prev->size += bucket->size;
            bucket->prev->next = bucket->next;
            if (bucket->next) {
                bucket->next->prev = bucket->prev;
            }
            SDL_free(freeable);
        }
    }
    surface->pixels = NULL;
    surface->hwdata = NULL;
}

static __inline__ void
DGA_dst_to_xy(_THIS, SDL_Surface * dst, int *x, int *y)
{
    *x = (long) ((Uint8 *) dst->pixels - memory_base) % memory_pitch;
    *y = (long) ((Uint8 *) dst->pixels - memory_base) / memory_pitch;
}

static int
DGA_FillHWRect(_THIS, SDL_Surface * dst, SDL_Rect * rect, Uint32 color)
{
    int x, y;
    unsigned int w, h;

    /* Don't fill the visible part of the screen, wait until flipped */
    LOCK_DISPLAY();
    if (was_flipped && (dst == this->screen)) {
        while (SDL_NAME(XDGAGetViewportStatus) (DGA_Display, DGA_Screen))
            /* Keep waiting for the hardware ... */ ;
        was_flipped = 0;
    }
    DGA_dst_to_xy(this, dst, &x, &y);
    x += rect->x;
    y += rect->y;
    w = rect->w;
    h = rect->h;
#if 0
    printf("Hardware accelerated rectangle fill: %dx%d at %d,%d\n", w, h, x,
           y);
#endif
    SDL_NAME(XDGAFillRectangle) (DGA_Display, DGA_Screen, x, y, w, h, color);
    if (!(this->screen->flags & SDL_DOUBLEBUF)) {
        XFlush(DGA_Display);
    }
    DGA_AddBusySurface(dst);
    UNLOCK_DISPLAY();
    return (0);
}

static int
HWAccelBlit(SDL_Surface * src, SDL_Rect * srcrect,
            SDL_Surface * dst, SDL_Rect * dstrect)
{
    SDL_VideoDevice *this;
    int srcx, srcy;
    int dstx, dsty;
    unsigned int w, h;

    this = current_video;
    /* Don't blit to the visible part of the screen, wait until flipped */
    LOCK_DISPLAY();
    if (was_flipped && (dst == this->screen)) {
        while (SDL_NAME(XDGAGetViewportStatus) (DGA_Display, DGA_Screen))
            /* Keep waiting for the hardware ... */ ;
        was_flipped = 0;
    }
    DGA_dst_to_xy(this, src, &srcx, &srcy);
    srcx += srcrect->x;
    srcy += srcrect->y;
    DGA_dst_to_xy(this, dst, &dstx, &dsty);
    dstx += dstrect->x;
    dsty += dstrect->y;
    w = srcrect->w;
    h = srcrect->h;
#if 0
    printf("Blitting %dx%d from %d,%d to %d,%d\n", w, h, srcx, srcy, dstx,
           dsty);
#endif
    if ((src->flags & SDL_SRCCOLORKEY) == SDL_SRCCOLORKEY) {
        SDL_NAME(XDGACopyTransparentArea) (DGA_Display, DGA_Screen,
                                           srcx, srcy, w, h, dstx, dsty,
                                           src->format->colorkey);
    } else {
        SDL_NAME(XDGACopyArea) (DGA_Display, DGA_Screen,
                                srcx, srcy, w, h, dstx, dsty);
    }
    if (!(this->screen->flags & SDL_DOUBLEBUF)) {
        XFlush(DGA_Display);
    }
    DGA_AddBusySurface(src);
    DGA_AddBusySurface(dst);
    UNLOCK_DISPLAY();
    return (0);
}

static int
DGA_CheckHWBlit(_THIS, SDL_Surface * src, SDL_Surface * dst)
{
    int accelerated;

    /* Set initial acceleration on */
    src->flags |= SDL_HWACCEL;

    /* Set the surface attributes */
    if ((src->flags & SDL_SRCALPHA) == SDL_SRCALPHA) {
        if (!this->info.blit_hw_A) {
            src->flags &= ~SDL_HWACCEL;
        }
    }
    if ((src->flags & SDL_SRCCOLORKEY) == SDL_SRCCOLORKEY) {
        if (!this->info.blit_hw_CC) {
            src->flags &= ~SDL_HWACCEL;
        }
    }

    /* Check to see if final surface blit is accelerated */
    accelerated = !!(src->flags & SDL_HWACCEL);
    if (accelerated) {
        src->map->hw_blit = HWAccelBlit;
    }
    return (accelerated);
}

static __inline__ void
DGA_WaitFlip(_THIS)
{
    if (was_flipped) {
        while (SDL_NAME(XDGAGetViewportStatus) (DGA_Display, DGA_Screen))
            /* Keep waiting for the hardware ... */ ;
        was_flipped = 0;
    }
}

static int
DGA_LockHWSurface(_THIS, SDL_Surface * surface)
{
    if (surface == this->screen) {
        SDL_mutexP(hw_lock);
        LOCK_DISPLAY();
        if (DGA_IsSurfaceBusy(surface)) {
            DGA_WaitBusySurfaces(this);
        }
        DGA_WaitFlip(this);
        UNLOCK_DISPLAY();
    } else {
        if (DGA_IsSurfaceBusy(surface)) {
            LOCK_DISPLAY();
            DGA_WaitBusySurfaces(this);
            UNLOCK_DISPLAY();
        }
    }
    return (0);
}
static void
DGA_UnlockHWSurface(_THIS, SDL_Surface * surface)
{
    if (surface == this->screen) {
        SDL_mutexV(hw_lock);
    }
}

static int
DGA_FlipHWSurface(_THIS, SDL_Surface * surface)
{
    /* Wait for vertical retrace and then flip display */
    LOCK_DISPLAY();
    if (DGA_IsSurfaceBusy(this->screen)) {
        DGA_WaitBusySurfaces(this);
    }
    DGA_WaitFlip(this);
    SDL_NAME(XDGASetViewport) (DGA_Display, DGA_Screen,
                               0, flip_yoffset[flip_page], XDGAFlipRetrace);
    XFlush(DGA_Display);
    UNLOCK_DISPLAY();
    was_flipped = 1;
    flip_page = !flip_page;

    surface->pixels = flip_address[flip_page];
    return (0);
}

static void
DGA_DirectUpdate(_THIS, int numrects, SDL_Rect * rects)
{
    /* The application is already updating the visible video memory */
    return;
}

static int
DGA_SetColors(_THIS, int firstcolor, int ncolors, SDL_Color * colors)
{
    int i;
    XColor *xcmap;

    /* This happens on initialization */
    if (!DGA_colormap) {
        return (0);
    }
    xcmap = SDL_stack_alloc(XColor, ncolors);
    for (i = 0; i < ncolors; ++i) {
        xcmap[i].pixel = firstcolor + i;
        xcmap[i].red = (colors[i].r << 8) | colors[i].r;
        xcmap[i].green = (colors[i].g << 8) | colors[i].g;
        xcmap[i].blue = (colors[i].b << 8) | colors[i].b;
        xcmap[i].flags = (DoRed | DoGreen | DoBlue);
    }
    LOCK_DISPLAY();
    XStoreColors(DGA_Display, DGA_colormap, xcmap, ncolors);
    XSync(DGA_Display, False);
    UNLOCK_DISPLAY();
    SDL_stack_free(xcmap);

    /* That was easy. :) */
    return (1);
}

int
DGA_SetGammaRamp(_THIS, Uint16 * ramp)
{
    int i, ncolors;
    XColor xcmap[256];

    /* See if actually setting the gamma is supported */
    if (DGA_visualClass != DirectColor) {
        SDL_SetError("Gamma correction not supported on this visual");
        return (-1);
    }

    /* Calculate the appropriate palette for the given gamma ramp */
    if (this->screen->format->BitsPerPixel <= 16) {
        ncolors = 64;           /* Is this right? */
    } else {
        ncolors = 256;
    }
    for (i = 0; i < ncolors; ++i) {
        Uint8 c = (256 * i / ncolors);
        xcmap[i].pixel = SDL_MapRGB(this->screen->format, c, c, c);
        xcmap[i].red = ramp[0 * 256 + c];
        xcmap[i].green = ramp[1 * 256 + c];
        xcmap[i].blue = ramp[2 * 256 + c];
        xcmap[i].flags = (DoRed | DoGreen | DoBlue);
    }
    LOCK_DISPLAY();
    XStoreColors(DGA_Display, DGA_colormap, xcmap, ncolors);
    XSync(DGA_Display, False);
    UNLOCK_DISPLAY();
    return (0);
}

void
DGA_VideoQuit(_THIS)
{
    int i, j;

    if (DGA_Display) {
        /* Free colormap, if necessary */
        if (DGA_colormap) {
            XFreeColormap(DGA_Display, DGA_colormap);
            DGA_colormap = 0;
        }

        /* Unmap memory and reset video mode */
        SDL_NAME(XDGACloseFramebuffer) (DGA_Display, DGA_Screen);
        if (this->screen) {
            /* Tell SDL not to free the pixels */
            DGA_FreeHWSurface(this, this->screen);
        }
        SDL_NAME(XDGASetMode) (DGA_Display, DGA_Screen, 0);

        /* Clear the lock mutex */
        if (hw_lock != NULL) {
            SDL_DestroyMutex(hw_lock);
            hw_lock = NULL;
        }
#ifdef LOCK_DGA_DISPLAY
        if (event_lock != NULL) {
            SDL_DestroyMutex(event_lock);
            event_lock = NULL;
        }
#endif /* LOCK_DGA_DISPLAY */

        /* Clean up defined video modes */
        for (i = 0; i < NUM_MODELISTS; ++i) {
            if (SDL_modelist[i] != NULL) {
                for (j = 0; SDL_modelist[i][j]; ++j) {
                    SDL_free(SDL_modelist[i][j]);
                }
                SDL_free(SDL_modelist[i]);
                SDL_modelist[i] = NULL;
            }
        }

        /* Clean up the memory bucket list */
        DGA_FreeHWSurfaces(this);

        /* Restore DPMS and screensaver settings */
        X11_RestoreScreenSaver(DGA_Display, screensaver_timeout,
                               dpms_enabled);

        /* Close up the display */
        XCloseDisplay(DGA_Display);
    }
}

/* vi: set ts=4 sw=4 expandtab: */