/*

     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"

 #include "SDL_video.h"

 #include "SDL_compat.h"

 #include "SDL_sysvideo.h"

 #include "SDL_blit.h"

 #include "SDL_RLEaccel_c.h"

 #include "SDL_pixels_c.h"

 #include "SDL_leaks.h"

 /* Public routines */

 /*

  * Create an empty RGB surface of the appropriate depth

  */

 SDL_Surface *

 SDL_CreateRGBSurface(Uint32 flags,

                      int width, int height, int depth,

                      Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)

 {

     SDL_Surface *surface;

     /* Allocate the surface */

     surface = (SDL_Surface *) SDL_calloc(1, sizeof(*surface));

     if (surface == NULL) {

         SDL_OutOfMemory();

         return NULL;

     }

     surface->format = SDL_AllocFormat(depth, Rmask, Gmask, Bmask, Amask);

     if (!surface->format) {

         SDL_FreeSurface(surface);

         return NULL;

     }

     surface->w = width;

     surface->h = height;

     surface->pitch = SDL_CalculatePitch(surface);

     SDL_SetClipRect(surface, NULL);

     if (surface->format->BitsPerPixel <= 8) {

         SDL_Palette *palette =

             SDL_AllocPalette((1 << surface->format->BitsPerPixel));

         if (!palette) {

             SDL_FreeSurface(surface);

             return NULL;

         }

         if (Rmask || Bmask || Gmask) {

             const SDL_PixelFormat *format = surface->format;

             /* create palette according to masks */

             int i;

             int Rm = 0, Gm = 0, Bm = 0;

             int Rw = 0, Gw = 0, Bw = 0;

             if (Rmask) {

                 Rw = 8 - format->Rloss;

                 for (i = format->Rloss; i > 0; i -= Rw)

                     Rm |= 1 << i;

             }

             if (Gmask) {

                 Gw = 8 - format->Gloss;

                 for (i = format->Gloss; i > 0; i -= Gw)

                     Gm |= 1 << i;

             }

             if (Bmask) {

                 Bw = 8 - format->Bloss;

                 for (i = format->Bloss; i > 0; i -= Bw)

                     Bm |= 1 << i;

             }

             for (i = 0; i < palette->ncolors; ++i) {

                 int r, g, b;

                 r = (i & Rmask) >> format->Rshift;

                 r = (r << format->Rloss) | ((r * Rm) >> Rw);

                 palette->colors[i].r = r;

                 g = (i & Gmask) >> format->Gshift;

                 g = (g << format->Gloss) | ((g * Gm) >> Gw);

                 palette->colors[i].g = g;

                 b = (i & Bmask) >> format->Bshift;

                 b = (b << format->Bloss) | ((b * Bm) >> Bw);

                 palette->colors[i].b = b;

             }

         } else if (palette->ncolors == 2) {

             /* Create a black and white bitmap palette */

             palette->colors[0].r = 0xFF;

             palette->colors[0].g = 0xFF;

             palette->colors[0].b = 0xFF;

             palette->colors[1].r = 0x00;

             palette->colors[1].g = 0x00;

             palette->colors[1].b = 0x00;

         }

         SDL_SetSurfacePalette(surface, palette);

         SDL_FreePalette(palette);

     }

     /* Get the pixels */

     if (surface->w && surface->h) {

         surface->pixels = SDL_malloc(surface->h * surface->pitch);

         if (!surface->pixels) {

             SDL_FreeSurface(surface);

             SDL_OutOfMemory();

             return NULL;

         }

         /* This is important for bitmaps */

         SDL_memset(surface->pixels, 0, surface->h * surface->pitch);

     }

     /* Allocate an empty mapping */

     surface->map = SDL_AllocBlitMap();

     if (!surface->map) {

         SDL_FreeSurface(surface);

         return NULL;

     }

     SDL_FormatChanged(surface);

     /* By default surface with an alpha mask are set up for blending */

     if (Amask) {

         SDL_SetSurfaceBlendMode(surface, SDL_TEXTUREBLENDMODE_BLEND);

     }

     /* The surface is ready to go */

     surface->refcount = 1;

 #ifdef CHECK_LEAKS

     ++surfaces_allocated;

 #endif

     return surface;

 }

 /*

  * Create an RGB surface from an existing memory buffer

  */

 SDL_Surface *

 SDL_CreateRGBSurfaceFrom(void *pixels,

                          int width, int height, int depth, int pitch,

                          Uint32 Rmask, Uint32 Gmask, Uint32 Bmask,

                          Uint32 Amask)

 {

     SDL_Surface *surface;

     surface =

         SDL_CreateRGBSurface(0, 0, 0, depth, Rmask, Gmask, Bmask, Amask);

     if (surface != NULL) {

         surface->flags |= SDL_PREALLOC;

         surface->pixels = pixels;

         surface->w = width;

         surface->h = height;

         surface->pitch = pitch;

         SDL_SetClipRect(surface, NULL);

     }

     return surface;

 }

 static int

 SDL_SurfacePaletteChanged(void *userdata, SDL_Palette * palette)

 {

     SDL_Surface *surface = (SDL_Surface *) userdata;

     SDL_FormatChanged(surface);

     return 0;

 }

 int

 SDL_SetSurfacePalette(SDL_Surface * surface, SDL_Palette * palette)

 {

     if (!surface || !surface->format) {

         SDL_SetError("SDL_SetSurfacePalette() passed a NULL surface");

         return -1;

     }

     if (palette && palette->ncolors != (1 << surface->format->BitsPerPixel)) {

         SDL_SetError

             ("SDL_SetSurfacePalette() passed a palette that doesn't match the surface format");

         return -1;

     }

     if (surface->format->palette == palette) {

         return 0;

     }

     if (surface->format->palette) {

         SDL_DelPaletteWatch(surface->format->palette,

                             SDL_SurfacePaletteChanged, surface);

     }

     surface->format->palette = palette;

     if (surface->format->palette) {

         SDL_AddPaletteWatch(surface->format->palette,

                             SDL_SurfacePaletteChanged, surface);

     }

     return 0;

 }

 int

 SDL_SetSurfaceRLE(SDL_Surface * surface, int flag)

 {

     int flags;

     if (!surface) {

         return -1;

     }

     flags = surface->map->info.flags;

     if (flag) {

         surface->map->info.flags |= SDL_COPY_RLE_DESIRED;

     } else {

         surface->map->info.flags &= ~SDL_COPY_RLE_DESIRED;

     }

     if (surface->map->info.flags != flags) {

         SDL_InvalidateMap(surface->map);

     }

     return 0;

 }

 int

 SDL_SetColorKey(SDL_Surface * surface, Uint32 flag, Uint32 key)

 {

     int flags;

     if (!surface) {

         return -1;

     }

     if (flag & SDL_RLEACCEL) {

         SDL_SetSurfaceRLE(surface, 1);

     }

     flags = surface->map->info.flags;

     if (flag) {

         surface->map->info.flags |= SDL_COPY_COLORKEY;

         surface->map->info.colorkey = key;

     } else {

         surface->map->info.flags &= ~SDL_COPY_COLORKEY;

     }

     if (surface->map->info.flags != flags) {

         SDL_InvalidateMap(surface->map);

     }

     /* Compatibility mode */

     if (surface->map->info.flags & SDL_COPY_COLORKEY) {

         surface->flags |= SDL_SRCCOLORKEY;

     } else {

         surface->flags &= ~SDL_SRCCOLORKEY;

     }

     return 0;

 }

 int

 SDL_SetSurfaceColorMod(SDL_Surface * surface, Uint8 r, Uint8 g, Uint8 b)

 {

     int flags;

     if (!surface) {

         return -1;

     }

     surface->map->info.r = r;

     surface->map->info.g = g;

     surface->map->info.b = b;

     flags = surface->map->info.flags;

     if (r != 0xFF || g != 0xFF || b != 0xFF) {

         surface->map->info.flags |= SDL_COPY_MODULATE_COLOR;

     } else {

         surface->map->info.flags &= ~SDL_COPY_MODULATE_COLOR;

     }

     if (surface->map->info.flags != flags) {

         SDL_InvalidateMap(surface->map);

     }

     return 0;

 }

 int

 SDL_GetSurfaceColorMod(SDL_Surface * surface, Uint8 * r, Uint8 * g, Uint8 * b)

 {

     if (!surface) {

         return -1;

     }

     if (r) {

         *r = surface->map->info.r;

     }

     if (g) {

         *g = surface->map->info.g;

     }

     if (b) {

         *b = surface->map->info.b;

     }

     return 0;

 }

 int

 SDL_SetSurfaceAlphaMod(SDL_Surface * surface, Uint8 alpha)

 {

     int flags;

     if (!surface) {

         return -1;

     }

     surface->map->info.a = alpha;

     flags = surface->map->info.flags;

     if (alpha != 0xFF) {

         surface->map->info.flags |= SDL_COPY_MODULATE_ALPHA;

     } else {

         surface->map->info.flags &= ~SDL_COPY_MODULATE_ALPHA;

     }

     if (surface->map->info.flags != flags) {

         SDL_InvalidateMap(surface->map);

     }

     return 0;

 }

 int

 SDL_GetSurfaceAlphaMod(SDL_Surface * surface, Uint8 * alpha)

 {

     if (!surface) {

         return -1;

     }

     if (alpha) {

         *alpha = surface->map->info.a;

     }

     return 0;

 }

 int

 SDL_SetSurfaceBlendMode(SDL_Surface * surface, int blendMode)

 {

     int flags, status;

     if (!surface) {

         return -1;

     }

     status = 0;

     flags = surface->map->info.flags;

     surface->map->info.flags &=

         ~(SDL_COPY_MASK | SDL_COPY_BLEND | SDL_COPY_ADD | SDL_COPY_MOD);

     switch (blendMode) {

     case SDL_TEXTUREBLENDMODE_NONE:

         break;

     case SDL_TEXTUREBLENDMODE_MASK:

         surface->map->info.flags |= SDL_COPY_MASK;

         break;

     case SDL_TEXTUREBLENDMODE_BLEND:

         surface->map->info.flags |= SDL_COPY_BLEND;

         break;

     case SDL_TEXTUREBLENDMODE_ADD:

         surface->map->info.flags |= SDL_COPY_ADD;

         break;

     case SDL_TEXTUREBLENDMODE_MOD:

         surface->map->info.flags |= SDL_COPY_MOD;

         break;

     default:

         SDL_Unsupported();

         status = -1;

         break;

     }

     if (surface->map->info.flags != flags) {

         SDL_InvalidateMap(surface->map);

     }

     /* Compatibility mode */

     if (surface->map->info.flags & SDL_COPY_BLEND) {

         surface->flags |= SDL_SRCALPHA;

     } else {

         surface->flags &= ~SDL_SRCALPHA;

     }

     return status;

 }

 int

 SDL_GetSurfaceBlendMode(SDL_Surface * surface, int *blendMode)

 {

     if (!surface) {

         return -1;

     }

     if (!blendMode) {

         return 0;

     }

     switch (surface->map->info.

             flags & (SDL_COPY_MASK | SDL_COPY_BLEND | SDL_COPY_ADD |

                      SDL_COPY_MOD)) {

     case SDL_COPY_MASK:

         *blendMode = SDL_TEXTUREBLENDMODE_MASK;

         break;

     case SDL_COPY_BLEND:

         *blendMode = SDL_TEXTUREBLENDMODE_BLEND;

         break;

     case SDL_COPY_ADD:

         *blendMode = SDL_TEXTUREBLENDMODE_ADD;

         break;

     case SDL_COPY_MOD:

         *blendMode = SDL_TEXTUREBLENDMODE_MOD;

         break;

     default:

         *blendMode = SDL_TEXTUREBLENDMODE_NONE;

         break;

     }

     return 0;

 }

 int

 SDL_SetSurfaceScaleMode(SDL_Surface * surface, int scaleMode)

 {

     int flags, status;

     if (!surface) {

         return -1;

     }

     status = 0;

     flags = surface->map->info.flags;

     surface->map->info.flags &= ~(SDL_COPY_NEAREST);

     switch (scaleMode) {

     case SDL_TEXTURESCALEMODE_NONE:

         break;

     case SDL_TEXTURESCALEMODE_FAST:

         surface->map->info.flags |= SDL_COPY_NEAREST;

         break;

     case SDL_TEXTURESCALEMODE_SLOW:

     case SDL_TEXTURESCALEMODE_BEST:

         SDL_Unsupported();

         surface->map->info.flags |= SDL_COPY_NEAREST;

         status = -1;

         break;

     default:

         SDL_Unsupported();

         status = -1;

         break;

     }

     if (surface->map->info.flags != flags) {

         SDL_InvalidateMap(surface->map);

     }

     return status;

 }

 int

 SDL_GetSurfaceScaleMode(SDL_Surface * surface, int *scaleMode)

 {

     if (!surface) {

         return -1;

     }

     if (!scaleMode) {

         return 0;

     }

     switch (surface->map->info.flags & (SDL_COPY_NEAREST)) {

     case SDL_COPY_NEAREST:

         *scaleMode = SDL_TEXTURESCALEMODE_FAST;

         break;

     default:

         *scaleMode = SDL_TEXTURESCALEMODE_NONE;

         break;

     }

     return 0;

 }

 SDL_bool

 SDL_SetClipRect(SDL_Surface * surface, const SDL_Rect * rect)

 {

     SDL_Rect full_rect;

     /* Don't do anything if there's no surface to act on */

     if (!surface) {

         return SDL_FALSE;

     }

     /* Set up the full surface rectangle */

     full_rect.x = 0;

     full_rect.y = 0;

     full_rect.w = surface->w;

     full_rect.h = surface->h;

     /* Set the clipping rectangle */

     if (!rect) {

         surface->clip_rect = full_rect;

         return 1;

     }

     return SDL_IntersectRect(rect, &full_rect, &surface->clip_rect);

 }

 void

 SDL_GetClipRect(SDL_Surface * surface, SDL_Rect * rect)

 {

     if (surface && rect) {

         *rect = surface->clip_rect;

     }

 }

 /* 

  * Set up a blit between two surfaces -- split into three parts:

  * The upper part, SDL_UpperBlit(), performs clipping and rectangle 

  * verification.  The lower part is a pointer to a low level

  * accelerated blitting function.

  *

  * These parts are separated out and each used internally by this 

  * library in the optimimum places.  They are exported so that if

  * you know exactly what you are doing, you can optimize your code

  * by calling the one(s) you need.

  */

 int

 SDL_LowerBlit(SDL_Surface * src, SDL_Rect * srcrect,

               SDL_Surface * dst, SDL_Rect * dstrect)

 {

     /* Check to make sure the blit mapping is valid */

     if ((src->map->dst != dst) ||

         (src->map->dst->format_version != src->map->format_version)) {

         if (SDL_MapSurface(src, dst) < 0) {

             return (-1);

         }

     }

     return (src->map->blit(src, srcrect, dst, dstrect));

 }

 int

 SDL_UpperBlit(SDL_Surface * src, SDL_Rect * srcrect,

               SDL_Surface * dst, SDL_Rect * dstrect)

 {

     SDL_Rect fulldst;

     int srcx, srcy, w, h;

     /* Make sure the surfaces aren't locked */

     if (!src || !dst) {

         SDL_SetError("SDL_UpperBlit: passed a NULL surface");

         return (-1);

     }

     if (src->locked || dst->locked) {

         SDL_SetError("Surfaces must not be locked during blit");

         return (-1);

     }

     /* If the destination rectangle is NULL, use the entire dest surface */

     if (dstrect == NULL) {

         fulldst.x = fulldst.y = 0;

         dstrect = &fulldst;

     }

     /* clip the source rectangle to the source surface */

     if (srcrect) {

         int maxw, maxh;

         srcx = srcrect->x;

         w = srcrect->w;

         if (srcx < 0) {

             w += srcx;

             dstrect->x -= srcx;

             srcx = 0;

         }

         maxw = src->w - srcx;

         if (maxw < w)

             w = maxw;

         srcy = srcrect->y;

         h = srcrect->h;

         if (srcy < 0) {

             h += srcy;

             dstrect->y -= srcy;

             srcy = 0;

         }

         maxh = src->h - srcy;

         if (maxh < h)

             h = maxh;

     } else {

         srcx = srcy = 0;

         w = src->w;

         h = src->h;

     }

     /* clip the destination rectangle against the clip rectangle */

     {

         SDL_Rect *clip = &dst->clip_rect;

         int dx, dy;

         dx = clip->x - dstrect->x;

         if (dx > 0) {

             w -= dx;

             dstrect->x += dx;

             srcx += dx;

         }

         dx = dstrect->x + w - clip->x - clip->w;

         if (dx > 0)

             w -= dx;

         dy = clip->y - dstrect->y;

         if (dy > 0) {

             h -= dy;

             dstrect->y += dy;

             srcy += dy;

         }

         dy = dstrect->y + h - clip->y - clip->h;

         if (dy > 0)

             h -= dy;

     }

     if (w > 0 && h > 0) {

         SDL_Rect sr;

         sr.x = srcx;

         sr.y = srcy;

         sr.w = dstrect->w = w;

         sr.h = dstrect->h = h;

         return SDL_LowerBlit(src, &sr, dst, dstrect);

     }

     dstrect->w = dstrect->h = 0;

     return 0;

 }

 /*

  * Lock a surface to directly access the pixels

  */

 int

 SDL_LockSurface(SDL_Surface * surface)

 {

     if (!surface->locked) {

         /* Perform the lock */

         if (surface->flags & SDL_RLEACCEL) {

             SDL_UnRLESurface(surface, 1);

             surface->flags |= SDL_RLEACCEL;     /* save accel'd state */

         }

     }

     /* Increment the surface lock count, for recursive locks */

     ++surface->locked;

     /* Ready to go.. */

     return (0);

 }

 /*

  * Unlock a previously locked surface

  */

 void

 SDL_UnlockSurface(SDL_Surface * surface)

 {

     /* Only perform an unlock if we are locked */

     if (!surface->locked || (--surface->locked > 0)) {

         return;

     }

     /* Update RLE encoded surface with new data */

     if ((surface->flags & SDL_RLEACCEL) == SDL_RLEACCEL) {

         surface->flags &= ~SDL_RLEACCEL;        /* stop lying */

         SDL_RLESurface(surface);

     }

 }

 /* 

  * Convert a surface into the specified pixel format.

  */

 SDL_Surface *

 SDL_ConvertSurface(SDL_Surface * surface,

                    SDL_PixelFormat * format, Uint32 flags)

 {

     SDL_Surface *convert;

     Uint32 copy_flags;

     SDL_Rect bounds;

     /* Check for empty destination palette! (results in empty image) */

     if (format->palette != NULL) {

         int i;

         for (i = 0; i < format->palette->ncolors; ++i) {

             if ((format->palette->colors[i].r != 0xFF) ||

                 (format->palette->colors[i].g != 0xFF) ||

                 (format->palette->colors[i].b != 0xFF))

                 break;

         }

         if (i == format->palette->ncolors) {

             SDL_SetError("Empty destination palette");

             return (NULL);

         }

     }

     /* Create a new surface with the desired format */

     convert = SDL_CreateRGBSurface(0, surface->w, surface->h,

                                    format->BitsPerPixel, format->Rmask,

                                    format->Gmask, format->Bmask,

                                    format->Amask);

     if (convert == NULL) {

         return (NULL);

     }

     /* Copy the palette if any */

     if (format->palette && convert->format->palette) {

         SDL_memcpy(convert->format->palette->colors,

                    format->palette->colors,

                    format->palette->ncolors * sizeof(SDL_Color));

         convert->format->palette->ncolors = format->palette->ncolors;

     }

     /* Save the original copy flags */

     copy_flags = surface->map->info.flags;

     surface->map->info.flags = 0;

     /* Copy over the image data */

     bounds.x = 0;

     bounds.y = 0;

     bounds.w = surface->w;

     bounds.h = surface->h;

     SDL_LowerBlit(surface, &bounds, convert, &bounds);

     /* Clean up the original surface, and update converted surface */

     SDL_SetClipRect(convert, &surface->clip_rect);

     if (copy_flags & SDL_COPY_COLORKEY) {

         Uint8 keyR, keyG, keyB, keyA;

         SDL_GetRGBA(surface->map->info.colorkey, surface->format, &keyR,

                     &keyG, &keyB, &keyA);

         SDL_SetColorKey(convert, 1,

                         SDL_MapRGBA(convert->format, keyR, keyG, keyB, keyA));

     }

     convert->map->info.r = surface->map->info.r;

     convert->map->info.g = surface->map->info.g;

     convert->map->info.b = surface->map->info.b;

     convert->map->info.a = surface->map->info.a;

     convert->map->info.flags = copy_flags;

     surface->map->info.flags = copy_flags;

     /* Enable alpha blending by default if the new surface has an

      * alpha channel or alpha modulation */

     if (format->Amask || (copy_flags & SDL_COPY_MODULATE_ALPHA)) {

         SDL_SetSurfaceBlendMode(convert, SDL_TEXTUREBLENDMODE_BLEND);

     }

     /* We're ready to go! */

     return (convert);

 }

 /*

  * Free a surface created by the above function.

  */

 void

 SDL_FreeSurface(SDL_Surface * surface)

 {

     if (surface == NULL) {

         return;

     }

     if (--surface->refcount > 0) {

         return;

     }

     while (surface->locked > 0) {

         SDL_UnlockSurface(surface);

     }

     if (surface->flags & SDL_RLEACCEL) {

         SDL_UnRLESurface(surface, 0);

     }

     if (surface->format) {

         SDL_SetSurfacePalette(surface, NULL);

         SDL_FreeFormat(surface->format);

         surface->format = NULL;

     }

     if (surface->map != NULL) {

         SDL_FreeBlitMap(surface->map);

         surface->map = NULL;

     }

     if (surface->pixels && ((surface->flags & SDL_PREALLOC) != SDL_PREALLOC)) {

         SDL_free(surface->pixels);

     }

     SDL_free(surface);

 #ifdef CHECK_LEAKS

     --surfaces_allocated;

 #endif

 }

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