--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/video/SDL_surface.c	Thu Apr 26 16:45:43 2001 +0000
@@ -0,0 +1,820 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997, 1998, 1999, 2000, 2001  Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 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
+    Library General Public License for more details.
+
+    You should have received a copy of the GNU Library General Public
+    License along with this library; if not, write to the Free
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+    Sam Lantinga
+    slouken@devolution.com
+*/
+
+#ifdef SAVE_RCSID
+static char rcsid =
+ "@(#) $Id$";
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "SDL_error.h"
+#include "SDL_video.h"
+#include "SDL_sysvideo.h"
+#include "SDL_cursor_c.h"
+#include "SDL_blit.h"
+#include "SDL_RLEaccel_c.h"
+#include "SDL_pixels_c.h"
+#include "SDL_memops.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_VideoDevice *video = current_video;
+	SDL_VideoDevice *this  = current_video;
+	SDL_Surface *screen;
+	SDL_Surface *surface;
+
+	/* Check to see if we desire the surface in video memory */
+	if ( video ) {
+		screen = SDL_PublicSurface;
+	} else {
+		screen = NULL;
+	}
+	if ( screen && ((screen->flags&SDL_HWSURFACE) == SDL_HWSURFACE) ) {
+		if ( (flags&(SDL_SRCCOLORKEY|SDL_SRCALPHA)) != 0 ) {
+			flags |= SDL_HWSURFACE;
+		}
+		if ( (flags & SDL_SRCCOLORKEY) == SDL_SRCCOLORKEY ) {
+			if ( ! current_video->info.blit_hw_CC ) {
+				flags &= ~SDL_HWSURFACE;
+			}
+		}
+		if ( (flags & SDL_SRCALPHA) == SDL_SRCALPHA ) {
+			if ( ! current_video->info.blit_hw_A ) {
+				flags &= ~SDL_HWSURFACE;
+			}
+		}
+	} else {
+		flags &= ~SDL_HWSURFACE;
+	}
+
+	/* Allocate the surface */
+	surface = (SDL_Surface *)malloc(sizeof(*surface));
+	if ( surface == NULL ) {
+		SDL_OutOfMemory();
+		return(NULL);
+	}
+	surface->flags = SDL_SWSURFACE;
+	if ( (flags & SDL_HWSURFACE) == SDL_HWSURFACE ) {
+		depth = screen->format->BitsPerPixel;
+		Rmask = screen->format->Rmask;
+		Gmask = screen->format->Gmask;
+		Bmask = screen->format->Bmask;
+		Amask = screen->format->Amask;
+	}
+	surface->format = SDL_AllocFormat(depth, Rmask, Gmask, Bmask, Amask);
+	if ( surface->format == NULL ) {
+		free(surface);
+		return(NULL);
+	}
+	if ( Amask ) {
+		surface->flags |= SDL_SRCALPHA;
+	}
+	surface->w = width;
+	surface->h = height;
+	surface->pitch = SDL_CalculatePitch(surface);
+	surface->pixels = NULL;
+	surface->offset = 0;
+	surface->hwdata = NULL;
+	surface->locked = 0;
+	surface->map = NULL;
+	surface->format_version = 0;
+	SDL_SetClipRect(surface, NULL);
+
+	/* Get the pixels */
+	if ( ((flags&SDL_HWSURFACE) == SDL_SWSURFACE) || 
+				(video->AllocHWSurface(this, surface) < 0) ) {
+		if ( surface->w && surface->h ) {
+			surface->pixels = malloc(surface->h*surface->pitch);
+			if ( surface->pixels == NULL ) {
+				SDL_FreeSurface(surface);
+				SDL_OutOfMemory();
+				return(NULL);
+			}
+			/* This is important for bitmaps */
+			memset(surface->pixels, 0, surface->h*surface->pitch);
+		}
+	}
+
+	/* Allocate an empty mapping */
+	surface->map = SDL_AllocBlitMap();
+	if ( surface->map == NULL ) {
+		SDL_FreeSurface(surface);
+		return(NULL);
+	}
+
+	/* 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(SDL_SWSURFACE, 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);
+}
+/*
+ * Set the color key in a blittable surface
+ */
+int SDL_SetColorKey (SDL_Surface *surface, Uint32 flag, Uint32 key)
+{
+	/* Sanity check the flag as it gets passed in */
+	if ( flag & SDL_SRCCOLORKEY ) {
+		if ( flag & (SDL_RLEACCEL|SDL_RLEACCELOK) ) {
+			flag = (SDL_SRCCOLORKEY | SDL_RLEACCELOK);
+		} else {
+			flag = SDL_SRCCOLORKEY;
+		}
+	} else {
+		flag = 0;
+	}
+
+	/* Optimize away operations that don't change anything */
+	if ( (flag == (surface->flags & (SDL_SRCCOLORKEY|SDL_RLEACCELOK))) &&
+	     (key == surface->format->colorkey) ) {
+		return(0);
+	}
+
+	/* UnRLE surfaces before we change the colorkey */
+	if ( surface->flags & SDL_RLEACCEL ) {
+	        SDL_UnRLESurface(surface, 1);
+	}
+
+	if ( flag ) {
+		SDL_VideoDevice *video = current_video;
+		SDL_VideoDevice *this  = current_video;
+
+
+		surface->flags |= SDL_SRCCOLORKEY;
+		surface->format->colorkey = key;
+		if ( (surface->flags & SDL_HWACCEL) == SDL_HWACCEL ) {
+			if ( (video->SetHWColorKey == NULL) ||
+			     (video->SetHWColorKey(this, surface, key) < 0) ) {
+				surface->flags &= ~SDL_HWACCEL;
+			}
+		}
+		if ( flag & SDL_RLEACCELOK ) {
+			surface->flags |= SDL_RLEACCELOK;
+		} else {
+			surface->flags &= ~SDL_RLEACCELOK;
+		}
+	} else {
+		surface->flags &= ~(SDL_SRCCOLORKEY|SDL_RLEACCELOK);
+		surface->format->colorkey = 0;
+	}
+	SDL_InvalidateMap(surface->map);
+	return(0);
+}
+int SDL_SetAlpha (SDL_Surface *surface, Uint32 flag, Uint8 value)
+{
+	Uint32 oldflags = surface->flags;
+	Uint32 oldalpha = surface->format->alpha;
+
+	/* Sanity check the flag as it gets passed in */
+	if ( flag & SDL_SRCALPHA ) {
+		if ( flag & (SDL_RLEACCEL|SDL_RLEACCELOK) ) {
+			flag = (SDL_SRCALPHA | SDL_RLEACCELOK);
+		} else {
+			flag = SDL_SRCALPHA;
+		}
+	} else {
+		flag = 0;
+	}
+
+	/* Optimize away operations that don't change anything */
+	if ( (flag == (surface->flags & (SDL_SRCALPHA|SDL_RLEACCELOK))) &&
+	     (!flag || value == oldalpha) ) {
+		return(0);
+	}
+
+	if(!(flag & SDL_RLEACCELOK) && (surface->flags & SDL_RLEACCEL))
+		SDL_UnRLESurface(surface, 1);
+
+	if ( flag ) {
+		SDL_VideoDevice *video = current_video;
+		SDL_VideoDevice *this  = current_video;
+
+		surface->flags |= SDL_SRCALPHA;
+		surface->format->alpha = value;
+		if ( (surface->flags & SDL_HWACCEL) == SDL_HWACCEL ) {
+			if ( (video->SetHWAlpha == NULL) ||
+			     (video->SetHWAlpha(this, surface, value) < 0) ) {
+				surface->flags &= ~SDL_HWACCEL;
+			}
+		}
+		if ( flag & SDL_RLEACCELOK ) {
+		        surface->flags |= SDL_RLEACCELOK;
+		} else {
+		        surface->flags &= ~SDL_RLEACCELOK;
+		}
+	} else {
+		surface->flags &= ~SDL_SRCALPHA;
+		surface->format->alpha = SDL_ALPHA_OPAQUE;
+	}
+	/*
+	 * The representation for software surfaces is independent of
+	 * per-surface alpha, so no need to invalidate the blit mapping
+	 * if just the alpha value was changed. (If either is 255, we still
+	 * need to invalidate.)
+	 */
+	if((surface->flags & SDL_HWACCEL) == SDL_HWACCEL
+	   || oldflags != surface->flags
+	   || (((oldalpha + 1) ^ (value + 1)) & 0x100))
+		SDL_InvalidateMap(surface->map);
+	return(0);
+}
+
+/*
+ * A function to calculate the intersection of two rectangles:
+ * return true if the rectangles intersect, false otherwise
+ */
+static __inline__
+SDL_bool SDL_IntersectRect(SDL_Rect *A, SDL_Rect *B, SDL_Rect *intersection)
+{
+	int Amin, Amax, Bmin, Bmax;
+
+	/* Horizontal intersection */
+	Amin = A->x;
+	Amax = Amin + A->w;
+	Bmin = B->x;
+	Bmax = Bmin + B->w;
+	if(Bmin > Amin)
+	        Amin = Bmin;
+	intersection->x = Amin;
+	if(Bmax < Amax)
+	        Amax = Bmax;
+	intersection->w = Amax - Amin > 0 ? Amax - Amin : 0;
+
+	/* Vertical intersection */
+	Amin = A->y;
+	Amax = Amin + A->h;
+	Bmin = B->y;
+	Bmax = Bmin + B->h;
+	if(Bmin > Amin)
+	        Amin = Bmin;
+	intersection->y = Amin;
+	if(Bmax < Amax)
+	        Amax = Bmax;
+	intersection->h = Amax - Amin > 0 ? Amax - Amin : 0;
+
+	return (intersection->w && intersection->h);
+}
+/*
+ * Set the clipping rectangle for a blittable surface
+ */
+SDL_bool SDL_SetClipRect(SDL_Surface *surface, 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)
+{
+	SDL_blit do_blit;
+
+	/* 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);
+		}
+	}
+
+	/* Figure out which blitter to use */
+	if ( (src->flags & SDL_HWACCEL) == SDL_HWACCEL ) {
+		do_blit = src->map->hw_blit;
+	} else {
+		do_blit = src->map->sw_blit;
+	}
+	return(do_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;
+}
+
+/* 
+ * This function performs a fast fill of the given rectangle with 'color'
+ */
+int SDL_FillRect(SDL_Surface *dst, SDL_Rect *dstrect, Uint32 color)
+{
+	SDL_VideoDevice *video = current_video;
+	SDL_VideoDevice *this  = current_video;
+	int x, y;
+	Uint8 *row;
+
+	/* If 'dstrect' == NULL, then fill the whole surface */
+	if ( dstrect ) {
+		/* Perform clipping */
+		if ( !SDL_IntersectRect(dstrect, &dst->clip_rect, dstrect) ) {
+			return(0);
+		}
+	} else {
+		dstrect = &dst->clip_rect;
+	}
+
+	/* Check for hardware acceleration */
+	if ( ((dst->flags & SDL_HWSURFACE) == SDL_HWSURFACE) &&
+					video->info.blit_fill ) {
+		return(video->FillHWRect(this, dst, dstrect, color));
+	}
+
+	/* Perform software fill */
+	if ( SDL_LockSurface(dst) != 0 ) {
+		return(-1);
+	}
+	row = (Uint8 *)dst->pixels+dstrect->y*dst->pitch+
+			dstrect->x*dst->format->BytesPerPixel;
+	if ( dst->format->palette || (color == 0) ) {
+		x = dstrect->w*dst->format->BytesPerPixel;
+		if ( !color && !((long)row&3) && !(x&3) && !(dst->pitch&3) ) {
+			int n = x >> 2;
+			for ( y=dstrect->h; y; --y ) {
+				SDL_memset4(row, 0, n);
+				row += dst->pitch;
+			}
+		} else {
+#ifdef __powerpc__
+			/*
+			 * memset() on PPC (both glibc and codewarrior) uses
+			 * the dcbz (Data Cache Block Zero) instruction, which
+			 * causes an alignment exception if the destination is
+			 * uncachable, so only use it on software surfaces
+			 */
+			if((dst->flags & SDL_HWSURFACE) == SDL_HWSURFACE) {
+				if(dstrect->w >= 8) {
+					/*
+					 * 64-bit stores are probably most
+					 * efficient to uncached video memory
+					 */
+					double fill;
+					memset(&fill, color, (sizeof fill));
+					for(y = dstrect->h; y; y--) {
+						Uint8 *d = row;
+						unsigned n = x;
+						unsigned nn;
+						Uint8 c = color;
+						double f = fill;
+						while((unsigned long)d
+						      & (sizeof(double) - 1)) {
+							*d++ = c;
+							n--;
+						}
+						nn = n / (sizeof(double) * 4);
+						while(nn) {
+							((double *)d)[0] = f;
+							((double *)d)[1] = f;
+							((double *)d)[2] = f;
+							((double *)d)[3] = f;
+							d += 4*sizeof(double);
+							nn--;
+						}
+						n &= ~(sizeof(double) * 4 - 1);
+						nn = n / sizeof(double);
+						while(nn) {
+							*(double *)d = f;
+							d += sizeof(double);
+							nn--;
+						}
+						n &= ~(sizeof(double) - 1);
+						while(n) {
+							*d++ = c;
+							n--;
+						}
+						row += dst->pitch;
+					}
+				} else {
+					/* narrow boxes */
+					for(y = dstrect->h; y; y--) {
+						Uint8 *d = row;
+						Uint8 c = color;
+						int n = x;
+						while(n) {
+							*d++ = c;
+							n--;
+						}
+						row += dst->pitch;
+					}
+				}
+			} else
+#endif /* __powerpc__ */
+			{
+				for(y = dstrect->h; y; y--) {
+					memset(row, color, x);
+					row += dst->pitch;
+				}
+			}
+		}
+	} else {
+		switch (dst->format->BytesPerPixel) {
+		    case 2:
+			for ( y=dstrect->h; y; --y ) {
+				Uint16 *pixels = (Uint16 *)row;
+				Uint16 c = color;
+				Uint32 cc = (Uint32)c << 16 | c;
+				int n = dstrect->w;
+				if((unsigned long)pixels & 3) {
+					*pixels++ = c;
+					n--;
+				}
+				if(n >> 1)
+					SDL_memset4(pixels, cc, n >> 1);
+				if(n & 1)
+					pixels[n - 1] = c;
+				row += dst->pitch;
+			}
+			break;
+
+		    case 3:
+			if(SDL_BYTEORDER == SDL_BIG_ENDIAN)
+				color <<= 8;
+			for ( y=dstrect->h; y; --y ) {
+				Uint8 *pixels = row;
+				for ( x=dstrect->w; x; --x ) {
+					memcpy(pixels, &color, 3);
+					pixels += 3;
+				}
+				row += dst->pitch;
+			}
+			break;
+
+		    case 4:
+			for(y = dstrect->h; y; --y) {
+				SDL_memset4(row, color, dstrect->w);
+				row += dst->pitch;
+			}
+			break;
+		}
+	}
+	SDL_UnlockSurface(dst);
+
+	/* We're done! */
+	return(0);
+}
+
+/*
+ * Lock a surface to directly access the pixels
+ * -- Do not call this from any blit function, as SDL_DrawCursor() may recurse
+ *    Instead, use:
+ *    if ( (surface->flags & SDL_HWSURFACE) == SDL_HWSURFACE )
+ *               video->LockHWSurface(video, surface);
+ */
+int SDL_LockSurface (SDL_Surface *surface)
+{
+	if ( ! surface->locked ) {
+		/* Perform the lock */
+		if ( surface->flags & (SDL_HWSURFACE|SDL_ASYNCBLIT) ) {
+			SDL_VideoDevice *video = current_video;
+			SDL_VideoDevice *this  = current_video;
+			if ( video->LockHWSurface(this, surface) < 0 ) {
+				return(-1);
+			}
+		}
+		if ( surface->flags & SDL_RLEACCEL ) {
+			SDL_UnRLESurface(surface, 1);
+			surface->flags |= SDL_RLEACCEL;	/* save accel'd state */
+		}
+		/* This needs to be done here in case pixels changes value */
+		surface->pixels = (Uint8 *)surface->pixels + surface->offset;
+	}
+
+	/* Increment the surface lock count, for recursive locks */
+	++surface->locked;
+
+	/* Ready to go.. */
+	return(0);
+}
+/*
+ * Unlock a previously locked surface
+ * -- Do not call this from any blit function, as SDL_DrawCursor() may recurse
+ *    Instead, use:
+ *    if ( (surface->flags & SDL_HWSURFACE) == SDL_HWSURFACE )
+ *               video->UnlockHWSurface(video, surface);
+ */
+void SDL_UnlockSurface (SDL_Surface *surface)
+{
+	/* Only perform an unlock if we are locked */
+	if ( ! surface->locked || (--surface->locked > 0) ) {
+		return;
+	}
+
+	/* Perform the unlock */
+	surface->pixels = (Uint8 *)surface->pixels - surface->offset;
+
+	/* Unlock hardware or accelerated surfaces */
+	if ( surface->flags & (SDL_HWSURFACE|SDL_ASYNCBLIT) ) {
+		SDL_VideoDevice *video = current_video;
+		SDL_VideoDevice *this  = current_video;
+		video->UnlockHWSurface(this, surface);
+	} else {
+		/* 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 colorkey = 0;
+	Uint8 alpha = 0;
+	Uint32 surface_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 != 0) ||
+			     (format->palette->colors[i].g != 0) ||
+			     (format->palette->colors[i].b != 0) )
+				break;
+		}
+		if ( i == format->palette->ncolors ) {
+			SDL_SetError("Empty destination palette");
+			return(NULL);
+		}
+	}
+
+	/* Create a new surface with the desired format */
+	convert = SDL_CreateRGBSurface(flags,
+				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 ) {
+		memcpy(convert->format->palette->colors,
+				format->palette->colors,
+				format->palette->ncolors*sizeof(SDL_Color));
+		convert->format->palette->ncolors = format->palette->ncolors;
+	}
+
+	/* Save the original surface color key and alpha */
+	surface_flags = surface->flags;
+	if ( (surface_flags & SDL_SRCCOLORKEY) == SDL_SRCCOLORKEY ) {
+		/* Convert colourkeyed surfaces to RGBA if requested */
+		if((flags & SDL_SRCCOLORKEY) != SDL_SRCCOLORKEY
+		   && format->Amask) {
+			surface_flags &= ~SDL_SRCCOLORKEY;
+		} else {
+			colorkey = surface->format->colorkey;
+			SDL_SetColorKey(surface, 0, 0);
+		}
+	}
+	if ( (surface_flags & SDL_SRCALPHA) == SDL_SRCALPHA ) {
+		alpha = surface->format->alpha;
+		SDL_SetAlpha(surface, 0, 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 */
+	if ( convert != NULL ) {
+		SDL_SetClipRect(convert, &surface->clip_rect);
+	}
+	if ( (surface_flags & SDL_SRCCOLORKEY) == SDL_SRCCOLORKEY ) {
+		Uint32 cflags = surface_flags&(SDL_SRCCOLORKEY|SDL_RLEACCELOK);
+		if ( convert != NULL ) {
+			Uint8 keyR, keyG, keyB;
+
+			SDL_GetRGB(colorkey,surface->format,&keyR,&keyG,&keyB);
+			SDL_SetColorKey(convert, cflags|(flags&SDL_RLEACCELOK),
+				SDL_MapRGB(convert->format, keyR, keyG, keyB));
+		}
+		SDL_SetColorKey(surface, cflags, colorkey);
+	}
+	if ( (surface_flags & SDL_SRCALPHA) == SDL_SRCALPHA ) {
+		Uint32 aflags = surface_flags&(SDL_SRCALPHA|SDL_RLEACCELOK);
+		if ( convert != NULL ) {
+		        SDL_SetAlpha(convert, aflags|(flags&SDL_RLEACCELOK),
+				alpha);
+		}
+		SDL_SetAlpha(surface, aflags, alpha);
+	}
+
+	/* We're ready to go! */
+	return(convert);
+}
+
+/*
+ * Free a surface created by the above function.
+ */
+void SDL_FreeSurface (SDL_Surface *surface)
+{
+	/* Free anything that's not NULL, and not the screen surface */
+	if ((surface == NULL) ||
+	    (current_video &&
+	    ((surface == SDL_ShadowSurface)||(surface == SDL_VideoSurface)))) {
+		return;
+	}
+	if ( --surface->refcount > 0 ) {
+		return;
+	}
+	if ( (surface->flags & SDL_RLEACCEL) == SDL_RLEACCEL ) {
+	        SDL_UnRLESurface(surface, 0);
+	}
+	if ( surface->format ) {
+		SDL_FreeFormat(surface->format);
+		surface->format = NULL;
+	}
+	if ( surface->map != NULL ) {
+		SDL_FreeBlitMap(surface->map);
+		surface->map = NULL;
+	}
+	if ( (surface->flags & SDL_HWSURFACE) == SDL_HWSURFACE ) {
+		SDL_VideoDevice *video = current_video;
+		SDL_VideoDevice *this  = current_video;
+		video->FreeHWSurface(this, surface);
+	}
+	if ( surface->pixels &&
+	     ((surface->flags & SDL_PREALLOC) != SDL_PREALLOC) ) {
+		free(surface->pixels);
+	}
+	free(surface);
+#ifdef CHECK_LEAKS
+	--surfaces_allocated;
+#endif
+}