[sdl_omap.git] / src / video / SDL_bmp.c

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 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"

/* 
   Code to load and save surfaces in Windows BMP format.

   Why support BMP format?  Well, it's a native format for Windows, and
   most image processing programs can read and write it.  It would be nice
   to be able to have at least one image format that we can natively load
   and save, and since PNG is so complex that it would bloat the library,
   BMP is a good alternative. 

   This code currently supports Win32 DIBs in uncompressed 8 and 24 bpp.
*/

#include "SDL_video.h"
#include "SDL_endian.h"

/* Compression encodings for BMP files */
#ifndef BI_RGB
#define BI_RGB		0
#define BI_RLE8		1
#define BI_RLE4		2
#define BI_BITFIELDS	3
#endif


SDL_Surface * SDL_LoadBMP_RW (SDL_RWops *src, int freesrc)
{
	SDL_bool was_error;
	long fp_offset;
	int bmpPitch;
	int i, pad;
	SDL_Surface *surface;
	Uint32 Rmask;
	Uint32 Gmask;
	Uint32 Bmask;
	SDL_Palette *palette;
	Uint8 *bits;
	Uint8 *top, *end;
	SDL_bool topDown;
	int ExpandBMP;

	/* The Win32 BMP file header (14 bytes) */
	char   magic[2];
	Uint32 bfSize;
	Uint16 bfReserved1;
	Uint16 bfReserved2;
	Uint32 bfOffBits;

	/* The Win32 BITMAPINFOHEADER struct (40 bytes) */
	Uint32 biSize;
	Sint32 biWidth;
	Sint32 biHeight;
	Uint16 biPlanes;
	Uint16 biBitCount;
	Uint32 biCompression;
	Uint32 biSizeImage;
	Sint32 biXPelsPerMeter;
	Sint32 biYPelsPerMeter;
	Uint32 biClrUsed;
	Uint32 biClrImportant;

	/* Make sure we are passed a valid data source */
	surface = NULL;
	was_error = SDL_FALSE;
	if ( src == NULL ) {
		was_error = SDL_TRUE;
		goto done;
	}

	/* Read in the BMP file header */
	fp_offset = SDL_RWtell(src);
	SDL_ClearError();
	if ( SDL_RWread(src, magic, 1, 2) != 2 ) {
		SDL_Error(SDL_EFREAD);
		was_error = SDL_TRUE;
		goto done;
	}
	if ( SDL_strncmp(magic, "BM", 2) != 0 ) {
		SDL_SetError("File is not a Windows BMP file");
		was_error = SDL_TRUE;
		goto done;
	}
	bfSize		= SDL_ReadLE32(src);
	bfReserved1	= SDL_ReadLE16(src);
	bfReserved2	= SDL_ReadLE16(src);
	bfOffBits	= SDL_ReadLE32(src);

	/* Read the Win32 BITMAPINFOHEADER */
	biSize		= SDL_ReadLE32(src);
	if ( biSize == 12 ) {
		biWidth		= (Uint32)SDL_ReadLE16(src);
		biHeight	= (Uint32)SDL_ReadLE16(src);
		biPlanes	= SDL_ReadLE16(src);
		biBitCount	= SDL_ReadLE16(src);
		biCompression	= BI_RGB;
		biSizeImage	= 0;
		biXPelsPerMeter	= 0;
		biYPelsPerMeter	= 0;
		biClrUsed	= 0;
		biClrImportant	= 0;
	} else {
		biWidth		= SDL_ReadLE32(src);
		biHeight	= SDL_ReadLE32(src);
		biPlanes	= SDL_ReadLE16(src);
		biBitCount	= SDL_ReadLE16(src);
		biCompression	= SDL_ReadLE32(src);
		biSizeImage	= SDL_ReadLE32(src);
		biXPelsPerMeter	= SDL_ReadLE32(src);
		biYPelsPerMeter	= SDL_ReadLE32(src);
		biClrUsed	= SDL_ReadLE32(src);
		biClrImportant	= SDL_ReadLE32(src);
	}
	if (biHeight < 0) {
		topDown = SDL_TRUE;
		biHeight = -biHeight;
	} else {
		topDown = SDL_FALSE;
	}

	/* Check for read error */
	if ( SDL_strcmp(SDL_GetError(), "") != 0 ) {
		was_error = SDL_TRUE;
		goto done;
	}

	/* Expand 1 and 4 bit bitmaps to 8 bits per pixel */
	switch (biBitCount) {
		case 1:
		case 4:
			ExpandBMP = biBitCount;
			biBitCount = 8;
			break;
		default:
			ExpandBMP = 0;
			break;
	}

	/* We don't support any BMP compression right now */
	Rmask = Gmask = Bmask = 0;
	switch (biCompression) {
		case BI_RGB:
			/* If there are no masks, use the defaults */
			if ( bfOffBits == (14+biSize) ) {
				/* Default values for the BMP format */
				switch (biBitCount) {
					case 15:
					case 16:
						Rmask = 0x7C00;
						Gmask = 0x03E0;
						Bmask = 0x001F;
						break;
					case 24:
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
					        Rmask = 0x000000FF;
					        Gmask = 0x0000FF00;
					        Bmask = 0x00FF0000;
						break;
#endif
					case 32:
						Rmask = 0x00FF0000;
						Gmask = 0x0000FF00;
						Bmask = 0x000000FF;
						break;
					default:
						break;
				}
				break;
			}
			/* Fall through -- read the RGB masks */

		case BI_BITFIELDS:
			switch (biBitCount) {
				case 15:
				case 16:
				case 32:
					Rmask = SDL_ReadLE32(src);
					Gmask = SDL_ReadLE32(src);
					Bmask = SDL_ReadLE32(src);
					break;
				default:
					break;
			}
			break;
		default:
			SDL_SetError("Compressed BMP files not supported");
			was_error = SDL_TRUE;
			goto done;
	}

	/* Create a compatible surface, note that the colors are RGB ordered */
	surface = SDL_CreateRGBSurface(SDL_SWSURFACE,
			biWidth, biHeight, biBitCount, Rmask, Gmask, Bmask, 0);
	if ( surface == NULL ) {
		was_error = SDL_TRUE;
		goto done;
	}

	/* Load the palette, if any */
	palette = (surface->format)->palette;
	if ( palette ) {
		if ( biClrUsed == 0 ) {
			biClrUsed = 1 << biBitCount;
		}
		if ( biSize == 12 ) {
			for ( i = 0; i < (int)biClrUsed; ++i ) {
				SDL_RWread(src, &palette->colors[i].b, 1, 1);
				SDL_RWread(src, &palette->colors[i].g, 1, 1);
				SDL_RWread(src, &palette->colors[i].r, 1, 1);
				palette->colors[i].unused = 0;
			}	
		} else {
			for ( i = 0; i < (int)biClrUsed; ++i ) {
				SDL_RWread(src, &palette->colors[i].b, 1, 1);
				SDL_RWread(src, &palette->colors[i].g, 1, 1);
				SDL_RWread(src, &palette->colors[i].r, 1, 1);
				SDL_RWread(src, &palette->colors[i].unused, 1, 1);
			}	
		}
		palette->ncolors = biClrUsed;
	}

	/* Read the surface pixels.  Note that the bmp image is upside down */
	if ( SDL_RWseek(src, fp_offset+bfOffBits, RW_SEEK_SET) < 0 ) {
		SDL_Error(SDL_EFSEEK);
		was_error = SDL_TRUE;
		goto done;
	}
	top = (Uint8 *)surface->pixels;
	end = (Uint8 *)surface->pixels+(surface->h*surface->pitch);
	switch (ExpandBMP) {
		case 1:
			bmpPitch = (biWidth + 7) >> 3;
			pad  = (((bmpPitch)%4) ? (4-((bmpPitch)%4)) : 0);
			break;
		case 4:
			bmpPitch = (biWidth + 1) >> 1;
			pad  = (((bmpPitch)%4) ? (4-((bmpPitch)%4)) : 0);
			break;
		default:
			pad  = ((surface->pitch%4) ?
					(4-(surface->pitch%4)) : 0);
			break;
	}
	if ( topDown ) {
		bits = top;
	} else {
		bits = end - surface->pitch;
	}
	while ( bits >= top && bits < end ) {
		switch (ExpandBMP) {
			case 1:
			case 4: {
			Uint8 pixel = 0;
			int   shift = (8-ExpandBMP);
			for ( i=0; i<surface->w; ++i ) {
				if ( i%(8/ExpandBMP) == 0 ) {
					if ( !SDL_RWread(src, &pixel, 1, 1) ) {
						SDL_SetError(
					"Error reading from BMP");
						was_error = SDL_TRUE;
						goto done;
					}
				}
				*(bits+i) = (pixel>>shift);
				pixel <<= ExpandBMP;
			} }
			break;

			default:
			if ( SDL_RWread(src, bits, 1, surface->pitch)
							 != surface->pitch ) {
				SDL_Error(SDL_EFREAD);
				was_error = SDL_TRUE;
				goto done;
			}
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
			/* Byte-swap the pixels if needed. Note that the 24bpp
			   case has already been taken care of above. */
			switch(biBitCount) {
				case 15:
				case 16: {
				        Uint16 *pix = (Uint16 *)bits;
					for(i = 0; i < surface->w; i++)
					        pix[i] = SDL_Swap16(pix[i]);
					break;
				}

				case 32: {
				        Uint32 *pix = (Uint32 *)bits;
					for(i = 0; i < surface->w; i++)
					        pix[i] = SDL_Swap32(pix[i]);
					break;
				}
			}
#endif
			break;
		}
		/* Skip padding bytes, ugh */
		if ( pad ) {
			Uint8 padbyte;
			for ( i=0; i<pad; ++i ) {
				SDL_RWread(src, &padbyte, 1, 1);
			}
		}
		if ( topDown ) {
			bits += surface->pitch;
		} else {
			bits -= surface->pitch;
		}
	}
done:
	if ( was_error ) {
		if ( src ) {
			SDL_RWseek(src, fp_offset, RW_SEEK_SET);
		}
		if ( surface ) {
			SDL_FreeSurface(surface);
		}
		surface = NULL;
	}
	if ( freesrc && src ) {
		SDL_RWclose(src);
	}
	return(surface);
}

int SDL_SaveBMP_RW (SDL_Surface *saveme, SDL_RWops *dst, int freedst)
{
	long fp_offset;
	int i, pad;
	SDL_Surface *surface;
	Uint8 *bits;

	/* The Win32 BMP file header (14 bytes) */
	char   magic[2] = { 'B', 'M' };
	Uint32 bfSize;
	Uint16 bfReserved1;
	Uint16 bfReserved2;
	Uint32 bfOffBits;

	/* The Win32 BITMAPINFOHEADER struct (40 bytes) */
	Uint32 biSize;
	Sint32 biWidth;
	Sint32 biHeight;
	Uint16 biPlanes;
	Uint16 biBitCount;
	Uint32 biCompression;
	Uint32 biSizeImage;
	Sint32 biXPelsPerMeter;
	Sint32 biYPelsPerMeter;
	Uint32 biClrUsed;
	Uint32 biClrImportant;

	/* Make sure we have somewhere to save */
	surface = NULL;
	if ( dst ) {
		if ( saveme->format->palette ) {
			if ( saveme->format->BitsPerPixel == 8 ) {
				surface = saveme;
			} else {
				SDL_SetError("%d bpp BMP files not supported",
						saveme->format->BitsPerPixel);
			}
		}
		else if ( (saveme->format->BitsPerPixel == 24) &&
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
				(saveme->format->Rmask == 0x00FF0000) &&
				(saveme->format->Gmask == 0x0000FF00) &&
				(saveme->format->Bmask == 0x000000FF)
#else
				(saveme->format->Rmask == 0x000000FF) &&
				(saveme->format->Gmask == 0x0000FF00) &&
				(saveme->format->Bmask == 0x00FF0000)
#endif
			  ) {
			surface = saveme;
		} else {
			SDL_Rect bounds;

			/* Convert to 24 bits per pixel */
			surface = SDL_CreateRGBSurface(SDL_SWSURFACE,
					saveme->w, saveme->h, 24,
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
					0x00FF0000, 0x0000FF00, 0x000000FF,
#else
					0x000000FF, 0x0000FF00, 0x00FF0000,
#endif
					0);
			if ( surface != NULL ) {
				bounds.x = 0;
				bounds.y = 0;
				bounds.w = saveme->w;
				bounds.h = saveme->h;
				if ( SDL_LowerBlit(saveme, &bounds, surface,
							&bounds) < 0 ) {
					SDL_FreeSurface(surface);
					SDL_SetError(
					"Couldn't convert image to 24 bpp");
					surface = NULL;
				}
			}
		}
	}

	if ( surface && (SDL_LockSurface(surface) == 0) ) {
		const int bw = surface->w*surface->format->BytesPerPixel;

		/* Set the BMP file header values */
		bfSize = 0;		 /* We'll write this when we're done */
		bfReserved1 = 0;
		bfReserved2 = 0;
		bfOffBits = 0;		/* We'll write this when we're done */

		/* Write the BMP file header values */
		fp_offset = SDL_RWtell(dst);
		SDL_ClearError();
		SDL_RWwrite(dst, magic, 2, 1);
		SDL_WriteLE32(dst, bfSize);
		SDL_WriteLE16(dst, bfReserved1);
		SDL_WriteLE16(dst, bfReserved2);
		SDL_WriteLE32(dst, bfOffBits);

		/* Set the BMP info values */
		biSize = 40;
		biWidth = surface->w;
		biHeight = surface->h;
		biPlanes = 1;
		biBitCount = surface->format->BitsPerPixel;
		biCompression = BI_RGB;
		biSizeImage = surface->h*surface->pitch;
		biXPelsPerMeter = 0;
		biYPelsPerMeter = 0;
		if ( surface->format->palette ) {
			biClrUsed = surface->format->palette->ncolors;
		} else {
			biClrUsed = 0;
		}
		biClrImportant = 0;

		/* Write the BMP info values */
		SDL_WriteLE32(dst, biSize);
		SDL_WriteLE32(dst, biWidth);
		SDL_WriteLE32(dst, biHeight);
		SDL_WriteLE16(dst, biPlanes);
		SDL_WriteLE16(dst, biBitCount);
		SDL_WriteLE32(dst, biCompression);
		SDL_WriteLE32(dst, biSizeImage);
		SDL_WriteLE32(dst, biXPelsPerMeter);
		SDL_WriteLE32(dst, biYPelsPerMeter);
		SDL_WriteLE32(dst, biClrUsed);
		SDL_WriteLE32(dst, biClrImportant);

		/* Write the palette (in BGR color order) */
		if ( surface->format->palette ) {
			SDL_Color *colors;
			int       ncolors;

			colors = surface->format->palette->colors;
			ncolors = surface->format->palette->ncolors;
			for ( i=0; i<ncolors; ++i ) {
				SDL_RWwrite(dst, &colors[i].b, 1, 1);
				SDL_RWwrite(dst, &colors[i].g, 1, 1);
				SDL_RWwrite(dst, &colors[i].r, 1, 1);
				SDL_RWwrite(dst, &colors[i].unused, 1, 1);
			}
		}

		/* Write the bitmap offset */
		bfOffBits = SDL_RWtell(dst)-fp_offset;
		if ( SDL_RWseek(dst, fp_offset+10, RW_SEEK_SET) < 0 ) {
			SDL_Error(SDL_EFSEEK);
		}
		SDL_WriteLE32(dst, bfOffBits);
		if ( SDL_RWseek(dst, fp_offset+bfOffBits, RW_SEEK_SET) < 0 ) {
			SDL_Error(SDL_EFSEEK);
		}

		/* Write the bitmap image upside down */
		bits = (Uint8 *)surface->pixels+(surface->h*surface->pitch);
		pad  = ((bw%4) ? (4-(bw%4)) : 0);
		while ( bits > (Uint8 *)surface->pixels ) {
			bits -= surface->pitch;
			if ( SDL_RWwrite(dst, bits, 1, bw) != bw) {
				SDL_Error(SDL_EFWRITE);
				break;
			}
			if ( pad ) {
				const Uint8 padbyte = 0;
				for ( i=0; i<pad; ++i ) {
					SDL_RWwrite(dst, &padbyte, 1, 1);
				}
			}
		}

		/* Write the BMP file size */
		bfSize = SDL_RWtell(dst)-fp_offset;
		if ( SDL_RWseek(dst, fp_offset+2, RW_SEEK_SET) < 0 ) {
			SDL_Error(SDL_EFSEEK);
		}
		SDL_WriteLE32(dst, bfSize);
		if ( SDL_RWseek(dst, fp_offset+bfSize, RW_SEEK_SET) < 0 ) {
			SDL_Error(SDL_EFSEEK);
		}

		/* Close it up.. */
		SDL_UnlockSurface(surface);
		if ( surface != saveme ) {
			SDL_FreeSurface(surface);
		}
	}

	if ( freedst && dst ) {
		SDL_RWclose(dst);
	}
	return((SDL_strcmp(SDL_GetError(), "") == 0) ? 0 : -1);
}
Commit	Line	Data
e14743d1	1	/*
	2	SDL - Simple DirectMedia Layer
	3	Copyright (C) 1997-2009 Sam Lantinga
	4
	5	This library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	This library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
	16	License along with this library; if not, write to the Free Software
	17	Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	18
	19	Sam Lantinga
	20	slouken@libsdl.org
	21	*/
	22	#include "SDL_config.h"
	23
	24	/*
	25	Code to load and save surfaces in Windows BMP format.
	26
	27	Why support BMP format? Well, it's a native format for Windows, and
	28	most image processing programs can read and write it. It would be nice
	29	to be able to have at least one image format that we can natively load
	30	and save, and since PNG is so complex that it would bloat the library,
	31	BMP is a good alternative.
	32
	33	This code currently supports Win32 DIBs in uncompressed 8 and 24 bpp.
	34	*/
	35
	36	#include "SDL_video.h"
	37	#include "SDL_endian.h"
	38
	39	/* Compression encodings for BMP files */
	40	#ifndef BI_RGB
	41	#define BI_RGB 0
	42	#define BI_RLE8 1
	43	#define BI_RLE4 2
	44	#define BI_BITFIELDS 3
	45	#endif
	46
	47
	48	SDL_Surface * SDL_LoadBMP_RW (SDL_RWops *src, int freesrc)
	49	{
	50	SDL_bool was_error;
	51	long fp_offset;
	52	int bmpPitch;
	53	int i, pad;
	54	SDL_Surface *surface;
	55	Uint32 Rmask;
	56	Uint32 Gmask;
	57	Uint32 Bmask;
	58	SDL_Palette *palette;
	59	Uint8 *bits;
	60	Uint8 top, end;
	61	SDL_bool topDown;
	62	int ExpandBMP;
	63
	64	/* The Win32 BMP file header (14 bytes) */
65	char magic[2];
66	Uint32 bfSize;
67	Uint16 bfReserved1;
68	Uint16 bfReserved2;
69	Uint32 bfOffBits;
70
71	/* The Win32 BITMAPINFOHEADER struct (40 bytes) */
72	Uint32 biSize;
73	Sint32 biWidth;
74	Sint32 biHeight;
75	Uint16 biPlanes;
76	Uint16 biBitCount;
77	Uint32 biCompression;
78	Uint32 biSizeImage;
79	Sint32 biXPelsPerMeter;
80	Sint32 biYPelsPerMeter;
81	Uint32 biClrUsed;
82	Uint32 biClrImportant;
83
84	/* Make sure we are passed a valid data source */
85	surface = NULL;
86	was_error = SDL_FALSE;
87	if ( src == NULL ) {
88	was_error = SDL_TRUE;
89	goto done;
90	}
91
92	/* Read in the BMP file header */
93	fp_offset = SDL_RWtell(src);
94	SDL_ClearError();
95	if ( SDL_RWread(src, magic, 1, 2) != 2 ) {
96	SDL_Error(SDL_EFREAD);
97	was_error = SDL_TRUE;
98	goto done;
99	}
100	if ( SDL_strncmp(magic, "BM", 2) != 0 ) {
101	SDL_SetError("File is not a Windows BMP file");
102	was_error = SDL_TRUE;
103	goto done;
104	}
105	bfSize = SDL_ReadLE32(src);
106	bfReserved1 = SDL_ReadLE16(src);
107	bfReserved2 = SDL_ReadLE16(src);
108	bfOffBits = SDL_ReadLE32(src);
109
110	/* Read the Win32 BITMAPINFOHEADER */
111	biSize = SDL_ReadLE32(src);
112	if ( biSize == 12 ) {
113	biWidth = (Uint32)SDL_ReadLE16(src);
114	biHeight = (Uint32)SDL_ReadLE16(src);
115	biPlanes = SDL_ReadLE16(src);
116	biBitCount = SDL_ReadLE16(src);
117	biCompression = BI_RGB;
118	biSizeImage = 0;
119	biXPelsPerMeter = 0;
120	biYPelsPerMeter = 0;
121	biClrUsed = 0;
122	biClrImportant = 0;
123	} else {
124	biWidth = SDL_ReadLE32(src);
125	biHeight = SDL_ReadLE32(src);
126	biPlanes = SDL_ReadLE16(src);
127	biBitCount = SDL_ReadLE16(src);
128	biCompression = SDL_ReadLE32(src);
129	biSizeImage = SDL_ReadLE32(src);
130	biXPelsPerMeter = SDL_ReadLE32(src);
131	biYPelsPerMeter = SDL_ReadLE32(src);
132	biClrUsed = SDL_ReadLE32(src);
133	biClrImportant = SDL_ReadLE32(src);
134	}
135	if (biHeight < 0) {
136	topDown = SDL_TRUE;
137	biHeight = -biHeight;
138	} else {
139	topDown = SDL_FALSE;
140	}
141
142	/* Check for read error */
143	if ( SDL_strcmp(SDL_GetError(), "") != 0 ) {
144	was_error = SDL_TRUE;
145	goto done;
146	}
147
148	/* Expand 1 and 4 bit bitmaps to 8 bits per pixel */
149	switch (biBitCount) {
150	case 1:
151	case 4:
152	ExpandBMP = biBitCount;
153	biBitCount = 8;
154	break;
155	default:
156	ExpandBMP = 0;
157	break;
158	}
159
160	/* We don't support any BMP compression right now */
161	Rmask = Gmask = Bmask = 0;
162	switch (biCompression) {
163	case BI_RGB:
164	/* If there are no masks, use the defaults */
165	if ( bfOffBits == (14+biSize) ) {
166	/* Default values for the BMP format */
167	switch (biBitCount) {
168	case 15:
169	case 16:
170	Rmask = 0x7C00;
171	Gmask = 0x03E0;
172	Bmask = 0x001F;
173	break;
174	case 24:
175	#if SDL_BYTEORDER == SDL_BIG_ENDIAN
176	Rmask = 0x000000FF;
177	Gmask = 0x0000FF00;
178	Bmask = 0x00FF0000;
179	break;
180	#endif
181	case 32:
182	Rmask = 0x00FF0000;
183	Gmask = 0x0000FF00;
184	Bmask = 0x000000FF;
185	break;
186	default:
187	break;
188	}
189	break;
190	}
191	/* Fall through -- read the RGB masks */
192
193	case BI_BITFIELDS:
194	switch (biBitCount) {
195	case 15:
196	case 16:
197	case 32:
198	Rmask = SDL_ReadLE32(src);
199	Gmask = SDL_ReadLE32(src);
200	Bmask = SDL_ReadLE32(src);
201	break;
202	default:
203	break;
204	}
205	break;
206	default:
207	SDL_SetError("Compressed BMP files not supported");
208	was_error = SDL_TRUE;
209	goto done;
210	}
211
212	/* Create a compatible surface, note that the colors are RGB ordered */
213	surface = SDL_CreateRGBSurface(SDL_SWSURFACE,
214	biWidth, biHeight, biBitCount, Rmask, Gmask, Bmask, 0);
215	if ( surface == NULL ) {
216	was_error = SDL_TRUE;
217	goto done;
218	}
219
220	/* Load the palette, if any */
221	palette = (surface->format)->palette;
222	if ( palette ) {
223	if ( biClrUsed == 0 ) {
224	biClrUsed = 1 << biBitCount;
225	}
226	if ( biSize == 12 ) {
227	for ( i = 0; i < (int)biClrUsed; ++i ) {
228	SDL_RWread(src, &palette->colors[i].b, 1, 1);
229	SDL_RWread(src, &palette->colors[i].g, 1, 1);
230	SDL_RWread(src, &palette->colors[i].r, 1, 1);
231	palette->colors[i].unused = 0;
232	}
233	} else {
234	for ( i = 0; i < (int)biClrUsed; ++i ) {
235	SDL_RWread(src, &palette->colors[i].b, 1, 1);
236	SDL_RWread(src, &palette->colors[i].g, 1, 1);
237	SDL_RWread(src, &palette->colors[i].r, 1, 1);
238	SDL_RWread(src, &palette->colors[i].unused, 1, 1);
239	}
240	}
241	palette->ncolors = biClrUsed;
242	}
243
244	/* Read the surface pixels. Note that the bmp image is upside down */
245	if ( SDL_RWseek(src, fp_offset+bfOffBits, RW_SEEK_SET) < 0 ) {
246	SDL_Error(SDL_EFSEEK);
247	was_error = SDL_TRUE;
248	goto done;
249	}
250	top = (Uint8 *)surface->pixels;
251	end = (Uint8 )surface->pixels+(surface->hsurface->pitch);
252	switch (ExpandBMP) {
253	case 1:
254	bmpPitch = (biWidth + 7) >> 3;
255	pad = (((bmpPitch)%4) ? (4-((bmpPitch)%4)) : 0);
256	break;
257	case 4:
258	bmpPitch = (biWidth + 1) >> 1;
259	pad = (((bmpPitch)%4) ? (4-((bmpPitch)%4)) : 0);
260	break;
261	default:
262	pad = ((surface->pitch%4) ?
263	(4-(surface->pitch%4)) : 0);
264	break;
265	}
266	if ( topDown ) {
267	bits = top;
268	} else {
269	bits = end - surface->pitch;
270	}
271	while ( bits >= top && bits < end ) {
272	switch (ExpandBMP) {
273	case 1:
274	case 4: {
275	Uint8 pixel = 0;
276	int shift = (8-ExpandBMP);
277	for ( i=0; i<surface->w; ++i ) {
278	if ( i%(8/ExpandBMP) == 0 ) {
279	if ( !SDL_RWread(src, &pixel, 1, 1) ) {
280	SDL_SetError(
281	"Error reading from BMP");
282	was_error = SDL_TRUE;
283	goto done;
284	}
285	}
286	*(bits+i) = (pixel>>shift);
287	pixel <<= ExpandBMP;
288	} }
289	break;
290
291	default:
292	if ( SDL_RWread(src, bits, 1, surface->pitch)
293	!= surface->pitch ) {
294	SDL_Error(SDL_EFREAD);
295	was_error = SDL_TRUE;
296	goto done;
297	}
298	#if SDL_BYTEORDER == SDL_BIG_ENDIAN
299	/* Byte-swap the pixels if needed. Note that the 24bpp
300	case has already been taken care of above. */
301	switch(biBitCount) {
302	case 15:
303	case 16: {
304	Uint16 pix = (Uint16 )bits;
305	for(i = 0; i < surface->w; i++)
306	pix[i] = SDL_Swap16(pix[i]);
307	break;
308	}
309
310	case 32: {
311	Uint32 pix = (Uint32 )bits;
312	for(i = 0; i < surface->w; i++)
313	pix[i] = SDL_Swap32(pix[i]);
314	break;
315	}
316	}
317	#endif
318	break;
319	}
320	/* Skip padding bytes, ugh */
321	if ( pad ) {
322	Uint8 padbyte;
323	for ( i=0; i<pad; ++i ) {
324	SDL_RWread(src, &padbyte, 1, 1);
325	}
326	}
327	if ( topDown ) {
328	bits += surface->pitch;
329	} else {
330	bits -= surface->pitch;
331	}
332	}
333	done:
334	if ( was_error ) {
335	if ( src ) {
336	SDL_RWseek(src, fp_offset, RW_SEEK_SET);
337	}
338	if ( surface ) {
339	SDL_FreeSurface(surface);
340	}
341	surface = NULL;
342	}
343	if ( freesrc && src ) {
344	SDL_RWclose(src);
345	}
346	return(surface);
347	}
348
349	int SDL_SaveBMP_RW (SDL_Surface saveme, SDL_RWops dst, int freedst)
350	{
351	long fp_offset;
352	int i, pad;
353	SDL_Surface *surface;
354	Uint8 *bits;
355
356	/* The Win32 BMP file header (14 bytes) */
357	char magic[2] = { 'B', 'M' };
358	Uint32 bfSize;
359	Uint16 bfReserved1;
360	Uint16 bfReserved2;
361	Uint32 bfOffBits;
362
363	/* The Win32 BITMAPINFOHEADER struct (40 bytes) */
364	Uint32 biSize;
365	Sint32 biWidth;
366	Sint32 biHeight;
367	Uint16 biPlanes;
368	Uint16 biBitCount;
369	Uint32 biCompression;
370	Uint32 biSizeImage;
371	Sint32 biXPelsPerMeter;
372	Sint32 biYPelsPerMeter;
373	Uint32 biClrUsed;
374	Uint32 biClrImportant;
375
376	/* Make sure we have somewhere to save */
377	surface = NULL;
378	if ( dst ) {
379	if ( saveme->format->palette ) {
380	if ( saveme->format->BitsPerPixel == 8 ) {
381	surface = saveme;
382	} else {
383	SDL_SetError("%d bpp BMP files not supported",
384	saveme->format->BitsPerPixel);
385	}
386	}
387	else if ( (saveme->format->BitsPerPixel == 24) &&
388	#if SDL_BYTEORDER == SDL_LIL_ENDIAN
389	(saveme->format->Rmask == 0x00FF0000) &&
390	(saveme->format->Gmask == 0x0000FF00) &&
391	(saveme->format->Bmask == 0x000000FF)
392	#else
393	(saveme->format->Rmask == 0x000000FF) &&
394	(saveme->format->Gmask == 0x0000FF00) &&
395	(saveme->format->Bmask == 0x00FF0000)
396	#endif
397	) {
398	surface = saveme;
399	} else {
400	SDL_Rect bounds;
401
402	/* Convert to 24 bits per pixel */
403	surface = SDL_CreateRGBSurface(SDL_SWSURFACE,
404	saveme->w, saveme->h, 24,
405	#if SDL_BYTEORDER == SDL_LIL_ENDIAN
406	0x00FF0000, 0x0000FF00, 0x000000FF,
407	#else
408	0x000000FF, 0x0000FF00, 0x00FF0000,
409	#endif
410	0);
411	if ( surface != NULL ) {
412	bounds.x = 0;
413	bounds.y = 0;
414	bounds.w = saveme->w;
415	bounds.h = saveme->h;
416	if ( SDL_LowerBlit(saveme, &bounds, surface,
417	&bounds) < 0 ) {
418	SDL_FreeSurface(surface);
419	SDL_SetError(
420	"Couldn't convert image to 24 bpp");
421	surface = NULL;
422	}
423	}
424	}
425	}
426
427	if ( surface && (SDL_LockSurface(surface) == 0) ) {
428	const int bw = surface->w*surface->format->BytesPerPixel;
429
430	/* Set the BMP file header values */
431	bfSize = 0; /* We'll write this when we're done */
432	bfReserved1 = 0;
433	bfReserved2 = 0;
434	bfOffBits = 0; /* We'll write this when we're done */
435
436	/* Write the BMP file header values */
437	fp_offset = SDL_RWtell(dst);
438	SDL_ClearError();
439	SDL_RWwrite(dst, magic, 2, 1);
440	SDL_WriteLE32(dst, bfSize);
441	SDL_WriteLE16(dst, bfReserved1);
442	SDL_WriteLE16(dst, bfReserved2);
443	SDL_WriteLE32(dst, bfOffBits);
444
445	/* Set the BMP info values */
446	biSize = 40;
447	biWidth = surface->w;
448	biHeight = surface->h;
449	biPlanes = 1;
450	biBitCount = surface->format->BitsPerPixel;
451	biCompression = BI_RGB;
452	biSizeImage = surface->h*surface->pitch;
453	biXPelsPerMeter = 0;
454	biYPelsPerMeter = 0;
455	if ( surface->format->palette ) {
456	biClrUsed = surface->format->palette->ncolors;
457	} else {
458	biClrUsed = 0;
459	}
460	biClrImportant = 0;
461
462	/* Write the BMP info values */
463	SDL_WriteLE32(dst, biSize);
464	SDL_WriteLE32(dst, biWidth);
465	SDL_WriteLE32(dst, biHeight);
466	SDL_WriteLE16(dst, biPlanes);
467	SDL_WriteLE16(dst, biBitCount);
468	SDL_WriteLE32(dst, biCompression);
469	SDL_WriteLE32(dst, biSizeImage);
470	SDL_WriteLE32(dst, biXPelsPerMeter);
471	SDL_WriteLE32(dst, biYPelsPerMeter);
472	SDL_WriteLE32(dst, biClrUsed);
473	SDL_WriteLE32(dst, biClrImportant);
474
475	/* Write the palette (in BGR color order) */
476	if ( surface->format->palette ) {
477	SDL_Color *colors;
478	int ncolors;
479
480	colors = surface->format->palette->colors;
481	ncolors = surface->format->palette->ncolors;
482	for ( i=0; i<ncolors; ++i ) {
483	SDL_RWwrite(dst, &colors[i].b, 1, 1);
484	SDL_RWwrite(dst, &colors[i].g, 1, 1);
485	SDL_RWwrite(dst, &colors[i].r, 1, 1);
486	SDL_RWwrite(dst, &colors[i].unused, 1, 1);
487	}
488	}
489
490	/* Write the bitmap offset */
491	bfOffBits = SDL_RWtell(dst)-fp_offset;
492	if ( SDL_RWseek(dst, fp_offset+10, RW_SEEK_SET) < 0 ) {
493	SDL_Error(SDL_EFSEEK);
494	}
495	SDL_WriteLE32(dst, bfOffBits);
496	if ( SDL_RWseek(dst, fp_offset+bfOffBits, RW_SEEK_SET) < 0 ) {
497	SDL_Error(SDL_EFSEEK);
498	}
499
500	/* Write the bitmap image upside down */
501	bits = (Uint8 )surface->pixels+(surface->hsurface->pitch);
502	pad = ((bw%4) ? (4-(bw%4)) : 0);
503	while ( bits > (Uint8 *)surface->pixels ) {
504	bits -= surface->pitch;
505	if ( SDL_RWwrite(dst, bits, 1, bw) != bw) {
506	SDL_Error(SDL_EFWRITE);
507	break;
508	}
509	if ( pad ) {
510	const Uint8 padbyte = 0;
511	for ( i=0; i<pad; ++i ) {
512	SDL_RWwrite(dst, &padbyte, 1, 1);
513	}
514	}
515	}
516
517	/* Write the BMP file size */
518	bfSize = SDL_RWtell(dst)-fp_offset;
519	if ( SDL_RWseek(dst, fp_offset+2, RW_SEEK_SET) < 0 ) {
520	SDL_Error(SDL_EFSEEK);
521	}
522	SDL_WriteLE32(dst, bfSize);
523	if ( SDL_RWseek(dst, fp_offset+bfSize, RW_SEEK_SET) < 0 ) {
524	SDL_Error(SDL_EFSEEK);
525	}
526
527	/* Close it up.. */
528	SDL_UnlockSurface(surface);
529	if ( surface != saveme ) {
530	SDL_FreeSurface(surface);
531	}
532	}
533
534	if ( freedst && dst ) {
535	SDL_RWclose(dst);
536	}
537	return((SDL_strcmp(SDL_GetError(), "") == 0) ? 0 : -1);
538	}