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LoadBMP: use code from SDL_image which allows loading compressed BMP files

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This commit is contained in:
Sylvain Becker 2019-08-31 22:52:15 +02:00
parent cc64b369fb
commit 830979c555
1 changed files with 278 additions and 204 deletions
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286
src/video/SDL_bmp.c
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@ -54,6 +54,92 @@
#define LCS_WINDOWS_COLOR_SPACE 0x57696E20 #define LCS_WINDOWS_COLOR_SPACE 0x57696E20
#endif #endif
static int readRlePixels(SDL_Surface * surface, SDL_RWops * src, int isRle8)
{
/*
| Sets the surface pixels from src. A bmp image is upside down.
*/
int pitch = surface->pitch;
int height = surface->h;
Uint8 *start = (Uint8 *)surface->pixels;
Uint8 *end = start + (height*pitch);
Uint8 *bits = end-pitch, *spot;
int ofs = 0;
Uint8 ch;
Uint8 needsPad;
#define COPY_PIXEL(x) spot = &bits[ofs++]; if(spot >= start && spot < end) *spot = (x)
for (;;) {
if ( !SDL_RWread(src, &ch, 1, 1) ) return 1;
/*
| encoded mode starts with a run length, and then a byte
| with two colour indexes to alternate between for the run
*/
if ( ch ) {
Uint8 pixel;
if ( !SDL_RWread(src, &pixel, 1, 1) ) return 1;
if ( isRle8 ) { /* 256-color bitmap, compressed */
do {
COPY_PIXEL(pixel);
} while (--ch);
} else { /* 16-color bitmap, compressed */
Uint8 pixel0 = pixel >> 4;
Uint8 pixel1 = pixel & 0x0F;
for (;;) {
COPY_PIXEL(pixel0); /* even count, high nibble */
if (!--ch) break;
COPY_PIXEL(pixel1); /* odd count, low nibble */
if (!--ch) break;
}
}
} else {
/*
| A leading zero is an escape; it may signal the end of the bitmap,
| a cursor move, or some absolute data.
| zero tag may be absolute mode or an escape
*/
if ( !SDL_RWread(src, &ch, 1, 1) ) return 1;
switch (ch) {
case 0: /* end of line */
ofs = 0;
bits -= pitch; /* go to previous */
break;
case 1: /* end of bitmap */
return 0; /* success! */
case 2: /* delta */
if ( !SDL_RWread(src, &ch, 1, 1) ) return 1;
ofs += ch;
if ( !SDL_RWread(src, &ch, 1, 1) ) return 1;
bits -= (ch * pitch);
break;
default: /* no compression */
if (isRle8) {
needsPad = ( ch & 1 );
do {
Uint8 pixel;
if ( !SDL_RWread(src, &pixel, 1, 1) ) return 1;
COPY_PIXEL(pixel);
} while (--ch);
} else {
needsPad = ( ((ch+1)>>1) & 1 ); /* (ch+1)>>1: bytes size */
for (;;) {
Uint8 pixel;
if ( !SDL_RWread(src, &pixel, 1, 1) ) return 1;
COPY_PIXEL(pixel >> 4);
if (!--ch) break;
COPY_PIXEL(pixel & 0x0F);
if (!--ch) break;
}
}
/* pad at even boundary */
if ( needsPad && !SDL_RWread(src, &ch, 1, 1) ) return 1;
break;
}
}
}
}
static void CorrectAlphaChannel(SDL_Surface *surface) static void CorrectAlphaChannel(SDL_Surface *surface)
{ {
/* Check to see if there is any alpha channel data */ /* Check to see if there is any alpha channel data */
@ -87,7 +173,7 @@ SDL_Surface *
SDL_LoadBMP_RW(SDL_RWops * src, int freesrc) SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
{ {
SDL_bool was_error; SDL_bool was_error;
Sint64 fp_offset = 0; Sint64 fp_offset;
int bmpPitch; int bmpPitch;
int i, pad; int i, pad;
SDL_Surface *surface; SDL_Surface *surface;
@ -106,31 +192,28 @@ SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
/* The Win32 BMP file header (14 bytes) */ /* The Win32 BMP file header (14 bytes) */
char magic[2]; char magic[2];
/* Uint32 bfSize = 0; */ Uint32 bfSize;
/* Uint16 bfReserved1 = 0; */ Uint16 bfReserved1;
/* Uint16 bfReserved2 = 0; */ Uint16 bfReserved2;
Uint32 bfOffBits = 0; Uint32 bfOffBits;
/* The Win32 BITMAPINFOHEADER struct (40 bytes) */ /* The Win32 BITMAPINFOHEADER struct (40 bytes) */
Uint32 biSize = 0; Uint32 biSize;
Sint32 biWidth = 0; Sint32 biWidth;
Sint32 biHeight = 0; Sint32 biHeight = 0;
/* Uint16 biPlanes = 0; */ Uint16 biPlanes;
Uint16 biBitCount = 0; Uint16 biBitCount;
Uint32 biCompression = 0; Uint32 biCompression;
/* Uint32 biSizeImage = 0; */ Uint32 biSizeImage;
/* Sint32 biXPelsPerMeter = 0; */ Sint32 biXPelsPerMeter;
/* Sint32 biYPelsPerMeter = 0; */ Sint32 biYPelsPerMeter;
Uint32 biClrUsed = 0; Uint32 biClrUsed;
/* Uint32 biClrImportant = 0; */ Uint32 biClrImportant;
(void) haveRGBMasks;
(void) haveAlphaMask;
/* Make sure we are passed a valid data source */ /* Make sure we are passed a valid data source */
surface = NULL; surface = NULL;
was_error = SDL_FALSE; was_error = SDL_FALSE;
if (src == NULL) { if ( src == NULL ) {
was_error = SDL_TRUE; was_error = SDL_TRUE;
goto done; goto done;
} }
@ -138,52 +221,49 @@ SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
/* Read in the BMP file header */ /* Read in the BMP file header */
fp_offset = SDL_RWtell(src); fp_offset = SDL_RWtell(src);
SDL_ClearError(); SDL_ClearError();
if (SDL_RWread(src, magic, 1, 2) != 2) { if ( SDL_RWread(src, magic, 1, 2) != 2 ) {
SDL_Error(SDL_EFREAD); SDL_Error(SDL_EFREAD);
was_error = SDL_TRUE; was_error = SDL_TRUE;
goto done; goto done;
} }
if (SDL_strncmp(magic, "BM", 2) != 0) { if ( SDL_strncmp(magic, "BM", 2) != 0 ) {
SDL_SetError("File is not a Windows BMP file"); SDL_SetError("File is not a Windows BMP file");
was_error = SDL_TRUE; was_error = SDL_TRUE;
goto done; goto done;
} }
/* bfSize = */ SDL_ReadLE32(src); bfSize = SDL_ReadLE32(src);
/* bfReserved1 = */ SDL_ReadLE16(src); bfReserved1 = SDL_ReadLE16(src);
/* bfReserved2 = */ SDL_ReadLE16(src); bfReserved2 = SDL_ReadLE16(src);
bfOffBits = SDL_ReadLE32(src); bfOffBits = SDL_ReadLE32(src);
/* Read the Win32 BITMAPINFOHEADER */ /* Read the Win32 BITMAPINFOHEADER */
biSize = SDL_ReadLE32(src); biSize = SDL_ReadLE32(src);
if (biSize == 12) { /* really old BITMAPCOREHEADER */ if ( biSize == 12 ) { /* really old BITMAPCOREHEADER */
biWidth = (Uint32) SDL_ReadLE16(src); biWidth = (Uint32)SDL_ReadLE16(src);
biHeight = (Uint32) SDL_ReadLE16(src); biHeight = (Uint32)SDL_ReadLE16(src);
/* biPlanes = */ SDL_ReadLE16(src); biPlanes = SDL_ReadLE16(src);
biBitCount = SDL_ReadLE16(src); biBitCount = SDL_ReadLE16(src);
biCompression = BI_RGB; biCompression = BI_RGB;
biSizeImage = 0;
biXPelsPerMeter = 0;
biYPelsPerMeter = 0;
biClrUsed = 0;
biClrImportant = 0;
} else if (biSize >= 40) { /* some version of BITMAPINFOHEADER */ } else if (biSize >= 40) { /* some version of BITMAPINFOHEADER */
Uint32 headerSize; Uint32 headerSize;
biWidth = SDL_ReadLE32(src); biWidth = SDL_ReadLE32(src);
biHeight = SDL_ReadLE32(src); biHeight = SDL_ReadLE32(src);
/* biPlanes = */ SDL_ReadLE16(src); biPlanes = SDL_ReadLE16(src);
biBitCount = SDL_ReadLE16(src); biBitCount = SDL_ReadLE16(src);
biCompression = SDL_ReadLE32(src); biCompression = SDL_ReadLE32(src);
/* biSizeImage = */ SDL_ReadLE32(src); biSizeImage = SDL_ReadLE32(src);
/* biXPelsPerMeter = */ SDL_ReadLE32(src); biXPelsPerMeter = SDL_ReadLE32(src);
/* biYPelsPerMeter = */ SDL_ReadLE32(src); biYPelsPerMeter = SDL_ReadLE32(src);
biClrUsed = SDL_ReadLE32(src); biClrUsed = SDL_ReadLE32(src);
/* biClrImportant = */ SDL_ReadLE32(src); biClrImportant = SDL_ReadLE32(src);
/* 64 == BITMAPCOREHEADER2, an incompatible OS/2 2.x extension. Skip this stuff for now. */ /* 64 == BITMAPCOREHEADER2, an incompatible OS/2 2.x extension. Skip this stuff for now. */
if (biSize == 64) { if (biSize != 64) {
/* ignore these extra fields. */
if (biCompression == BI_BITFIELDS) {
/* this value is actually huffman compression in this variant. */
SDL_SetError("Compressed BMP files not supported");
was_error = SDL_TRUE;
goto done;
}
} else {
/* This is complicated. If compression is BI_BITFIELDS, then /* This is complicated. If compression is BI_BITFIELDS, then
we have 3 DWORDS that specify the RGB masks. This is either we have 3 DWORDS that specify the RGB masks. This is either
stored here in an BITMAPV2INFOHEADER (which only differs in stored here in an BITMAPV2INFOHEADER (which only differs in
@ -264,7 +344,7 @@ SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
break; break;
} }
/* We don't support any BMP compression right now */ /* RLE4 and RLE8 BMP compression is supported */
switch (biCompression) { switch (biCompression) {
case BI_RGB: case BI_RGB:
/* If there are no masks, use the defaults */ /* If there are no masks, use the defaults */
@ -306,57 +386,42 @@ SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
break; /* we handled this in the info header. */ break; /* we handled this in the info header. */
default: default:
SDL_SetError("Compressed BMP files not supported"); break;
was_error = SDL_TRUE;
goto done;
} }
/* Create a compatible surface, note that the colors are RGB ordered */ /* Create a compatible surface, note that the colors are RGB ordered */
surface = surface = SDL_CreateRGBSurface(SDL_SWSURFACE,
SDL_CreateRGBSurface(0, biWidth, biHeight, biBitCount, Rmask, Gmask, biWidth, biHeight, biBitCount, Rmask, Gmask, Bmask, Amask);
Bmask, Amask); if ( surface == NULL ) {
if (surface == NULL) {
was_error = SDL_TRUE; was_error = SDL_TRUE;
goto done; goto done;
} }
/* Load the palette, if any */ /* Load the palette, if any */
palette = (surface->format)->palette; palette = (surface->format)->palette;
if (palette) { if ( palette ) {
SDL_assert(biBitCount <= 8); if ( SDL_RWseek(src, fp_offset+14+biSize, RW_SEEK_SET) < 0 ) {
if (biClrUsed == 0) { SDL_Error(SDL_EFSEEK);
was_error = SDL_TRUE;
goto done;
}
/*
| guich: always use 1<<bpp b/c some bitmaps can bring wrong information
| for colorsUsed
*/
/* if ( biClrUsed == 0 ) { */
biClrUsed = 1 << biBitCount; biClrUsed = 1 << biBitCount;
} else if (biClrUsed > (Uint32)(1 << biBitCount)) { /* } */
SDL_SetError("BMP file has an invalid number of colors"); if ( biSize == 12 ) {
was_error = SDL_TRUE; for ( i = 0; i < (int)biClrUsed; ++i ) {
goto done;
}
if ((int) biClrUsed > palette->ncolors) {
SDL_Color *colors;
int ncolors = biClrUsed;
colors =
(SDL_Color *) SDL_realloc(palette->colors,
ncolors *
sizeof(*palette->colors));
if (!colors) {
SDL_OutOfMemory();
was_error = SDL_TRUE;
goto done;
}
palette->ncolors = ncolors;
palette->colors = colors;
} else if ((int) biClrUsed < palette->ncolors) {
palette->ncolors = biClrUsed;
}
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].b, 1, 1);
SDL_RWread(src, &palette->colors[i].g, 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].r, 1, 1);
palette->colors[i].a = SDL_ALPHA_OPAQUE; palette->colors[i].a = SDL_ALPHA_OPAQUE;
} }
} else { } else {
for (i = 0; i < (int) biClrUsed; ++i) { for ( i = 0; i < (int)biClrUsed; ++i ) {
SDL_RWread(src, &palette->colors[i].b, 1, 1); SDL_RWread(src, &palette->colors[i].b, 1, 1);
SDL_RWread(src, &palette->colors[i].g, 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].r, 1, 1);
@ -369,43 +434,50 @@ SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
palette->colors[i].a = SDL_ALPHA_OPAQUE; palette->colors[i].a = SDL_ALPHA_OPAQUE;
} }
} }
palette->ncolors = biClrUsed;
} }
/* Read the surface pixels. Note that the bmp image is upside down */ /* Read the surface pixels. Note that the bmp image is upside down */
if (SDL_RWseek(src, fp_offset + bfOffBits, RW_SEEK_SET) < 0) { if ( SDL_RWseek(src, fp_offset+bfOffBits, RW_SEEK_SET) < 0 ) {
SDL_Error(SDL_EFSEEK); SDL_Error(SDL_EFSEEK);
was_error = SDL_TRUE; was_error = SDL_TRUE;
goto done; goto done;
} }
if ((biCompression == BI_RLE4) || (biCompression == BI_RLE8)) {
was_error = (SDL_bool)readRlePixels(surface, src, biCompression == BI_RLE8);
if (was_error) SDL_SetError("Error reading from BMP");
goto done;
}
top = (Uint8 *)surface->pixels; top = (Uint8 *)surface->pixels;
end = (Uint8 *)surface->pixels+(surface->h*surface->pitch); end = (Uint8 *)surface->pixels+(surface->h*surface->pitch);
switch (ExpandBMP) { switch (ExpandBMP) {
case 1: case 1:
bmpPitch = (biWidth + 7) >> 3; bmpPitch = (biWidth + 7) >> 3;
pad = (((bmpPitch) % 4) ? (4 - ((bmpPitch) % 4)) : 0); pad = (((bmpPitch)%4) ? (4-((bmpPitch)%4)) : 0);
break; break;
case 4: case 4:
bmpPitch = (biWidth + 1) >> 1; bmpPitch = (biWidth + 1) >> 1;
pad = (((bmpPitch) % 4) ? (4 - ((bmpPitch) % 4)) : 0); pad = (((bmpPitch)%4) ? (4-((bmpPitch)%4)) : 0);
break; break;
default: default:
pad = ((surface->pitch % 4) ? (4 - (surface->pitch % 4)) : 0); pad = ((surface->pitch%4) ?
(4-(surface->pitch%4)) : 0);
break; break;
} }
if (topDown) { if ( topDown ) {
bits = top; bits = top;
} else { } else {
bits = end - surface->pitch; bits = end - surface->pitch;
} }
while (bits >= top && bits < end) { while ( bits >= top && bits < end ) {
switch (ExpandBMP) { switch (ExpandBMP) {
case 1: case 1:
case 4:{ case 4: {
Uint8 pixel = 0; Uint8 pixel = 0;
int shift = (8 - ExpandBMP); int shift = (8-ExpandBMP);
for (i = 0; i < surface->w; ++i) { for ( i=0; i<surface->w; ++i ) {
if (i % (8 / ExpandBMP) == 0) { if ( i%(8/ExpandBMP) == 0 ) {
if (!SDL_RWread(src, &pixel, 1, 1)) { if ( !SDL_RWread(src, &pixel, 1, 1) ) {
SDL_SetError("Error reading from BMP"); SDL_SetError("Error reading from BMP");
was_error = SDL_TRUE; was_error = SDL_TRUE;
goto done; goto done;
@ -423,12 +495,12 @@ SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
break; break;
default: default:
if (SDL_RWread(src, bits, 1, surface->pitch) != surface->pitch) { if ( SDL_RWread(src, bits, 1, surface->pitch) != surface->pitch ) {
SDL_Error(SDL_EFREAD); SDL_Error(SDL_EFREAD);
was_error = SDL_TRUE; was_error = SDL_TRUE;
goto done; goto done;
} }
if (biBitCount == 8 && palette && biClrUsed < (Uint32)(1 << biBitCount)) { if (biBitCount == 8 && palette && biClrUsed < (1 << biBitCount)) {
for (i = 0; i < surface->w; ++i) { for (i = 0; i < surface->w; ++i) {
if (bits[i] >= biClrUsed) { if (bits[i] >= biClrUsed) {
SDL_SetError("A BMP image contains a pixel with a color out of the palette"); SDL_SetError("A BMP image contains a pixel with a color out of the palette");
@ -440,18 +512,18 @@ SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
#if SDL_BYTEORDER == SDL_BIG_ENDIAN #if SDL_BYTEORDER == SDL_BIG_ENDIAN
/* Byte-swap the pixels if needed. Note that the 24bpp /* Byte-swap the pixels if needed. Note that the 24bpp
case has already been taken care of above. */ case has already been taken care of above. */
switch (biBitCount) { switch(biBitCount) {
case 15: case 15:
case 16:{ case 16: {
Uint16 *pix = (Uint16 *) bits; Uint16 *pix = (Uint16 *)bits;
for (i = 0; i < surface->w; i++) for(i = 0; i < surface->w; i++)
pix[i] = SDL_Swap16(pix[i]); pix[i] = SDL_Swap16(pix[i]);
break; break;
} }
case 32:{ case 32: {
Uint32 *pix = (Uint32 *) bits; Uint32 *pix = (Uint32 *)bits;
for (i = 0; i < surface->w; i++) for(i = 0; i < surface->w; i++)
pix[i] = SDL_Swap32(pix[i]); pix[i] = SDL_Swap32(pix[i]);
break; break;
} }
@ -460,13 +532,13 @@ SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
break; break;
} }
/* Skip padding bytes, ugh */ /* Skip padding bytes, ugh */
if (pad) { if ( pad ) {
Uint8 padbyte; Uint8 padbyte;
for (i = 0; i < pad; ++i) { for ( i=0; i<pad; ++i ) {
SDL_RWread(src, &padbyte, 1, 1); SDL_RWread(src, &padbyte, 1, 1);
} }
} }
if (topDown) { if ( topDown ) {
bits += surface->pitch; bits += surface->pitch;
} else { } else {
bits -= surface->pitch; bits -= surface->pitch;
@ -475,18 +547,20 @@ SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
if (correctAlpha) { if (correctAlpha) {
CorrectAlphaChannel(surface); CorrectAlphaChannel(surface);
} }
done: done:
if (was_error) { if ( was_error ) {
if (src) { if ( src ) {
SDL_RWseek(src, fp_offset, RW_SEEK_SET); SDL_RWseek(src, fp_offset, RW_SEEK_SET);
} }
if ( surface ) {
SDL_FreeSurface(surface); SDL_FreeSurface(surface);
}
surface = NULL; surface = NULL;
} }
if (freesrc && src) { if ( freesrc && src ) {
SDL_RWclose(src); SDL_RWclose(src);
} }
return (surface); return(surface);
} }
int int