/
IMG_bmp.c
934 lines (856 loc) · 27.5 KB
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/*
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SDL_image: An example image loading library for use with SDL
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Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
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This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
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*/
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#if (!defined(__APPLE__) || defined(SDL_IMAGE_USE_COMMON_BACKEND)) || !defined(BMP_USES_IMAGEIO)
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/* This is a BMP image file loading framework
*
* ICO/CUR file support is here as well since it uses similar internal
* representation
*
* A good test suite of BMP images is available at:
* http://entropymine.com/jason/bmpsuite/bmpsuite/html/bmpsuite.html
*/
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#include "SDL_image.h"
#ifdef LOAD_BMP
/* See if an image is contained in a data source */
int IMG_isBMP(SDL_RWops *src)
{
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Sint64 start;
int is_BMP;
char magic[2];
if ( !src )
return 0;
start = SDL_RWtell(src);
is_BMP = 0;
if ( SDL_RWread(src, magic, sizeof(magic), 1) ) {
if ( SDL_strncmp(magic, "BM", 2) == 0 ) {
is_BMP = 1;
}
}
SDL_RWseek(src, start, RW_SEEK_SET);
return(is_BMP);
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}
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static int IMG_isICOCUR(SDL_RWops *src, int type)
{
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Sint64 start;
int is_ICOCUR;
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/* The Win32 ICO file header (14 bytes) */
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Uint16 bfReserved;
Uint16 bfType;
Uint16 bfCount;
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if ( !src )
return 0;
start = SDL_RWtell(src);
is_ICOCUR = 0;
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bfReserved = SDL_ReadLE16(src);
bfType = SDL_ReadLE16(src);
bfCount = SDL_ReadLE16(src);
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if ((bfReserved == 0) && (bfType == type) && (bfCount != 0))
is_ICOCUR = 1;
SDL_RWseek(src, start, RW_SEEK_SET);
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return (is_ICOCUR);
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}
int IMG_isICO(SDL_RWops *src)
{
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return IMG_isICOCUR(src, 1);
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}
int IMG_isCUR(SDL_RWops *src)
{
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return IMG_isICOCUR(src, 2);
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}
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#include "SDL_error.h"
#include "SDL_video.h"
#include "SDL_endian.h"
/* Compression encodings for BMP files */
#ifndef BI_RGB
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#define BI_RGB 0
#define BI_RLE8 1
#define BI_RLE4 2
#define BI_BITFIELDS 3
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#endif
static int readRlePixels(SDL_Surface * surface, SDL_RWops * src, int isRle8)
{
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/*
| 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;
}
}
}
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}
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static void CorrectAlphaChannel(SDL_Surface *surface)
{
/* Check to see if there is any alpha channel data */
SDL_bool hasAlpha = SDL_FALSE;
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
int alphaChannelOffset = 0;
#else
int alphaChannelOffset = 3;
#endif
Uint8 *alpha = ((Uint8*)surface->pixels) + alphaChannelOffset;
Uint8 *end = alpha + surface->h * surface->pitch;
while (alpha < end) {
if (*alpha != 0) {
hasAlpha = SDL_TRUE;
break;
}
alpha += 4;
}
if (!hasAlpha) {
alpha = ((Uint8*)surface->pixels) + alphaChannelOffset;
while (alpha < end) {
*alpha = SDL_ALPHA_OPAQUE;
alpha += 4;
}
}
}
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static SDL_Surface *LoadBMP_RW (SDL_RWops *src, int freesrc)
{
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SDL_bool was_error;
Sint64 fp_offset;
int bmpPitch;
int i, pad;
SDL_Surface *surface;
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Uint32 Rmask = 0;
Uint32 Gmask = 0;
Uint32 Bmask = 0;
Uint32 Amask = 0;
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SDL_Palette *palette;
Uint8 *bits;
Uint8 *top, *end;
SDL_bool topDown;
int ExpandBMP;
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SDL_bool haveRGBMasks = SDL_FALSE;
SDL_bool haveAlphaMask = SDL_FALSE;
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SDL_bool correctAlpha = SDL_FALSE;
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/* 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;
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Sint32 biHeight = 0;
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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 ) {
IMG_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);
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if ( biSize == 12 ) { /* really old BITMAPCOREHEADER */
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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;
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} else if (biSize >= 40) { /* some version of BITMAPINFOHEADER */
Uint32 headerSize;
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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);
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/* 64 == BITMAPCOREHEADER2, an incompatible OS/2 2.x extension. Skip this stuff for now. */
if (biSize != 64) {
/* This is complicated. If compression is BI_BITFIELDS, then
we have 3 DWORDS that specify the RGB masks. This is either
stored here in an BITMAPV2INFOHEADER (which only differs in
that it adds these RGB masks) and biSize >= 52, or we've got
these masks stored in the exact same place, but strictly
speaking, this is the bmiColors field in BITMAPINFO immediately
following the legacy v1 info header, just past biSize. */
if (biCompression == BI_BITFIELDS) {
haveRGBMasks = SDL_TRUE;
Rmask = SDL_ReadLE32(src);
Gmask = SDL_ReadLE32(src);
Bmask = SDL_ReadLE32(src);
/* ...v3 adds an alpha mask. */
if (biSize >= 56) { /* BITMAPV3INFOHEADER; adds alpha mask */
haveAlphaMask = SDL_TRUE;
Amask = SDL_ReadLE32(src);
}
} else {
/* the mask fields are ignored for v2+ headers if not BI_BITFIELD. */
if (biSize >= 52) { /* BITMAPV2INFOHEADER; adds RGB masks */
/*Rmask = */ SDL_ReadLE32(src);
/*Gmask = */ SDL_ReadLE32(src);
/*Bmask = */ SDL_ReadLE32(src);
}
if (biSize >= 56) { /* BITMAPV3INFOHEADER; adds alpha mask */
/*Amask = */ SDL_ReadLE32(src);
}
}
/* Insert other fields here; Wikipedia and MSDN say we're up to
v5 of this header, but we ignore those for now (they add gamma,
color spaces, etc). Ignoring the weird OS/2 2.x format, we
currently parse up to v3 correctly (hopefully!). */
}
/* skip any header bytes we didn't handle... */
headerSize = (Uint32) (SDL_RWtell(src) - (fp_offset + 14));
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if (biSize > headerSize) {
SDL_RWseek(src, (biSize - headerSize), RW_SEEK_CUR);
}
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}
if (biHeight < 0) {
topDown = SDL_TRUE;
biHeight = -biHeight;
} else {
topDown = SDL_FALSE;
}
/* Check for read error */
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if (SDL_strcmp(SDL_GetError(), "") != 0) {
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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;
}
/* RLE4 and RLE8 BMP compression is supported */
switch (biCompression) {
case BI_RGB:
/* If there are no masks, use the defaults */
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SDL_assert(!haveRGBMasks);
SDL_assert(!haveAlphaMask);
/* Default values for the BMP format */
switch (biBitCount) {
case 15:
case 16:
Rmask = 0x7C00;
Gmask = 0x03E0;
Bmask = 0x001F;
break;
case 24:
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#if SDL_BYTEORDER == SDL_BIG_ENDIAN
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Rmask = 0x000000FF;
Gmask = 0x0000FF00;
Bmask = 0x00FF0000;
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#else
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Rmask = 0x00FF0000;
Gmask = 0x0000FF00;
Bmask = 0x000000FF;
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#endif
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break;
case 32:
/* We don't know if this has alpha channel or not */
correctAlpha = SDL_TRUE;
Amask = 0xFF000000;
Rmask = 0x00FF0000;
Gmask = 0x0000FF00;
Bmask = 0x000000FF;
break;
default:
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break;
}
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break;
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case BI_BITFIELDS:
break; /* we handled this in the info header. */
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default:
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break;
}
/* Create a compatible surface, note that the colors are RGB ordered */
surface = SDL_CreateRGBSurface(SDL_SWSURFACE,
biWidth, biHeight, biBitCount, Rmask, Gmask, Bmask, Amask);
if ( surface == NULL ) {
was_error = SDL_TRUE;
goto done;
}
/* Load the palette, if any */
palette = (surface->format)->palette;
if ( palette ) {
if ( SDL_RWseek(src, fp_offset+14+biSize, RW_SEEK_SET) < 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;
/* } */
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].a = SDL_ALPHA_OPAQUE;
}
} 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].a, 1, 1);
/* According to Microsoft documentation, the fourth element
is reserved and must be zero, so we shouldn't treat it as
alpha.
*/
palette->colors[i].a = SDL_ALPHA_OPAQUE;
}
}
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;
}
if ((biCompression == BI_RLE4) || (biCompression == BI_RLE8)) {
was_error = (SDL_bool)readRlePixels(surface, src, biCompression == BI_RLE8);
if (was_error) IMG_SetError("Error reading from BMP");
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) ) {
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IMG_SetError("Error reading from BMP");
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was_error = SDL_TRUE;
goto done;
}
}
*(bits+i) = (pixel>>shift);
pixel <<= ExpandBMP;
} }
break;
default:
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if ( SDL_RWread(src, bits, 1, surface->pitch) != surface->pitch ) {
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SDL_Error(SDL_EFREAD);
was_error = SDL_TRUE;
goto done;
}
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#if SDL_BYTEORDER == SDL_BIG_ENDIAN
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/* Byte-swap the pixels if needed. Note that the 24bpp
case has already been taken care of above. */
switch(biBitCount) {
case 15:
case 16: {
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Uint16 *pix = (Uint16 *)bits;
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for(i = 0; i < surface->w; i++)
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pix[i] = SDL_Swap16(pix[i]);
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break;
}
case 32: {
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Uint32 *pix = (Uint32 *)bits;
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for(i = 0; i < surface->w; i++)
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pix[i] = SDL_Swap32(pix[i]);
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break;
}
}
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#endif
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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;
}
}
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if (correctAlpha) {
CorrectAlphaChannel(surface);
}
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done:
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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);
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}
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static Uint8
SDL_Read8(SDL_RWops * src)
{
Uint8 value;
SDL_RWread(src, &value, 1, 1);
return (value);
}
static SDL_Surface *
LoadICOCUR_RW(SDL_RWops * src, int type, int freesrc)
{
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SDL_bool was_error;
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Sint64 fp_offset;
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int bmpPitch;
int i, pad;
SDL_Surface *surface;
Uint32 Rmask;
Uint32 Gmask;
Uint32 Bmask;
Uint8 *bits;
int ExpandBMP;
int maxCol = 0;
int icoOfs = 0;
Uint32 palette[256];
/* The Win32 ICO file header (14 bytes) */
Uint16 bfReserved;
Uint16 bfType;
Uint16 bfCount;
/* 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;
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was_error = SDL_FALSE;
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if (src == NULL) {
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was_error = SDL_TRUE;
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goto done;
}
/* Read in the ICO file header */
fp_offset = SDL_RWtell(src);
SDL_ClearError();
bfReserved = SDL_ReadLE16(src);
bfType = SDL_ReadLE16(src);
bfCount = SDL_ReadLE16(src);
if ((bfReserved != 0) || (bfType != type) || (bfCount == 0)) {
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IMG_SetError("File is not a Windows %s file", type == 1 ? "ICO" : "CUR");
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was_error = SDL_TRUE;
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646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
goto done;
}
/* Read the Win32 Icon Directory */
for (i = 0; i < bfCount; i++) {
/* Icon Directory Entries */
int bWidth = SDL_Read8(src); /* Uint8, but 0 = 256 ! */
int bHeight = SDL_Read8(src); /* Uint8, but 0 = 256 ! */
int bColorCount = SDL_Read8(src); /* Uint8, but 0 = 256 ! */
Uint8 bReserved = SDL_Read8(src);
Uint16 wPlanes = SDL_ReadLE16(src);
Uint16 wBitCount = SDL_ReadLE16(src);
Uint32 dwBytesInRes = SDL_ReadLE32(src);
Uint32 dwImageOffset = SDL_ReadLE32(src);
if (!bWidth)
bWidth = 256;
if (!bHeight)
bHeight = 256;
if (!bColorCount)
bColorCount = 256;
//printf("%dx%d@%d - %08x\n", bWidth, bHeight, bColorCount, dwImageOffset);
if (bColorCount > maxCol) {
maxCol = bColorCount;
icoOfs = dwImageOffset;
//printf("marked\n");
}
}
/* Advance to the DIB Data */
if (SDL_RWseek(src, icoOfs, RW_SEEK_SET) < 0) {
SDL_Error(SDL_EFSEEK);
678
was_error = SDL_TRUE;
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
goto done;
}
/* Read the Win32 BITMAPINFOHEADER */
biSize = SDL_ReadLE32(src);
if (biSize == 40) {
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);
} else {
696
IMG_SetError("Unsupported ICO bitmap format");
697
was_error = SDL_TRUE;
698
699
700
701
702
goto done;
}
/* Check for read error */
if (SDL_strcmp(SDL_GetError(), "") != 0) {
703
was_error = SDL_TRUE;
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
goto done;
}
/* We don't support any BMP compression right now */
switch (biCompression) {
case BI_RGB:
/* Default values for the BMP format */
switch (biBitCount) {
case 1:
case 4:
ExpandBMP = biBitCount;
biBitCount = 8;
break;
case 8:
ExpandBMP = 8;
break;
case 32:
Rmask = 0x00FF0000;
Gmask = 0x0000FF00;
Bmask = 0x000000FF;
ExpandBMP = 0;
break;
default:
727
IMG_SetError("ICO file with unsupported bit count");
728
was_error = SDL_TRUE;
729
730
731
732
goto done;
}
break;
default:
733
IMG_SetError("Compressed ICO files not supported");
734
was_error = SDL_TRUE;
735
736
737
goto done;
}
738
739
740
741
742
743
744
745
/* sanity check image size, so we don't overflow integers, etc. */
if ((biWidth < 0) || (biWidth > 0xFFFFFF) ||
(biHeight < 0) || (biHeight > 0xFFFFFF)) {
IMG_SetError("Unsupported or invalid ICO dimensions");
was_error = SDL_TRUE;
goto done;
}
746
747
748
749
750
751
752
/* Create a RGBA surface */
biHeight = biHeight >> 1;
//printf("%d x %d\n", biWidth, biHeight);
surface =
SDL_CreateRGBSurface(0, biWidth, biHeight, 32, 0x00FF0000,
0x0000FF00, 0x000000FF, 0xFF000000);
if (surface == NULL) {
753
was_error = SDL_TRUE;
754
755
756
757
758
759
760
761
762
goto done;
}
/* Load the palette, if any */
//printf("bc %d bused %d\n", biBitCount, biClrUsed);
if (biBitCount <= 8) {
if (biClrUsed == 0) {
biClrUsed = 1 << biBitCount;
}
763
764
765
766
767
if (biClrUsed > SDL_arraysize(palette)) {
IMG_SetError("Unsupported or incorrect biClrUsed field");
was_error = SDL_TRUE;
goto done;
}
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
for (i = 0; i < (int) biClrUsed; ++i) {
SDL_RWread(src, &palette[i], 4, 1);
}
}
/* Read the surface pixels. Note that the bmp image is upside down */
bits = (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;
case 8:
bmpPitch = biWidth;
pad = (((bmpPitch) % 4) ? (4 - ((bmpPitch) % 4)) : 0);
break;
default:
bmpPitch = biWidth * 4;
pad = 0;
break;
}
while (bits > (Uint8 *) surface->pixels) {
bits -= surface->pitch;
switch (ExpandBMP) {
case 1:
case 4:
case 8:
{
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)) {
805
IMG_SetError("Error reading from ICO");
806
was_error = SDL_TRUE;
807
808
809
810
811
812
813
814
815
816
817
818
819
goto done;
}
}
*((Uint32 *) bits + i) = (palette[pixel >> shift]);
pixel <<= ExpandBMP;
}
}
break;
default:
if (SDL_RWread(src, bits, 1, surface->pitch)
!= surface->pitch) {
SDL_Error(SDL_EFREAD);
820
was_error = SDL_TRUE;
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
goto done;
}
break;
}
/* Skip padding bytes, ugh */
if (pad) {
Uint8 padbyte;
for (i = 0; i < pad; ++i) {
SDL_RWread(src, &padbyte, 1, 1);
}
}
}
/* Read the mask pixels. Note that the bmp image is upside down */
bits = (Uint8 *) surface->pixels + (surface->h * surface->pitch);
ExpandBMP = 1;
bmpPitch = (biWidth + 7) >> 3;
pad = (((bmpPitch) % 4) ? (4 - ((bmpPitch) % 4)) : 0);
while (bits > (Uint8 *) surface->pixels) {
Uint8 pixel = 0;
int shift = (8 - ExpandBMP);
bits -= surface->pitch;
for (i = 0; i < surface->w; ++i) {
if (i % (8 / ExpandBMP) == 0) {
if (!SDL_RWread(src, &pixel, 1, 1)) {
846
IMG_SetError("Error reading from ICO");
847
was_error = SDL_TRUE;
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
goto done;
}
}
*((Uint32 *) bits + i) |= ((pixel >> shift) ? 0 : 0xFF000000);
pixel <<= ExpandBMP;
}
/* Skip padding bytes, ugh */
if (pad) {
Uint8 padbyte;
for (i = 0; i < pad; ++i) {
SDL_RWread(src, &padbyte, 1, 1);
}
}
}
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);
}
878
879
880
/* Load a BMP type image from an SDL datasource */
SDL_Surface *IMG_LoadBMP_RW(SDL_RWops *src)
{
881
return(LoadBMP_RW(src, 0));
882
883
}
884
885
886
/* Load a ICO type image from an SDL datasource */
SDL_Surface *IMG_LoadICO_RW(SDL_RWops *src)
{
887
return(LoadICOCUR_RW(src, 1, 0));
888
889
890
891
892
}
/* Load a CUR type image from an SDL datasource */
SDL_Surface *IMG_LoadCUR_RW(SDL_RWops *src)
{
893
return(LoadICOCUR_RW(src, 2, 0));
894
895
}
896
897
898
899
900
#else
/* See if an image is contained in a data source */
int IMG_isBMP(SDL_RWops *src)
{
901
return(0);
902
903
}
904
905
int IMG_isICO(SDL_RWops *src)
{
906
return(0);
907
908
909
910
}
int IMG_isCUR(SDL_RWops *src)
{
911
return(0);
912
913
}
914
915
916
/* Load a BMP type image from an SDL datasource */
SDL_Surface *IMG_LoadBMP_RW(SDL_RWops *src)
{
917
return(NULL);
918
919
}
920
921
922
/* Load a BMP type image from an SDL datasource */
SDL_Surface *IMG_LoadCUR_RW(SDL_RWops *src)
{
923
return(NULL);
924
925
926
927
928
}
/* Load a BMP type image from an SDL datasource */
SDL_Surface *IMG_LoadICO_RW(SDL_RWops *src)
{
929
return(NULL);
930
931
}
932
#endif /* LOAD_BMP */
933
934
#endif /* !defined(__APPLE__) || defined(SDL_IMAGE_USE_COMMON_BACKEND) */