mirror of https://github.com/encounter/SDL.git
808 lines
26 KiB
C
808 lines
26 KiB
C
/*
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Simple DirectMedia Layer
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Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>
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This software is provided 'as-is', without any express or implied
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warranty. In no event will the authors be held liable for any damages
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arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely, subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software
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in a product, an acknowledgment in the product documentation would be
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appreciated but is not required.
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2. Altered source versions must be plainly marked as such, and must not be
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misrepresented as being the original software.
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3. This notice may not be removed or altered from any source distribution.
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*/
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#include "../SDL_internal.h"
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/*
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Code to load and save surfaces in Windows BMP format.
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Why support BMP format? Well, it's a native format for Windows, and
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most image processing programs can read and write it. It would be nice
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to be able to have at least one image format that we can natively load
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and save, and since PNG is so complex that it would bloat the library,
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BMP is a good alternative.
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This code currently supports Win32 DIBs in uncompressed 8 and 24 bpp.
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*/
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#include "SDL_hints.h"
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#include "SDL_video.h"
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#include "SDL_assert.h"
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#include "SDL_endian.h"
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#include "SDL_pixels_c.h"
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#define SAVE_32BIT_BMP
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/* Compression encodings for BMP files */
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#ifndef BI_RGB
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#define BI_RGB 0
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#define BI_RLE8 1
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#define BI_RLE4 2
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#define BI_BITFIELDS 3
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#endif
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/* Logical color space values for BMP files */
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#ifndef LCS_WINDOWS_COLOR_SPACE
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/* 0x57696E20 == "Win " */
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#define LCS_WINDOWS_COLOR_SPACE 0x57696E20
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#endif
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static int readRlePixels(SDL_Surface * surface, SDL_RWops * src, int isRle8)
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{
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/*
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| Sets the surface pixels from src. A bmp image is upside down.
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*/
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int pitch = surface->pitch;
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int height = surface->h;
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Uint8 *start = (Uint8 *)surface->pixels;
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Uint8 *end = start + (height*pitch);
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Uint8 *bits = end-pitch, *spot;
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int ofs = 0;
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Uint8 ch;
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Uint8 needsPad;
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#define COPY_PIXEL(x) spot = &bits[ofs++]; if(spot >= start && spot < end) *spot = (x)
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for (;;) {
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if (!SDL_RWread(src, &ch, 1, 1)) return 1;
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/*
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| encoded mode starts with a run length, and then a byte
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| with two colour indexes to alternate between for the run
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*/
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if (ch) {
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Uint8 pixel;
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if (!SDL_RWread(src, &pixel, 1, 1)) return 1;
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if (isRle8) { /* 256-color bitmap, compressed */
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do {
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COPY_PIXEL(pixel);
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} while (--ch);
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} else { /* 16-color bitmap, compressed */
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Uint8 pixel0 = pixel >> 4;
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Uint8 pixel1 = pixel & 0x0F;
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for (;;) {
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COPY_PIXEL(pixel0); /* even count, high nibble */
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if (!--ch) break;
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COPY_PIXEL(pixel1); /* odd count, low nibble */
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if (!--ch) break;
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}
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}
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} else {
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/*
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| A leading zero is an escape; it may signal the end of the bitmap,
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| a cursor move, or some absolute data.
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| zero tag may be absolute mode or an escape
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*/
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if (!SDL_RWread(src, &ch, 1, 1)) return 1;
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switch (ch) {
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case 0: /* end of line */
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ofs = 0;
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bits -= pitch; /* go to previous */
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break;
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case 1: /* end of bitmap */
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return 0; /* success! */
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case 2: /* delta */
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if (!SDL_RWread(src, &ch, 1, 1)) return 1;
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ofs += ch;
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if (!SDL_RWread(src, &ch, 1, 1)) return 1;
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bits -= (ch * pitch);
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break;
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default: /* no compression */
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if (isRle8) {
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needsPad = (ch & 1);
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do {
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Uint8 pixel;
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if (!SDL_RWread(src, &pixel, 1, 1)) return 1;
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COPY_PIXEL(pixel);
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} while (--ch);
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} else {
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needsPad = (((ch+1)>>1) & 1); /* (ch+1)>>1: bytes size */
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for (;;) {
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Uint8 pixel;
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if (!SDL_RWread(src, &pixel, 1, 1)) return 1;
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COPY_PIXEL(pixel >> 4);
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if (!--ch) break;
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COPY_PIXEL(pixel & 0x0F);
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if (!--ch) break;
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}
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}
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/* pad at even boundary */
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if (needsPad && !SDL_RWread(src, &ch, 1, 1)) return 1;
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break;
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}
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}
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}
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}
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static void CorrectAlphaChannel(SDL_Surface *surface)
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{
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/* Check to see if there is any alpha channel data */
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SDL_bool hasAlpha = SDL_FALSE;
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#if SDL_BYTEORDER == SDL_BIG_ENDIAN
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int alphaChannelOffset = 0;
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#else
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int alphaChannelOffset = 3;
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#endif
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Uint8 *alpha = ((Uint8*)surface->pixels) + alphaChannelOffset;
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Uint8 *end = alpha + surface->h * surface->pitch;
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while (alpha < end) {
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if (*alpha != 0) {
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hasAlpha = SDL_TRUE;
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break;
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}
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alpha += 4;
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}
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if (!hasAlpha) {
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alpha = ((Uint8*)surface->pixels) + alphaChannelOffset;
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while (alpha < end) {
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*alpha = SDL_ALPHA_OPAQUE;
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alpha += 4;
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}
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}
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}
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SDL_Surface *
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SDL_LoadBMP_RW(SDL_RWops * src, int freesrc)
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{
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SDL_bool was_error;
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Sint64 fp_offset = 0;
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int bmpPitch;
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int i, pad;
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SDL_Surface *surface;
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Uint32 Rmask = 0;
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Uint32 Gmask = 0;
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Uint32 Bmask = 0;
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Uint32 Amask = 0;
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SDL_Palette *palette;
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Uint8 *bits;
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Uint8 *top, *end;
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SDL_bool topDown;
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int ExpandBMP;
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SDL_bool haveRGBMasks = SDL_FALSE;
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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) */
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char magic[2];
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/* Uint32 bfSize; */
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/* Uint16 bfReserved1; */
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/* Uint16 bfReserved2; */
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Uint32 bfOffBits;
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/* The Win32 BITMAPINFOHEADER struct (40 bytes) */
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Uint32 biSize;
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Sint32 biWidth = 0;
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Sint32 biHeight = 0;
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/* Uint16 biPlanes; */
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Uint16 biBitCount = 0;
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Uint32 biCompression = 0;
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/* Uint32 biSizeImage; */
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/* Sint32 biXPelsPerMeter; */
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/* Sint32 biYPelsPerMeter; */
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Uint32 biClrUsed = 0;
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/* Uint32 biClrImportant; */
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/* Make sure we are passed a valid data source */
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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;
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}
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/* Read in the BMP file header */
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fp_offset = SDL_RWtell(src);
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SDL_ClearError();
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if (SDL_RWread(src, magic, 1, 2) != 2) {
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SDL_Error(SDL_EFREAD);
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was_error = SDL_TRUE;
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goto done;
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}
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if (SDL_strncmp(magic, "BM", 2) != 0) {
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SDL_SetError("File is not a Windows BMP file");
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was_error = SDL_TRUE;
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goto done;
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}
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/* bfSize = */ SDL_ReadLE32(src);
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/* bfReserved1 = */ SDL_ReadLE16(src);
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/* bfReserved2 = */ SDL_ReadLE16(src);
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bfOffBits = SDL_ReadLE32(src);
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/* Read the Win32 BITMAPINFOHEADER */
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biSize = SDL_ReadLE32(src);
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if (biSize == 12) { /* really old BITMAPCOREHEADER */
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biWidth = (Uint32) SDL_ReadLE16(src);
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biHeight = (Uint32) SDL_ReadLE16(src);
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/* biPlanes = */ SDL_ReadLE16(src);
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biBitCount = SDL_ReadLE16(src);
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biCompression = BI_RGB;
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/* biSizeImage = 0; */
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/* biXPelsPerMeter = 0; */
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/* biYPelsPerMeter = 0; */
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biClrUsed = 0;
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/* biClrImportant = 0; */
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} else if (biSize >= 40) { /* some version of BITMAPINFOHEADER */
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Uint32 headerSize;
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biWidth = SDL_ReadLE32(src);
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biHeight = SDL_ReadLE32(src);
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/* biPlanes = */ SDL_ReadLE16(src);
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biBitCount = SDL_ReadLE16(src);
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biCompression = SDL_ReadLE32(src);
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/* biSizeImage = */ SDL_ReadLE32(src);
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/* biXPelsPerMeter = */ SDL_ReadLE32(src);
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/* biYPelsPerMeter = */ SDL_ReadLE32(src);
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biClrUsed = SDL_ReadLE32(src);
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/* biClrImportant = */ SDL_ReadLE32(src);
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/* 64 == BITMAPCOREHEADER2, an incompatible OS/2 2.x extension. Skip this stuff for now. */
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if (biSize != 64) {
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/* This is complicated. If compression is BI_BITFIELDS, then
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we have 3 DWORDS that specify the RGB masks. This is either
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stored here in an BITMAPV2INFOHEADER (which only differs in
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that it adds these RGB masks) and biSize >= 52, or we've got
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these masks stored in the exact same place, but strictly
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speaking, this is the bmiColors field in BITMAPINFO immediately
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following the legacy v1 info header, just past biSize. */
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if (biCompression == BI_BITFIELDS) {
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haveRGBMasks = SDL_TRUE;
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Rmask = SDL_ReadLE32(src);
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Gmask = SDL_ReadLE32(src);
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Bmask = SDL_ReadLE32(src);
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/* ...v3 adds an alpha mask. */
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if (biSize >= 56) { /* BITMAPV3INFOHEADER; adds alpha mask */
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haveAlphaMask = SDL_TRUE;
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Amask = SDL_ReadLE32(src);
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}
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} else {
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/* the mask fields are ignored for v2+ headers if not BI_BITFIELD. */
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if (biSize >= 52) { /* BITMAPV2INFOHEADER; adds RGB masks */
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/*Rmask = */ SDL_ReadLE32(src);
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/*Gmask = */ SDL_ReadLE32(src);
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/*Bmask = */ SDL_ReadLE32(src);
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}
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if (biSize >= 56) { /* BITMAPV3INFOHEADER; adds alpha mask */
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/*Amask = */ SDL_ReadLE32(src);
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}
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}
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/* Insert other fields here; Wikipedia and MSDN say we're up to
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v5 of this header, but we ignore those for now (they add gamma,
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color spaces, etc). Ignoring the weird OS/2 2.x format, we
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currently parse up to v3 correctly (hopefully!). */
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}
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/* skip any header bytes we didn't handle... */
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headerSize = (Uint32) (SDL_RWtell(src) - (fp_offset + 14));
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if (biSize > headerSize) {
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SDL_RWseek(src, (biSize - headerSize), RW_SEEK_CUR);
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}
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}
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if (biWidth <= 0 || biHeight == 0) {
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SDL_SetError("BMP file with bad dimensions (%dx%d)", biWidth, biHeight);
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was_error = SDL_TRUE;
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goto done;
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}
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if (biHeight < 0) {
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topDown = SDL_TRUE;
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biHeight = -biHeight;
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} else {
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topDown = SDL_FALSE;
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}
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/* Check for read error */
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if (SDL_strcmp(SDL_GetError(), "") != 0) {
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was_error = SDL_TRUE;
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goto done;
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}
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/* Expand 1 and 4 bit bitmaps to 8 bits per pixel */
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switch (biBitCount) {
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case 1:
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case 4:
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ExpandBMP = biBitCount;
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biBitCount = 8;
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break;
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case 0:
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case 2:
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case 3:
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case 5:
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case 6:
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case 7:
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SDL_SetError("%d-bpp BMP images are not supported", biBitCount);
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was_error = SDL_TRUE;
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goto done;
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default:
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ExpandBMP = 0;
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break;
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}
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/* RLE4 and RLE8 BMP compression is supported */
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switch (biCompression) {
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case BI_RGB:
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/* If there are no masks, use the defaults */
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SDL_assert(!haveRGBMasks);
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SDL_assert(!haveAlphaMask);
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/* Default values for the BMP format */
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switch (biBitCount) {
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case 15:
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case 16:
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Rmask = 0x7C00;
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Gmask = 0x03E0;
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Bmask = 0x001F;
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break;
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case 24:
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#if SDL_BYTEORDER == SDL_BIG_ENDIAN
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Rmask = 0x000000FF;
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Gmask = 0x0000FF00;
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Bmask = 0x00FF0000;
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#else
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Rmask = 0x00FF0000;
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Gmask = 0x0000FF00;
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Bmask = 0x000000FF;
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#endif
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break;
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case 32:
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/* We don't know if this has alpha channel or not */
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correctAlpha = SDL_TRUE;
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Amask = 0xFF000000;
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Rmask = 0x00FF0000;
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Gmask = 0x0000FF00;
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Bmask = 0x000000FF;
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break;
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default:
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break;
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}
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break;
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case BI_BITFIELDS:
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break; /* we handled this in the info header. */
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default:
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break;
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}
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/* Create a compatible surface, note that the colors are RGB ordered */
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surface =
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SDL_CreateRGBSurface(0, biWidth, biHeight, biBitCount, Rmask, Gmask,
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Bmask, Amask);
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if (surface == NULL) {
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was_error = SDL_TRUE;
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goto done;
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}
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/* Load the palette, if any */
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palette = (surface->format)->palette;
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if (palette) {
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if (SDL_RWseek(src, fp_offset+14+biSize, RW_SEEK_SET) < 0) {
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SDL_Error(SDL_EFSEEK);
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was_error = SDL_TRUE;
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goto done;
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}
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/*
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| guich: always use 1<<bpp b/c some bitmaps can bring wrong information
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| for colorsUsed
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*/
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/* if (biClrUsed == 0) { */
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biClrUsed = 1 << biBitCount;
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/* } */
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if (biSize == 12) {
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for (i = 0; i < (int) biClrUsed; ++i) {
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SDL_RWread(src, &palette->colors[i].b, 1, 1);
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SDL_RWread(src, &palette->colors[i].g, 1, 1);
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SDL_RWread(src, &palette->colors[i].r, 1, 1);
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palette->colors[i].a = SDL_ALPHA_OPAQUE;
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}
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} else {
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for (i = 0; i < (int) biClrUsed; ++i) {
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SDL_RWread(src, &palette->colors[i].b, 1, 1);
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SDL_RWread(src, &palette->colors[i].g, 1, 1);
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SDL_RWread(src, &palette->colors[i].r, 1, 1);
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SDL_RWread(src, &palette->colors[i].a, 1, 1);
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/* According to Microsoft documentation, the fourth element
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is reserved and must be zero, so we shouldn't treat it as
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alpha.
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*/
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palette->colors[i].a = SDL_ALPHA_OPAQUE;
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}
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}
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palette->ncolors = biClrUsed;
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}
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/* Read the surface pixels. Note that the bmp image is upside down */
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if (SDL_RWseek(src, fp_offset + bfOffBits, RW_SEEK_SET) < 0) {
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SDL_Error(SDL_EFSEEK);
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was_error = SDL_TRUE;
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goto done;
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}
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if ((biCompression == BI_RLE4) || (biCompression == BI_RLE8)) {
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was_error = (SDL_bool)readRlePixels(surface, src, biCompression == BI_RLE8);
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if (was_error) SDL_SetError("Error reading from BMP");
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goto done;
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}
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top = (Uint8 *)surface->pixels;
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end = (Uint8 *)surface->pixels+(surface->h*surface->pitch);
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switch (ExpandBMP) {
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case 1:
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bmpPitch = (biWidth + 7) >> 3;
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pad = (((bmpPitch) % 4) ? (4 - ((bmpPitch) % 4)) : 0);
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break;
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case 4:
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bmpPitch = (biWidth + 1) >> 1;
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pad = (((bmpPitch) % 4) ? (4 - ((bmpPitch) % 4)) : 0);
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break;
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default:
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pad = ((surface->pitch % 4) ? (4 - (surface->pitch % 4)) : 0);
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break;
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}
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if (topDown) {
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bits = top;
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} else {
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bits = end - surface->pitch;
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}
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while (bits >= top && bits < end) {
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switch (ExpandBMP) {
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case 1:
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case 4:{
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Uint8 pixel = 0;
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int shift = (8 - ExpandBMP);
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for (i = 0; i < surface->w; ++i) {
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if (i % (8 / ExpandBMP) == 0) {
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if (!SDL_RWread(src, &pixel, 1, 1)) {
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SDL_SetError("Error reading from BMP");
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was_error = SDL_TRUE;
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goto done;
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}
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}
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bits[i] = (pixel >> shift);
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if (bits[i] >= biClrUsed) {
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SDL_SetError("A BMP image contains a pixel with a color out of the palette");
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was_error = SDL_TRUE;
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goto done;
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}
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pixel <<= ExpandBMP;
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}
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}
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break;
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default:
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if (SDL_RWread(src, bits, 1, surface->pitch) != surface->pitch) {
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SDL_Error(SDL_EFREAD);
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was_error = SDL_TRUE;
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goto done;
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}
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if (biBitCount == 8 && palette && biClrUsed < (1u << biBitCount)) {
|
|
for (i = 0; i < surface->w; ++i) {
|
|
if (bits[i] >= biClrUsed) {
|
|
SDL_SetError("A BMP image contains a pixel with a color out of the palette");
|
|
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;
|
|
}
|
|
}
|
|
if (correctAlpha) {
|
|
CorrectAlphaChannel(surface);
|
|
}
|
|
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)
|
|
{
|
|
Sint64 fp_offset;
|
|
int i, pad;
|
|
SDL_Surface *surface;
|
|
Uint8 *bits;
|
|
SDL_bool save32bit = SDL_FALSE;
|
|
SDL_bool saveLegacyBMP = SDL_FALSE;
|
|
|
|
/* 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;
|
|
|
|
/* The additional header members from the Win32 BITMAPV4HEADER struct (108 bytes in total) */
|
|
Uint32 bV4RedMask = 0;
|
|
Uint32 bV4GreenMask = 0;
|
|
Uint32 bV4BlueMask = 0;
|
|
Uint32 bV4AlphaMask = 0;
|
|
Uint32 bV4CSType = 0;
|
|
Sint32 bV4Endpoints[3 * 3] = {0};
|
|
Uint32 bV4GammaRed = 0;
|
|
Uint32 bV4GammaGreen = 0;
|
|
Uint32 bV4GammaBlue = 0;
|
|
|
|
/* Make sure we have somewhere to save */
|
|
surface = NULL;
|
|
if (dst) {
|
|
#ifdef SAVE_32BIT_BMP
|
|
/* We can save alpha information in a 32-bit BMP */
|
|
if (saveme->format->BitsPerPixel >= 8 && (saveme->format->Amask ||
|
|
saveme->map->info.flags & SDL_COPY_COLORKEY)) {
|
|
save32bit = SDL_TRUE;
|
|
}
|
|
#endif /* SAVE_32BIT_BMP */
|
|
|
|
if (saveme->format->palette && !save32bit) {
|
|
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) && !save32bit &&
|
|
#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_PixelFormat format;
|
|
|
|
/* If the surface has a colorkey or alpha channel we'll save a
|
|
32-bit BMP with alpha channel, otherwise save a 24-bit BMP. */
|
|
if (save32bit) {
|
|
SDL_InitFormat(&format, SDL_PIXELFORMAT_BGRA32);
|
|
} else {
|
|
SDL_InitFormat(&format, SDL_PIXELFORMAT_BGR24);
|
|
}
|
|
surface = SDL_ConvertSurface(saveme, &format, 0);
|
|
if (!surface) {
|
|
SDL_SetError("Couldn't convert image to %d bpp",
|
|
format.BitsPerPixel);
|
|
}
|
|
}
|
|
} else {
|
|
/* Set no error here because it may overwrite a more useful message from
|
|
SDL_RWFromFile() if SDL_SaveBMP_RW() is called from SDL_SaveBMP(). */
|
|
return -1;
|
|
}
|
|
|
|
if (save32bit) {
|
|
saveLegacyBMP = SDL_GetHintBoolean(SDL_HINT_BMP_SAVE_LEGACY_FORMAT, SDL_FALSE);
|
|
}
|
|
|
|
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;
|
|
|
|
/* Set the BMP info values for the version 4 header */
|
|
if (save32bit && !saveLegacyBMP) {
|
|
biSize = 108;
|
|
biCompression = BI_BITFIELDS;
|
|
/* The BMP format is always little endian, these masks stay the same */
|
|
bV4RedMask = 0x00ff0000;
|
|
bV4GreenMask = 0x0000ff00;
|
|
bV4BlueMask = 0x000000ff;
|
|
bV4AlphaMask = 0xff000000;
|
|
bV4CSType = LCS_WINDOWS_COLOR_SPACE;
|
|
bV4GammaRed = 0;
|
|
bV4GammaGreen = 0;
|
|
bV4GammaBlue = 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 BMP info values for the version 4 header */
|
|
if (save32bit && !saveLegacyBMP) {
|
|
SDL_WriteLE32(dst, bV4RedMask);
|
|
SDL_WriteLE32(dst, bV4GreenMask);
|
|
SDL_WriteLE32(dst, bV4BlueMask);
|
|
SDL_WriteLE32(dst, bV4AlphaMask);
|
|
SDL_WriteLE32(dst, bV4CSType);
|
|
for (i = 0; i < 3 * 3; i++) {
|
|
SDL_WriteLE32(dst, bV4Endpoints[i]);
|
|
}
|
|
SDL_WriteLE32(dst, bV4GammaRed);
|
|
SDL_WriteLE32(dst, bV4GammaGreen);
|
|
SDL_WriteLE32(dst, bV4GammaBlue);
|
|
}
|
|
|
|
/* 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].a, 1, 1);
|
|
}
|
|
}
|
|
|
|
/* Write the bitmap offset */
|
|
bfOffBits = (Uint32)(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 = (Uint32)(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);
|
|
}
|
|
|
|
/* vi: set ts=4 sw=4 expandtab: */
|