/* $Id: winbmp.c,v 1.14 2004/10/19 07:34:54 weiym Exp $**** Low-level Windows bitmap read/save function.**** Copyright (C) 2003 Feynman Software.** Copyright (C) 2000 ~ 2002 Wei Yongming.**** Create date: 2000/08/26, derived from original bitmap.c**** Current maintainer: Wei Yongming.*//*** This program is free software; you can redistribute it and/or modify** it under the terms of the GNU General Public License as published by** the Free Software Foundation; either version 2 of the License, or** (at your option) any later version.**** This program 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 General Public License for more details.**** You should have received a copy of the GNU General Public License** along with this program; if not, write to the Free Software** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA*/#include <stdio.h>#include <stdlib.h>#include <string.h>#include "common.h"#include "gdi.h"#include "readbmp.h"/************************* Bitmap-related structures  ************************/typedef struct tagRGBTRIPLE{    BYTE    rgbtBlue;    BYTE    rgbtGreen;    BYTE    rgbtRed;} RGBTRIPLE;typedef RGBTRIPLE* PRGBTRIPLE;typedef struct tagRGBQUAD{    BYTE    rgbBlue;    BYTE    rgbGreen;    BYTE    rgbRed;    BYTE    rgbReserved;} RGBQUAD;typedef RGBQUAD* PRGBQUAD;#define SIZEOF_RGBQUAD      4#define BI_RGB          0#define BI_RLE8         1#define BI_RLE4         2#define BI_BITFIELDS    3#define SIZEOF_BMFH     14#define SIZEOF_BMIH     40#define OS2INFOHEADERSIZE  12#define WININFOHEADERSIZE  40typedef struct BITMAPFILEHEADER{   unsigned short bfType;   unsigned long  bfSize;   unsigned short bfReserved1;   unsigned short bfReserved2;   unsigned long  bfOffBits;} BITMAPFILEHEADER;/* Used for both OS/2 and Windows BMP.  * Contains only the parameters needed to load the image  */typedef struct BITMAPINFOHEADER{   unsigned long  biWidth;   unsigned long  biHeight;   unsigned short biBitCount;   unsigned long  biCompression;} BITMAPINFOHEADER;typedef struct WINBMPINFOHEADER  /* size: 40 */{   unsigned long  biSize;   unsigned long  biWidth;   unsigned long  biHeight;   unsigned short biPlanes;   unsigned short biBitCount;   unsigned long  biCompression;   unsigned long  biSizeImage;   unsigned long  biXPelsPerMeter;   unsigned long  biYPelsPerMeter;   unsigned long  biClrUsed;   unsigned long  biClrImportant;} WINBMPINFOHEADER;typedef struct OS2BMPINFOHEADER  /* size: 12 */{   unsigned long  biSize;   unsigned short biWidth;   unsigned short biHeight;   unsigned short biPlanes;   unsigned short biBitCount;} OS2BMPINFOHEADER;/* read_bmfileheader: *  Reads a BMP file header and check that it has the BMP magic number. */static int read_bmfileheader(MG_RWops *f, BITMAPFILEHEADER *fileheader){   fileheader->bfType = fp_igetw(f);   fileheader->bfSize= fp_igetl(f);   fileheader->bfReserved1= fp_igetw(f);   fileheader->bfReserved2= fp_igetw(f);   fileheader->bfOffBits= fp_igetl(f);   if (fileheader->bfType != 19778)      return -1;   return 0;}/* read_win_bminfoheader: *  Reads information from a BMP file header. */static int read_win_bminfoheader(MG_RWops *f, BITMAPINFOHEADER *infoheader){   WINBMPINFOHEADER win_infoheader;   win_infoheader.biWidth = fp_igetl(f);   win_infoheader.biHeight = fp_igetl(f);   win_infoheader.biPlanes = fp_igetw(f);   win_infoheader.biBitCount = fp_igetw(f);   win_infoheader.biCompression = fp_igetl(f);   win_infoheader.biSizeImage = fp_igetl(f);   win_infoheader.biXPelsPerMeter = fp_igetl(f);   win_infoheader.biYPelsPerMeter = fp_igetl(f);   win_infoheader.biClrUsed = fp_igetl(f);   win_infoheader.biClrImportant = fp_igetl(f);   infoheader->biWidth = win_infoheader.biWidth;   infoheader->biHeight = win_infoheader.biHeight;   infoheader->biBitCount = win_infoheader.biBitCount;   infoheader->biCompression = win_infoheader.biCompression;   return 0;}/* read_os2_bminfoheader: *  Reads information from an OS/2 format BMP file header. */static int read_os2_bminfoheader(MG_RWops *f, BITMAPINFOHEADER *infoheader){   OS2BMPINFOHEADER os2_infoheader;   os2_infoheader.biWidth = fp_igetw(f);   os2_infoheader.biHeight = fp_igetw(f);   os2_infoheader.biPlanes = fp_igetw(f);   os2_infoheader.biBitCount = fp_igetw(f);   infoheader->biWidth = os2_infoheader.biWidth;   infoheader->biHeight = os2_infoheader.biHeight;   infoheader->biBitCount = os2_infoheader.biBitCount;   infoheader->biCompression = 0;   return 0;}/* read_bmicolors: *  Loads the color palette for 1,4,8 bit formats. */static void read_bmicolors (int ncols, RGB *pal, MG_RWops *f, int win_flag){   int i;   for (i=0; i<ncols; i++) {      pal[i].b = fp_getc(f);      pal[i].g = fp_getc(f);      pal[i].r = fp_getc(f);      if (win_flag)	    fp_getc(f);   }}/* read_RLE8_compressed_image: *  For reading the 8 bit RLE compressed BMP image format. */static void read_RLE8_compressed_image (MG_RWops *f, BYTE *bits, int pitch, BITMAPINFOHEADER *infoheader){    unsigned char count, val, val0;    int j, pos, line;    int eolflag, eopicflag;    eopicflag = 0;    line = infoheader->biHeight - 1;   while (eopicflag == 0) {      pos = 0;                               /* x position in bitmap */      eolflag = 0;                           /* end of line flag */      while ((eolflag == 0) && (eopicflag == 0)) {	 count = fp_getc(f);	 val = fp_getc(f);	 if (count > 0) {                    /* repeat pixel count times */	    for (j=0;j<count;j++) {	       bits [pos] = val;	       pos++;	    }	 }	 else {	    switch (val) {	       case 0:                       /* end of line flag */		  eolflag=1;		  break;	       case 1:                       /* end of picture flag */		  eopicflag=1;		  break;	       case 2:                       /* displace picture */		  count = fp_getc(f);		  val = fp_getc(f);		  pos += count;		  line -= val;		  break;	       default:                      /* read in absolute mode */		  for (j=0; j<val; j++) {		     val0 = fp_getc(f);             bits [pos] = val0;		     pos++;		  }		  if (j%2 == 1)		     val0 = fp_getc(f);    /* align on word boundary */		  break;	    }	 }	 if (pos-1 > (int)infoheader->biWidth)	    eolflag=1;      }      bits += pitch;      line--;      if (line < 0)	    eopicflag = 1;   }}/* read_RLE4_compressed_image: *  For reading the 4 bit RLE compressed BMP image format. */static void read_RLE4_compressed_image (MG_RWops *f, BYTE *bits, int pitch, BITMAPINFOHEADER *infoheader){   unsigned char b[8];   unsigned char count;   unsigned short val0, val;   int j, k, pos, line;   int eolflag, eopicflag;   eopicflag = 0;                            /* end of picture flag */   line = infoheader->biHeight - 1;   while (eopicflag == 0) {      pos = 0;      eolflag = 0;                           /* end of line flag */      while ((eolflag == 0) && (eopicflag == 0)) {	 count = fp_getc(f);	 val = fp_getc(f);	 if (count > 0) {                    /* repeat pixels count times */	    b[1] = val & 15;	    b[0] = (val >> 4) & 15;	    for (j=0; j<count; j++) {            if (pos % 2 == 0)                bits [pos/2] = b[j%2] << 4;            else                bits [pos/2] = bits [pos/2] | b[j%2];	       pos++;	    }	 }	 else {	    switch (val) {	       case 0:                       /* end of line */		  eolflag=1;		  break;	       case 1:                       /* end of picture */		  eopicflag=1;		  break;	       case 2:                       /* displace image */		  count = fp_getc(f);		  val = fp_getc(f);		  pos += count;		  line -= val;		  break;	       default:                      /* read in absolute mode */		  for (j=0; j<val; j++) {		     if ((j%4) == 0) {			val0 = fp_igetw(f);			for (k=0; k<2; k++) {			   b[2*k+1] = val0 & 15;			   val0 = val0 >> 4;			   b[2*k] = val0 & 15;			   val0 = val0 >> 4;			}		     }            if (pos % 2 == 0)                bits [pos/2] = b[j%4] << 4;            else                bits [pos/2] = bits [pos/2] | b[j%4];		     pos++;		  }		  break;	    }	 }	 if (pos-1 > (int)infoheader->biWidth)	    eolflag=1;      }      bits += pitch;      line--;      if (line < 0)	    eopicflag = 1;   }}/* read_16bit_image: *  For reading the 16-bit BMP image format. * This only support bit masks specific to Windows 95. */static void read_16bit_image (MG_RWops *f, BYTE *bits, int pitch, BITMAPINFOHEADER *infoheader, DWORD gmask){    int i, j;    WORD pixel;    BYTE *line;    for (i = 0; i < infoheader->biHeight; i++) {        line = bits;        for (j = 0; j < infoheader->biWidth; j++) {            pixel = fp_igetw (f);            if (gmask == 0x03e0)    /* 5-5-5 */            {                line [2] = ((pixel >> 10) & 0x1f) << 3;                line [1] = ((pixel >> 5) & 0x1f) << 3;                line [0] = (pixel & 0x1f) << 3;            }            else                    /* 5-6-5 */            {                line [2] = ((pixel >> 11) & 0x1f) << 3;                line [1] = ((pixel >> 5) & 0x3f) << 2;                line [0] = (pixel & 0x1f) << 3;            }            line += 3;        }        if (infoheader->biWidth & 0x01)