bmp.c

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/*
 * $Id: bmp.c 35336 2011-03-03 17:58:06Z campbellbarton $
 *
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include "BLI_blenlib.h"

#include "imbuf.h"

#include "IMB_imbuf_types.h"
#include "IMB_imbuf.h"
#include "IMB_allocimbuf.h"
#include "IMB_filetype.h"

/* some code copied from article on microsoft.com, copied
  here for enhanced BMP support in the future
  http://www.microsoft.com/msj/defaultframe.asp?page=/msj/0197/mfcp1/mfcp1.htm&nav=/msj/0197/newnav.htm
*/

typedef struct BMPINFOHEADER{
        unsigned int    biSize;
        unsigned int    biWidth;
        unsigned int    biHeight;
        unsigned short  biPlanes;
        unsigned short  biBitCount;
        unsigned int    biCompression;
        unsigned int    biSizeImage;
        unsigned int    biXPelsPerMeter;
        unsigned int    biYPelsPerMeter;
        unsigned int    biClrUsed;
        unsigned int    biClrImportant;
} BMPINFOHEADER;

typedef struct BMPHEADER {
        unsigned short biType;
        unsigned int biSize;
        unsigned short biRes1;
        unsigned short biRes2;
        unsigned int biOffBits;
} BMPHEADER;

#define BMP_FILEHEADER_SIZE 14

static int checkbmp(unsigned char *mem)
{
        int ret_val = 0;
        BMPINFOHEADER bmi;
        unsigned int u;

        if (mem) {
                if ((mem[0] == 'B') && (mem[1] == 'M')) {
                        /* skip fileheader */
                        mem += BMP_FILEHEADER_SIZE;
                } else {
                }

                /* for systems where an int needs to be 4 bytes aligned */
                memcpy(&bmi, mem, sizeof(bmi));

                u = LITTLE_LONG(bmi.biSize);
                /* we only support uncompressed 24 or 32 bits images for now */
                if (u >= sizeof(BMPINFOHEADER)) {
                        if ((bmi.biCompression == 0) && (bmi.biClrUsed == 0)) {
                                u = LITTLE_SHORT(bmi.biBitCount);
                                if (u >= 16) {
                                        ret_val = 1;
                                }
                        }
                }
        }

        return(ret_val);
}

int imb_is_a_bmp(unsigned char *buf) {
        
        return checkbmp(buf);
}

struct ImBuf *imb_bmp_decode(unsigned char *mem, size_t size, int flags)
{
        struct ImBuf *ibuf = NULL;
        BMPINFOHEADER bmi;
        int x, y, depth, skip, i;
        unsigned char *bmp, *rect;
        unsigned short col;
        
        (void)size; /* unused */

        if (checkbmp(mem) == 0) return(NULL);

        if ((mem[0] == 'B') && (mem[1] == 'M')) {
                /* skip fileheader */
                mem += BMP_FILEHEADER_SIZE;
        }

        /* for systems where an int needs to be 4 bytes aligned */
        memcpy(&bmi, mem, sizeof(bmi));

        skip = LITTLE_LONG(bmi.biSize);
        x = LITTLE_LONG(bmi.biWidth);
        y = LITTLE_LONG(bmi.biHeight);
        depth = LITTLE_SHORT(bmi.biBitCount);

        /* printf("skip: %d, x: %d y: %d, depth: %d (%x)\n", skip, x, y, 
                depth, bmi.biBitCount); */
        /* printf("skip: %d, x: %d y: %d, depth: %d (%x)\n", skip, x, y, 
                depth, bmi.biBitCount); */
        if (flags & IB_test) {
                ibuf = IMB_allocImBuf(x, y, depth, 0);
        } else {
                ibuf = IMB_allocImBuf(x, y, depth, IB_rect);
                bmp = mem + skip;
                rect = (unsigned char *) ibuf->rect;

                if (depth == 16) {
                        for (i = x * y; i > 0; i--) {
                                col = bmp[0] + (bmp[1] << 8);
                                rect[0] = ((col >> 10) & 0x1f) << 3;
                                rect[1] = ((col >>  5) & 0x1f) << 3;
                                rect[2] = ((col >>  0) & 0x1f) << 3;
                                
                                rect[3] = 255;
                                rect += 4; bmp += 2;
                        }

                } else if (depth == 24) {
                        for (i = y; i > 0; i--) {
                                int j;
                                for (j = x ; j > 0; j--) {
                                        rect[0] = bmp[2];
                                        rect[1] = bmp[1];
                                        rect[2] = bmp[0];
                                        
                                        rect[3] = 255;
                                        rect += 4; bmp += 3;
                                }
                                /* for 24-bit images, rows are padded to multiples of 4 */
                                bmp += x % 4;   
                        }
                } else if (depth == 32) {
                        for (i = x * y; i > 0; i--) {
                                rect[0] = bmp[2];
                                rect[1] = bmp[1];
                                rect[2] = bmp[0];
                                rect[3] = bmp[3];
                                rect += 4; bmp += 4;
                        }
                }
        }

        if (ibuf) {
                ibuf->ftype = BMP;
                ibuf->profile = IB_PROFILE_SRGB;
        }
        
        return(ibuf);
}

/* Couple of helper functions for writing our data */
static int putIntLSB(unsigned int ui,FILE *ofile) { 
        putc((ui>>0)&0xFF,ofile); 
        putc((ui>>8)&0xFF,ofile); 
        putc((ui>>16)&0xFF,ofile); 
        return putc((ui>>24)&0xFF,ofile); 
}

static int putShortLSB(unsigned short us,FILE *ofile) { 
        putc((us>>0)&0xFF,ofile); 
        return putc((us>>8)&0xFF,ofile); 
} 

/* Found write info at http://users.ece.gatech.edu/~slabaugh/personal/c/bitmapUnix.c */
int imb_savebmp(struct ImBuf *ibuf, const char *name, int flags) {

        BMPINFOHEADER infoheader;
        int bytesize, extrabytes, x, y, t, ptr;
        uchar *data;
        FILE *ofile;
        
        (void)flags; /* unused */

        extrabytes = (4 - ibuf->x*3 % 4) % 4;
        bytesize = (ibuf->x * 3 + extrabytes) * ibuf->y;

        data = (uchar *) ibuf->rect;
        ofile = fopen(name,"wb");
                if (!ofile) return 0;

        putShortLSB(19778,ofile); /* "BM" */
        putIntLSB(0,ofile); /* This can be 0 for BI_RGB bitmaps */
        putShortLSB(0,ofile); /* Res1 */
        putShortLSB(0,ofile); /* Res2 */
        putIntLSB(BMP_FILEHEADER_SIZE + sizeof(infoheader),ofile); 

        putIntLSB(sizeof(infoheader),ofile);
        putIntLSB(ibuf->x,ofile);
        putIntLSB(ibuf->y,ofile);
        putShortLSB(1,ofile);
        putShortLSB(24,ofile);
        putIntLSB(0,ofile);
        putIntLSB(bytesize + BMP_FILEHEADER_SIZE + sizeof(infoheader),ofile);
        putIntLSB(0,ofile);
        putIntLSB(0,ofile);
        putIntLSB(0,ofile);
        putIntLSB(0,ofile);

        /* Need to write out padded image data in bgr format */
        for (y=0;y<ibuf->y;y++) {
                for (x=0;x<ibuf->x;x++) {
                        ptr=(x + y * ibuf->x) * 4;
                        if (putc(data[ptr+2],ofile) == EOF) return 0;
                        if (putc(data[ptr+1],ofile) == EOF) return 0;
                        if (putc(data[ptr],ofile) == EOF) return 0;
                }
                /* add padding here */
                for (t=0;t<extrabytes;t++) if (putc(0,ofile) == EOF) return 0;
        }
        if (ofile) {
                fflush(ofile);
                fclose(ofile);
        }
        return 1;
}