source: trunk/packages/vizservers/nanovis/imgLoaders/BMPImageLoaderImpl.cpp @ 1380

Last change on this file since 1380 was 1380, checked in by gah, 13 years ago
File size: 3.5 KB
Line 
1#include "BMPImageLoaderImpl.h"
2#include "Image.h"
3#include <stdio.h>
4#include <memory.h>
5#include <stdlib.h>
6
7BMPImageLoaderImpl::BMPImageLoaderImpl()
8{
9}
10
11BMPImageLoaderImpl::~BMPImageLoaderImpl()
12{
13}
14
15// I referred to cjbackhouse@hotmail.com                www.backhouse.tk
16Image* BMPImageLoaderImpl::load(const char* fileName)
17{
18    printf("BMP loader\n");
19    fflush(stdout);
20    Image* image = 0;
21
22    printf("opening image file \"%s\"\n", fileName);
23    FILE* f = fopen(fileName, "rb");
24
25    if (!f)  {
26        printf("File not found\n");
27        return 0;
28    }
29
30    char header[54];
31    if (fread(&header, 54, 1, f) != 1) {
32        printf("can't read header of BMP file\n");
33        return 0;
34    };
35
36    if (header[0] != 'B' ||  header[1] != 'M') {
37        printf("File is not BMP format\n");
38        return 0;
39    }
40
41    //it seems gimp sometimes makes its headers small, so we have to do
42    //this. hence all the fseeks
43    int offset=*(unsigned int*)(header+10);
44       
45    const unsigned int width =*(int*) (header+18);
46    const unsigned int height =*(int*) (header+22);
47
48    int bits=int(header[28]);           //colourdepth
49
50    printf("image width = %d height = %d bits=%d\n", width, height, bits);
51    fflush(stdout);
52   
53    image = new Image(width, height, _targetImageFormat,
54                      Image::IMG_UNSIGNED_BYTE, 0);
55
56    printf("image created\n");
57    fflush(stdout);
58
59    unsigned char* bytes = (unsigned char*) image->getImageBuffer();
60    memset(bytes, 0, sizeof(unsigned char) * width * height * _targetImageFormat);
61
62    printf("reset image buffer\n");
63    fflush(stdout);
64
65    unsigned int x,y;
66    unsigned char cols[256*4];  //colourtable
67    switch(bits) {
68    case 24:
69        fseek(f,offset,SEEK_SET);
70        if (_targetImageFormat == Image::IMG_RGB) {
71            if (fread(bytes,width*height*3,1,f) != 1) {
72                fprintf(stderr, "can't read image data\n");
73            }
74            for(x=0;x<width*height*3;x+=3)  { //except the format is BGR, grr
75                unsigned char temp = bytes[x];
76                bytes[x] = bytes[x+2];
77                bytes[x+2] = temp;
78            }
79        } else if (_targetImageFormat == Image::IMG_RGBA) {
80            char* buff = (char*) malloc(width * height * sizeof(unsigned char) * 3);
81            if (fread(buff,width*height*3,1,f) != 1) {
82                fprintf(stderr, "can't read BMP image data\n");
83            }
84            for(x=0, y = 0;x<width*height*3;x+=3, y+=4)     {       //except the format is BGR, grr
85                bytes[y] = buff[x+2];
86                bytes[y+2] = buff[x];
87                bytes[y+3] = 255;
88            }
89            free(buff);
90        }
91        break;
92    case 8:
93        if (fread(cols,256 * 4,1,f) != 1) {
94            fprintf(stderr, "can't read colortable from BMP file\n");
95        }
96        fseek(f,offset,SEEK_SET); 
97        for(y=0;y<height;++y) { //(Notice 4bytes/col for some reason)
98            for(x=0;x<width;++x) {
99                unsigned char byte;                 
100                if (fread(&byte,1,1,f) != 1) {
101                    fprintf(stderr, "error reading BMP file\n");
102                }
103                for(int c=0; c< 3; ++c) {
104                    //bytes[(y*width+x)*3+c] = cols[byte*4+2-c];        //and look up in the table
105                    bytes[(y*width+x)*_targetImageFormat + c] = cols[byte*4+2-c];       //and look up in the table
106                }
107            }
108        }
109        break;
110        /*
111          case(4):
112          fread(cols,16*4,1,f);
113          fseek(f,offset,SEEK_SET);
114          for(y=0;y<256;++y)
115          for(x=0;x<256;x+=2)
116          {
117          BYTE byte;
118          fread(&byte,1,1,f);                                               //as above, but need to exract two
119         
120          for(c=0;c<_targetImageFormat;++c)                                         //pixels from each byte
121          bmp.pixel(x,y,c)=cols[byte/16*4+2-c];
122
123          for(c=0;c<_targetImageFormat;++c)
124          bmp.pixel(x+1,y,c)=cols[byte%16*4+2-c];
125        */
126    }
127   
128    printf("image initialized\n");
129    fflush(stdout);
130    return image;
131}
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