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-rw-r--r--src/bmp.c111
1 files changed, 111 insertions, 0 deletions
diff --git a/src/bmp.c b/src/bmp.c
new file mode 100644
index 0000000..9f79a9f
--- /dev/null
+++ b/src/bmp.c
@@ -0,0 +1,111 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "meh.h"
+
+unsigned short getshort(FILE *f){
+ unsigned short ret;
+ ret = getc(f);
+ ret = ret | (getc(f) << 8);
+ return ret;
+}
+
+unsigned long getlong(FILE *f){
+ unsigned short ret;
+ ret = getc(f);
+ ret = ret | (getc(f) << 8);
+ ret = ret | (getc(f) << 16);
+ ret = ret | (getc(f) << 24);
+ return ret;
+}
+
+struct rgb_t{
+ unsigned char r, g, b;
+};
+
+struct bmp_t{
+ struct image img;
+ unsigned long bitmapoffset;
+ int bpp;
+ int ncolors;
+ struct rgb_t *colours;
+};
+
+struct image *bmp_open(FILE *f){
+ struct bmp_t *b;
+ unsigned long headerend;
+
+ rewind(f);
+ if(getc(f) != 'B' || getc(f) != 'M')
+ return NULL;
+
+ b = malloc(sizeof(struct bmp_t));
+ b->img.f = f;
+
+ fseek(f, 10, SEEK_SET);
+ b->bitmapoffset = getlong(f);
+
+ fseek(f, 18, SEEK_SET);
+ b->img.width = getlong(f);
+ b->img.height = getlong(f);
+
+ fseek(f, 14, SEEK_SET);
+ headerend = 14 + getlong(f);
+
+ fseek(f, 28, SEEK_SET);
+ b->bpp = getshort(f);
+
+ if(b->bpp == 24){
+ b->ncolors = 0;
+ }else{
+ int i;
+ fseek(f, 46, SEEK_SET);
+ if(!(b->ncolors = getlong(f))){
+ b->ncolors = 1 << b->bpp;
+ }
+
+ b->colours = malloc(b->ncolors * sizeof(struct rgb_t));
+ fseek(f, headerend, SEEK_SET);
+ for(i = 0; i < b->ncolors; i++){
+ b->colours[i].b = getc(f);
+ b->colours[i].g = getc(f);
+ b->colours[i].r = getc(f);
+ }
+ }
+
+ return (struct image *)b;
+}
+
+int bmp_read(struct image *img){
+ struct bmp_t *b = (struct bmp_t *)img;
+ FILE *f = img->f;
+
+ fseek(f, b->bitmapoffset, SEEK_SET);
+ if(b->bpp == 24){
+ int i, x, y;
+ int row = img->width * 3;
+ i = img->height * row;
+ for(y = img->height; y; y--){
+ i -= row;
+ for(x = 0; x < img->width * 3; x+=3){
+ img->buf[i + x + 2] = getc(f);
+ img->buf[i + x + 1] = getc(f);
+ img->buf[i + x + 0] = getc(f);
+ }
+ if(x & 3){
+ fseek(f, 4 - (x & 3), SEEK_CUR);
+ }
+ }
+ }else{
+ //TODO
+ }
+
+ return 0;
+}
+
+struct imageformat gif = {
+ bmp_open,
+ bmp_read
+};
+