1 #include <stdio.h>

2 #include <stdlib.h>

3 #include <string.h>

4 #include <errno.h>

5 #include "opengl.h"

6 #include "tex.h"

7

8 unsigned int load_texture(const char *fname)

9 {

10 unsigned int tex;

11 FILE *fp;

12 void *pixels;

13 int xsz, ysz, sz;

14 char buf[512];

15

16 if(!(fp = fopen(fname, "r"))) {

17 fprintf(stderr, "failed to open texture: %s: %s\n", fname, strerror(errno));

18 return 0;

19 }

20

21 if(!fgets(buf, sizeof buf, fp) || buf[0] != 'P' || buf[1] != '6') {

22 fprintf(stderr, "invalid format (1): %s\n", fname);

23 fclose(fp);

24 return 0;

25 }

26 if(!fgets(buf, sizeof buf, fp) || sscanf(buf, "%d %d", &xsz, &ysz) != 2) {

27 fprintf(stderr, "invalid format (2): %s\n", fname);

28 fclose(fp);

29 return 0;

30 }

31 fgets(buf, sizeof buf, fp);

32

33 sz = xsz * ysz * 3;

34 if(!(pixels = malloc(sz))) {

35 fprintf(stderr, "failed to allocate %d bytes\n", sz);

36 fclose(fp);

37 return 0;

38 }

39 if(fread(pixels, 1, xsz * ysz * 3, fp) < sz) {

40 fprintf(stderr, "partial read: %s\n", fname);

41 free(pixels);

42 fclose(fp);

43 return 0;

44 }

45 fclose(fp);

46

47 glGenTextures(1, &tex);

48 glBindTexture(GL_TEXTURE_2D, tex);

49 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);

50 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

51 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

52 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

53 glTexImage2D(GL_TEXTURE_2D, 0, 4, xsz, ysz, 0, GL_RGB, GL_UNSIGNED_BYTE, pixels);

54 free(pixels);

55

56 return tex;

57 }