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 #include "config.h"

8

9 unsigned int load_texture(const char *fname)

10 {

11 unsigned int tex;

12 FILE *fp;

13 void *pixels;

14 int xsz, ysz, sz;

15 char buf[512];

16

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

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

19 return 0;

20 }

21

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

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

24 fclose(fp);

25 return 0;

26 }

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

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

29 fclose(fp);

30 return 0;

31 }

32 fgets(buf, sizeof buf, fp);

33

34 sz = xsz * ysz * 3;

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

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

37 fclose(fp);

38 return 0;

39 }

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

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

42 free(pixels);

43 fclose(fp);

44 return 0;

45 }

46 fclose(fp);

47

48 glGenTextures(1, &tex);

49 glBindTexture(GL_TEXTURE_2D, tex);

50 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);

51 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

52 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

53 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

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

55 free(pixels);

56

57 return tex;

58 }

59

60 void bind_texture(unsigned int tex, int unit)

61 {

62 glActiveTexture(GL_TEXTURE0 + unit);

63

64 #ifndef IPHONE

65 if(tex) {

66 glEnable(GL_TEXTURE_2D);

67 } else {

68 glDisable(GL_TEXTURE_2D);

69 }

70 #endif

71

72 glBindTexture(GL_TEXTURE_2D, tex);

73 }