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 unsigned char *pixels;

14 int xsz, ysz, sz, i;

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 * 4;

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

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

37 fclose(fp);

38 return 0;

39 }

40 for(i=0; i<sz; i++) {

41 int c;

42

43 if(i % 4 == 3) {

44 pixels[i] = 255;

45 continue;

46 }

47

48 if((c = fgetc(fp)) == -1) {

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

50 free(pixels);

51 fclose(fp);

52 return 0;

53 }

54 pixels[i] = c;

55 }

56 fclose(fp);

57

58 glGenTextures(1, &tex);

59 glBindTexture(GL_TEXTURE_2D, tex);

60 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);

61 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

62 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

63 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

64 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, xsz, ysz, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);

65 free(pixels);

66

67 return tex;

68 }

69

70 void bind_texture(unsigned int tex, int unit)

71 {

72 glActiveTexture(GL_TEXTURE0 + unit);

73

74 #ifndef IPHONE

75 if(tex) {

76 glEnable(GL_TEXTURE_2D);

77 } else {

78 glDisable(GL_TEXTURE_2D);

79 }

80 #endif

81

82 glBindTexture(GL_TEXTURE_2D, tex);

83 }