1 #include <stdio.h>

2 #include "texture.h"

3 #include "image.h"

4 #include "opengl.h"

5

6 #ifndef GL_GENERATE_MIPMAP_SGIS

7 #define GL_GENERATE_MIPMAP_SGIS 0x8191

8 #endif

9

10 static unsigned int default_texture(void);

11

12 unsigned int load_texture(const char *fname)

13 {

14 unsigned int tex;

15 struct image *img;

16

17 if(!(img = load_image(fname))) {

18 fprintf(stderr, "failed to load image: %s\n", fname);

19 return default_texture();

20 }

21

22 glGenTextures(1, &tex);

23 glBindTexture(GL_TEXTURE_2D, tex);

24 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);

25 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

26 glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_TRUE);

27 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, img->width, img->height, 0, GL_RGB, GL_UNSIGNED_BYTE, img->pixels);

28 free_image(img);

29 return tex;

30 }

31

32 #define DEF_TEX_SZ 64

33

34 static unsigned int default_texture(void)

35 {

36 static unsigned int tex;

37 static unsigned char pixels[DEF_TEX_SZ * DEF_TEX_SZ * 3];

38

39 if(!tex) {

40 /* generate it */

41 int i, j;

42 unsigned char *pptr = pixels;

43

44 for(i=0; i<DEF_TEX_SZ; i++) {

45 for(j=0; j<DEF_TEX_SZ; j++) {

46 int c = ((i >> 3) & 1) == ((j >> 3) & 1);

47

48 *pptr++ = c ? 255 : 64;

49 *pptr++ = 100;

50 *pptr++ = c ? 64 : 255;

51 }

52 }

53

54 glGenTextures(1, &tex);

55 glBindTexture(GL_TEXTURE_2D, tex);

56 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);

57 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

58 glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, GL_TRUE);

59 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, DEF_TEX_SZ, DEF_TEX_SZ, 0, GL_RGB, GL_UNSIGNED_BYTE, pixels);

60 }

61

62 return tex;

63 }