1 #include <GL/gl.h>

2 #include "texture.h"

3

4 static int next_pow2(int x);

5

6 int image_texture(struct texture *tex, struct image *img)

7 {

8 glGenTextures(1, &tex->id);

9 glBindTexture(GL_TEXTURE_2D, tex->id);

10 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

11 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

12

13 tex->width = img->width;

14 tex->height = img->height;

15 tex->tex_width = next_pow2(tex->width);

16 tex->tex_height = next_pow2(tex->height);

17

18 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, tex->tex_width, tex->tex_height, 0,

19 GL_RGBA, GL_UNSIGNED_BYTE, 0);

20 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, tex->width, tex->height,

21 GL_RGBA, GL_UNSIGNED_BYTE, img->pixels);

22 return 0;

23 }

24

25 void destroy_texture(struct texture *tex)

26 {

27 glDeleteTextures(1, &tex->id);

28 tex->id = 0;

29 }

30

31 static int next_pow2(int x)

32 {

33 --x;

34 x |= x >> 1;

35 x |= x >> 2;

36 x |= x >> 4;

37 x |= x >> 8;

38 return x + 1;

39 }