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#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
texture_t load_texture(arena_t *arena, const char *filename, i32 gamma)
{
texture_t texture = {0};
i32 nchannels;
stbi_set_flip_vertically_on_load(1);
u8 *data = stbi_load(filename, &texture.width, &texture.height, &nchannels, 0);
if (!data) {
printf("error: \"%s\" failed to load\n", filename);
return texture;
}
u32 internal_format, data_format;
switch (nchannels) {
case 1:
texture.type = texture_type_r;
internal_format = data_format = GL_RED;
break;
case 3:
texture.type = texture_type_rgb;
internal_format = gamma ? GL_SRGB : GL_RGB;
data_format = GL_RGB;
break;
case 4:
texture.type = texture_type_rgba;
internal_format = gamma ? GL_SRGB_ALPHA : GL_RGBA;
data_format = GL_RGBA;
break;
default:
printf("error: \"%s\" unsupported type\n", filename);
goto end;
}
u64 size = texture.type * texture.width * texture.height;
texture.data = push_arena(arena, size);
prb_memmove(texture.data, data, size);
glGenTextures(1, &texture.id);
glBindTexture(GL_TEXTURE_2D, texture.id);
glTexImage2D(GL_TEXTURE_2D, 0, internal_format, texture.width, texture.height,
0, data_format, GL_UNSIGNED_BYTE, texture.data);
glGenerateMipmap(GL_TEXTURE_2D);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glBindTexture(GL_TEXTURE_2D, 0);
printf("info: \"%s\" loaded successfully\n", filename);
end:
stbi_image_free(data);
return texture;
}
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