#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;
}