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#include "../../include/mgl/graphics/image.h"
#include <assert.h>
#define STBI_NO_PSD
#define STBI_NO_TGA
#define STBI_NO_HDR
#define STBI_NO_PIC
#define STBI_NO_PNM
#define STB_IMAGE_IMPLEMENTATION
#include "../../external/stb_image.h"
static mgl_image_format stbi_format_to_mgl_image_format(int stbi_format) {
switch(stbi_format) {
case STBI_grey:
return MGL_IMAGE_FORMAT_GRAY;
case STBI_grey_alpha:
return MGL_IMAGE_FORMAT_GRAY_ALPHA;
case STBI_rgb:
return MGL_IMAGE_FORMAT_RGB;
case STBI_rgb_alpha:
return MGL_IMAGE_FORMAT_RGBA;
}
assert(0);
return MGL_IMAGE_FORMAT_RGBA;
}
static size_t mgl_image_format_num_channels(mgl_image_format image_format) {
switch(image_format) {
case MGL_IMAGE_FORMAT_ALPHA: return 1;
case MGL_IMAGE_FORMAT_GRAY: return 1;
case MGL_IMAGE_FORMAT_GRAY_ALPHA: return 2;
case MGL_IMAGE_FORMAT_RGB: return 3;
case MGL_IMAGE_FORMAT_RGBA: return 4;
}
assert(0);
return 4;
}
/* TODO: Ensure texture is power of 2 if the hardware doesn't support non power of two textures */
/* TODO: Verify if source format should always be 4 components (RGBA) because apparently if its another format then opengl will internally convert it to RGBA */
int mgl_image_load_from_file(mgl_image *self, const char *filepath) {
self->data = NULL;
self->width = 0;
self->height = 0;
int format;
self->data = stbi_load(filepath, &self->width, &self->height, &format, 0);
if(!self->data) {
fprintf(stderr, "Error: failed to load image %s, error: %s\n", filepath, stbi_failure_reason());
mgl_image_unload(self);
return -1;
}
self->format = stbi_format_to_mgl_image_format(format);
return 0;
}
/* TODO: Ensure texture is power of 2 if the hardware doesn't support non power of two textures */
/* TODO: Verify if source format should always be 4 components (RGBA) because apparently if its another format then opengl will internally convert it to RGBA */
int mgl_image_load_from_memory(mgl_image *self, const unsigned char *data, size_t size) {
self->data = NULL;
self->width = 0;
self->height = 0;
int format;
self->data = stbi_load_from_memory(data, size, &self->width, &self->height, &format, 0);
if(!self->data) {
fprintf(stderr, "Error: failed to load image from memory, error: %s\n", stbi_failure_reason());
mgl_image_unload(self);
return -1;
}
self->format = stbi_format_to_mgl_image_format(format);
return 0;
}
void mgl_image_unload(mgl_image *self) {
if(self->data) {
stbi_image_free(self->data);
self->data = NULL;
}
self->width = 0;
self->height = 0;
self->format = 0;
}
size_t mgl_image_get_size(const mgl_image *self) {
return (size_t)self->width * (size_t)self->height * mgl_image_format_num_channels(self->format);
}
int mgl_image_get_num_channels(const mgl_image *self) {
return mgl_image_format_num_channels(self->format);
}
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