cpp-game-engine/graphics/src/texture.cpp

//
//  texture.cpp
//  graphics
//
//  Created by Sam Jaffe on 7/5/16.
//

#include "game/graphics/texture.hpp"

#include <unordered_map>

#include "scope_guard/scope_guard.hpp"

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wcomma"
#define STB_IMAGE_IMPLEMENTATION
#include "stb/stb_image.h"
#pragma clang diagnostic pop

#include "game/graphics/exception.h"
#include "game/util/env.hpp"
#include "game/util/hash.hpp"
#include "helper.hpp"

unsigned char * stbi_load(char const *, int *, int *, int *, int);
void stbi_image_free(void *);

using namespace graphics;
using namespace textures;

static format as_format(int comps) {
  switch (comps) {
  case 3:
    return format::RGB;
  case 4:
    return format::RGBA;
  default:
    throw unknown_texture_format(comps);
  }
}

external_data::external_data(std::string const & rel_path) {
  std::string abs_path = env::resource_file(rel_path);
  int components = 0;
  buffer = stbi_load(abs_path.c_str(), &size.x(), &size.y(), &components, 0);
  if (!buffer) { throw file_read_error("texture", rel_path); }
  color = as_format(components);
}

external_data::~external_data() {
  if (buffer) { stbi_image_free(buffer); }
}

texture::texture(unsigned int id, math::vec2i const & size)
    : identity<texture>(id), size(size) {}