Dengine/src/AssetManager.cpp

#include <Dengine\AssetManager.h>

#define STBI_FAILURE_USERMSG
#define STB_IMAGE_IMPLEMENTATION
#include <STB/stb_image.h>
#include <fstream>

namespace Dengine
{

	AssetManager::AssetManager(){}
	AssetManager::~AssetManager(){}

	Texture *AssetManager::getTexture(std::string name)
	{
		// NOTE(doyle): Since we're using a map, the count of an object can
		// only be 1 or 0
		if (mTextures.count(name) == 1)
			return &mTextures[name];

		return nullptr;
	}

	i32 AssetManager::loadTextureImage(std::string path, std::string name)
	{
	    /* Open the texture image */
	    i32 imgWidth, imgHeight, bytesPerPixel;
	    stbi_set_flip_vertically_on_load(TRUE);
	    u8 *image =
	        stbi_load(path.c_str(), &imgWidth, &imgHeight, &bytesPerPixel, 0);

	    if (!image)
	    {
		    std::cerr << "stdbi_load() failed: " << stbi_failure_reason()
		              << std::endl;
		    return -1;
	    }

		Texture tex;
		tex.generate(imgWidth, imgHeight, image);
	    stbi_image_free(image);

		mTextures[name] = tex;
		return 0;
    }

	Shader *AssetManager::getShader(std::string name)
	{
		if (mShaders.count(name) == 1)
			return &mShaders[name];

		return nullptr;
	}

    INTERNAL std::string stringFromFile(const std::string &filename)
    {
	    std::ifstream file;
	    file.open(filename.c_str(), std::ios::in | std::ios::binary);

	    std::string output;
	    std::string line;

	    if (!file.is_open())
	    {
		    std::runtime_error(std::string("Failed to open file: ") + filename);
	    }
	    else
	    {
		    while (file.good())
		    {
			    std::getline(file, line);
			    output.append(line + "\n");
		    }
	    }
	    file.close();
	    return output;
    }

    INTERNAL GLuint createShaderFromPath(std::string path, GLuint shadertype)
    {
	    std::string shaderSource = stringFromFile(path);
	    const GLchar *source     = shaderSource.c_str();

	    GLuint result = glCreateShader(shadertype);
	    glShaderSource(result, 1, &source, NULL);
	    glCompileShader(result);

	    GLint success;
	    GLchar infoLog[512];
	    glGetShaderiv(result, GL_COMPILE_STATUS, &success);
	    if (!success)
	    {
		    glGetShaderInfoLog(result, 512, NULL, infoLog);
		    std::cout << "glCompileShader failed: " << infoLog << std::endl;
	    }

	    return result;
    }

    i32 AssetManager::loadShaderFiles(std::string vertexPath,
                                     std::string fragmentPath, std::string name)
    {

	    GLuint vertexShader =
	        createShaderFromPath(vertexPath, GL_VERTEX_SHADER);
	    GLuint fragmentShader =
	        createShaderFromPath(fragmentPath, GL_FRAGMENT_SHADER);

	    Shader shader;
		i32 result = shader.loadProgram(vertexShader, fragmentShader);
		if (result)
			return result;

		mShaders[name] = shader;
		return 0;
	}

}