shader.cpp

#include <learn_OpenGL/shader.h>

void Shader::init(const char* vertexPath, const char* fragmentPath)
{
	// 1. Retrieve the vertex/fragment source code from filePath
	std::string vertexCode;
	std::string fragmentCode;
	try
	{
		FileReader file{ vertexPath };
		vertexCode = file.str();
		file.get_file( fragmentPath );
		fragmentCode = file.str();
	}
	catch (std::ifstream::failure e)
	{

		std::cout << "ERROR::SHADER::FILE_NOT_SUCCESFULLY_READ\n" << e.what() << std::endl;
	}
	const char* vShaderCode = vertexCode.c_str();
	const char* fShaderCode = fragmentCode.c_str();
	// 2. Compile shaders
	unsigned int vertex, fragment;
	int success;
	char infoLog[512];

	// Vertex Shader
	vertex = glCreateShader(GL_VERTEX_SHADER);
	glShaderSource(vertex, 1, &vShaderCode, NULL);
	glCompileShader(vertex);

	// Print compile errors if any
	glGetShaderiv(vertex, GL_COMPILE_STATUS, &success);
	if (!success)
	{
		glGetShaderInfoLog(vertex, 512, NULL, infoLog);
		std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
	}
	// Fragment Shader
	fragment = glCreateShader(GL_FRAGMENT_SHADER);
	glShaderSource(fragment, 1, &fShaderCode, NULL);
	glCompileShader(fragment);
	// Print compile errors if any
	glGetShaderiv(fragment, GL_COMPILE_STATUS, &success);
	if (!success)
	{
		glGetShaderInfoLog(fragment, 512, NULL, infoLog);
		std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
	}
	// Shader Program
	ID = glCreateProgram();
	glAttachShader(ID, vertex);
	glAttachShader(ID, fragment);
	glLinkProgram(ID);
	// Print linking errors if any
	glGetProgramiv(ID, GL_LINK_STATUS, &success);
	if (!success)
	{
		glGetProgramInfoLog(ID, 512, NULL, infoLog);
		std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
	}
	// Delete the shaders as they're linked into our program now and no longer necessery
	glDeleteShader(vertex);
	glDeleteShader(fragment);
}

void Shader::setBool(const std::string& name, bool value) const {
	glUniform1i(glGetUniformLocation(ID, name.c_str()), (int)value);
}
void Shader::setInt(const std::string& name, int value) const {
	glUniform1i(glGetUniformLocation(ID, name.c_str()), value);
}
void Shader::setFloat(const std::string& name, float value) const {
	glUniform1f(glGetUniformLocation(ID, name.c_str()), value);
}

void Shader::setVec2(const std::string & name, float value1, float value2) const
{
	glUniform2f(glGetUniformLocation(ID, name.c_str()), value1, value2);
}

void Shader::setVec3v(const std::string & name, const float * value, GLsizei count) const
{
	glUniform3fv(glGetUniformLocation(ID, name.c_str()), count, value);
}

void Shader::setVec4v(const std::string & name, const float * value, GLsizei count) const
{
	glUniform4fv(glGetUniformLocation(ID, name.c_str()), count, value);
}

void Shader::setMat4(const std::string& name, const float* value) const {
	glUniformMatrix4fv(glGetUniformLocation(ID, name.c_str()), 1, GL_FALSE, value);
}