ShaderProgram.cpp

#include <GL/glew.h>
#include <GL/glut.h>
#include <iostream>
#include <fstream>
#include <string>
using namespace std;

#include "ShaderProgram.h"

const char* ShaderProgram::SHADER_FOLDER = "shaders";

ShaderProgram::ShaderProgram() {
	programID = glCreateProgram();
}

void ShaderProgram::addShader(GLuint type, string path) {
	GLuint shaderID = glCreateShader(type);
	loadSource(shaderID, path);
	std::cout << "Compiling Shader " << path << std::endl;
	glCompileShader(shaderID);
	printCompileInfoLog(shaderID);
	glAttachShader(programID, shaderID);
}

void ShaderProgram::compile() {
	glLinkProgram(programID);
	printLinkInfoLog(programID);
	validateProgram(programID);
}

void ShaderProgram::uniformMatrix4fv(std::string str, GLuint n, GLboolean b, const GLfloat* pointer) {
	GLuint loc = glGetUniformLocation(programID, str.c_str());
	glUniformMatrix4fv( loc, n, b, pointer );
}

void ShaderProgram::vertexAttribPointer(BufferObject<GL_SHADER_STORAGE_BUFFER>* buffer, std::string str, GLuint size, GLuint type, GLboolean b, GLuint offset, void* pointer) {
	glBindBuffer(GL_ARRAY_BUFFER, buffer->id());    
	GLuint loc = glGetAttribLocation(programID, str.c_str()); 
	glEnableVertexAttribArray(loc); 
	glVertexAttribPointer( loc, size, type, b, offset, (char *)NULL + 0 );
}

// BEGIN: Carga shaders ////////////////////////////////////////////////////////////////////////////////////////////

void loadSource(GLuint &shaderID, std::string name) {
	std::ifstream f(name.c_str());
	if (!f.is_open()) {
		std::cerr << "File not found " << name.c_str() << std::endl;
		system("pause");
		exit(EXIT_FAILURE);
	}
	// now read in the data
	std::string *source;
	source = new std::string( std::istreambuf_iterator<char>(f),   
						std::istreambuf_iterator<char>() );
	f.close();
   
	// add a null to the string
	*source += "\0";
	const GLchar * data = source->c_str();
	glShaderSource(shaderID, 1, &data, NULL);
	delete source;
}

void printCompileInfoLog(GLuint shadID) 
{
GLint compiled;
	glGetShaderiv( shadID, GL_COMPILE_STATUS, &compiled );
	if (compiled == GL_FALSE)
	{
		GLint infoLength = 0;
		glGetShaderiv( shadID, GL_INFO_LOG_LENGTH, &infoLength );

		GLchar *infoLog = new GLchar[infoLength];
		GLint chsWritten = 0;
		glGetShaderInfoLog( shadID, infoLength, &chsWritten, infoLog );

		std::cerr << "Shader compiling failed:" << infoLog << std::endl;
		system("pause");
		delete [] infoLog;

		exit(EXIT_FAILURE);
	}
}

void printLinkInfoLog(GLuint programID)
{
GLint linked;
	glGetProgramiv( programID, GL_LINK_STATUS, &linked );
	if(! linked)
	{
		GLint infoLength = 0;
		glGetProgramiv( programID, GL_INFO_LOG_LENGTH, &infoLength );

		GLchar *infoLog = new GLchar[infoLength];
		GLint chsWritten = 0;
		glGetProgramInfoLog( programID, infoLength, &chsWritten, infoLog );

		std::cerr << "Shader linking failed:" << infoLog << std::endl;
		system("pause");
		delete [] infoLog;

		exit(EXIT_FAILURE);
	}
}

void validateProgram(GLuint programID)
{
GLint status;
    glValidateProgram( programID );
    glGetProgramiv( programID, GL_VALIDATE_STATUS, &status );

    if( status == GL_FALSE ) 
	{
		GLint infoLength = 0;
		glGetProgramiv( programID, GL_INFO_LOG_LENGTH, &infoLength );

        if( infoLength > 0 ) 
		{
			GLchar *infoLog = new GLchar[infoLength];
			GLint chsWritten = 0;
            glGetProgramInfoLog( programID, infoLength, &chsWritten, infoLog );
			std::cerr << "Program validating failed:" << infoLog << std::endl;
			system("pause");
            delete [] infoLog;

			exit(EXIT_FAILURE);
		}
    }
}

// END:   Carga shaders ////////////////////////////////////////////////////////////////////////////////////////////