Mesh.cpp

/*
 * Mesh.cpp
 *
 *  Created on: Jan 19, 2015
 *      Author: alxndr
 */

#include "Mesh.hpp"

Mesh::Mesh(vector<Vertex> vertices, vector<GLuint> indices, vector<Texture> textures)
{
	this->vertices = vertices;
	this->indices = indices;
	this->textures = textures;

	this->setupMesh();
}

void::Mesh::Draw(Shader shader)
{
    // Bind appropriate textures
    GLuint diffuseNr = 1;
    GLuint specularNr = 1;
    for(GLuint i = 0; i < this->textures.size(); i++)
    {
        glActiveTexture(GL_TEXTURE0 + i); // Active proper texture unit before binding
        // Retrieve texture number (the N in diffuse_textureN)
        stringstream ss;
        string number;
        string name = this->textures[i].type;
        if(name == "texture_diffuse")
            ss << diffuseNr++; // Transfer GLuint to stream
        else if(name == "texture_specular")
            ss << specularNr++; // Transfer GLuint to stream
        number = ss.str();
        // Now set the sampler to the correct texture unit
        glUniform1f(glGetUniformLocation(shader.Program, (name + number).c_str()), i);
        // And finally bind the texture
        glBindTexture(GL_TEXTURE_2D, this->textures[i].id);
    }

    // Also set each mesh's shininess property to a default value (if you want you could extend this to another mesh property and possibly change this value)
    glUniform1f(glGetUniformLocation(shader.Program, "material.shininess"), 16.0f);

    // Draw mesh
    glBindVertexArray(this->VAO);
    glDrawElements(GL_TRIANGLES, this->indices.size(), GL_UNSIGNED_INT, 0);
    glBindVertexArray(0);

    // Always good practice to set everything back to defaults once configured.
    for (GLuint i = 0; i < this->textures.size(); i++)
    {
        glActiveTexture(GL_TEXTURE0 + i);
        glBindTexture(GL_TEXTURE_2D, 0);
    }
}

void Mesh::setupMesh()
{
	glGenVertexArrays(1, &this->VAO);
	glGenBuffers(1, &this->VBO);
	glGenBuffers(1, &this->EBO);

	glBindVertexArray(this->VAO);
	glBindBuffer(GL_ARRAY_BUFFER, this->VBO);

	glBufferData(GL_ARRAY_BUFFER, this->vertices.size() * sizeof(Vertex), &this->vertices[0], GL_STATIC_DRAW);

	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, this->EBO);
	glBufferData(GL_ELEMENT_ARRAY_BUFFER, this->indices.size() * sizeof(Vertex), &this->indices[0], GL_STATIC_DRAW);

	glEnableVertexAttribArray(0);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*)0);

	glEnableVertexAttribArray(1);
	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*)offsetof(Vertex, Normal));

	glEnableVertexAttribArray(2);
	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*)offsetof(Vertex, TexCoords));

	glBindVertexArray(0);
}