VAO.cpp

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#include "VAO.hpp"
 
namespace BARE2D {
 
    VAO::VAO()
    {
        m_numAttributes = 0;
    }
 
    VAO::~VAO()
    {
    }
 
    void VAO::init()
    {
        // Generate VAO, VBO, and connect em up
        // Generate VAO
        glGenVertexArrays(1, &m_vaoHandle);
        
        // Now bind it so the VBO is created as a part of it
        bind();
        
        // Generate VBO inside of the VAO
        glGenBuffers(1, &m_vboHandle);
        
        // Bind the VBO to the VAO
        glBindBuffer(GL_ARRAY_BUFFER, m_vboHandle);
        
        // Unbind, we're done for now.
        unbind();
    }
 
    void VAO::destroy()
    {
        // Unbind first!
        unbind();
        
        // Disable all vertex attributes
        for(unsigned int i = 0; i < m_numAttributes; i++) {
            glDisableVertexAttribArray(i);
        }
        
        // Delete buffers
        glDeleteBuffers(1, &m_vboHandle);
        glDeleteVertexArrays(1, &m_vaoHandle);
    }
 
    void VAO::bind()
    {
        glBindVertexArray(m_vaoHandle);
    }
    
    void VAO::unbind() {
        glBindVertexArray(0);
    }
 
    void VAO::bindVBO()
    {
        glBindBuffer(GL_ARRAY_BUFFER, m_vboHandle);
    }
    
    void VAO::unbindVBO() {
        glBindBuffer(GL_ARRAY_BUFFER, 0);
    }
 
    void VAO::addVertexAttribute(GLint size, GLenum type, GLboolean normalized, GLsizei stride, const void* data)
    {
        // Bind first - It doesn't matter that this is inefficient because we're only calling this like 3 times in the whole program
        bind();
        bindVBO();
        
        // Tell OpenGL what kind of data goes in that array
        glVertexAttribPointer(m_numAttributes, size, type, normalized, stride, data);
        // Enable the array
        glEnableVertexAttribArray(m_numAttributes);
        
        // Increment our number of attributes to reflect reality.
        m_numAttributes++;
        
        // Unbind for safety!
        unbind();
    }
 
}