/*
 * File:   VertexBuffer.cpp
 * Author: bombpersons
 *
 * Created on May 17, 2011, 7:40 PM
 */

#include "VertexBuffer.h"

VertexBuffer::VertexBuffer() {
    // Allocate a buffer
    //glGenBuffers(1, &name);
}

VertexBuffer::VertexBuffer(const VertexBuffer& orig) {
}

VertexBuffer::~VertexBuffer() {
    // We're finished with the buffers now
    glDeleteBuffers(1, &name);
}

/* ------------------------------- Generate a buffer name --------------------*/
void VertexBuffer::GenBuffer() {
    glGenBuffers(1, &name);
}

/* -------------------------- Fill the buffer --------------------------------*/
void VertexBuffer::Fill(void* _vertexData, GLsizeiptr _vertexSize, GLsizeiptr _vertexItemSize,
                        void* _colorData, GLsizeiptr _colorSize, GLsizeiptr _colorItemSize,
                        void* _texData, GLsizeiptr _texSize, GLsizeiptr _texItemSize,
                        void* _normalData, GLsizeiptr _normalSize, GLsizeiptr _normalItemSize) {
    // Bind the buffer
    glBindBuffer(GL_ARRAY_BUFFER, name);

    // Allocate memory in the buffer
    glBufferData(GL_ARRAY_BUFFER, _vertexSize+_colorSize+_texSize+_normalSize, 0, GL_STATIC_DRAW);

    // Map the buffer to memory
    uint8_t* buffer = (uint8_t*)glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
    if (!buffer)
        throw OutOfMemoryException();

    // Create more convenient pointers to the data
    uint8_t* v = (uint8_t*)_vertexData;
    uint8_t* c = (uint8_t*)_colorData;
    uint8_t* t = (uint8_t*)_texData;
    uint8_t* n = (uint8_t*)_normalData;

    // The length
    unsigned int length = _vertexSize / _vertexItemSize;

    // The total size of one element
    GLsizeiptr totalSize = _vertexItemSize+_colorItemSize+_texItemSize+_normalItemSize;

    // Loop through and write to the buffer
    for (unsigned int i = 0; i < length; ++i) {
        // Write vertex data
        if (_vertexData) {
            for (int j = 0; j < _vertexItemSize; ++j) {
                buffer[totalSize*i + j] = v[i*_vertexItemSize + j];
            }
        }

        // Write color data
        if (_colorData) {
            for (int j = 0; j < _colorItemSize; ++j) {
                buffer[totalSize*i + j + _vertexItemSize] = c[i*_colorItemSize + j];
            }
        }

        // Write texture data
        if (_texData) {
            for (int j = 0; j < _texItemSize; ++j) {
                buffer[totalSize*i + j + _vertexItemSize + _colorItemSize] = t[i*_texItemSize + j];
            }
        }

        // Write normal data
        if (_normalData) {
            for (int j = 0; j < _normalItemSize; ++j) {
                buffer[totalSize*i + j + _vertexItemSize + _colorItemSize + _texItemSize] = n[i*_normalItemSize + j];
            }
        }
    }

    // Unmap the buffer
    glUnmapBuffer(GL_ARRAY_BUFFER);

    // Unbind the buffer
    glBindBuffer(GL_ARRAY_BUFFER, 0);

    // Set the sizes of the buffers
    vertexSize = _vertexItemSize;
    colorSize = _colorItemSize;
    texSize = _texItemSize;
    normalSize = _normalItemSize;
    itemSize = vertexSize + colorSize + texSize + normalSize;
    bufferSize = _vertexSize+_colorSize+_texSize+_normalSize;
    bufferLength = length;
}