// ----------------------------------------------------------------

// From Game Programming in C++ by Sanjay Madhav

// Copyright (C) 2017 Sanjay Madhav. All rights reserved.

//

// Released under the BSD License

// See LICENSE in root directory for full details.

// ----------------------------------------------------------------

#include "VertexArray.h"

#include <GL/glew.h>

VertexArray::VertexArray(const float* verts, const int size, unsigned int numVerts, const unsigned int* indices, unsigned int numIndices): mNumVerts(numVerts), mNumIndices(numIndices)

{

// Create vertex array

glGenVertexArrays(1, &mVertexArray);

glBindVertexArray(mVertexArray);

// Create vertex buffer

glGenBuffers(1, &mVertexBuffer);

glBindBuffer(GL_ARRAY_BUFFER, mVertexBuffer);

glBufferData(GL_ARRAY_BUFFER, numVerts * size * sizeof(float), verts, GL_STATIC_DRAW);

// Create index buffer

glGenBuffers(1, &mIndexBuffer);

glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mIndexBuffer);

glBufferData(GL_ELEMENT_ARRAY_BUFFER, numIndices * sizeof(unsigned int), indices, GL_STATIC_DRAW);

/* Specify the vertex attributes (For now, assume one vertex format)

NOTE: Position is 3 floats starting at offset 0*/

glEnableVertexAttribArray(0);

glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(float) * size, 0);

glEnableVertexAttribArray(1);

glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(float) * size, reinterpret_cast<void*>(sizeof(float) * 3));

// Tell OpenGl we want to create a new Attribute ID=2

glEnableVertexAttribArray(2);

// Tell OpenGL we want to create a Vecter3 of floats

// NOTE: ID, vector size, type, IDK, total size, starting index

glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, sizeof(float) * size, reinterpret_cast<void*>(sizeof(float) * 5));

}

VertexArray::~VertexArray()

{

glDeleteBuffers(1, &mVertexBuffer);

glDeleteBuffers(1, &mIndexBuffer);

glDeleteVertexArrays(1, &mVertexArray);

}

void VertexArray::SetActive()

{

glBindVertexArray(mVertexArray);

}