block.cpp

#include "Block.h"
#include <GL\glew.h>
#include <GLFW\glfw3.h>

Block::Block(const unsigned int blockID, const Vec3<double> position)
    : blockID(blockID), position(position)
{
    // Generate a vertex array
    double vertices[] =
    {
        position.x,     position.y,     position.z,
        position.x + 1, position.y,     position.z,
        position.x + 1, position.y + 1, position.z,
        position.x,     position.y + 1, position.z,
        position.x,     position.y,     position.z + 1,
        position.x + 1, position.y,     position.z + 1,
        position.x + 1, position.y + 1, position.z + 1,
        position.x,     position.y + 1, position.z + 1,
    };

    // "Generate" an index array
    const unsigned char indices[] =
    {
        1, 2, 5, 6,     // x+
        0, 4, 7, 3,     // x-
        0, 1, 5, 4,     // y+
        2, 3, 7, 6,     // y-
        3, 2, 1, 0,     // z+
        4, 5, 6, 7      // z-
    };

    // Generate buffers for the vertex and index arrays
    glGenBuffers(1, &_vertexBuffer);
    glGenBuffers(1, &_indexBuffer);

    // Bind the vertex buffer
    glBindBuffer(GL_ARRAY_BUFFER, _vertexBuffer);

    // Send vertex array to the GPU
    glBufferData(GL_ARRAY_BUFFER, sizeof(long long) * 8 * 3, vertices, GL_STATIC_DRAW);

    
    // Bind the index buffer
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _indexBuffer);

    // Send indx array to the GPU
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(char) * 4 * 6, indices, GL_STATIC_DRAW);
}

Block::~Block()
{
    glDeleteBuffers(1, &_vertexBuffer);
}

void Block::render()
{
    // Bind vertex and index buffers
    glBindBuffer(GL_ARRAY_BUFFER, _vertexBuffer);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _indexBuffer);

    // Enable vertex array for writing
    glEnableClientState(GL_VERTEX_ARRAY);

    // Define the array of vertex data
    glVertexPointer(3, GL_DOUBLE, 0, 0);

    // Draw 6 quads using offset from index buffer
    glDrawElements(GL_QUADS, 4 * 6, GL_UNSIGNED_BYTE, 0);

    // Disable vertex array for writing
    glDisableClientState(GL_VERTEX_ARRAY);

    // Unbind (bind to 0) vertex and index buffers
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}