#include "gl/DrawBuffer.hpp"

#include <map>

#include <gl/gl_core_3_3.h>
#include <gl/GeometryBuffer.hpp>

/* TODO: Come up with a more elegant solution to "WHICH ARRAY IS IT?" */
std::map<AttributeSemantic, GLuint> semantic_to_attrib_array = {
    {ATRS_Position, 0}, {ATRS_Normal, 1}, {ATRS_Colour, 2}, {ATRS_TexCoord, 3}};

DrawBuffer::DrawBuffer() : vao(0) {
}

DrawBuffer::~DrawBuffer() {
    if (vao) {
        glDeleteVertexArrays(1, &vao);
    }
}

void DrawBuffer::addGeometry(GeometryBuffer* gbuff) {
    if (vao == 0) {
        glGenVertexArrays(1, &vao);
    }

    glBindVertexArray(vao);
    glBindBuffer(GL_ARRAY_BUFFER, gbuff->getVBOName());
    // Iterate the attributes present in the gbuff
    for (const AttributeIndex& at : gbuff->getDataAttributes()) {
        GLuint vaoindex = semantic_to_attrib_array[at.sem];
        glEnableVertexAttribArray(vaoindex);
        glVertexAttribPointer(vaoindex, at.size, at.type, GL_TRUE, at.stride,
                              reinterpret_cast<GLvoid*>(at.offset));
    }
}