#include "renderer/mesh.h"

Mesh::Mesh() {
    glGenVertexArrays(1, &m_vao);
    glGenBuffers(1, &m_vbo);
    glGenBuffers(1, &m_ebo);

    glBindVertexArray(m_vao);

    // VBO (vertex buffer)
    glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
    glBufferData(GL_ARRAY_BUFFER, 0, nullptr, GL_STATIC_DRAW);

    // EBO (index buffer)
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ebo);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, 0, nullptr, GL_STATIC_DRAW);

    Vertex::DefineAttrib();

    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindVertexArray(0);
}

void Mesh::Upload()
{
    glBindVertexArray(m_vao);

    glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
    glBufferData(GL_ARRAY_BUFFER, m_vertexBuffer.size() * sizeof(Vertex), m_vertexBuffer.data(), GL_STATIC_DRAW);

    // Upload indices
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ebo);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, m_indexBuffer.size() * sizeof(unsigned int), m_indexBuffer.data(), GL_STATIC_DRAW);

    glBindVertexArray(0);
}

void Mesh::Render()
{
    Bind();
    glDrawElements(GL_TRIANGLES, static_cast<GLsizei>(m_indexBuffer.size()), GL_UNSIGNED_INT, 0);
    Unbind();
}