#include "index_buffer.h"

#include <glad/glad.h>

namespace Donut
{
    IndexBuffer::IndexBuffer(const uint32_t* indices, uint32_t count)
        : m_count(count)
    {
        glGenBuffers(1, &m_renderer_id); // glCreateBuffers is 4.5 DSA; unavailable on macOS 4.1
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_renderer_id);
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, count * sizeof(uint32_t), indices, GL_STATIC_DRAW);
    }

    IndexBuffer::~IndexBuffer()
    {
        glDeleteBuffers(1, &m_renderer_id);
    }

    auto IndexBuffer::bind() const -> void
    {
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_renderer_id);
    }

    auto IndexBuffer::unbind() const -> void
    {
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
    }

    auto IndexBuffer::create(const uint32_t* indices, uint32_t count) -> IndexBuffer*
    {
        return new IndexBuffer(indices, count);
    }
};