GLBuffer.hpp

#ifndef GLBUFFER_H
#define GLBUFFER_H
#include <cstddef>
#include "Buffer.hpp"
#include "GLUtil.hpp"
namespace Engine {
  class GLVertexBuffer : public VertexBuffer {
    private:
      unsigned int m_id = 0;
      size_t m_size{0};
      size_t m_offset{0};
 
    public:
      GLVertexBuffer(std::size_t size){
        // create buffer
        GLCall( glGenBuffers(1, &m_id) );
        // bind it to array
        GLCall( glBindBuffer(GL_ARRAY_BUFFER, m_id) );
        m_size = size;
        GLCall( glBufferData(GL_ARRAY_BUFFER, size, nullptr, GL_DYNAMIC_DRAW) );
      };
 
      ~GLVertexBuffer() {
        GLCall( glDeleteBuffers(1, &m_id) );
      };
 
      void Bind() override { 
        GLCall( glBindBuffer(GL_ARRAY_BUFFER, m_id) );
      };
 
      void Unbind() override {
        GLCall( glBindBuffer(GL_ARRAY_BUFFER, 0) );
      };
 
      void Load(float verts[], std::size_t size) override {
        // if size is zero then we will take this to mean that we are reseting
        if (size == 0) {
          m_offset = 0;
          return;
        }
        GLCall( glBufferSubData(GL_ARRAY_BUFFER, m_offset, size, verts) );
        m_offset += size;
      };
 
      size_t GetSize() override { return m_size; };
  };
 
  class GLIndexBuffer : public IndexBuffer {
    private:
      unsigned int m_id = 0;
      size_t m_size = 0;
    public:
      GLIndexBuffer() {
        // create buffer
        GLCall( glGenBuffers(1, &m_id) );
        // bind it to array
        GLCall( glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_id) );
      };
 
      ~GLIndexBuffer(){
        GLCall( glDeleteBuffers(1, &m_id) );
      };
 
      void Bind() override {
        GLCall( glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_id) );
      }
 
      void Unbind() override {
        GLCall( glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0) );
      }
 
      void Load(unsigned int inds[], std::size_t size) override {
        m_size = size;
        GLCall( glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_id) );
        GLCall( glBufferData(GL_ELEMENT_ARRAY_BUFFER,
              size,
              inds, GL_DYNAMIC_DRAW) );
      };
 
      size_t GetSize() override { return m_size; };
  };
 
}
#endif