#include <vector>
#include <glbinding/gl/gl.h>

#include "shaders.hh"
#include "Overlay.hh"

using namespace gl;

Overlay::Overlay(std::vector<ovlVertexAttribs> const& vas)
  : vbo_(VBOManager::getInstance().alloc(sizeof(ovlVertexAttribs)*vas.size())),
    vaID_(0), vertices_(vas.size())
{
  glBindBuffer(GL_ARRAY_BUFFER, vbo_.getVBOId());
  glBufferSubData(GL_ARRAY_BUFFER, vbo_.getOfs(),
		  sizeof(ovlVertexAttribs)*vas.size(),
		  static_cast<void const*>(vas.data()));

  glGenVertexArrays(1, &vaID_);
  try {
    glBindVertexArray(vaID_);

    glEnableVertexAttribArray(ATTRIB_VERTEX_POS);
    glVertexAttribPointer(ATTRIB_VERTEX_POS, 2, GL_SHORT, GL_FALSE,
			  sizeof(ovlVertexAttribs),
			  (void*)(vbo_.getOfs()+offsetof(ovlVertexAttribs, vertex)));

    glEnableVertexAttribArray(ATTRIB_VERTEX_TC);
    glVertexAttribPointer(ATTRIB_VERTEX_TC, 2, GL_UNSIGNED_SHORT, GL_TRUE,
			  sizeof(ovlVertexAttribs),
			  (void*)(vbo_.getOfs()+offsetof(ovlVertexAttribs, texCoords)));
  } catch(...) {
    glDeleteVertexArrays(1, &vaID_);
    throw;
  }
}

Overlay::~Overlay()
{
  glDeleteVertexArrays(1, &vaID_);
}

void Overlay::draw() const
{
  glBindVertexArray(vaID_);

  glDrawArrays(GL_TRIANGLES, 0, vertices_);
}