# ----------------------------------------------------------------------------
# cocos2d
# Copyright (c) 2008-2012 Daniel Moisset, Ricardo Quesada, Rayentray Tappa,
# Lucio Torre
# Copyright (c) 2009-2017  Richard Jones, Claudio Canepa
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# ----------------------------------------------------------------------------
"""A thin wrapper for OpenGL framebuffer objets. For implementation use only"""

from __future__ import division, print_function, unicode_literals

__docformat__ = 'restructuredtext'

import ctypes as ct

from pyglet import gl


class FramebufferObject (object):
    """
    Wrapper for framebuffer objects. See

    http://oss.sgi.com/projects/ogl-sample/registry/EXT/framebuffer_object.txt

    API is not very OO, should be improved.
    """
    def __init__(self):
        """Create a new framebuffer object"""
        id = gl.GLuint(0)
        gl.glGenFramebuffersEXT(1, ct.byref(id))
        self._id = id.value

    def bind(self):
        """Set FBO as current rendering target"""
        gl.glBindFramebufferEXT(gl.GL_FRAMEBUFFER_EXT, self._id)

    def unbind(self):
        """Set default framebuffer as current rendering target"""
        gl.glBindFramebufferEXT(gl.GL_FRAMEBUFFER_EXT, 0)

    def texture2d(self, texture):
        """Map currently bound framebuffer (not necessarily self) to texture"""
        gl.glFramebufferTexture2DEXT(
            gl.GL_FRAMEBUFFER_EXT,
            gl.GL_COLOR_ATTACHMENT0_EXT,
            texture.target,
            texture.id,
            texture.level)

    def check_status(self):
        """Check that currently set framebuffer is ready for rendering"""
        status = gl.glCheckFramebufferStatusEXT(gl.GL_FRAMEBUFFER_EXT)
        if status != gl.GL_FRAMEBUFFER_COMPLETE_EXT:
            raise Exception("Frambuffer not complete: %d" % status)

    def __del__(self):
        """Delete the framebuffer from the GPU memory"""
        id = gl.GLuint(self._id)
        gl.glDeleteFramebuffersEXT(1, ct.byref(id))
