Source code for silx.gui._glutils.gl

# coding: utf-8
# /*##########################################################################
#
# Copyright (c) 2014-2017 European Synchrotron Radiation Facility
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
# ###########################################################################*/
"""This module loads PyOpenGL and provides a namespace for OpenGL."""

__authors__ = ["T. Vincent"]
__license__ = "MIT"
__date__ = "25/07/2016"


from contextlib import contextmanager as _contextmanager
from ctypes import c_uint
import logging

_logger = logging.getLogger(__name__)

import OpenGL
# Set the following to true for debugging
if _logger.getEffectiveLevel() <= logging.DEBUG:
    _logger.debug('Enabling PyOpenGL debug flags')
    OpenGL.ERROR_LOGGING = True
    OpenGL.ERROR_CHECKING = True
    OpenGL.ERROR_ON_COPY = True
else:
    OpenGL.ERROR_LOGGING = False
    OpenGL.ERROR_CHECKING = False
    OpenGL.ERROR_ON_COPY = False

import OpenGL.GL as _GL
from OpenGL.GL import *  # noqa

# Extentions core in OpenGL 3
from OpenGL.GL.ARB import framebuffer_object as _FBO
from OpenGL.GL.ARB.framebuffer_object import *  # noqa
from OpenGL.GL.ARB.texture_rg import GL_R32F, GL_R16F  # noqa
from OpenGL.GL.ARB.texture_rg import GL_R16, GL_R8  # noqa

# PyOpenGL 3.0.1 does not define it
try:
    GLchar
except NameError:
    from ctypes import c_char
    GLchar = c_char


[docs]def testGL(): """Test if required OpenGL version and extensions are available. This MUST be run with an active OpenGL context. """ version = glGetString(GL_VERSION).split()[0] # get version number major, minor = int(version[0]), int(version[2]) if major < 2 or (major == 2 and minor < 1): raise RuntimeError( "Requires at least OpenGL version 2.1, running with %s" % version) from OpenGL.GL.ARB.framebuffer_object import glInitFramebufferObjectARB from OpenGL.GL.ARB.texture_rg import glInitTextureRgARB if not glInitFramebufferObjectARB(): raise RuntimeError( "OpenGL GL_ARB_framebuffer_object extension required !") if not glInitTextureRgARB(): raise RuntimeError("OpenGL GL_ARB_texture_rg extension required !")
# Additional setup if hasattr(glget, 'addGLGetConstant'): glget.addGLGetConstant(GL_FRAMEBUFFER_BINDING, (1,)) @_contextmanager
[docs]def enabled(capacity, enable=True): """Context manager enabling an OpenGL capacity. This is not checking the current state of the capacity. :param capacity: The OpenGL capacity enum to enable/disable :param bool enable: True (default) to enable during context, False to disable """ if enable: glEnable(capacity) yield glDisable(capacity) else: glDisable(capacity) yield glEnable(capacity)
[docs]def disabled(capacity, disable=True): """Context manager disabling an OpenGL capacity. This is not checking the current state of the capacity. :param capacity: The OpenGL capacity enum to disable/enable :param bool disable: True (default) to disable during context, False to enable """ return enabled(capacity, not disable)
# Additional OpenGL wrapping
[docs]def glGetActiveAttrib(program, index): """Wrap PyOpenGL glGetActiveAttrib""" bufsize = glGetProgramiv(program, GL_ACTIVE_ATTRIBUTE_MAX_LENGTH) length = GLsizei() size = GLint() type_ = GLenum() name = (GLchar * bufsize)() _GL.glGetActiveAttrib(program, index, bufsize, length, size, type_, name) return name.value, size.value, type_.value
def glDeleteRenderbuffers(buffers): if not hasattr(buffers, '__len__'): # Support single int argument buffers = [buffers] length = len(buffers) _FBO.glDeleteRenderbuffers(length, (c_uint * length)(*buffers)) def glDeleteFramebuffers(buffers): if not hasattr(buffers, '__len__'): # Support single int argument buffers = [buffers] length = len(buffers) _FBO.glDeleteFramebuffers(length, (c_uint * length)(*buffers)) def glDeleteBuffers(buffers): if not hasattr(buffers, '__len__'): # Support single int argument buffers = [buffers] length = len(buffers) _GL.glDeleteBuffers(length, (c_uint * length)(*buffers)) def glDeleteTextures(textures): if not hasattr(textures, '__len__'): # Support single int argument textures = [textures] length = len(textures) _GL.glDeleteTextures((c_uint * length)(*textures))