root/trunk/RBRapier/RBRapier/Renderer/Appearance/Blending.py

#!/usr/bin/env python
##~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
##~ License 
##~ 
##- The RuneBlade Foundation library is intended to ease some 
##- aspects of writing intricate Jabber, XML, and User Interface (wxPython, etc.) 
##- applications, while providing the flexibility to modularly change the 
##- architecture. Enjoy.
##~ 
##~ Copyright (C) 2002  TechGame Networks, LLC.
##~ 
##~ This library is free software; you can redistribute it and/or
##~ modify it under the terms of the BSD style License as found in the 
##~ LICENSE file included with this distribution.
##~ 
##~ TechGame Networks, LLC can be reached at:
##~ 3578 E. Hartsel Drive #211
##~ Colorado Springs, Colorado, USA, 80920
##~
##~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#~ Imports 
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

from OpenGL import GL

from RBFoundation.Objects.Properties import LazyProperty

from RBRapier.Renderer.AttributeMgr import AttributeChangeElement
from RBRapier.Tools import Vector

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#~ Definitions 
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

class Blend(object):
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #~ Constants / Variables / Etc. 
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    AttributeChange = AttributeChangeElement(GL.GL_COLOR_BUFFER_BIT)
    SourceFactor = GL.GL_SRC_ALPHA
    DestinationFactor = GL.GL_ONE_MINUS_SRC_ALPHA

    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #~ Public Methods 
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    def __init__(self, SourceFactor=GL.GL_SRC_ALPHA, DestinationFactor=GL.GL_ONE_MINUS_SRC_ALPHA):
        self.SourceFactor = SourceFactor
        self.DestinationFactor = DestinationFactor

    def GLSelect(self, context):
        context.StateMgr.Enable(GL.GL_BLEND)
        GL.glBlendFunc(self.SourceFactor, self.DestinationFactor)

    def GLDeselect(self, context):
        context.StateMgr.Disable(GL.GL_BLEND)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

class BlendSeperateAlpha(Blend):
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #~ Constants / Variables / Etc. 
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    SourceAlphaFactor = None
    DestinationAlphaFactor = None

    class _Extensions(object):
        def __init__(self):
            from OpenGL.GL.EXT import blend_func_separate
            self.blend_func_separate = blend_func_separate.glInitBlendFuncSeparateEXT() and blend_func_separate or None
    _extensions = LazyProperty(_Extensions)

    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #~ Public Methods 
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    def __init__(self, SourceFactor=GL.GL_SRC_ALPHA, SourceAlphaFactor=None, DestinationFactor=GL.GL_ONE_MINUS_SRC_ALPHA, DestinationAlphaFactor=None):
        self.SourceFactor = SourceFactor
        self.SourceAlphaFactor = SourceAlphaFactor
        self.DestinationFactor = DestinationFactor
        self.DestinationAlphaFactor = DestinationAlphaFactor

    def GLSelect(self, context):
        SourceAlphaFactor = self.SourceAlphaFactor 
        if SourceAlphaFactor is None: SourceAlphaFactor = self.SourceFactor 
        DestinationAlphaFactor = self.DestinationAlphaFactor 
        if DestinationAlphaFactor is None: DestinationAlphaFactor = self.DestinationFactor 

        context.StateMgr.Enable(GL.GL_BLEND)
        ex = self._extensions.blend_func_separate
        ex.glBlendFuncSeparateEXT(self.SourceFactor, SourceAlphaFactor, self.DestinationFactor, DestinationAlphaFactor)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

class BlendConstant(object):
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #~ Title 
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    AttributeChange = AttributeChangeElement(GL.GL_COLOR_BUFFER_BIT)
    Constant = Vector.ColorVectorProperty('BlendConstant', (1., 1., 1., 1.))

    class _Extensions(object):
        def __init__(self):
            from OpenGL.GL.EXT import blend_color
            self.blend_color = blend_color.glInitBlendColorEXT() and blend_color or None
    _extensions = LazyProperty(_Extensions)

    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #~ Public Methods 
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    def __init__(self, constant=None):
        if constant is not None:
            self.Constant = constant

    def GLSelect(self, context):
        ex = self._extensions.blend_color
        ex.glBlendColorEXT(*self.Constant.tolist())

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

class BlendEquation(object):
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #~ Constants / Variables / Etc. 
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    AttributeChange = AttributeChangeElement(GL.GL_COLOR_BUFFER_BIT)
    Equation = None

    class _Extensions(object):
        def __init__(self):
            from OpenGL.GL.EXT import blend_minmax
            self.blend_minmax = blend_minmax.glInitBlendMinmaxEXT() and blend_minmax or None
    _extensions = LazyProperty(_Extensions)

    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #~ Public Methods 
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    def __init__(self, Equation):
        self.Equation = Equation

    def GLSelect(self, context):
        ex = self._extensions.blend_minmax
        ex.glBlendEquationEXT(self.Equation)