OpenSceneGraph/src/osg/BlendColor.cpp
2012-03-21 17:36:20 +00:00

113 lines
3.2 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* OpenSceneGraph Public License for more details.
*/
#include <osg/BlendColor>
#include <osg/GLExtensions>
#include <osg/State>
#include <osg/Notify>
#include <osg/buffered_value>
using namespace osg;
BlendColor::BlendColor() :
_constantColor(1.0f,1.0f,1.0f,1.0f)
{
}
BlendColor::BlendColor(const osg::Vec4& constantColor):
_constantColor(constantColor)
{
}
BlendColor::~BlendColor()
{
}
void BlendColor::apply(State& state) const
{
// get the contextID (user defined ID of 0 upwards) for the
// current OpenGL context.
const unsigned int contextID = state.getContextID();
const Extensions* extensions = getExtensions(contextID,true);
if (!extensions->isBlendColorSupported())
{
OSG_WARN<<"Warning: BlendColor::apply(..) failed, BlendColor is not support by OpenGL driver."<<std::endl;
return;
}
extensions->glBlendColor(_constantColor[0], _constantColor[1],
_constantColor[2], _constantColor[3]);
}
typedef buffered_value< ref_ptr<BlendColor::Extensions> > BufferedExtensions;
static BufferedExtensions s_extensions;
BlendColor::Extensions* BlendColor::getExtensions(unsigned int contextID,bool createIfNotInitalized)
{
if (!s_extensions[contextID] && createIfNotInitalized) s_extensions[contextID] = new Extensions(contextID);
return s_extensions[contextID].get();
}
void BlendColor::setExtensions(unsigned int contextID,Extensions* extensions)
{
s_extensions[contextID] = extensions;
}
BlendColor::Extensions::Extensions(unsigned int contextID)
{
setupGLExtensions(contextID);
}
BlendColor::Extensions::Extensions(const Extensions& rhs):
Referenced()
{
_isBlendColorSupported = rhs._isBlendColorSupported;
_glBlendColor = rhs._glBlendColor;
}
void BlendColor::Extensions::lowestCommonDenominator(const Extensions& rhs)
{
if (!rhs._isBlendColorSupported) _isBlendColorSupported = false;
if (!rhs._glBlendColor) _glBlendColor = 0;
}
void BlendColor::Extensions::setupGLExtensions(unsigned int contextID)
{
_isBlendColorSupported = OSG_GLES2_FEATURES || OSG_GL3_FEATURES ||
isGLExtensionSupported(contextID,"GL_EXT_blend_color") ||
strncmp((const char*)glGetString(GL_VERSION),"1.2",3)>=0;
setGLExtensionFuncPtr(_glBlendColor, "glBlendColor", "glBlendColorEXT");
}
void BlendColor::Extensions::glBlendColor(GLclampf red , GLclampf green , GLclampf blue , GLclampf alpha) const
{
if (_glBlendColor)
{
_glBlendColor(red, green, blue, alpha);
}
else
{
OSG_WARN<<"Error: glBlendColor not supported by OpenGL driver"<<std::endl;
}
}