Got rid of glBlendFuncSeparate which caused problems on old hardware -- need to find a proper fix for incorrect alpha values when rendering to a RenderImage

git-svn-id: https://sfml.svn.sourceforge.net/svnroot/sfml/branches/sfml2@1172 4e206d99-4929-0410-ac5d-dfc041789085
This commit is contained in:
LaurentGom 2009-07-12 10:27:28 +00:00
parent 9c959777d3
commit 0f7cb43902

View File

@ -46,8 +46,6 @@ myBlendMode (Blend::Alpha),
myNeedUpdate (true),
myInvNeedUpdate(true)
{
// Make sure that GLEW is initialized (for glBlendFuncSeparate)
EnsureGlewInit();
}
@ -378,22 +376,14 @@ void Drawable::Draw(RenderTarget& target) const
{
GLCheck(glEnable(GL_BLEND));
// We have to use glBlendFuncSeparate so that the resulting alpha is
// not alpha², which is incorrect and would cause problems when rendering
// alpha pixels to a RenderImage that would be in turn rendered to another render target
// @todo the resulting alpha may not be correct, which matters when target is a RenderImage.
// find a fix for this (glBlendFuncSeparate -- but not supported by every graphics card)
switch (myBlendMode)
{
case Blend::Alpha :
GLCheck(glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA));
break;
case Blend::Add :
GLCheck(glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE, GL_ONE, GL_ONE_MINUS_SRC_ALPHA));
break;
case Blend::Multiply :
GLCheck(glBlendFuncSeparate(GL_DST_COLOR, GL_ZERO, GL_ONE, GL_ONE_MINUS_SRC_ALPHA));
break;
default :
break;
case Blend::Alpha : GLCheck(glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)); break;
case Blend::Add : GLCheck(glBlendFunc(GL_SRC_ALPHA, GL_ONE)); break;
case Blend::Multiply : GLCheck(glBlendFunc(GL_DST_COLOR, GL_ZERO)); break;
default : break;
}
}