Hi, I don't know of a way to pass #define values, other than composing a shader of multiple strings:
(enableSimple ? "#define SIMPLE\n" : "#undef SIMPLE\n"), "#ifdef SIMPLE\n" "vec4 Color = vec4(1.0);\n" "#else if NOT_SO_SIMPLE\n" "vec4 Color = unimaginableComplicatedColorFunction(...)\n" "#endif\n" OpenGL doesn't have an interface analogous to compiler commandline parameters (eg: "gcc -DSIMPLE") Perhaps this is an area OSG could formalize and provide a value-add? Of course, the preprocessor is a compile-time conditional, and so probably wont be an issue beyond app startup; runtime conditionals should be expressed using uniforms. cheers -- mew > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:osg-users- > [EMAIL PROTECTED] On Behalf Of Sebastian Messerschmidt > Sent: Monday, February 25, 2008 4:02 AM > To: [email protected] > Subject: [osg-users] GLSL Preprocessor > > Hello, > > I was wondering if the preprocessor language in GLSL is somehow useable > for osg. > Imagine I had a shader with > > .. > #ifdef SIMPLE > vec4 Color = vec4(1.0); > #else if NOT_SO_SIMPLE > vec4 Color = unimaginableComplicatedColorFunction(...) > #endif > > Can I pass those defines to osg::Shader? I didn't find anything. > So the only way to achive this is to modify the shader-code before > loading, right? > > cheers > Sebastian > > > .. > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users- > openscenegraph.org _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
