PIX debugging in XNA

Most of the information on how to use PIX with Xna is readiliy available on the net. Two issues took me a while to finally get my shader’s source code to display in PIX for my Xna applications though:

• Xna will add debug information to shaders compiled with the default processor if you’re running a debug build. Apparently you should take that quite literally: your project configuration should actually be named “Debug”. In stead of using the DEBUG preprocessor define, it seems they are doing a string compare on the configuration name. I renamed my project configs since my build is set up a bit more complex than just Debug/Release, and didn’t have shader debug info in PIX
• To resolve this, I extended the content pipeline with my own basic effect processor that adds the debug flag depending on the DEBUG preprocessor define. What I didn’t know was that Effect.CompileEffectFromSource doesn’t do anything with the CompilerOptions.Debug flag, since PIX needs a link between the source file and the debug info. In stead, use Effect.CompileEffectFromFile.

Here’s the code for my custom effect processor:

[ContentProcessor(DisplayName = "Effect - Hyperion Effect Debug Processor")]
public class EffectDebugProcessor : EffectProcessor
{
    public override CompiledEffect Process(EffectContent input, ContentProcessorContext context)
    {
        CompiledEffect compiledEffect = Effect.CompileEffectFromFile(
            input.Identity.SourceFilename,
            null,
            null,
            CompilerOptions.NoPreShader
            #if DEBUG
                | CompilerOptions.Debug
                | CompilerOptions.SkipOptimization
                | CompilerOptions.AvoidFlowControl
            #endif
            ,
            context.TargetPlatform
            );

        if (!compiledEffect.Success)
        {
            compiledEffect = Effect.CompileEffectFromFile(
            input.Identity.SourceFilename,
            null,
            null,
            CompilerOptions.NoPreShader
            #if DEBUG
                | CompilerOptions.Debug
                | CompilerOptions.AvoidFlowControl
            #endif
            ,
            context.TargetPlatform
            );
        }

        return compiledEffect;
    }
}