# PBR effect with metallic texture support
# This effect extends the default PBR pipeline to support metallic textures
# Provides both multiplicative and direct control modes

fragment:
    defines: |
        #define USE_METALLIC_TEXTURE 1
        #define METALLIC_CONTROL_MODE 0  // 0=multiply, 1=direct, 2=additive

    inout: |
        uniform sampler2D p3d_Texture5;  // Metallic texture

    material: |
        // Add metallic texture support to the default material processing
        // Note: Don't override the default material processing, just extend it
        #if USE_METALLIC_TEXTURE
            // Sample metallic texture
            float sampled_metallic = texture(p3d_Texture5, texcoord).x;

            // Apply metallic texture based on control mode
            #if METALLIC_CONTROL_MODE == 0
                // Multiplicative mode (original behavior)
                m.metallic = mInput.metallic * sampled_metallic;
            #elif METALLIC_CONTROL_MODE == 1
                // Direct control mode
                m.metallic = sampled_metallic;
            #elif METALLIC_CONTROL_MODE == 2
                // Additive mode
                m.metallic = clamp(mInput.metallic + sampled_metallic, 0.0, 1.0);
            #else
                // Fallback to multiplicative
                m.metallic = mInput.metallic * sampled_metallic;
            #endif

            // Ensure valid range
            m.metallic = clamp(m.metallic, 0.0, 1.0);
        #endif

        // Note: Other material properties (basecolor, roughness, etc.) are handled by the default template
        // We don't override them here to avoid conflicts