/// <summary> /// Lazily computes derived parameter values immediately before applying the effect. /// </summary> protected override void OnApply() { // Recompute the world+view+projection matrix or fog vector? dirtyFlags = EffectHelpers.SetWorldViewProjAndFog(dirtyFlags, ref world, ref view, ref projection, ref worldView, fogEnabled, fogStart, fogEnd, worldViewProjParam, fogVectorParam); // Recompute the world inverse transpose and eye position? dirtyFlags = EffectHelpers.SetLightingMatrices(dirtyFlags, ref world, ref view, worldParam, worldInverseTransposeParam, eyePositionParam); // Recompute the diffuse/emissive/alpha material color parameters? if ((dirtyFlags & EffectDirtyFlags.MaterialColor) != 0) { EffectHelpers.SetMaterialColor(true, alpha, ref diffuseColor, ref emissiveColor, ref ambientLightColor, diffuseColorParam, emissiveColorParam); dirtyFlags &= ~EffectDirtyFlags.MaterialColor; } // Check if we can use the only-bother-with-the-first-light shader optimization. bool newOneLight = !light1.Enabled && !light2.Enabled; if (oneLight != newOneLight) { oneLight = newOneLight; dirtyFlags |= EffectDirtyFlags.ShaderIndex; } // Recompute the shader index? if ((dirtyFlags & EffectDirtyFlags.ShaderIndex) != 0) { int shaderIndex = 0; if (!fogEnabled) { shaderIndex += 1; } if (weightsPerVertex == 2) { shaderIndex += 2; } else if (weightsPerVertex == 4) { shaderIndex += 4; } if (preferPerPixelLighting) { shaderIndex += 12; } else if (oneLight) { shaderIndex += 6; } shaderIndexParam.SetValue(shaderIndex); dirtyFlags &= ~EffectDirtyFlags.ShaderIndex; } }