/// <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;
}
}
