public override ShaderSource GenerateShaderSource(ShaderGeneratorContext context, MaterialComputeColorKeys baseKeys)
{
if (!Enabled || Texture == null) // generate shader from default value when the texture is null or disabled
{
var fallbackValue = GenerateShaderFromFallbackValue(context, baseKeys);
if (fallbackValue != null)
{
return(fallbackValue);
}
}
// generate shader from the texture
// TODO: Use a generated UsedTexcoordIndex when backing textures
var usedTexcoord = "TEXCOORD" + MaterialUtility.GetTextureIndex(TexcoordIndex);
var textureKey = context.GetTextureKey(this, baseKeys);
var samplerKey = context.GetSamplerKey(Sampler);
UsedKey = textureKey;
var scale = Scale;
var scaleFactor = context.CurrentOverrides.UVScale;
if (scaleFactor != Vector2.One)
{
scale *= scaleFactor;
}
var channelStr = GetTextureChannelAsString();
// "TTEXTURE", "TStream"
ShaderClassSource shaderSource;
// TODO: Workaround bad to have to copy all the new ShaderClassSource(). Check how to improve this
if (context.OptimizeMaterials)
{
var scaleStr = MaterialUtility.GetAsShaderString(scale);
var offsetStr = MaterialUtility.GetAsShaderString(Offset);
// If materials are optimized, we precompute best shader combination (note: will generate shader permutations!)
if (context.IsNotPixelStage)
{
if (Offset != Vector2.Zero)
{
shaderSource = new ShaderClassSource("ComputeColorTextureLodScaledOffsetSampler", textureKey, usedTexcoord, samplerKey, channelStr, scaleStr, offsetStr, 0.0f);
}
else if (scale != Vector2.One)
{
shaderSource = new ShaderClassSource("ComputeColorTextureLodScaledSampler", textureKey, usedTexcoord, samplerKey, channelStr, scaleStr, 0.0f);
}
else
{
shaderSource = new ShaderClassSource("ComputeColorTextureLodSampler", textureKey, usedTexcoord, samplerKey, channelStr, 0.0f);
}
}
else
{
if (Offset != Vector2.Zero)
{
shaderSource = new ShaderClassSource("ComputeColorTextureScaledOffsetSampler", textureKey, usedTexcoord, samplerKey, channelStr, scaleStr, offsetStr);
}
else if (scale != Vector2.One)
{
shaderSource = new ShaderClassSource("ComputeColorTextureScaledSampler", textureKey, usedTexcoord, samplerKey, channelStr, scaleStr);
}
else
{
shaderSource = new ShaderClassSource("ComputeColorTextureSampler", textureKey, usedTexcoord, samplerKey, channelStr);
}
}
}
else
{
// Try to avoid shader permutations, by putting UV scaling/offset in shader parameters
var textureScale = (ValueParameterKey <Vector2>)context.GetParameterKey(MaterialKeys.TextureScale);
var textureOffset = (ValueParameterKey <Vector2>)context.GetParameterKey(MaterialKeys.TextureOffset);
context.Parameters.Set(textureScale, scale);
context.Parameters.Set(textureOffset, Offset);
if (context.IsNotPixelStage)
{
shaderSource = new ShaderClassSource("ComputeColorTextureLodScaledOffsetDynamicSampler", textureKey, usedTexcoord, samplerKey, channelStr, textureScale, textureOffset, 0.0f);
}
else
{
shaderSource = new ShaderClassSource("ComputeColorTextureScaledOffsetDynamicSampler", textureKey, usedTexcoord, samplerKey, channelStr, textureScale, textureOffset);
}
}
return(shaderSource);
}
