// MonoGame Effect Parser
//
// For use with our fork of the "Tiny Parser Generator"
// https://github.com/SickheadGames/TinyPG
//

<% @TinyPG Namespace="TwoMGFX.TPGParser" Language="C#"%>

[Skip] BlockComment -> @"/\*([^*]|\*[^/])*\*/";
[Skip] Comment -> @"//[^\n\r]*";
[Skip] Whitespace -> @"[ \t\n\r]+";
[FileAndLine] LinePragma -> @"^[ \t]*#line[ \t]*(?<Line>\d*)[ \t]*(\""(?<File>[^\""\\]*(?:\\.[^\""\\]*)*)\"")?\n";

// TOKENS
[IgnoreCase] Pass -> @"pass";
[IgnoreCase] Technique -> @"technique";
[IgnoreCase] Sampler -> @"sampler1D|sampler2D|sampler3D|samplerCUBE|SamplerState|sampler";
[IgnoreCase] SamplerState -> @"sampler_state";
[IgnoreCase] VertexShader -> @"VertexShader";
[IgnoreCase] PixelShader -> @"PixelShader";
[IgnoreCase] Register -> @"register";
[IgnoreCase] Boolean -> @"true|false|0|1";
Number -> @"[+-]? ?[0-9]?\.?[0-9]+[fF]?";
[IgnoreCase] HexColor -> @"0x[0-9a-f]{6}([0-9a-f][0-9a-f])?";
Identifier -> @"[A-Za-z_][A-Za-z0-9_]*";
OpenBracket -> @"{";
CloseBracket -> @"}";
Equals -> @"=";
Colon -> @":";
Comma -> @",";
Semicolon -> @";";
Or -> @"\|";
OpenParenthesis -> @"\(";
CloseParenthesis -> @"\)";
OpenSquareBracket -> @"\[";
CloseSquareBracket -> @"\]";
LessThan -> @"<";
GreaterThan -> @">";
[IgnoreCase] Compile -> @"compile";
ShaderModel -> @"[A-Za-z_][A-Za-z0-9_]*";
Code -> @"[\S]+";
EndOfFile -> @"^$";

// Sampler states
[IgnoreCase] MinFilter -> @"MinFilter";
[IgnoreCase] MagFilter -> @"MagFilter";
[IgnoreCase] MipFilter -> @"MipFilter";
[IgnoreCase] Filter -> @"Filter";
[IgnoreCase] Texture -> @"Texture";
[IgnoreCase] AddressU -> @"AddressU";
[IgnoreCase] AddressV -> @"AddressV";
[IgnoreCase] AddressW -> @"AddressW";
[IgnoreCase] BorderColor -> @"BorderColor";
[IgnoreCase] MaxAnisotropy -> @"MaxAnisotropy";
[IgnoreCase] MaxMipLevel -> @"MaxMipLevel|MaxLod";
[IgnoreCase] MipLodBias -> @"MipLodBias";

// Address Mode
[IgnoreCase] Clamp -> @"Clamp";
[IgnoreCase] Wrap -> @"Wrap";
[IgnoreCase] Mirror -> @"Mirror";
[IgnoreCase] Border -> @"Border";

// Texture Filters
[IgnoreCase] None -> @"None";
[IgnoreCase] Linear -> @"Linear";
[IgnoreCase] Point -> @"Point";
[IgnoreCase] Anisotropic -> @"Anisotropic";

// Render states
[IgnoreCase] AlphaBlendEnable -> @"AlphaBlendEnable";
[IgnoreCase] SrcBlend -> @"SrcBlend";
[IgnoreCase] DestBlend -> @"DestBlend";
[IgnoreCase] BlendOp -> @"BlendOp";
[IgnoreCase] ColorWriteEnable -> @"ColorWriteEnable";
[IgnoreCase] ZEnable -> @"ZEnable";
[IgnoreCase] ZWriteEnable -> @"ZWriteEnable";
[IgnoreCase] ZFunc-> @"ZFunc";
[IgnoreCase] DepthBias -> @"DepthBias";
[IgnoreCase] CullMode -> @"CullMode";
[IgnoreCase] FillMode -> @"FillMode";
[IgnoreCase] MultiSampleAntiAlias -> @"MultiSampleAntiAlias";
[IgnoreCase] ScissorTestEnable -> @"ScissorTestEnable";
[IgnoreCase] SlopeScaleDepthBias -> @"SlopeScaleDepthBias";
[IgnoreCase] StencilEnable -> @"StencilEnable";
[IgnoreCase] StencilFail -> @"StencilFail";
[IgnoreCase] StencilFunc -> @"StencilFunc";
[IgnoreCase] StencilMask -> @"StencilMask";
[IgnoreCase] StencilPass -> @"StencilPass";
[IgnoreCase] StencilRef -> @"StencilRef";
[IgnoreCase] StencilWriteMask -> @"StencilWriteMask";
[IgnoreCase] StencilZFail -> @"StencilZFail";
 

// Compare function
[IgnoreCase] Never -> @"Never";
[IgnoreCase] Less -> @"Less";
[IgnoreCase] Equal -> @"Equal";
[IgnoreCase] LessEqual -> @"LessEqual";
[IgnoreCase] Greater -> @"Greater";
[IgnoreCase] NotEqual -> @"NotEqual";
[IgnoreCase] GreaterEqual -> @"GreaterEqual";
[IgnoreCase] Always -> @"Always";

// Stencil operation
[IgnoreCase] Keep -> @"Keep";
[IgnoreCase] Zero -> @"Zero";
[IgnoreCase] Replace -> @"Replace";
[IgnoreCase] IncrSat -> @"IncrSat";
[IgnoreCase] DecrSat -> @"DecrSat";
[IgnoreCase] Invert -> @"Invert";
[IgnoreCase] Incr -> @"Incr";
[IgnoreCase] Decr -> @"Decr";

// Colors
[IgnoreCase] Red -> @"Red";
[IgnoreCase] Green -> @"Green";
[IgnoreCase] Blue -> @"Blue";
[IgnoreCase] Alpha -> @"Alpha";
[IgnoreCase] All -> @"All";

// Cull mode
[IgnoreCase] Cw -> @"Cw";
[IgnoreCase] Ccw -> @"Ccw";

// Fill mode
[IgnoreCase] Solid -> @"Solid";
[IgnoreCase] WireFrame -> @"WireFrame";

// Blend function
[IgnoreCase] Add -> @"Add";
[IgnoreCase] Subtract -> @"Subtract";
[IgnoreCase] RevSubtract -> @"RevSubtract";
[IgnoreCase] Min -> @"Min";
[IgnoreCase] Max -> @"Max";

// Blend 
[IgnoreCase] Zero -> @"Zero";
[IgnoreCase] One -> @"One";
[IgnoreCase] SrcColor -> @"SrcColor";
[IgnoreCase] InvSrcColor -> @"InvSrcColor";
[IgnoreCase] SrcAlpha -> @"SrcAlpha";
[IgnoreCase] InvSrcAlpha -> @"InvSrcAlpha";
[IgnoreCase] DestAlpha -> @"DestAlpha";
[IgnoreCase] InvDestAlpha -> @"InvDestAlpha";
[IgnoreCase] DestColor -> @"DestColor";
[IgnoreCase] InvDestColor -> @"InvDestColor";
[IgnoreCase] SrcAlphaSat -> @"SrcAlphaSat";
[IgnoreCase] BlendFactor -> @"BlendFactor";
[IgnoreCase] InvBlendFactor -> @"InvBlendFactor";


// Productions
Start -> (Code | Technique_Declaration | Sampler_Declaration)* EndOfFile
{
   var shader = new ShaderInfo();

   foreach (var node in Nodes)
      node.Eval(tree, shader);

   return shader; 
};

Technique_Declaration -> Technique Identifier? OpenBracket Pass_Declaration+ CloseBracket 
{
   var technique = new TechniqueInfo();
   technique.name = $Identifier as string ?? string.Empty;
   technique.startPos = Token.StartPos;
   technique.length = Token.Length;

   foreach (var node in Nodes)
      node.Eval(tree, technique);
   
   // Make sure we have at least one pass.
   if (technique.Passes.Count > 0)
   {
      var shaderInfo = paramlist[0] as ShaderInfo;
      shaderInfo.Techniques.Add(technique);
   }

   return null;
};

FillMode_Solid -> Solid { return FillMode.Solid; };
FillMode_WireFrame -> WireFrame { return FillMode.WireFrame; };
FillModes -> (FillMode_Solid|FillMode_WireFrame)
{
	return $FillMode_Solid ?? $FillMode_WireFrame;
};

CullMode_None -> None { return CullMode.None; };
CullMode_Cw -> Cw { return CullMode.CullClockwiseFace; };
CullMode_Ccw -> Ccw { return CullMode.CullCounterClockwiseFace; };
CullModes -> (CullMode_None|CullMode_Cw|CullMode_Ccw)
{
	return $CullMode_None ?? $CullMode_Cw ?? $CullMode_Ccw;
};

Colors_None -> None { return ColorWriteChannels.None; };
Colors_Red -> Red { return ColorWriteChannels.Red; };
Colors_Green -> Green { return ColorWriteChannels.Green; };
Colors_Blue -> Blue { return ColorWriteChannels.Blue; };
Colors_Alpha -> Alpha { return ColorWriteChannels.Alpha; };
Colors_All -> All { return ColorWriteChannels.All; };
Colors_Boolean -> Boolean { return ParseTreeTools.ParseBool((string)$Boolean) ?  ColorWriteChannels.All : ColorWriteChannels.None; };
Colors -> (Colors_Red|Colors_Green|Colors_Blue|Colors_Alpha|Colors_None|Colors_All|Colors_Boolean)
{
	return $Colors_Red ?? $Colors_Green ?? $Colors_Blue ?? $Colors_Alpha ?? $Colors_None ?? $Colors_All ?? $Colors_Boolean;
};
ColorsMasks -> Colors (Or Colors)? (Or Colors)? (Or Colors)?
{
	return	(ColorWriteChannels)($Colors[0] ?? 0) | 
			(ColorWriteChannels)($Colors[1] ?? 0) | 
			(ColorWriteChannels)($Colors[2] ?? 0) | 
			(ColorWriteChannels)($Colors[3] ?? 0);
};

Blend_Zero -> Zero { return Blend.Zero; };
Blend_One -> One { return Blend.One; };
Blend_SrcColor -> SrcColor { return Blend.SourceColor; };
Blend_InvSrcColor -> InvSrcColor { return Blend.InverseSourceColor; };
Blend_SrcAlpha -> SrcAlpha { return Blend.SourceAlpha; };
Blend_InvSrcAlpha -> InvSrcAlpha { return Blend.InverseSourceAlpha; };
Blend_DestAlpha -> DestAlpha { return Blend.DestinationAlpha; };
Blend_InvDestAlpha -> InvDestAlpha { return Blend.InverseDestinationAlpha; };
Blend_DestColor -> DestColor { return Blend.DestinationColor; };
Blend_InvDestColor -> InvDestColor { return Blend.InverseDestinationColor; };
Blend_SrcAlphaSat -> SrcAlphaSat { return Blend.SourceAlphaSaturation; };
Blend_BlendFactor -> BlendFactor { return Blend.BlendFactor; };
Blend_InvBlendFactor -> InvBlendFactor { return Blend.InverseBlendFactor; };
Blends -> (	Blend_Zero|Blend_One|Blend_SrcColor|Blend_InvSrcColor|Blend_SrcAlpha|Blend_InvSrcAlpha|
			Blend_DestAlpha|Blend_InvDestAlpha|Blend_DestColor|Blend_InvDestColor|Blend_SrcAlphaSat|
			Blend_BlendFactor|Blend_InvBlendFactor)
{
	return	$Blend_Zero ?? $Blend_One ?? $Blend_SrcColor ?? $Blend_InvSrcColor ?? $Blend_SrcAlpha ?? $Blend_InvSrcAlpha ?? 
			$Blend_DestAlpha ?? $Blend_InvDestAlpha ?? $Blend_DestColor ?? $Blend_InvDestColor ?? $Blend_SrcAlphaSat ??
			$Blend_BlendFactor ?? $Blend_InvBlendFactor;
};

BlendOp_Add -> Add { return BlendFunction.Add; };
BlendOp_Subtract -> Subtract { return BlendFunction.Subtract; };
BlendOp_RevSubtract -> RevSubtract { return BlendFunction.ReverseSubtract; };
BlendOp_Min -> Min { return BlendFunction.Min; };
BlendOp_Max -> Max { return BlendFunction.Max; };
BlendOps -> (BlendOp_Add|BlendOp_Subtract|BlendOp_RevSubtract|BlendOp_Min|BlendOp_Max)
{
	return	$BlendOp_Add ?? $BlendOp_Subtract ?? $BlendOp_RevSubtract ?? $BlendOp_Min ?? $BlendOp_Max;
};

CmpFunc_Never -> Never { return CompareFunction.Never; };
CmpFunc_Less -> Less { return CompareFunction.Less; };
CmpFunc_Equal -> Equal { return CompareFunction.Equal; };
CmpFunc_LessEqual -> LessEqual { return CompareFunction.LessEqual; };
CmpFunc_Greater -> Greater { return CompareFunction.Greater; };
CmpFunc_NotEqual -> NotEqual { return CompareFunction.NotEqual; };
CmpFunc_GreaterEqual -> GreaterEqual { return CompareFunction.GreaterEqual; };
CmpFunc_Always -> Always { return CompareFunction.Always; };
CmpFunc -> (CmpFunc_Never|CmpFunc_Less|CmpFunc_Equal|CmpFunc_LessEqual|CmpFunc_Greater|CmpFunc_NotEqual|CmpFunc_GreaterEqual|CmpFunc_Always)
{
	return	$CmpFunc_Never ?? $CmpFunc_Less ?? $CmpFunc_Equal ?? $CmpFunc_LessEqual ?? $CmpFunc_Greater ?? $CmpFunc_NotEqual ?? $CmpFunc_GreaterEqual ?? $CmpFunc_Always;
};

StencilOp_Keep -> Keep { return StencilOperation.Keep; };
StencilOp_Zero -> Zero { return StencilOperation.Zero; };
StencilOp_Replace -> Replace { return StencilOperation.Replace; };
StencilOp_IncrSat -> IncrSat { return StencilOperation.IncrementSaturation; };
StencilOp_DecrSat -> DecrSat { return StencilOperation.DecrementSaturation; };
StencilOp_Invert -> Invert { return StencilOperation.Invert; };
StencilOp_Incr -> Incr { return StencilOperation.Increment; };
StencilOp_Decr -> Decr { return StencilOperation.Decrement; };
StencilOp -> (StencilOp_Keep|StencilOp_Zero|StencilOp_Replace|StencilOp_IncrSat|StencilOp_DecrSat|StencilOp_Invert|StencilOp_Incr|StencilOp_Decr)
{
	return	$StencilOp_Keep ?? $StencilOp_Zero ?? $StencilOp_Replace ?? $StencilOp_IncrSat ?? $StencilOp_DecrSat ?? $StencilOp_Invert ?? $StencilOp_Incr ?? $StencilOp_Decr;
};

// Render states
Render_State_CullMode -> CullMode Equals CullModes Semicolon { (paramlist[0] as PassInfo).CullMode = (CullMode)$CullModes; return null; };
Render_State_FillMode -> FillMode Equals FillModes Semicolon { (paramlist[0] as PassInfo).FillMode = (FillMode)$FillModes; return null; };
Render_State_AlphaBlendEnable -> AlphaBlendEnable Equals Boolean Semicolon { (paramlist[0] as PassInfo).AlphaBlendEnable = ParseTreeTools.ParseBool((string)$Boolean); return null; };
Render_State_SrcBlend -> SrcBlend Equals Blends Semicolon { (paramlist[0] as PassInfo).SrcBlend = (Blend)$Blends; return null; };
Render_State_DestBlend -> DestBlend Equals Blends Semicolon { (paramlist[0] as PassInfo).DestBlend = (Blend)$Blends; return null; };
Render_State_BlendOp -> BlendOp Equals BlendOps Semicolon { (paramlist[0] as PassInfo).BlendOp = (BlendFunction)$BlendOps; return null; };
Render_State_ColorWriteEnable -> ColorWriteEnable Equals ColorsMasks Semicolon { (paramlist[0] as PassInfo).ColorWriteEnable = (ColorWriteChannels)$ColorsMasks; return null; };
Render_State_DepthBias -> DepthBias Equals Number Semicolon { (paramlist[0] as PassInfo).DepthBias = ParseTreeTools.ParseFloat((string)$Number); return null; };
Render_State_SlopeScaleDepthBias -> SlopeScaleDepthBias Equals Number Semicolon { (paramlist[0] as PassInfo).SlopeScaleDepthBias = ParseTreeTools.ParseFloat((string)$Number); return null; };
Render_State_ZEnable -> ZEnable Equals Boolean Semicolon { (paramlist[0] as PassInfo).ZEnable = ParseTreeTools.ParseBool((string)$Boolean); return null; };
Render_State_ZWriteEnable -> ZWriteEnable Equals Boolean Semicolon { (paramlist[0] as PassInfo).ZWriteEnable = ParseTreeTools.ParseBool((string)$Boolean); return null; };
Render_State_ZFunc -> ZFunc Equals CmpFunc Semicolon { (paramlist[0] as PassInfo).DepthBufferFunction = (CompareFunction)$CmpFunc; return null; };
Render_State_MultiSampleAntiAlias -> MultiSampleAntiAlias Equals Boolean Semicolon { (paramlist[0] as PassInfo).MultiSampleAntiAlias = ParseTreeTools.ParseBool((string)$Boolean); return null; };
Render_State_ScissorTestEnable -> ScissorTestEnable Equals Boolean Semicolon { (paramlist[0] as PassInfo).ScissorTestEnable = ParseTreeTools.ParseBool((string)$Boolean); return null; };
Render_State_StencilEnable -> StencilEnable Equals Boolean Semicolon { (paramlist[0] as PassInfo).StencilEnable = ParseTreeTools.ParseBool((string)$Boolean); return null; };
Render_State_StencilFail -> StencilFail Equals StencilOp Semicolon { (paramlist[0] as PassInfo).StencilFail = (StencilOperation)$StencilOp; return null; };
Render_State_StencilFunc -> StencilFunc Equals CmpFunc Semicolon { (paramlist[0] as PassInfo).StencilFunc = (CompareFunction)$CmpFunc; return null; };
Render_State_StencilMask -> StencilMask Equals Number Semicolon { (paramlist[0] as PassInfo).StencilMask = ParseTreeTools.ParseInt((string)$Number); return null; };
Render_State_StencilPass -> StencilPass Equals StencilOp Semicolon { (paramlist[0] as PassInfo).StencilPass = (StencilOperation)$StencilOp; return null; };
Render_State_StencilRef -> StencilRef Equals Number Semicolon { (paramlist[0] as PassInfo).StencilRef = ParseTreeTools.ParseInt((string)$Number); return null; };
Render_State_StencilWriteMask -> StencilWriteMask Equals Number Semicolon { (paramlist[0] as PassInfo).StencilWriteMask = ParseTreeTools.ParseInt((string)$Number); return null; };
Render_State_StencilZFail -> StencilZFail Equals StencilOp Semicolon { (paramlist[0] as PassInfo).StencilZFail = (StencilOperation)$StencilOp; return null; };


Render_State_Expression ->	
				Render_State_CullMode |
				Render_State_FillMode |
				Render_State_AlphaBlendEnable |
				Render_State_SrcBlend |
				Render_State_DestBlend |
				Render_State_BlendOp |
				Render_State_ColorWriteEnable |
				Render_State_DepthBias |
				Render_State_SlopeScaleDepthBias |
				Render_State_ZEnable |
				Render_State_ZWriteEnable |
				Render_State_ZFunc |
				Render_State_MultiSampleAntiAlias |
				Render_State_ScissorTestEnable |
				Render_State_StencilEnable |
				Render_State_StencilFail |
				Render_State_StencilFunc |
				Render_State_StencilMask |
				Render_State_StencilPass |
				Render_State_StencilRef |
				Render_State_StencilWriteMask |
				Render_State_StencilZFail;

Pass_Declaration ->	Pass Identifier? OpenBracket (VertexShader_Pass_Expression | PixelShader_Pass_Expression | Render_State_Expression)* CloseBracket 
{ 
   var pass = new PassInfo();
   pass.name = $Identifier as string ?? string.Empty;

   foreach (var node in Nodes)
      node.Eval(tree, pass);

   // We need to have a pixel or vertex shader to keep this pass.
   if (!string.IsNullOrEmpty(pass.psFunction) || !string.IsNullOrEmpty(pass.vsFunction))
   {
      var technique = paramlist[0] as TechniqueInfo;
      technique.Passes.Add(pass);
   }

   return null;
};

VertexShader_Pass_Expression -> VertexShader Equals Compile ShaderModel Identifier OpenParenthesis CloseParenthesis Semicolon
{
   var pass = paramlist[0] as PassInfo;
   pass.vsModel = $ShaderModel as string;
   pass.vsFunction = $Identifier as string;
   return null;
};

PixelShader_Pass_Expression -> PixelShader Equals Compile ShaderModel Identifier OpenParenthesis CloseParenthesis Semicolon
{
   var pass = paramlist[0] as PassInfo;
   pass.psModel = $ShaderModel as string;
   pass.psFunction = $Identifier as string;
   return null;
};

AddressMode_Clamp -> Clamp { return TextureAddressMode.Clamp; };
AddressMode_Wrap -> Wrap { return TextureAddressMode.Wrap; };
AddressMode_Mirror -> Mirror { return TextureAddressMode.Mirror; };
AddressMode_Border -> Border { return TextureAddressMode.Border; };
AddressMode -> (AddressMode_Clamp|AddressMode_Wrap|AddressMode_Mirror|AddressMode_Border)
{
	return $AddressMode_Clamp ?? $AddressMode_Wrap ?? $AddressMode_Mirror ?? $AddressMode_Border;
};

TextureFilter_None -> None { return TextureFilterType.None; };
TextureFilter_Linear -> Linear { return TextureFilterType.Linear; };
TextureFilter_Point -> Point { return TextureFilterType.Point; };
TextureFilter_Anisotropic -> Anisotropic { return TextureFilterType.Anisotropic; };
TextureFilter -> (TextureFilter_None|TextureFilter_Linear|TextureFilter_Point|TextureFilter_Anisotropic)
{
	return $TextureFilter_None ?? $TextureFilter_Linear ?? $TextureFilter_Point ?? $TextureFilter_Anisotropic;
};

// Sampler States
Sampler_State_Texture -> Texture Equals (LessThan|OpenParenthesis) Identifier (GreaterThan|CloseParenthesis) Semicolon { (paramlist[0] as SamplerStateInfo).TextureName = (string)$Identifier; return null; };
Sampler_State_MinFilter -> MinFilter Equals TextureFilter Semicolon { (paramlist[0] as SamplerStateInfo).MinFilter = (TextureFilterType)$TextureFilter; return null; };
Sampler_State_MagFilter -> MagFilter Equals TextureFilter Semicolon { (paramlist[0] as SamplerStateInfo).MagFilter = (TextureFilterType)$TextureFilter; return null; };
Sampler_State_MipFilter -> MipFilter Equals TextureFilter Semicolon { (paramlist[0] as SamplerStateInfo).MipFilter = (TextureFilterType)$TextureFilter; return null; };
Sampler_State_Filter -> Filter Equals TextureFilter Semicolon { (paramlist[0] as SamplerStateInfo).Filter = (TextureFilterType)$TextureFilter; return null; };
Sampler_State_AddressU -> AddressU Equals AddressMode Semicolon { (paramlist[0] as SamplerStateInfo).AddressU = (TextureAddressMode)$AddressMode; return null; };
Sampler_State_AddressV -> AddressV Equals AddressMode Semicolon { (paramlist[0] as SamplerStateInfo).AddressV = (TextureAddressMode)$AddressMode; return null; };
Sampler_State_AddressW -> AddressW Equals AddressMode Semicolon { (paramlist[0] as SamplerStateInfo).AddressW = (TextureAddressMode)$AddressMode; return null; };
Sampler_State_BorderColor -> BorderColor Equals HexColor Semicolon { (paramlist[0] as SamplerStateInfo).BorderColor = ParseTreeTools.ParseColor((string)$HexColor); return null; };
Sampler_State_MaxMipLevel -> MaxMipLevel Equals Number Semicolon { (paramlist[0] as SamplerStateInfo).MaxMipLevel = ParseTreeTools.ParseInt((string)$Number); return null; };
Sampler_State_MaxAnisotropy -> MaxAnisotropy Equals Number Semicolon { (paramlist[0] as SamplerStateInfo).MaxAnisotropy = ParseTreeTools.ParseInt((string)$Number); return null; };
Sampler_State_MipLodBias -> MipLodBias Equals Number Semicolon { (paramlist[0] as SamplerStateInfo).MipMapLevelOfDetailBias = ParseTreeTools.ParseFloat((string)$Number); return null; };


Sampler_State_Expression ->	
				Sampler_State_Texture |
				Sampler_State_MinFilter |
				Sampler_State_MagFilter |
				Sampler_State_MipFilter |
				Sampler_State_Filter |
				Sampler_State_AddressU |
				Sampler_State_AddressV |
				Sampler_State_AddressW |
                Sampler_State_BorderColor |
				Sampler_State_MaxMipLevel |
				Sampler_State_MaxAnisotropy |
				Sampler_State_MipLodBias;

Sampler_Register_Expression -> Colon Register OpenParenthesis Identifier (Comma Identifier (OpenSquareBracket Number CloseSquareBracket)?)? CloseParenthesis
{
	return null;
};

Sampler_Declaration_States -> (Equals SamplerState)? OpenBracket Sampler_State_Expression* CloseBracket;

Sampler_Declaration -> Sampler Identifier Sampler_Register_Expression* Sampler_Declaration_States? (Semicolon | Comma | CloseParenthesis)
{
	// if there is a comma or closing paren at the end this is a sampler as a parameter of a function
	if ($Semicolon == null) return null;

	var sampler = new SamplerStateInfo();
	sampler.Name = $Identifier[0] as string;
	
	foreach (ParseNode node in Nodes)
		node.Eval(tree, sampler);
	
	var shaderInfo = paramlist[0] as ShaderInfo;
	shaderInfo.SamplerStates.Add(sampler.Name, sampler);
	
	return null;
};