Added many shader source files

This should include the latest version of every shader that was in the
2007 SDK. It also includes a smattering of debug shaders, both VR
distortion shaders, and other assorted shaders that will hopefully be
useful.

None of these new files are included in the game shader DLL project. If
you need to modify one of these shaders for use in your mod you will
need to rename it so that you don't collide with the version of that
shader that lives in stdshader_dx9.dll.

mp/src/materialsystem/stdshaders/cable_ps2x.fxc

@@ -0,0 +1,54 @@
+// DYNAMIC: "PIXELFOGTYPE"				"0..1"
+// DYNAMIC: "WRITE_DEPTH_TO_DESTALPHA"	"0..1"		[ps20b] [PC]
+// DYNAMIC: "WRITE_DEPTH_TO_DESTALPHA"	"0..0"		[ps20b] [XBOX]
+
+// STATIC: "CONVERT_TO_SRGB" "0..1"	[ps20b][= g_pHardwareConfig->NeedsShaderSRGBConversion()] [PC]
+// STATIC: "CONVERT_TO_SRGB" "0..0"	[= 0] [XBOX]
+
+#if defined( SHADER_MODEL_PS_2_0 )
+#	define WRITE_DEPTH_TO_DESTALPHA 0
+#endif
+
+#include "common_ps_fxc.h"
+#include "shader_constant_register_map.h"
+
+sampler NormalSampler	: register( s0 );
+sampler BaseTextureSampler	: register( s1 );
+
+const float4 g_FogParams				: register( PSREG_FOG_PARAMS );
+const float4 g_EyePos_SpecExponent		: register( PSREG_EYEPOS_SPEC_EXPONENT );
+
+struct PS_INPUT
+{
+	float2 vTexCoord0	: TEXCOORD0;
+	float2 vTexCoord1	: TEXCOORD1;
+	
+	float4 worldPos_projPosZ		: TEXCOORD7;		// Necessary for pixel fog
+
+	float4 directionalLightColor : COLOR0;
+	float4 fogFactorW	: COLOR1;
+};
+
+float4 main( PS_INPUT i ) : COLOR
+{
+	float3 vNormalMapDir = tex2D( NormalSampler, i.vTexCoord0 ); // Get the 3-vector from the normal map
+	float4 textureColor = tex2D( BaseTextureSampler, i.vTexCoord1 ); // Interpret tcoord t1 as color data.
+
+	//Expand compacted vectors
+	//TODO: find if there's a better way to expand a color normal to a full vector ( _bx2 was used in the assembly code )
+	vNormalMapDir = (vNormalMapDir - 0.5) * 2.0;
+	float3 vLightDir = float3( 0.0f, 0.0f, 1.0f );
+	
+	float lightDirDotNormalMap = dot( vNormalMapDir, vLightDir ); //normalMap dot dirLightDir
+
+	// do half-lambert on the dot
+	lightDirDotNormalMap = lightDirDotNormalMap * 0.5 + 0.5;
+	lightDirDotNormalMap = lightDirDotNormalMap * lightDirDotNormalMap;
+
+	float4 resultColor;
+	resultColor.xyz = lightDirDotNormalMap * ( textureColor.rgb * i.directionalLightColor.rgb );
+	resultColor.a = textureColor.a * i.directionalLightColor.a;
+
+	float fogFactor = CalcPixelFogFactor( PIXELFOGTYPE, g_FogParams, g_EyePos_SpecExponent.z, i.worldPos_projPosZ.z, i.worldPos_projPosZ.w );
+	return FinalOutput( resultColor, fogFactor, PIXELFOGTYPE, TONEMAP_SCALE_LINEAR, (WRITE_DEPTH_TO_DESTALPHA != 0), i.worldPos_projPosZ.w );
+}