Added GPU SoftBody constraint solvers for DirectX 11 (Direct Compute) and OpenCL, thanks to AMD.

See also http://code.google.com/p/bullet/issues/detail?id=390
Added Demos/DX11ClothDemo
(an OpenCL cloth demo will follow soon)

Demos/DX11ClothDemo/cloth_renderer_PS.hlsl

@@ -0,0 +1,90 @@
+//--------------------------------------------------------------------------------------
+// File: BasicHLSL11_PS.hlsl
+//
+// The pixel shader file for the BasicHLSL11 sample.  
+// 
+// Copyright (c) Microsoft Corporation. All rights reserved.
+//--------------------------------------------------------------------------------------
+
+//--------------------------------------------------------------------------------------
+// Globals
+//--------------------------------------------------------------------------------------
+cbuffer cbPerObject : register( b0 )
+{
+	float4		g_vObjectColor			: packoffset( c0 );
+};
+
+cbuffer cbPerFrame : register( b1 )
+{
+	float3		g_vLightDir				: packoffset( c0 );
+	float		g_fAmbient				: packoffset( c0.w );
+};
+
+//--------------------------------------------------------------------------------------
+// Textures and Samplers
+//--------------------------------------------------------------------------------------
+Texture2D	g_txDiffuse : register( t0 );
+SamplerState g_samLinear : register( s0 );
+
+//--------------------------------------------------------------------------------------
+// Input / Output structures
+//--------------------------------------------------------------------------------------
+struct PS_INPUT
+{
+	float3 vNormal		: NORMAL;
+	float2 vTexcoord	: TEXCOORD0;
+	float4 vPosition : SV_POSITION;
+};
+
+//--------------------------------------------------------------------------------------
+// Pixel Shader
+//--------------------------------------------------------------------------------------
+float4 PSMain( PS_INPUT Input ) : SV_TARGET
+{
+	float4 vDiffuse = g_txDiffuse.Sample( g_samLinear, Input.vTexcoord );
+	
+	
+	float fLighting = saturate( dot( g_vLightDir, (Input.vNormal)/length(Input.vNormal) ) );
+	//float fLighting = saturate( dot( g_vLightDir, float3(Input.vTexcoord.x,0,0) )  );
+	fLighting = max( fLighting, g_fAmbient );
+	
+	//fLighting = dot(g_vLightDir,float3(0,1,0));
+	
+	return vDiffuse * fLighting;
+}
+
+
+struct VS_OUTPUT
+{
+	float3 vNormal		: NORMAL;
+	float2 vTexcoord	: TEXCOORD0;
+	float4 vPosition	: SV_POSITION;
+};
+
+[maxvertexcount(3)]
+void GSMain(triangle VS_OUTPUT input[3], inout TriangleStream<PS_INPUT> OutputStream)
+{
+PS_INPUT output = (PS_INPUT)0;
+
+
+/*
+float3 v1 = input[1].vPosition - input[0].vPosition;
+float3 v2 = input[2].vPosition - input[0].vPosition;
+float3 normal = cross(v1,v2);
+
+normal = normalize(normal);
+*/
+
+
+for(int i = 0; i < 3; i++)
+{
+
+output.vNormal = input[i].vNormal;
+output.vTexcoord = input[i].vTexcoord;
+output.vPosition = input[i].vPosition;
+OutputStream.Append(output);
+}
+
+OutputStream.RestartStrip();
+
+}