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.fx

@@ -0,0 +1,157 @@
+//--------------------------------------------------------------------------------------
+// File: BasicHLSL.fx
+//
+// The effect file for the BasicHLSL sample.  
+// 
+// Copyright (c) Microsoft Corporation. All rights reserved.
+//--------------------------------------------------------------------------------------
+
+
+//--------------------------------------------------------------------------------------
+// Global variables
+//--------------------------------------------------------------------------------------
+float4 g_MaterialAmbientColor;      // Material's ambient color
+float4 g_MaterialDiffuseColor;      // Material's diffuse color
+int g_nNumLights;
+
+float3 g_LightDir;               // Light's direction in world space
+float4 g_LightDiffuse;           // Light's diffuse color
+float4 g_LightAmbient;              // Light's ambient color
+
+texture g_MeshTexture;              // Color texture for mesh
+
+float    g_fTime;                   // App's time in seconds
+float4x4 g_mWorld;                  // World matrix for object
+float4x4 g_mWorldViewProjection;    // World * View * Projection matrix
+
+
+
+//--------------------------------------------------------------------------------------
+// Texture samplers
+//--------------------------------------------------------------------------------------
+sampler MeshTextureSampler = 
+sampler_state
+{
+    Texture = <g_MeshTexture>;
+    MipFilter = LINEAR;
+    MinFilter = LINEAR;
+    MagFilter = LINEAR;
+};
+
+
+//--------------------------------------------------------------------------------------
+// Vertex shader output structure
+//--------------------------------------------------------------------------------------
+struct VS_OUTPUT
+{
+    float4 Position   : POSITION;   // vertex position 
+    float4 Diffuse    : COLOR0;     // vertex diffuse color (note that COLOR0 is clamped from 0..1)
+    float2 TextureUV  : TEXCOORD0;  // vertex texture coords 
+};
+
+
+//--------------------------------------------------------------------------------------
+// This shader computes standard transform and lighting
+//--------------------------------------------------------------------------------------
+VS_OUTPUT RenderSceneVS( float4 vPos : POSITION, 
+                         float3 vNormal : NORMAL,
+                         float2 vTexCoord0 : TEXCOORD0,
+                         uniform int nNumLights,
+                         uniform bool bTexture,
+                         uniform bool bAnimate )
+{
+
+    VS_OUTPUT Output;
+    float3 vNormalWorldSpace;
+   
+    // Transform the position from object space to homogeneous projection space
+    Output.Position = mul(vPos, g_mWorldViewProjection);
+    
+    // Transform the normal from object space to world space    
+    vNormalWorldSpace = normalize(mul(vNormal, (float3x3)g_mWorld)); // normal (world space)
+    
+    // Compute simple directional lighting equation
+    float3 vTotalLightDiffuse = float3(0,0,0);
+    for(int i=0; i<nNumLights; i++ )
+        vTotalLightDiffuse += g_LightDiffuse * max(0,dot(vNormalWorldSpace, g_LightDir));
+        
+    Output.Diffuse.rgb = g_MaterialDiffuseColor * vTotalLightDiffuse + 
+                         g_MaterialAmbientColor * g_LightAmbient;   
+    Output.Diffuse.a = 1.0f; 
+    
+    // Just copy the texture coordinate through
+    if( bTexture ) 
+        Output.TextureUV = vTexCoord0; 
+    else
+        Output.TextureUV = 0; 
+    
+    return Output;    
+}
+
+
+//--------------------------------------------------------------------------------------
+// Pixel shader output structure
+//--------------------------------------------------------------------------------------
+struct PS_OUTPUT
+{
+    float4 RGBColor : COLOR0;  // Pixel color    
+};
+
+
+//--------------------------------------------------------------------------------------
+// This shader outputs the pixel's color by modulating the texture's
+//       color with diffuse material color
+//--------------------------------------------------------------------------------------
+PS_OUTPUT RenderScenePS( VS_OUTPUT In,
+                         uniform bool bTexture ) 
+{ 
+    PS_OUTPUT Output;
+
+    // Lookup mesh texture and modulate it with diffuse
+    if( bTexture )
+        Output.RGBColor = tex2D(MeshTextureSampler, In.TextureUV) * In.Diffuse;
+    else
+        Output.RGBColor = In.Diffuse;
+
+    return Output;
+}
+
+
+//--------------------------------------------------------------------------------------
+// Renders scene to render target
+//--------------------------------------------------------------------------------------
+technique RenderSceneWithTexture1Light
+{
+    pass P0
+    {          
+        VertexShader = compile vs_2_0 RenderSceneVS( 1, true, true );
+        PixelShader  = compile ps_2_0 RenderScenePS( true ); // trivial pixel shader (could use FF instead if desired)
+    }
+}
+
+technique RenderSceneWithTexture2Light
+{
+    pass P0
+    {          
+        VertexShader = compile vs_2_0 RenderSceneVS( 2, true, true );
+        PixelShader  = compile ps_2_0 RenderScenePS( true ); // trivial pixel shader (could use FF instead if desired)
+    }
+}
+
+technique RenderSceneWithTexture3Light
+{
+    pass P0
+    {          
+        VertexShader = compile vs_2_0 RenderSceneVS( 3, true, true );
+        PixelShader  = compile ps_2_0 RenderScenePS( true ); // trivial pixel shader (could use FF instead if desired)
+    }
+}
+
+technique RenderSceneNoTexture
+{
+    pass P0
+    {          
+        VertexShader = compile vs_2_0 RenderSceneVS( 1, false, false );
+        PixelShader  = compile ps_2_0 RenderScenePS( false ); // trivial pixel shader (could use FF instead if desired)
+    }
+}