Add support for programmable samplers in shaders

Source/Engine/GraphicsDevice/Null/GPUDeviceNull.cpp

@@ -10,6 +10,7 @@
 #include "GPUPipelineStateNull.h"
 #include "GPUTimerQueryNull.h"
 #include "GPUBufferNull.h"
+#include "GPUSamplerNull.h"
 #include "GPUSwapChainNull.h"
 
 GPUDeviceNull::GPUDeviceNull()
@@ -66,6 +67,7 @@ bool GPUDeviceNull::Init()
         limits.MaximumTexture2DArraySize = 512;
         limits.MaximumTexture3DSize = 2048;
         limits.MaximumTextureCubeSize = 16384;
+        limits.MaximumSamplerAnisotropy = 0;
 
         for (int32 i = 0; i < static_cast<int32>(PixelFormat::MAX); i++)
         {
@@ -177,6 +179,11 @@ GPUBuffer* GPUDeviceNull::CreateBuffer(const StringView& name)
     return New<GPUBufferNull>();
 }
 
+GPUSampler* GPUDeviceNull::CreateSampler()
+{
+    return New<GPUSamplerNull>();
+}
+
 GPUSwapChain* GPUDeviceNull::CreateSwapChain(Window* window)
 {
     return New<GPUSwapChainNull>(window);