Add shaders re-implemented in HLSL

These were written against the shaders at revision eddd724e7.
There have been changes made since then, which will need to be mirrored.

See `data/hlsl/README.md` for the current status of each sample.

data/hlsl/displacement/base.frag

@@ -0,0 +1,26 @@
+// Copyright 2020 Google LLC
+
+Texture2D textureColorMap : register(t2);
+SamplerState samplerColorMap : register(s2);
+
+struct DSOutput
+{
+[[vk::location(0)]] float3 Normal : NORMAL0;
+[[vk::location(1)]] float2 UV : TEXCOORD0;
+[[vk::location(2)]] float3 EyePos : POSITION0;
+[[vk::location(3)]] float3 LightVec : TEXCOORD2;
+};
+
+float4 main(DSOutput input) : SV_TARGET
+{
+	float3 N = normalize(input.Normal);
+	float3 L = normalize(float3(1.0, 1.0, 1.0));
+
+	float3 Eye = normalize(-input.EyePos);
+	float3 Reflected = normalize(reflect(-input.LightVec, input.Normal));
+
+	float4 IAmbient = float4(0.0, 0.0, 0.0, 1.0);
+	float4 IDiffuse = float4(1.0, 1.0, 1.0, 1.0) * max(dot(input.Normal, input.LightVec), 0.0);
+
+	return float4((IAmbient + IDiffuse) * float4(textureColorMap.Sample(samplerColorMap, input.UV).rgb, 1.0));
+}

data/hlsl/displacement/base.vert

@@ -0,0 +1,24 @@
+// Copyright 2020 Google LLC
+
+struct VSInput
+{
+[[vk::location(0)]] float3 Pos : POSITION0;
+[[vk::location(1)]] float3 Normal : NORMAL0;
+[[vk::location(2)]] float2 UV : TEXCOORD0;
+};
+
+struct VSOutput
+{
+[[vk::location(2)]]	float4 Pos : POSITION;
+[[vk::location(0)]] float3 Normal : NORMAL0;
+[[vk::location(1)]] float2 UV : TEXCOORD0;
+};
+
+VSOutput main(VSInput input)
+{
+	VSOutput output = (VSOutput)0;
+	output.Pos = float4(input.Pos.xyz, 1.0);
+    output.UV = input.UV * 3.0;
+	output.Normal = input.Normal;
+	return output;
+}

data/hlsl/displacement/displacement.tesc

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+// Copyright 2020 Google LLC
+
+struct UBO
+{
+	float tessLevel;
+};
+
+cbuffer ubo : register(b0) { UBO ubo; }
+
+struct VSOutput
+{
+[[vk::location(2)]]	float4 Pos : POSITION;
+[[vk::location(0)]] float3 Normal : NORMAL0;
+[[vk::location(1)]] float2 UV : TEXCOORD0;
+};
+
+struct HSOutput
+{
+[[vk::location(2)]]	float4 Pos : POSITION;
+[[vk::location(0)]] float3 Normal : NORMAL0;
+[[vk::location(1)]] float2 UV : TEXCOORD0;
+};
+
+struct ConstantsHSOutput
+{
+    float TessLevelOuter[3] : SV_TessFactor;
+    float TessLevelInner : SV_InsideTessFactor;
+};
+
+ConstantsHSOutput ConstantsHS(InputPatch<VSOutput, 3> patch, uint InvocationID : SV_PrimitiveID)
+{
+    ConstantsHSOutput output = (ConstantsHSOutput)0;
+    output.TessLevelInner = ubo.tessLevel;
+    output.TessLevelOuter[0] = ubo.tessLevel;
+    output.TessLevelOuter[1] = ubo.tessLevel;
+    output.TessLevelOuter[2] = ubo.tessLevel;
+    return output;
+}
+
+[domain("tri")]
+[partitioning("integer")]
+[outputtopology("triangle_ccw")]
+[outputcontrolpoints(3)]
+[patchconstantfunc("ConstantsHS")]
+[maxtessfactor(20.0f)]
+HSOutput main(InputPatch<VSOutput, 3> patch, uint InvocationID : SV_OutputControlPointID)
+{
+	HSOutput output = (HSOutput)0;
+	output.Pos = patch[InvocationID].Pos;
+	output.Normal = patch[InvocationID].Normal;
+	output.UV = patch[InvocationID].UV;
+	return output;
+}

data/hlsl/displacement/displacement.tese

@@ -0,0 +1,54 @@
+// Copyright 2020 Google LLC
+
+struct UBO
+{
+	float4x4 projection;
+	float4x4 model;
+	float4 lightPos;
+	float tessAlpha;
+	float tessStrength;
+};
+
+cbuffer ubo : register(b1) { UBO ubo; }
+
+Texture2D textureDisplacementMap : register(t2);
+SamplerState samplerDisplacementMap : register(s2);
+
+struct HSOutput
+{
+[[vk::location(2)]]	float4 Pos : POSITION;
+[[vk::location(0)]] float3 Normal : NORMAL0;
+[[vk::location(1)]] float2 UV : TEXCOORD0;
+};
+
+struct ConstantsHSOutput
+{
+    float TessLevelOuter[3] : SV_TessFactor;
+    float TessLevelInner : SV_InsideTessFactor;
+};
+
+struct DSOutput
+{
+	float4 Pos : SV_POSITION;
+[[vk::location(0)]] float3 Normal : NORMAL0;
+[[vk::location(1)]] float2 UV : TEXCOORD0;
+[[vk::location(2)]] float3 EyesPos : POSITION0;
+[[vk::location(3)]] float3 LightVec : TEXCOORD1;
+};
+
+[domain("tri")]
+DSOutput main(ConstantsHSOutput input, float3 TessCoord : SV_DomainLocation, const OutputPatch<HSOutput, 3> patch)
+{
+	DSOutput output = (DSOutput)0;
+	output.Pos = (TessCoord.x * patch[0].Pos) + (TessCoord.y * patch[1].Pos) + (TessCoord.z * patch[2].Pos);
+	output.UV = mul(TessCoord.x, patch[0].UV) + mul(TessCoord.y, patch[1].UV) + mul(TessCoord.z, patch[2].UV);
+	output.Normal = TessCoord.x * patch[0].Normal + TessCoord.y * patch[1].Normal + TessCoord.z * patch[2].Normal;
+
+	output.Pos.xyz += normalize(output.Normal) * (max(textureDisplacementMap.SampleLevel(samplerDisplacementMap, output.UV.xy, 0).a, 0.0) * ubo.tessStrength);
+
+	output.EyesPos = output.Pos.xyz;
+	output.LightVec = normalize(ubo.lightPos.xyz - output.EyesPos);
+
+	output.Pos = mul(ubo.projection, mul(ubo.model, output.Pos));
+	return output;
+}