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/debugmarker/colorpass.frag

@@ -0,0 +1,6 @@
+// Copyright 2020 Google LLC
+
+float4 main([[vk::location(0)]] float3 Color : COLOR0) : SV_TARGET
+{
+	return float4(Color, 1);
+}

data/hlsl/debugmarker/colorpass.vert

@@ -0,0 +1,29 @@
+// Copyright 2020 Google LLC
+
+struct VSInput
+{
+[[vk::location(0)]] float4 Pos : POSITION0;
+[[vk::location(3)]] float3 Color : COLOR0;
+};
+
+struct UBO
+{
+	float4x4 projection;
+	float4x4 model;
+};
+
+cbuffer ubo : register(b0) { UBO ubo; }
+
+struct VSOutput
+{
+	float4 Pos : SV_POSITION;
+[[vk::location(0)]] float3 Color : COLOR0;
+};
+
+VSOutput main(VSInput input)
+{
+	VSOutput output = (VSOutput)0;
+	output.Color = input.Color;
+	output.Pos = mul(ubo.projection, mul(ubo.model, input.Pos));
+	return output;
+}

data/hlsl/debugmarker/postprocess.frag

@@ -0,0 +1,36 @@
+// Copyright 2020 Google LLC
+
+Texture2D textureColor : register(t1);
+SamplerState samplerColor : register(s1);
+
+float4 main([[vk::location(0)]] float2 inUV : TEXCOORD0) : SV_TARGET
+{
+	// Single pass gauss blur
+
+	const float2 texOffset = float2(0.01, 0.01);
+
+	float2 tc0 = inUV + float2(-texOffset.x, -texOffset.y);
+	float2 tc1 = inUV + float2(         0.0, -texOffset.y);
+	float2 tc2 = inUV + float2(+texOffset.x, -texOffset.y);
+	float2 tc3 = inUV + float2(-texOffset.x,          0.0);
+	float2 tc4 = inUV + float2(         0.0,          0.0);
+	float2 tc5 = inUV + float2(+texOffset.x,          0.0);
+	float2 tc6 = inUV + float2(-texOffset.x, +texOffset.y);
+	float2 tc7 = inUV + float2(         0.0, +texOffset.y);
+	float2 tc8 = inUV + float2(+texOffset.x, +texOffset.y);
+
+	float4 col0 = textureColor.Sample(samplerColor, tc0);
+	float4 col1 = textureColor.Sample(samplerColor, tc1);
+	float4 col2 = textureColor.Sample(samplerColor, tc2);
+	float4 col3 = textureColor.Sample(samplerColor, tc3);
+	float4 col4 = textureColor.Sample(samplerColor, tc4);
+	float4 col5 = textureColor.Sample(samplerColor, tc5);
+	float4 col6 = textureColor.Sample(samplerColor, tc6);
+	float4 col7 = textureColor.Sample(samplerColor, tc7);
+	float4 col8 = textureColor.Sample(samplerColor, tc8);
+
+	float4 sum = (1.0 * col0 + 2.0 * col1 + 1.0 * col2 +
+			  2.0 * col3 + 4.0 * col4 + 2.0 * col5 +
+			  1.0 * col6 + 2.0 * col7 + 1.0 * col8) / 16.0;
+	return float4(sum.rgb, 1.0);
+}

data/hlsl/debugmarker/postprocess.vert

@@ -0,0 +1,15 @@
+// Copyright 2020 Google LLC
+
+struct VSOutput
+{
+	float4 Pos : SV_POSITION;
+[[vk::location(0)]] float2 UV : TEXCOORD0;
+};
+
+VSOutput main(uint VertexIndex : SV_VertexID)
+{
+	VSOutput output = (VSOutput)0;
+	output.UV = float2((VertexIndex << 1) & 2, VertexIndex & 2);
+	output.Pos = float4(output.UV * float2(2.0f, 2.0f) + float2(-1.0f, -1.0f), 0.0f, 1.0f);
+	return output;
+}

data/hlsl/debugmarker/toon.frag

@@ -0,0 +1,37 @@
+// Copyright 2020 Google LLC
+
+Texture2D textureColorMap : register(t1);
+SamplerState samplerColorMap : register(s1);
+
+struct VSOutput
+{
+[[vk::location(0)]] float3 Normal : NORMAL0;
+[[vk::location(1)]] float3 Color : COLOR0;
+[[vk::location(2)]] float2 UV : TEXCOORD0;
+[[vk::location(3)]] float3 ViewVec : TEXCOORD1;
+[[vk::location(4)]] float3 LightVec : TEXCOORD2;
+};
+
+float4 main(VSOutput input) : SV_TARGET
+{
+	// Desaturate color
+    float3 color = float3(lerp(input.Color, dot(float3(0.2126,0.7152,0.0722), input.Color).xxx, 0.65));
+
+	// High ambient colors because mesh materials are pretty dark
+	float3 ambient = color * float3(1.0, 1.0, 1.0);
+	float3 N = normalize(input.Normal);
+	float3 L = normalize(input.LightVec);
+	float3 V = normalize(input.ViewVec);
+	float3 R = reflect(-L, N);
+	float3 diffuse = max(dot(N, L), 0.0) * color;
+	float3 specular = pow(max(dot(R, V), 0.0), 16.0) * float3(0.75, 0.75, 0.75);
+
+	float intensity = dot(N,L);
+	float shade = 1.0;
+	shade = intensity < 0.5 ? 0.75 : shade;
+	shade = intensity < 0.35 ? 0.6 : shade;
+	shade = intensity < 0.25 ? 0.5 : shade;
+	shade = intensity < 0.1 ? 0.25 : shade;
+
+	return float4(input.Color * 3.0 * shade, 1);
+}

data/hlsl/debugmarker/toon.vert

@@ -0,0 +1,44 @@
+// Copyright 2020 Google LLC
+
+struct VSInput
+{
+[[vk::location(0)]] float3 Pos : POSITION0;
+[[vk::location(1)]] float3 Normal : NORMAL0;
+[[vk::location(2)]] float2 UV : TEXCOORD0;
+[[vk::location(3)]] float3 Color : COLOR0;
+};
+
+struct UBO
+{
+	float4x4 projection;
+	float4x4 model;
+	float4 lightPos;
+};
+
+cbuffer ubo : register(b0) { UBO ubo; }
+
+struct VSOutput
+{
+	float4 Pos : SV_POSITION;
+[[vk::location(0)]] float3 Normal : NORMAL0;
+[[vk::location(1)]] float3 Color : COLOR0;
+[[vk::location(2)]] float2 UV : TEXCOORD0;
+[[vk::location(3)]] float3 ViewVec : TEXCOORD1;
+[[vk::location(4)]] float3 LightVec : TEXCOORD2;
+};
+
+VSOutput main(VSInput input)
+{
+	VSOutput output = (VSOutput)0;
+	output.Normal = input.Normal;
+	output.Color = input.Color;
+	output.UV = input.UV;
+	output.Pos = mul(ubo.projection, mul(ubo.model, float4(input.Pos.xyz, 1.0)));
+
+	float4 pos = mul(ubo.model, float4(input.Pos, 1.0));
+	output.Normal = mul((float4x3)ubo.model, input.Normal).xyz;
+	float3 lPos = mul((float4x3)ubo.model, ubo.lightPos.xyz).xyz;
+	output.LightVec = lPos - pos.xyz;
+	output.ViewVec = -pos.xyz;
+	return output;
+}