Add slang shaders for additional samples

shaders/slang/viewportarray/scene.slang

@@ -0,0 +1,90 @@
+/* Copyright (c) 2025, Sascha Willems
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ */
+
+struct VSInput
+{
+	float3 Pos;
+	float3 Normal;
+	float3 Color;
+};
+
+struct VSOutput
+{
+    float4 Pos : SV_POSITION;
+    float3 Normal;
+    float3 Color;
+};
+
+struct GSOutput
+{
+    float4 Pos : SV_POSITION;
+    uint ViewportIndex : SV_ViewportArrayIndex;
+    uint PrimitiveID : SV_PrimitiveID;
+    float3 Normal;
+    float3 Color;
+    float3 ViewVec;
+    float3 LightVec;
+}
+
+struct UBO
+{
+    float4x4 projection[2];
+    float4x4 modelview[2];
+    float4 lightPos;
+};
+ConstantBuffer<UBO> ubo;
+
+[shader("vertex")]
+VSOutput vertexMain(VSInput input)
+{
+    VSOutput output;
+    output.Color = input.Color;
+    output.Normal = input.Normal;
+    output.Pos = float4(input.Pos.xyz, 1.0);
+    return output;
+}
+
+[shader("geometry")]
+[maxvertexcount(3)]
+[instance(2)]
+void geometryMain(triangle VSOutput input[3], inout TriangleStream<GSOutput> outStream, uint InvocationID: SV_GSInstanceID, uint PrimitiveID: SV_PrimitiveID)
+{
+    for (int i = 0; i < 3; i++)
+    {
+        GSOutput output;
+        output.Normal = mul((float3x3)ubo.modelview[InvocationID], input[i].Normal);
+        output.Color = input[i].Color;
+
+        float4 pos = input[i].Pos;
+        float4 worldPos = mul(ubo.modelview[InvocationID], pos);
+
+        float3 lPos = mul(ubo.modelview[InvocationID], ubo.lightPos).xyz;
+        output.LightVec = lPos - worldPos.xyz;
+        output.ViewVec = -worldPos.xyz;
+
+        output.Pos = mul(ubo.projection[InvocationID], worldPos);
+
+        // Set the viewport index that the vertex will be emitted to
+        output.ViewportIndex = InvocationID;
+        output.PrimitiveID = PrimitiveID;
+        outStream.Append(output);
+    }
+
+    outStream.RestartStrip();
+}
+
+[shader("fragment")]
+float4 fragmentMain(GSOutput input)
+{
+	float3 N = normalize(input.Normal);
+	float3 L = normalize(input.LightVec);
+	float3 V = normalize(input.ViewVec);
+	float3 R = reflect(-L, N);
+	float3 ambient = float3(0.1, 0.1, 0.1);
+	float3 diffuse = max(dot(N, L), 0.0) * float3(1.0, 1.0, 1.0);
+	float3 specular = pow(max(dot(R, V), 0.0), 16.0) * float3(0.75, 0.75, 0.75);
+	return float4((ambient + diffuse) * input.Color.rgb + specular, 1.0);
+}