Added slang shaders for additional samples

shaders/slang/offscreen/mirror.slang

@@ -0,0 +1,68 @@
+/* Copyright (c) 2025, Sascha Willems
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ */
+
+struct VSInput
+{
+	float3 Pos;
+};
+
+struct VSOutput
+{
+    float4 Pos : SV_POSITION;
+    float4 ProjCoord;
+};
+
+struct UBO
+{
+    float4x4 projection;
+    float4x4 view;
+    float4x4 model;
+};
+ConstantBuffer<UBO> ubo;
+
+Sampler2D samplerColor;
+
+[shader("vertex")]
+VSOutput vertexMain(VSInput input)
+{
+    VSOutput output;
+    output.ProjCoord = mul(ubo.projection, mul(ubo.view, mul(ubo.model, float4(input.Pos.xyz, 1.0))));
+    output.Pos = output.ProjCoord;
+    return output;
+}
+
+[shader("fragment")]
+float4 fragmentMain(VSOutput input, bool FrontFacing : SV_IsFrontFace)
+{
+	float4 tmp = (1.0 / input.ProjCoord.w).xxxx;
+	float4 projCoord = input.ProjCoord * tmp;
+
+	// Scale and bias
+	projCoord += float4(1.0, 1.0, 1.0, 1.0);
+	projCoord *= float4(0.5, 0.5, 0.5, 0.5);
+
+	// Slow single pass blur
+	// For demonstration purposes only
+	const float blurSize = 1.0 / 512.0;
+
+	float4 color = float4(float3(0.0, 0.0, 0.0), 1.);
+
+	if (FrontFacing)
+	{
+		// Only render mirrored scene on front facing (upper) side of mirror surface
+		float4 reflection = float4(0.0, 0.0, 0.0, 0.0);
+		for (int x = -3; x <= 3; x++)
+		{
+			for (int y = -3; y <= 3; y++)
+            {
+                reflection += samplerColor.Sample(float2(projCoord.x + x * blurSize, projCoord.y + y * blurSize)) / 49.0;
+			}
+		}
+		color += reflection;
+	}
+
+	return color;
+}