Added final missing slang shaders

Requires a very recent version of slang

shaders/slang/subpasses/composition.slang

@@ -0,0 +1,66 @@
+/* Copyright (c) 2025, Sascha Willems
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ */
+
+struct VSOutput
+{
+    float4 Pos : SV_POSITION;
+    float2 UV;
+};
+
+[[vk::input_attachment_index(0)]] SubpassInput inputPosition;
+[[vk::input_attachment_index(1)]] SubpassInput inputNormal;
+[[vk::input_attachment_index(2)]] SubpassInput inputAlbedo;
+
+struct Light {
+	float4 position;
+	float3 color;
+	float radius;
+};
+RWStructuredBuffer<Light> lights;
+
+[shader("vertex")]
+VSOutput vertexMain(uint VertexIndex: SV_VertexID)
+{
+    VSOutput output;
+    output.UV = float2((VertexIndex << 1) & 2, VertexIndex & 2);
+    output.Pos = float4(output.UV * 2.0f - 1.0f, 0.0f, 1.0f);
+    return output;
+}
+
+[shader("fragment")]
+float4 fragmentMain()
+{
+	// Read G-Buffer values from previous sub pass
+	float3 fragPos = inputPosition.SubpassLoad().rgb;
+	float3 normal = inputNormal.SubpassLoad().rgb;
+	float4 albedo = inputAlbedo.SubpassLoad();
+
+	#define ambient 0.05
+
+	// Ambient part
+	float3 fragcolor  = albedo.rgb * ambient;
+
+	uint lightsLength;
+	uint lightsStride;
+	lights.GetDimensions(lightsLength, lightsStride);
+
+	for(int i = 0; i < lightsLength; ++i)
+	{
+		float3 L = lights[i].position.xyz - fragPos;
+		float dist = length(L);
+
+		L = normalize(L);
+
+		float atten = lights[i].radius / (pow(dist, 3.0) + 1.0);
+		float3 N = normalize(normal);
+		float NdotL = max(0.0, dot(N, L));
+		float3 diff = lights[i].color * albedo.rgb * NdotL * atten;
+
+		fragcolor += diff;
+	}
+
+	return float4(fragcolor, 1.0);
+}