Refactoring Rendering backend

Ghost.Graphics/RenderPasses/ShaderCode.hlsl

@@ -0,0 +1,84 @@
+cbuffer ConstantBuffer : register(b0)
+{
+    float4 _Color;
+    uint _TextureIndex1;
+    uint _TextureIndex2;
+    uint _TextureIndex3;
+    uint _TextureIndex4;
+    uint _VertexBufferIndex;
+    uint _IndexBufferIndex;
+};
+
+// SM 6.6 approach - direct access to global descriptor heap
+SamplerState _MainSampler : register(s0);
+
+struct Vertex
+{
+    float4 position;
+    float4 normal;
+    float4 tangent;
+    float4 color;
+    float4 uv;
+};
+
+struct PixelInput
+{
+    float4 position : SV_POSITION;
+    float4 color : COLOR;
+    float4 uv : TEXCOORD0;
+};
+
+// Bindless vertex shader that fetches vertex data from bindless buffers
+PixelInput VSMain(uint vertexId : SV_VertexID, uint instanceId : SV_InstanceID)
+{
+    // Get bindless buffers
+    ByteAddressBuffer vertexBuffer = ResourceDescriptorHeap[_VertexBufferIndex];
+    ByteAddressBuffer indexBuffer = ResourceDescriptorHeap[_IndexBufferIndex];
+    
+    // For fully bindless rendering, we use instanced drawing where:
+    // - Each instance represents a triangle (instanceId = triangle index)
+    // - vertexId goes from 0 to 2 (the 3 vertices of the triangle)
+    
+    // Calculate the index into the index buffer
+    uint indexOffset = (instanceId * 3 + vertexId) * 4; // 4 bytes per index (uint32)
+    uint vertexIndex = indexBuffer.Load(indexOffset);
+    
+    // Calculate the offset into the vertex buffer
+    uint vertexOffset = vertexIndex * 80; // 80 bytes per vertex (5 * float4)
+    
+    // Load vertex data from bindless vertex buffer
+    Vertex vertex;
+    vertex.position = asfloat(vertexBuffer.Load4(vertexOffset + 0));
+    vertex.normal = asfloat(vertexBuffer.Load4(vertexOffset + 16));
+    vertex.tangent = asfloat(vertexBuffer.Load4(vertexOffset + 32));
+    vertex.color = asfloat(vertexBuffer.Load4(vertexOffset + 48));
+    vertex.uv = asfloat(vertexBuffer.Load4(vertexOffset + 64));
+    
+    // Output transformed vertex
+    PixelInput output;
+    output.position = vertex.position;
+    output.color = vertex.color;
+    output.uv = vertex.uv;
+    return output;
+}
+
+float4 PSMain(PixelInput input) : SV_TARGET
+{
+    // SM 6.6 Modern Bindless Approach:
+    // ResourceDescriptorHeap[index] directly accesses any texture in the heap
+    Texture2D tex1 = ResourceDescriptorHeap[_TextureIndex1];
+    Texture2D tex2 = ResourceDescriptorHeap[_TextureIndex2];
+    Texture2D tex3 = ResourceDescriptorHeap[_TextureIndex3];
+    Texture2D tex4 = ResourceDescriptorHeap[_TextureIndex4];
+    
+    // Sample the textures
+    float4 color1 = tex1.Sample(_MainSampler, input.uv.xy);
+    float4 color2 = tex2.Sample(_MainSampler, input.uv.xy);
+    float4 color3 = tex3.Sample(_MainSampler, input.uv.xy);
+    float4 color4 = tex4.Sample(_MainSampler, input.uv.xy);
+    
+    // Blend all textures together (simple average)
+    float4 blendedColor = (color1 + color2 + color3 + color4) * 0.25f;
+    
+    return blendedColor * _Color;
+}