procedural-3d-engine/shaders/slang/texturecubemap/reflect.slang
Sascha Willems 5833d766a7 Clean up
2025-05-31 16:33:19 +02:00

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/* Copyright (c) 2025, Sascha Willems
*
* SPDX-License-Identifier: MIT
*
*/
struct VSInput
{
float3 Pos;
float3 Normal;
};
struct VSOutput
{
float4 Pos : SV_POSITION;
float3 WorldPos;
float3 Normal;
float LodBias;
float3 ViewVec;
float3 LightVec;
};
struct UBO
{
float4x4 projection;
float4x4 model;
float4x4 invModel;
float lodBias;
};
ConstantBuffer<UBO> ubo;
SamplerCube samplerColor;
[shader("vertex")]
VSOutput vertexMain(VSInput input)
{
VSOutput output;
output.Pos = mul(ubo.projection, mul(ubo.model, float4(input.Pos.xyz, 1.0)));
output.WorldPos = mul(ubo.model, float4(input.Pos, 1.0)).xyz;
output.Normal = mul((float3x3)ubo.model, input.Normal);
output.LodBias = ubo.lodBias;
float3 lightPos = float3(0.0f, -5.0f, 5.0f);
output.LightVec = lightPos.xyz - output.WorldPos.xyz;
output.ViewVec = -output.WorldPos;
return output;
}
[shader("fragment")]
float4 fragmentMain(VSOutput input)
{
float3 cI = normalize (input.ViewVec);
float3 cR = reflect (cI, normalize(input.Normal));
cR = mul(ubo.invModel, float4(cR, 0.0)).xyz;
// Convert cubemap coordinates into Vulkan coordinate space
cR.z *= -1.0;
float4 color = samplerColor.SampleLevel(cR, input.LodBias);
float3 N = normalize(input.Normal);
float3 L = normalize(input.LightVec);
float3 V = normalize(input.ViewVec);
float3 R = reflect(-L, N);
float3 ambient = float3(0.5, 0.5, 0.5) * color.rgb;
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(0.5, 0.5, 0.5);
return float4(ambient + diffuse * color.rgb + specular, 1.0);
}