procedural-3d-engine/shaders/slang/shadowmappingomni/scene.slang

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/* Copyright (c) 2025, Sascha Willems
*
* SPDX-License-Identifier: MIT
*
*/
struct VSInput
{
float3 Pos;
float3 Color;
float3 Normal;
};
struct VSOutput
{
float4 Pos : SV_POSITION;
float3 Normal;
float3 Color;
float3 EyePos;
float3 LightVec;
float3 WorldPos;
float3 LightPos;
};
struct UBO
{
float4x4 projection;
float4x4 view;
float4x4 model;
float4 lightPos;
};
ConstantBuffer<UBO> ubo;
SamplerCube shadowCubeMapSampler;
#define EPSILON 0.15
#define SHADOW_OPACITY 0.5
[shader("vertex")]
VSOutput vertexMain(VSInput input)
{
VSOutput output;
output.Color = input.Color;
output.Normal = input.Normal;
output.Pos = mul(ubo.projection, mul(ubo.view, mul(ubo.model, float4(input.Pos.xyz, 1.0))));
output.EyePos = mul(ubo.model, float4(input.Pos, 1.0f)).xyz;
output.LightVec = normalize(ubo.lightPos.xyz - input.Pos.xyz);
output.WorldPos = input.Pos;
output.LightPos = ubo.lightPos.xyz;
return output;
}
[shader("fragment")]
float4 fragmentMain(VSOutput input)
{
// Lighting
float3 N = normalize(input.Normal);
float3 L = normalize(float3(1.0, 1.0, 1.0));
float3 Eye = normalize(-input.EyePos);
float3 Reflected = normalize(reflect(-input.LightVec, input.Normal));
float4 IAmbient = float4(float3(0.05, 0.05, 0.05), 1.0);
float4 IDiffuse = float4(1.0, 1.0, 1.0, 1.0) * max(dot(input.Normal, input.LightVec), 0.0);
float4 outFragColor = float4(IAmbient + IDiffuse * float4(input.Color, 1.0));
// Shadow
float3 lightVec = input.WorldPos - input.LightPos;
float sampledDist = shadowCubeMapSampler.Sample(lightVec).r;
float dist = length(lightVec);
// Check if fragment is in shadow
float shadow = (dist <= sampledDist + EPSILON) ? 1.0 : SHADOW_OPACITY;
outFragColor.rgb *= shadow;
return outFragColor;
}