procedural-3d-engine/shaders/hlsl/hdr/gbuffer.frag
2023-05-09 21:03:02 +02:00

108 lines
No EOL
2.7 KiB
GLSL

// Copyright 2020 Google LLC
TextureCube textureEnvMap : register(t1);
SamplerState samplerEnvMap : register(s1);
struct VSOutput
{
[[vk::location(0)]] float3 UVW : TEXCOORD0;
[[vk::location(1)]] float3 Pos : POSITION0;
[[vk::location(2)]] float3 Normal : NORMAL0;
[[vk::location(3)]] float3 ViewVec : TEXCOORD1;
[[vk::location(4)]] float3 LightVec : TEXCOORD2;
};
struct FSOutput
{
float4 Color0 : SV_TARGET0;
float4 Color1 : SV_TARGET1;
};
[[vk::constant_id(0)]] const int type = 0;
#define PI 3.1415926
#define TwoPI (2.0 * PI)
struct UBO {
float4x4 projection;
float4x4 modelview;
float4x4 inverseModelview;
};
cbuffer ubo : register(b0) { UBO ubo; }
cbuffer Exposure : register(b2)
{
float exposure;
}
FSOutput main(VSOutput input)
{
FSOutput output = (FSOutput)0;
float4 color;
float3 wcNormal;
switch (type) {
case 0: // Skybox
{
float3 normal = normalize(input.UVW);
color = textureEnvMap.Sample(samplerEnvMap, normal);
}
break;
case 1: // Reflect
{
float3 wViewVec = mul((float4x3)ubo.inverseModelview, normalize(input.ViewVec)).xyz;
float3 normal = normalize(input.Normal);
float3 wNormal = mul((float4x3)ubo.inverseModelview, normal).xyz;
float NdotL = max(dot(normal, input.LightVec), 0.0);
float3 eyeDir = normalize(input.ViewVec);
float3 halfVec = normalize(input.LightVec + eyeDir);
float NdotH = max(dot(normal, halfVec), 0.0);
float NdotV = max(dot(normal, eyeDir), 0.0);
float VdotH = max(dot(eyeDir, halfVec), 0.0);
// Geometric attenuation
float NH2 = 2.0 * NdotH;
float g1 = (NH2 * NdotV) / VdotH;
float g2 = (NH2 * NdotL) / VdotH;
float geoAtt = min(1.0, min(g1, g2));
const float F0 = 0.6;
const float k = 0.2;
// Fresnel (schlick approximation)
float fresnel = pow(1.0 - VdotH, 5.0);
fresnel *= (1.0 - F0);
fresnel += F0;
float spec = (fresnel * geoAtt) / (NdotV * NdotL * 3.14);
color = textureEnvMap.Sample(samplerEnvMap, reflect(-wViewVec, wNormal));
color = float4(color.rgb * NdotL * (k + spec * (1.0 - k)), 1.0);
}
break;
case 2: // Refract
{
float3 wViewVec = mul((float4x3)ubo.inverseModelview, normalize(input.ViewVec)).xyz;
float3 wNormal = mul((float4x3)ubo.inverseModelview, input.Normal).xyz;
color = textureEnvMap.Sample(samplerEnvMap, refract(-wViewVec, wNormal, 1.0/1.6));
}
break;
}
// Color with manual exposure into attachment 0
output.Color0.rgb = float3(1.0, 1.0, 1.0) - exp(-color.rgb * exposure);
// Bright parts for bloom into attachment 1
float l = dot(output.Color0.rgb, float3(0.2126, 0.7152, 0.0722));
float threshold = 0.75;
output.Color1.rgb = (l > threshold) ? output.Color0.rgb : float3(0.0, 0.0, 0.0);
output.Color1.a = 1.0;
return output;
}