Files
2026-07-13 13:13:17 +08:00

321 lines
11 KiB
HLSL

#include "shared/point.hlsl"
#include "shared/quat-functions.hlsl"
#include "shared/point-light.hlsl"
#include "shared/pbr.hlsl"
cbuffer Transforms : register(b0)
{
float4x4 CameraToClipSpace;
float4x4 ClipSpaceToCamera;
float4x4 WorldToCamera;
float4x4 CameraToWorld;
float4x4 WorldToClipSpace;
float4x4 ClipSpaceToWorld;
float4x4 ObjectToWorld;
float4x4 WorldToObject;
float4x4 ObjectToCamera;
float4x4 ObjectToClipSpace;
};
cbuffer Params : register(b1)
{
float4x4 WorldToLightClipSpace;
float4 Color;
float Size;
float AlphaCutOff;
float ShadowOffset;
float ShadowBias;
float4 ShadowColor;
};
cbuffer Params : register(b2)
{
int SegmentCount;
int UseWForSize;
int UseStretch;
int IsShadowPass;
};
cbuffer FogParams : register(b3)
{
float4 FogColor;
float FogDistance;
float FogBias;
}
cbuffer PointLights : register(b4)
{
PointLight Lights[8];
int ActiveLightCount;
}
cbuffer PbrParams : register(b5)
{
float4 BaseColor;
float4 EmissiveColor;
float Roughness;
float Specular;
float Metal;
}
struct psInput
{
float2 texCoord : TEXCOORD;
float4 pixelPosition : SV_POSITION;
float4 color : COLOR;
float3 worldPosition : POSITION;
float3x3 tbnToWorld : TBASIS;
float fog : VPOS;
float4 positionInLightClipSpace : LIGHTCLIPPOS;
};
struct IndicesForDraw
{
int PointIndex;
int3 VertexIndices;
};
sampler texSampler : register(s0);
sampler clampedSampler : register(s1);
StructuredBuffer<PbrVertex> PbrVertices : register(t0);
StructuredBuffer<Point> Points : register(t1);
StructuredBuffer<IndicesForDraw> DrawData : register(t2);
Texture2D<float4> BaseColorMap : register(t3);
Texture2D<float4> EmissiveColorMap : register(t4);
Texture2D<float4> RSMOMap : register(t5);
Texture2D<float4> NormalMap : register(t6);
TextureCube<float4> PrefilteredSpecular : register(t7);
Texture2D<float4> BRDFLookup : register(t8);
Texture2D<float> ShadowMap : register(t9);
psInput vsMain(uint id : SV_VertexID)
{
psInput output;
uint drawFaceIndex = id / 3;
uint faceVertexIndex = id % 3;
uint vertexIndex = DrawData[drawFaceIndex].VertexIndices[faceVertexIndex];
uint pointIndex = DrawData[drawFaceIndex].PointIndex;
PbrVertex vertex = PbrVertices[vertexIndex];
float4 posInObject = float4(vertex.Position, 1);
float resizeFromW = UseWForSize ? Points[pointIndex].FX1 : 1;
float3 resizeFromStretch = UseStretch ? Points[pointIndex].Scale : 1;
posInObject.xyz *= max(0, resizeFromW) * Size * resizeFromStretch;
float4x4 orientationMatrix = transpose(qToMatrix(normalize(Points[pointIndex].Rotation)));
posInObject = mul(float4(posInObject.xyz, 1), orientationMatrix);
posInObject += float4(Points[pointIndex].Position, 0);
output.color = Points[pointIndex].Color;
float4 posInClipSpace = mul(posInObject, ObjectToClipSpace);
output.pixelPosition = posInClipSpace;
float2 uv = vertex.TexCoord;
output.texCoord = float2(uv.x, 1 - uv.y);
// Offset position along normal for shadow mapping
float4 posInWorld = mul(posInObject, ObjectToWorld);
output.worldPosition = posInWorld.xyz;
float3 worldNormal = normalize(mul(float4(vertex.Normal, 0), (float4x4)ObjectToWorld).xyz);
float4 posInWorldOffset = posInWorld;
posInWorldOffset.xyz += worldNormal * ShadowOffset;
output.positionInLightClipSpace = mul(posInWorldOffset, WorldToLightClipSpace);
// Pass tangent space basis vectors (for normal mapping).
float3x3 TBN = float3x3(vertex.Tangent, vertex.Bitangent, vertex.Normal);
TBN = mul(TBN, (float3x3)orientationMatrix);
TBN = mul(TBN, (float3x3)ObjectToWorld);
output.tbnToWorld = float3x3(
normalize(TBN._m00_m01_m02),
normalize(TBN._m10_m11_m12),
normalize(TBN._m20_m21_m22));
// Fog
if (FogDistance > 0)
{
float4 posInCamera = mul(posInObject, ObjectToCamera);
float fog = pow(saturate(-posInCamera.z / FogDistance), FogBias);
output.fog = fog;
}
return output;
}
inline float ComputeShadowFactor(float3 shadowCoord, float2 texelSize, float bias)
{
float shadow = 0.0;
int samples = 0;
for (int y = -1; y <= 1; y++)
{
for (int x = -1; x <= 1; x++)
{
float2 offset = float2(x, y) * texelSize;
float2 sampleUV = shadowCoord.xy + offset;
// Sample only if sampleUV is within [0,1]
if (sampleUV.x >= 0 && sampleUV.x <= 1 && sampleUV.y >= 0 && sampleUV.y <= 1)
{
float sampleDepth = ShadowMap.Sample(clampedSampler, sampleUV);
// Compare depths with bias
if (shadowCoord.z > sampleDepth + bias)
{
shadow += 1.0;
}
}
samples++;
}
}
return 1.0 - (shadow / samples);
}
float4 psMain(psInput pin) : SV_TARGET
{
// Sample input textures to get shading model params.
float4 albedo = BaseColorMap.Sample(texSampler, pin.texCoord) * pin.color;
if (AlphaCutOff > 0 && albedo.a < AlphaCutOff)
discard;
float4 roughnessMetallicOcclusion = RSMOMap.Sample(texSampler, pin.texCoord);
float roughness = saturate(roughnessMetallicOcclusion.x + Roughness);
float metalness = saturate(roughnessMetallicOcclusion.y + Metal);
float occlusion = roughnessMetallicOcclusion.z;
// Outgoing light direction (vector from world-space fragment position to the "eye").
float3 eyePosition = mul(float4(0, 0, 0, 1), CameraToWorld).xyz;
float3 Lo = normalize(eyePosition - pin.worldPosition);
// Get current fragment's normal and transform to world space.
float3 N = normalize(2.0 * NormalMap.Sample(texSampler, pin.texCoord).rgb - 1.0);
// return float4(pin.tbnToWorld[0],1);
N = normalize(mul(N, pin.tbnToWorld));
// Angle between surface normal and outgoing light direction.
float cosLo = max(0.0, dot(N, Lo));
// Specular reflection vector.
float3 Lr = 2.0 * cosLo * N - Lo;
// Fresnel reflectance at normal incidence (for metals use albedo color).
float3 F0 = lerp(Fdielectric, albedo.rgb, metalness);
// Direct lighting calculation for analytical lights.
// Direct lighting calculation for analytical lights.
float3 directLighting = 0.0;
for (int i = 0; i < ActiveLightCount; ++i)
{
float3 Li = Lights[i].position - pin.worldPosition; //- Lights[i].direction;
float distance = length(Li);
float intensity = Lights[i].intensity / (pow(distance / Lights[i].range, Lights[i].decay) + 1);
float3 Lradiance = Lights[i].color.rgb * intensity; // Lights[i].radiance;
// Half-vector between Li and Lo.
float3 Lh = normalize(Li + Lo);
// Calculate angles between surface normal and various light vectors.
float cosLi = max(0.0, dot(N, Li));
float cosLh = max(0.0, dot(N, Lh));
// Calculate Fresnel term for direct lighting.
float3 F = fresnelSchlick(F0, max(0.0, dot(Lh, Lo)));
// Calculate normal distribution for specular BRDF.
float D = ndfGGX(cosLh, roughness);
// Calculate geometric attenuation for specular BRDF.
float G = gaSchlickGGX(cosLi, cosLo, roughness);
// Diffuse scattering happens due to light being refracted multiple times by a dielectric medium.
// Metals on the other hand either reflect or absorb energy, so diffuse contribution is always zero.
// To be energy conserving we must scale diffuse BRDF contribution based on Fresnel factor & metalness.
float3 kd = lerp(float3(1, 1, 1), float3(0, 0, 0), metalness);
// return float4(F, 1);
// Lambert diffuse BRDF.
// We don't scale by 1/PI for lighting & material units to be more convenient.
// See: https://seblagarde.wordpress.com/2012/01/08/pi-or-not-to-pi-in-game-lighting-equation/
float3 diffuseBRDF = kd * albedo.rgb;
// Cook-Torrance specular microfacet BRDF.
float3 specularBRDF = ((F * D * G) / max(Epsilon, 4.0 * cosLi * cosLo)) * Specular;
// Total contribution for this light.
directLighting += (diffuseBRDF + specularBRDF) * Lradiance * cosLi;
}
// Ambient lighting (IBL).
float3 ambientLighting = 0;
{
// Sample diffuse irradiance at normal direction.
uint width, height, levels;
PrefilteredSpecular.GetDimensions(0, width, height, levels);
float3 irradiance = PrefilteredSpecular.SampleLevel(texSampler, Lr.xyz, 0.8 * levels).rgb;
// Calculate Fresnel term for ambient lighting.
// Since we use pre-filtered cubemap(s) and irradiance is coming from many directions
// use cosLo instead of angle with light's half-vector (cosLh above).
// See: https://seblagarde.wordpress.com/2011/08/17/hello-world/
float3 F = fresnelSchlick(F0, cosLo);
// Get diffuse contribution factor (as with direct lighting).
float3 kd = lerp(1.0 - F, 0.0, metalness);
// Irradiance map contains exitant radiance assuming Lambertian BRDF, no need to scale by 1/PI here either.
float3 diffuseIBL = kd * albedo.rgb * irradiance;
// Sample pre-filtered specular reflection environment at correct mipmap level.
float3 specularIrradiance = PrefilteredSpecular.SampleLevel(texSampler, Lr.xyz, roughness * levels).rgb;
// Split-sum approximation factors for Cook-Torrance specular BRDF.
float2 specularBRDF = BRDFLookup.SampleLevel(clampedSampler, float2(cosLo, roughness), 0).rg;
// Total specular IBL contribution.
float3 specularIBL = (F0 * specularBRDF.x + specularBRDF.y) * specularIrradiance;
// Total ambient lighting contribution.
ambientLighting = diffuseIBL + specularIBL;
}
float shadowFactor = 1.0;
if (!IsShadowPass)
{
// Compute shadow coordinates
float3 shadowCoord = pin.positionInLightClipSpace.xyz / pin.positionInLightClipSpace.w;
shadowCoord.xy = shadowCoord.xy * 0.5 + 0.5;
shadowCoord.y = 1 - shadowCoord.y;
// Compute shadow map texel size
uint shadowMapWidth, shadowMapHeight;
ShadowMap.GetDimensions(shadowMapWidth, shadowMapHeight);
float2 shadowMapTexelSize = float2(1.0 / shadowMapWidth, 1.0 / shadowMapHeight);
// float shadowFactor = 1.0;
// Check if shadowCoord is within [0,1]
if (shadowCoord.x >= 0 && shadowCoord.x <= 1 && shadowCoord.y >= 0 && shadowCoord.y <= 1)
{
shadowFactor = ComputeShadowFactor(shadowCoord, shadowMapTexelSize, ShadowBias);
}
}
// Final fragment color.
float4 litColor = float4(directLighting + ambientLighting, 1.0) * BaseColor * Color;
litColor.rgb = lerp(litColor.rgb, ShadowColor.rgb, (1 - shadowFactor) * ShadowColor.a);
litColor += float4(EmissiveColorMap.Sample(texSampler, pin.texCoord).rgb * EmissiveColor.rgb, 0);
litColor.rgb = lerp(litColor.rgb, FogColor.rgb, pin.fog);
litColor.a *= albedo.a;
// if (!IsShadowPass)
// litColor.r = 0.5;
return litColor;
}