您最多选择25个主题 主题必须以中文或者字母或数字开头,可以包含连字符 (-),并且长度不得超过35个字符
 
 
 
 

176 行
8.6 KiB

#ifndef LIGHTWEIGHT_SHADOWS_INCLUDED
#define LIGHTWEIGHT_SHADOWS_INCLUDED
#include "CoreRP/ShaderLibrary/Common.hlsl"
#include "CoreRP/ShaderLibrary/Shadow/ShadowSamplingTent.hlsl"
#include "Core.hlsl"
#define MAX_SHADOW_CASCADES 4
#ifdef SHADER_API_GLES
#define SHADOWS_SCREEN 0
#else
#define SHADOWS_SCREEN 1
#endif
SCREENSPACE_TEXTURE(_ScreenSpaceShadowMap);
SAMPLER(sampler_ScreenSpaceShadowMap);
TEXTURE2D_SHADOW(_ShadowMap);
SAMPLER_CMP(sampler_ShadowMap);
CBUFFER_START(_ShadowBuffer)
// Last cascade is initialized with a no-op matrix. It always transforms
// shadow coord to half(0, 0, NEAR_PLANE). We use this trick to avoid
// branching since ComputeCascadeIndex can return cascade index = MAX_SHADOW_CASCADES
float4x4 _WorldToShadow[MAX_SHADOW_CASCADES + 1];
float4 _DirShadowSplitSpheres[MAX_SHADOW_CASCADES];
float4 _DirShadowSplitSphereRadii;
half4 _ShadowOffset0;
half4 _ShadowOffset1;
half4 _ShadowOffset2;
half4 _ShadowOffset3;
half4 _ShadowData; // (x: shadowStrength)
float4 _ShadowmapSize; // (xy: 1/width and 1/height, zw: width and height)
CBUFFER_END
#if UNITY_REVERSED_Z
#define BEYOND_SHADOW_FAR(shadowCoord) shadowCoord.z <= UNITY_RAW_FAR_CLIP_VALUE
#else
#define BEYOND_SHADOW_FAR(shadowCoord) shadowCoord.z >= UNITY_RAW_FAR_CLIP_VALUE
#endif
half GetShadowStrength()
{
return _ShadowData.x;
}
inline half SampleScreenSpaceShadowMap(float4 shadowCoord)
{
shadowCoord.xy /= shadowCoord.w;
// The stereo transform has to happen after the manual perspective divide
shadowCoord.xy = UnityStereoTransformScreenSpaceTex(shadowCoord.xy);
#if defined(UNITY_STEREO_INSTANCING_ENABLED) || defined(UNITY_STEREO_MULTIVIEW_ENABLED)
half attenuation = SAMPLE_TEXTURE2D_ARRAY(_ScreenSpaceShadowMap, sampler_ScreenSpaceShadowMap, shadowCoord.xy, unity_StereoEyeIndex).x;
#else
half attenuation = SAMPLE_TEXTURE2D(_ScreenSpaceShadowMap, sampler_ScreenSpaceShadowMap, shadowCoord.xy).x;
#endif
return attenuation;
}
inline real SampleShadowmap(float4 shadowCoord)
{
shadowCoord.xyz /= shadowCoord.w;
real attenuation;
#ifdef _SHADOWS_SOFT
#ifdef SHADER_API_MOBILE
// 4-tap hardware comparison
real4 attenuation4;
attenuation4.x = SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, shadowCoord.xyz + _ShadowOffset0.xyz);
attenuation4.y = SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, shadowCoord.xyz + _ShadowOffset1.xyz);
attenuation4.z = SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, shadowCoord.xyz + _ShadowOffset2.xyz);
attenuation4.w = SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, shadowCoord.xyz + _ShadowOffset3.xyz);
attenuation = dot(attenuation4, 0.25);
#else
#ifdef _SHADOWS_CASCADE //Assume screen space shadows when cascades enabled
float fetchesWeights[16];
float2 fetchesUV[16];
SampleShadow_ComputeSamples_Tent_7x7(_ShadowmapSize, shadowCoord.xy, fetchesWeights, fetchesUV);
attenuation = fetchesWeights[0] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[0].xy, shadowCoord.z));
attenuation += fetchesWeights[1] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[1].xy, shadowCoord.z));
attenuation += fetchesWeights[2] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[2].xy, shadowCoord.z));
attenuation += fetchesWeights[3] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[3].xy, shadowCoord.z));
attenuation += fetchesWeights[4] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[4].xy, shadowCoord.z));
attenuation += fetchesWeights[5] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[5].xy, shadowCoord.z));
attenuation += fetchesWeights[6] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[6].xy, shadowCoord.z));
attenuation += fetchesWeights[7] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[7].xy, shadowCoord.z));
attenuation += fetchesWeights[8] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[8].xy, shadowCoord.z));
attenuation += fetchesWeights[9] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[9].xy, shadowCoord.z));
attenuation += fetchesWeights[10] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[10].xy, shadowCoord.z));
attenuation += fetchesWeights[11] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[11].xy, shadowCoord.z));
attenuation += fetchesWeights[12] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[12].xy, shadowCoord.z));
attenuation += fetchesWeights[13] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[13].xy, shadowCoord.z));
attenuation += fetchesWeights[14] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[14].xy, shadowCoord.z));
attenuation += fetchesWeights[15] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[15].xy, shadowCoord.z));
#else
float fetchesWeights[9];
float2 fetchesUV[9];
SampleShadow_ComputeSamples_Tent_5x5(_ShadowmapSize, shadowCoord.xy, fetchesWeights, fetchesUV);
attenuation = fetchesWeights[0] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[0].xy, shadowCoord.z));
attenuation += fetchesWeights[1] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[1].xy, shadowCoord.z));
attenuation += fetchesWeights[2] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[2].xy, shadowCoord.z));
attenuation += fetchesWeights[3] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[3].xy, shadowCoord.z));
attenuation += fetchesWeights[4] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[4].xy, shadowCoord.z));
attenuation += fetchesWeights[5] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[5].xy, shadowCoord.z));
attenuation += fetchesWeights[6] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[6].xy, shadowCoord.z));
attenuation += fetchesWeights[7] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[7].xy, shadowCoord.z));
attenuation += fetchesWeights[8] * SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, float3(fetchesUV[8].xy, shadowCoord.z));
#endif
#endif
#else
// 1-tap hardware comparison
attenuation = SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, shadowCoord.xyz);
#endif
// Apply shadow strength
attenuation = LerpWhiteTo(attenuation, GetShadowStrength());
// Shadow coords that fall out of the light frustum volume must always return attenuation 1.0
return BEYOND_SHADOW_FAR(shadowCoord) ? 1.0 : attenuation;
}
inline half ComputeCascadeIndex(float3 positionWS)
{
// TODO: profile if there's a performance improvement if we avoid indexing here
float3 fromCenter0 = positionWS.xyz - _DirShadowSplitSpheres[0].xyz;
float3 fromCenter1 = positionWS.xyz - _DirShadowSplitSpheres[1].xyz;
float3 fromCenter2 = positionWS.xyz - _DirShadowSplitSpheres[2].xyz;
float3 fromCenter3 = positionWS.xyz - _DirShadowSplitSpheres[3].xyz;
float4 distances2 = float4(dot(fromCenter0, fromCenter0), dot(fromCenter1, fromCenter1), dot(fromCenter2, fromCenter2), dot(fromCenter3, fromCenter3));
half4 weights = half4(distances2 < _DirShadowSplitSphereRadii);
weights.yzw = saturate(weights.yzw - weights.xyz);
return 4 - dot(weights, half4(4, 3, 2, 1));
}
float4 TransformWorldToShadowCoord(float3 positionWS)
{
#ifdef _SHADOWS_CASCADE
half cascadeIndex = ComputeCascadeIndex(positionWS);
return mul(_WorldToShadow[cascadeIndex], float4(positionWS, 1.0));
#else
return mul(_WorldToShadow[0], float4(positionWS, 1.0));
#endif
}
float4 ComputeShadowCoord(float4 clipPos)
{
// TODO: This might have to be corrected for double-wide and texture arrays
return ComputeScreenPos(clipPos);
}
half RealtimeShadowAttenuation(float4 shadowCoord)
{
#ifndef _SHADOWS_ENABLED
return 1.0h;
#endif
#if defined(NO_SHADOWS)
return 1.0h;
#elif SHADOWS_SCREEN
return SampleScreenSpaceShadowMap(shadowCoord);
#else
return SampleShadowmap(shadowCoord);
#endif
}
#endif