110 lines
3.3 KiB
Plaintext
110 lines
3.3 KiB
Plaintext
/* Copyright (c) 2025, Sascha Willems
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 the "License";
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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struct VSOutput
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{
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float4 Pos : SV_POSITION;
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float3 UVW;
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float3 Normal;
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float3 ViewVec;
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float3 LightVec;
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};
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[[SpecializationConstant]] const int type = 0;
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#define PI 3.1415926
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#define TwoPI (2.0 * PI)
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struct UBOMatrices
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{
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float4x4 projection;
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float4x4 modelview;
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float4x4 skyboxModelview;
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float4x4 inverseModelView;
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float modelscale;
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};
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ConstantBuffer<UBOMatrices> uboMatrices;
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SamplerCube samplerEnvMap;
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[shader("fragment")]
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float4 main(VSOutput input)
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{
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float4 color;
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float3 wcNormal;
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switch (type)
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{
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case 0: // Skybox
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{
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float3 normal = normalize(input.UVW);
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color = samplerEnvMap.Sample(normal);
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}
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break;
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case 1: // Reflect
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{
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float3 wViewVec = mul((float3x3) uboMatrices.inverseModelView, normalize(input.ViewVec)).xyz;
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float3 normal = normalize(input.Normal);
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float3 wNormal = mul((float3x3) uboMatrices.inverseModelView, normal).xyz;
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float NdotL = max(dot(normal, input.LightVec), 0.0);
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float3 eyeDir = normalize(input.ViewVec);
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float3 halfVec = normalize(input.LightVec + eyeDir);
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float NdotH = max(dot(normal, halfVec), 0.0);
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float NdotV = max(dot(normal, eyeDir), 0.0);
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float VdotH = max(dot(eyeDir, halfVec), 0.0);
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// Geometric attenuation
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float NH2 = 2.0 * NdotH;
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float g1 = (NH2 * NdotV) / VdotH;
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float g2 = (NH2 * NdotL) / VdotH;
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float geoAtt = min(1.0, min(g1, g2));
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const float F0 = 0.6;
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const float k = 0.2;
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// Fresnel (schlick approximation)
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float fresnel = pow(1.0 - VdotH, 5.0);
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fresnel *= (1.0 - F0);
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fresnel += F0;
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float spec = max((fresnel * geoAtt) / (NdotV * NdotL * 3.14), 0.0);
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color = samplerEnvMap.Sample(reflect(-wViewVec, wNormal));
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color = float4(color.rgb * NdotL * (k + spec * (1.0 - k)), 1.0);
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}
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break;
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case 2: // Refract
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{
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float3 wViewVec = mul((float4x3) uboMatrices.inverseModelView, normalize(input.ViewVec)).xyz;
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float3 wNormal = mul((float4x3)uboMatrices.inverseModelView, input.Normal).xyz;
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color = samplerEnvMap.Sample(refract(-wViewVec, wNormal, 1.0 / 1.6));
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}
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break;
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}
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// Color with manual exposure into attachment 0
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const float exposure = 1.0;
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float3 outColor = float3(1.0, 1.0, 1.0) - exp(-color.rgb * exposure);
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return float4(outColor, 1.0);
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}
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