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251 lines
11 KiB
C++
251 lines
11 KiB
C++
// Copyright 2017 Citra Emulator Project
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// Licensed under GPLv2 or any later version
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// Refer to the license.txt file included.
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#include "common/math_util.h"
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#include "video_core/swrasterizer/fragment_lighting.h"
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namespace Pica {
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static float LookupLightingLut(const Pica::State::Lighting& lighting, size_t lut_index, u8 index,
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float delta) {
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ASSERT_MSG(lut_index < lighting.luts.size(), "Out of range lut");
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ASSERT_MSG(index < lighting.luts[lut_index].size(), "Out of range index");
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const auto& lut = lighting.luts[lut_index][index];
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float lut_value = lut.ToFloat();
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float lut_diff = lut.DiffToFloat();
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return lut_value + lut_diff * delta;
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}
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std::tuple<Math::Vec4<u8>, Math::Vec4<u8>> ComputeFragmentsColors(
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const Pica::LightingRegs& lighting, const Pica::State::Lighting& lighting_state,
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const Math::Quaternion<float>& normquat, const Math::Vec3<float>& view) {
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// TODO(Subv): Bump mapping
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Math::Vec3<float> surface_normal = {0.0f, 0.0f, 1.0f};
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if (lighting.config0.bump_mode != LightingRegs::LightingBumpMode::None) {
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LOG_CRITICAL(HW_GPU, "unimplemented bump mapping");
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UNIMPLEMENTED();
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}
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// Use the normalized the quaternion when performing the rotation
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auto normal = Math::QuaternionRotate(normquat, surface_normal);
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Math::Vec4<float> diffuse_sum = {0.0f, 0.0f, 0.0f, 1.0f};
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Math::Vec4<float> specular_sum = {0.0f, 0.0f, 0.0f, 1.0f};
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for (unsigned light_index = 0; light_index <= lighting.max_light_index; ++light_index) {
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unsigned num = lighting.light_enable.GetNum(light_index);
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const auto& light_config = lighting.light[num];
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Math::Vec3<float> refl_value = {};
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Math::Vec3<float> position = {float16::FromRaw(light_config.x).ToFloat32(),
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float16::FromRaw(light_config.y).ToFloat32(),
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float16::FromRaw(light_config.z).ToFloat32()};
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Math::Vec3<float> light_vector;
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if (light_config.config.directional)
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light_vector = position;
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else
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light_vector = position + view;
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light_vector.Normalize();
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float dist_atten = 1.0f;
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if (!lighting.IsDistAttenDisabled(num)) {
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auto distance = (-view - position).Length();
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float scale = Pica::float20::FromRaw(light_config.dist_atten_scale).ToFloat32();
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float bias = Pica::float20::FromRaw(light_config.dist_atten_bias).ToFloat32();
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size_t lut =
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static_cast<size_t>(LightingRegs::LightingSampler::DistanceAttenuation) + num;
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float sample_loc = MathUtil::Clamp(scale * distance + bias, 0.0f, 1.0f);
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u8 lutindex =
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static_cast<u8>(MathUtil::Clamp(std::floor(sample_loc * 256.0f), 0.0f, 255.0f));
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float delta = sample_loc * 256 - lutindex;
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dist_atten = LookupLightingLut(lighting_state, lut, lutindex, delta);
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}
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auto GetLutValue = [&](LightingRegs::LightingLutInput input, bool abs,
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LightingRegs::LightingScale scale_enum,
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LightingRegs::LightingSampler sampler) {
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Math::Vec3<float> norm_view = view.Normalized();
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Math::Vec3<float> half_angle = (norm_view + light_vector).Normalized();
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float result = 0.0f;
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switch (input) {
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case LightingRegs::LightingLutInput::NH:
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result = Math::Dot(normal, half_angle);
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break;
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case LightingRegs::LightingLutInput::VH:
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result = Math::Dot(norm_view, half_angle);
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break;
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case LightingRegs::LightingLutInput::NV:
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result = Math::Dot(normal, norm_view);
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break;
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case LightingRegs::LightingLutInput::LN:
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result = Math::Dot(light_vector, normal);
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break;
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default:
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LOG_CRITICAL(HW_GPU, "Unknown lighting LUT input %u\n", static_cast<u32>(input));
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UNIMPLEMENTED();
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result = 0.0f;
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}
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u8 index;
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float delta;
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if (abs) {
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if (light_config.config.two_sided_diffuse)
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result = std::abs(result);
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else
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result = std::max(result, 0.0f);
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float flr = std::floor(result * 256.0f);
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index = static_cast<u8>(MathUtil::Clamp(flr, 0.0f, 255.0f));
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delta = result * 256 - index;
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} else {
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float flr = std::floor(result * 128.0f);
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s8 signed_index = static_cast<s8>(MathUtil::Clamp(flr, -128.0f, 127.0f));
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delta = result * 128.0f - signed_index;
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index = static_cast<u8>(signed_index);
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}
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float scale = lighting.lut_scale.GetScale(scale_enum);
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return scale *
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LookupLightingLut(lighting_state, static_cast<size_t>(sampler), index, delta);
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};
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// Specular 0 component
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float d0_lut_value = 1.0f;
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if (lighting.config1.disable_lut_d0 == 0 &&
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LightingRegs::IsLightingSamplerSupported(
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lighting.config0.config, LightingRegs::LightingSampler::Distribution0)) {
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d0_lut_value =
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GetLutValue(lighting.lut_input.d0, lighting.abs_lut_input.disable_d0 == 0,
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lighting.lut_scale.d0, LightingRegs::LightingSampler::Distribution0);
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}
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Math::Vec3<float> specular_0 = d0_lut_value * light_config.specular_0.ToVec3f();
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// If enabled, lookup ReflectRed value, otherwise, 1.0 is used
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if (lighting.config1.disable_lut_rr == 0 &&
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LightingRegs::IsLightingSamplerSupported(lighting.config0.config,
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LightingRegs::LightingSampler::ReflectRed)) {
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refl_value.x =
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GetLutValue(lighting.lut_input.rr, lighting.abs_lut_input.disable_rr == 0,
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lighting.lut_scale.rr, LightingRegs::LightingSampler::ReflectRed);
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} else {
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refl_value.x = 1.0f;
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}
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// If enabled, lookup ReflectGreen value, otherwise, ReflectRed value is used
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if (lighting.config1.disable_lut_rg == 0 &&
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LightingRegs::IsLightingSamplerSupported(lighting.config0.config,
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LightingRegs::LightingSampler::ReflectGreen)) {
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refl_value.y =
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GetLutValue(lighting.lut_input.rg, lighting.abs_lut_input.disable_rg == 0,
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lighting.lut_scale.rg, LightingRegs::LightingSampler::ReflectGreen);
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} else {
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refl_value.y = refl_value.x;
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}
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// If enabled, lookup ReflectBlue value, otherwise, ReflectRed value is used
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if (lighting.config1.disable_lut_rb == 0 &&
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LightingRegs::IsLightingSamplerSupported(lighting.config0.config,
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LightingRegs::LightingSampler::ReflectBlue)) {
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refl_value.z =
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GetLutValue(lighting.lut_input.rb, lighting.abs_lut_input.disable_rb == 0,
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lighting.lut_scale.rb, LightingRegs::LightingSampler::ReflectBlue);
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} else {
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refl_value.z = refl_value.x;
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}
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// Specular 1 component
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float d1_lut_value = 1.0f;
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if (lighting.config1.disable_lut_d1 == 0 &&
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LightingRegs::IsLightingSamplerSupported(
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lighting.config0.config, LightingRegs::LightingSampler::Distribution1)) {
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d1_lut_value =
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GetLutValue(lighting.lut_input.d1, lighting.abs_lut_input.disable_d1 == 0,
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lighting.lut_scale.d1, LightingRegs::LightingSampler::Distribution1);
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}
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Math::Vec3<float> specular_1 =
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d1_lut_value * refl_value * light_config.specular_1.ToVec3f();
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// Fresnel
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if (lighting.config1.disable_lut_fr == 0 &&
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LightingRegs::IsLightingSamplerSupported(lighting.config0.config,
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LightingRegs::LightingSampler::Fresnel)) {
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float lut_value =
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GetLutValue(lighting.lut_input.fr, lighting.abs_lut_input.disable_fr == 0,
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lighting.lut_scale.fr, LightingRegs::LightingSampler::Fresnel);
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// Enabled for diffuse lighting alpha component
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if (lighting.config0.fresnel_selector ==
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LightingRegs::LightingFresnelSelector::PrimaryAlpha ||
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lighting.config0.fresnel_selector == LightingRegs::LightingFresnelSelector::Both) {
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diffuse_sum.a() *= lut_value;
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}
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// Enabled for the specular lighting alpha component
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if (lighting.config0.fresnel_selector ==
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LightingRegs::LightingFresnelSelector::SecondaryAlpha ||
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lighting.config0.fresnel_selector == LightingRegs::LightingFresnelSelector::Both) {
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specular_sum.a() *= lut_value;
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}
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}
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auto dot_product = Math::Dot(light_vector, normal);
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// Calculate clamp highlights before applying the two-sided diffuse configuration to the dot
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// product.
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float clamp_highlights = 1.0f;
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if (lighting.config0.clamp_highlights) {
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if (dot_product <= 0.0f)
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clamp_highlights = 0.0f;
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else
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clamp_highlights = 1.0f;
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}
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if (light_config.config.two_sided_diffuse)
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dot_product = std::abs(dot_product);
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else
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dot_product = std::max(dot_product, 0.0f);
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auto diffuse =
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light_config.diffuse.ToVec3f() * dot_product + light_config.ambient.ToVec3f();
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diffuse_sum += Math::MakeVec(diffuse * dist_atten, 0.0f);
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specular_sum +=
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Math::MakeVec((specular_0 + specular_1) * clamp_highlights * dist_atten, 0.0f);
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}
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diffuse_sum += Math::MakeVec(lighting.global_ambient.ToVec3f(), 0.0f);
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auto diffuse = Math::MakeVec<float>(MathUtil::Clamp(diffuse_sum.x, 0.0f, 1.0f) * 255,
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MathUtil::Clamp(diffuse_sum.y, 0.0f, 1.0f) * 255,
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MathUtil::Clamp(diffuse_sum.z, 0.0f, 1.0f) * 255,
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MathUtil::Clamp(diffuse_sum.w, 0.0f, 1.0f) * 255)
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.Cast<u8>();
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auto specular = Math::MakeVec<float>(MathUtil::Clamp(specular_sum.x, 0.0f, 1.0f) * 255,
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MathUtil::Clamp(specular_sum.y, 0.0f, 1.0f) * 255,
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MathUtil::Clamp(specular_sum.z, 0.0f, 1.0f) * 255,
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MathUtil::Clamp(specular_sum.w, 0.0f, 1.0f) * 255)
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.Cast<u8>();
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return {diffuse, specular};
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}
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} // namespace Pica
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