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-rw-r--r--src/video_core/swrasterizer/lighting.cpp250
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diff --git a/src/video_core/swrasterizer/lighting.cpp b/src/video_core/swrasterizer/lighting.cpp
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+++ b/src/video_core/swrasterizer/lighting.cpp
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+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/math_util.h"
+#include "video_core/swrasterizer/lighting.h"
+
+namespace Pica {
+
+static float LookupLightingLut(const Pica::State::Lighting& lighting, size_t lut_index, u8 index,
+ float delta) {
+ ASSERT_MSG(lut_index < lighting.luts.size(), "Out of range lut");
+ ASSERT_MSG(index < lighting.luts[lut_index].size(), "Out of range index");
+
+ const auto& lut = lighting.luts[lut_index][index];
+
+ float lut_value = lut.ToFloat();
+ float lut_diff = lut.DiffToFloat();
+
+ return lut_value + lut_diff * delta;
+}
+
+std::tuple<Math::Vec4<u8>, Math::Vec4<u8>> ComputeFragmentsColors(
+ const Pica::LightingRegs& lighting, const Pica::State::Lighting& lighting_state,
+ const Math::Quaternion<float>& normquat, const Math::Vec3<float>& view) {
+
+ // TODO(Subv): Bump mapping
+ Math::Vec3<float> surface_normal = {0.0f, 0.0f, 1.0f};
+
+ if (lighting.config0.bump_mode != LightingRegs::LightingBumpMode::None) {
+ LOG_CRITICAL(HW_GPU, "unimplemented bump mapping");
+ UNIMPLEMENTED();
+ }
+
+ // Use the normalized the quaternion when performing the rotation
+ auto normal = Math::QuaternionRotate(normquat, surface_normal);
+
+ Math::Vec4<float> diffuse_sum = {0.0f, 0.0f, 0.0f, 1.0f};
+ Math::Vec4<float> specular_sum = {0.0f, 0.0f, 0.0f, 1.0f};
+
+ for (unsigned light_index = 0; light_index <= lighting.max_light_index; ++light_index) {
+ unsigned num = lighting.light_enable.GetNum(light_index);
+ const auto& light_config = lighting.light[num];
+
+ Math::Vec3<float> refl_value = {};
+ Math::Vec3<float> position = {float16::FromRaw(light_config.x).ToFloat32(),
+ float16::FromRaw(light_config.y).ToFloat32(),
+ float16::FromRaw(light_config.z).ToFloat32()};
+ Math::Vec3<float> light_vector;
+
+ if (light_config.config.directional)
+ light_vector = position;
+ else
+ light_vector = position + view;
+
+ light_vector.Normalize();
+
+ float dist_atten = 1.0f;
+ if (!lighting.IsDistAttenDisabled(num)) {
+ auto distance = (-view - position).Length();
+ float scale = Pica::float20::FromRaw(light_config.dist_atten_scale).ToFloat32();
+ float bias = Pica::float20::FromRaw(light_config.dist_atten_bias).ToFloat32();
+ size_t lut =
+ static_cast<size_t>(LightingRegs::LightingSampler::DistanceAttenuation) + num;
+
+ float sample_loc = MathUtil::Clamp(scale * distance + bias, 0.0f, 1.0f);
+
+ u8 lutindex =
+ static_cast<u8>(MathUtil::Clamp(std::floor(sample_loc * 256.0f), 0.0f, 255.0f));
+ float delta = sample_loc * 256 - lutindex;
+ dist_atten = LookupLightingLut(lighting_state, lut, lutindex, delta);
+ }
+
+ auto GetLutValue = [&](LightingRegs::LightingLutInput input, bool abs,
+ LightingRegs::LightingScale scale_enum,
+ LightingRegs::LightingSampler sampler) {
+ Math::Vec3<float> norm_view = view.Normalized();
+ Math::Vec3<float> half_angle = (norm_view + light_vector).Normalized();
+ float result = 0.0f;
+
+ switch (input) {
+ case LightingRegs::LightingLutInput::NH:
+ result = Math::Dot(normal, half_angle);
+ break;
+
+ case LightingRegs::LightingLutInput::VH:
+ result = Math::Dot(norm_view, half_angle);
+ break;
+
+ case LightingRegs::LightingLutInput::NV:
+ result = Math::Dot(normal, norm_view);
+ break;
+
+ case LightingRegs::LightingLutInput::LN:
+ result = Math::Dot(light_vector, normal);
+ break;
+
+ default:
+ LOG_CRITICAL(HW_GPU, "Unknown lighting LUT input %u\n", static_cast<u32>(input));
+ UNIMPLEMENTED();
+ result = 0.0f;
+ }
+
+ u8 index;
+ float delta;
+
+ if (abs) {
+ if (light_config.config.two_sided_diffuse)
+ result = std::abs(result);
+ else
+ result = std::max(result, 0.0f);
+
+ float flr = std::floor(result * 256.0f);
+ index = static_cast<u8>(MathUtil::Clamp(flr, 0.0f, 255.0f));
+ delta = result * 256 - index;
+ } else {
+ float flr = std::floor(result * 128.0f);
+ s8 signed_index = static_cast<s8>(MathUtil::Clamp(flr, -128.0f, 127.0f));
+ delta = result * 128.0f - signed_index;
+ index = static_cast<u8>(signed_index);
+ }
+
+ float scale = lighting.lut_scale.GetScale(scale_enum);
+ return scale *
+ LookupLightingLut(lighting_state, static_cast<size_t>(sampler), index, delta);
+ };
+
+ // Specular 0 component
+ float d0_lut_value = 1.0f;
+ if (lighting.config1.disable_lut_d0 == 0 &&
+ LightingRegs::IsLightingSamplerSupported(
+ lighting.config0.config, LightingRegs::LightingSampler::Distribution0)) {
+ d0_lut_value =
+ GetLutValue(lighting.lut_input.d0, lighting.abs_lut_input.disable_d0 == 0,
+ lighting.lut_scale.d0, LightingRegs::LightingSampler::Distribution0);
+ }
+
+ Math::Vec3<float> specular_0 = d0_lut_value * light_config.specular_0.ToVec3f();
+
+ // If enabled, lookup ReflectRed value, otherwise, 1.0 is used
+ if (lighting.config1.disable_lut_rr == 0 &&
+ LightingRegs::IsLightingSamplerSupported(lighting.config0.config,
+ LightingRegs::LightingSampler::ReflectRed)) {
+ refl_value.x =
+ GetLutValue(lighting.lut_input.rr, lighting.abs_lut_input.disable_rr == 0,
+ lighting.lut_scale.rr, LightingRegs::LightingSampler::ReflectRed);
+ } else {
+ refl_value.x = 1.0f;
+ }
+
+ // If enabled, lookup ReflectGreen value, otherwise, ReflectRed value is used
+ if (lighting.config1.disable_lut_rg == 0 &&
+ LightingRegs::IsLightingSamplerSupported(lighting.config0.config,
+ LightingRegs::LightingSampler::ReflectGreen)) {
+ refl_value.y =
+ GetLutValue(lighting.lut_input.rg, lighting.abs_lut_input.disable_rg == 0,
+ lighting.lut_scale.rg, LightingRegs::LightingSampler::ReflectGreen);
+ } else {
+ refl_value.y = refl_value.x;
+ }
+
+ // If enabled, lookup ReflectBlue value, otherwise, ReflectRed value is used
+ if (lighting.config1.disable_lut_rb == 0 &&
+ LightingRegs::IsLightingSamplerSupported(lighting.config0.config,
+ LightingRegs::LightingSampler::ReflectBlue)) {
+ refl_value.z =
+ GetLutValue(lighting.lut_input.rb, lighting.abs_lut_input.disable_rb == 0,
+ lighting.lut_scale.rb, LightingRegs::LightingSampler::ReflectBlue);
+ } else {
+ refl_value.z = refl_value.x;
+ }
+
+ // Specular 1 component
+ float d1_lut_value = 1.0f;
+ if (lighting.config1.disable_lut_d1 == 0 &&
+ LightingRegs::IsLightingSamplerSupported(
+ lighting.config0.config, LightingRegs::LightingSampler::Distribution1)) {
+ d1_lut_value =
+ GetLutValue(lighting.lut_input.d1, lighting.abs_lut_input.disable_d1 == 0,
+ lighting.lut_scale.d1, LightingRegs::LightingSampler::Distribution1);
+ }
+
+ Math::Vec3<float> specular_1 =
+ d1_lut_value * refl_value * light_config.specular_1.ToVec3f();
+
+ // Fresnel
+ if (lighting.config1.disable_lut_fr == 0 &&
+ LightingRegs::IsLightingSamplerSupported(lighting.config0.config,
+ LightingRegs::LightingSampler::Fresnel)) {
+
+ float lut_value =
+ GetLutValue(lighting.lut_input.fr, lighting.abs_lut_input.disable_fr == 0,
+ lighting.lut_scale.fr, LightingRegs::LightingSampler::Fresnel);
+
+ // Enabled for diffuse lighting alpha component
+ if (lighting.config0.fresnel_selector ==
+ LightingRegs::LightingFresnelSelector::PrimaryAlpha ||
+ lighting.config0.fresnel_selector == LightingRegs::LightingFresnelSelector::Both) {
+ diffuse_sum.a() *= lut_value;
+ }
+
+ // Enabled for the specular lighting alpha component
+ if (lighting.config0.fresnel_selector ==
+ LightingRegs::LightingFresnelSelector::SecondaryAlpha ||
+ lighting.config0.fresnel_selector == LightingRegs::LightingFresnelSelector::Both) {
+ specular_sum.a() *= lut_value;
+ }
+ }
+
+ auto dot_product = Math::Dot(light_vector, normal);
+
+ // Calculate clamp highlights before applying the two-sided diffuse configuration to the dot
+ // product.
+ float clamp_highlights = 1.0f;
+ if (lighting.config0.clamp_highlights) {
+ if (dot_product <= 0.0f)
+ clamp_highlights = 0.0f;
+ else
+ clamp_highlights = 1.0f;
+ }
+
+ if (light_config.config.two_sided_diffuse)
+ dot_product = std::abs(dot_product);
+ else
+ dot_product = std::max(dot_product, 0.0f);
+
+ auto diffuse =
+ light_config.diffuse.ToVec3f() * dot_product + light_config.ambient.ToVec3f();
+ diffuse_sum += Math::MakeVec(diffuse * dist_atten, 0.0f);
+
+ specular_sum +=
+ Math::MakeVec((specular_0 + specular_1) * clamp_highlights * dist_atten, 0.0f);
+ }
+
+ diffuse_sum += Math::MakeVec(lighting.global_ambient.ToVec3f(), 0.0f);
+
+ auto diffuse = Math::MakeVec<float>(MathUtil::Clamp(diffuse_sum.x, 0.0f, 1.0f) * 255,
+ MathUtil::Clamp(diffuse_sum.y, 0.0f, 1.0f) * 255,
+ MathUtil::Clamp(diffuse_sum.z, 0.0f, 1.0f) * 255,
+ MathUtil::Clamp(diffuse_sum.w, 0.0f, 1.0f) * 255)
+ .Cast<u8>();
+ auto specular = Math::MakeVec<float>(MathUtil::Clamp(specular_sum.x, 0.0f, 1.0f) * 255,
+ MathUtil::Clamp(specular_sum.y, 0.0f, 1.0f) * 255,
+ MathUtil::Clamp(specular_sum.z, 0.0f, 1.0f) * 255,
+ MathUtil::Clamp(specular_sum.w, 0.0f, 1.0f) * 255)
+ .Cast<u8>();
+ return {diffuse, specular};
+}
+
+} // namespace Pica