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Diffstat (limited to '')
| -rw-r--r-- | src/video_core/swrasterizer/lighting.cpp | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/src/video_core/swrasterizer/lighting.cpp b/src/video_core/swrasterizer/lighting.cpp new file mode 100644 index 000000000..5fa748611 --- /dev/null +++ b/src/video_core/swrasterizer/lighting.cpp @@ -0,0 +1,308 @@ +// 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, + const Math::Vec4<u8> (&texture_color)[4]) { + + Math::Vec3<float> surface_normal; + Math::Vec3<float> surface_tangent; + + if (lighting.config0.bump_mode != LightingRegs::LightingBumpMode::None) { + Math::Vec3<float> perturbation = + texture_color[lighting.config0.bump_selector].xyz().Cast<float>() / 127.5f - + Math::MakeVec(1.0f, 1.0f, 1.0f); + if (lighting.config0.bump_mode == LightingRegs::LightingBumpMode::NormalMap) { + if (!lighting.config0.disable_bump_renorm) { + const float z_square = 1 - perturbation.xy().Length2(); + perturbation.z = std::sqrt(std::max(z_square, 0.0f)); + } + surface_normal = perturbation; + surface_tangent = Math::MakeVec(1.0f, 0.0f, 0.0f); + } else if (lighting.config0.bump_mode == LightingRegs::LightingBumpMode::TangentMap) { + surface_normal = Math::MakeVec(0.0f, 0.0f, 1.0f); + surface_tangent = perturbation; + } else { + LOG_ERROR(HW_GPU, "Unknown bump mode %u", lighting.config0.bump_mode.Value()); + } + } else { + surface_normal = Math::MakeVec(0.0f, 0.0f, 1.0f); + surface_tangent = Math::MakeVec(1.0f, 0.0f, 0.0f); + } + + // Use the normalized the quaternion when performing the rotation + auto normal = Math::QuaternionRotate(normquat, surface_normal); + auto tangent = Math::QuaternionRotate(normquat, surface_tangent); + + 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(); + + Math::Vec3<float> norm_view = view.Normalized(); + Math::Vec3<float> half_vector = norm_view + light_vector; + + 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) { + float result = 0.0f; + + switch (input) { + case LightingRegs::LightingLutInput::NH: + result = Math::Dot(normal, half_vector.Normalized()); + break; + + case LightingRegs::LightingLutInput::VH: + result = Math::Dot(norm_view, half_vector.Normalized()); + break; + + case LightingRegs::LightingLutInput::NV: + result = Math::Dot(normal, norm_view); + break; + + case LightingRegs::LightingLutInput::LN: + result = Math::Dot(light_vector, normal); + break; + + case LightingRegs::LightingLutInput::SP: { + Math::Vec3<s32> spot_dir{light_config.spot_x.Value(), light_config.spot_y.Value(), + light_config.spot_z.Value()}; + result = Math::Dot(light_vector, spot_dir.Cast<float>() / 2047.0f); + break; + } + case LightingRegs::LightingLutInput::CP: + if (lighting.config0.config == LightingRegs::LightingConfig::Config7) { + const Math::Vec3<float> norm_half_vector = half_vector.Normalized(); + const Math::Vec3<float> half_vector_proj = + norm_half_vector - normal * Math::Dot(normal, norm_half_vector); + result = Math::Dot(half_vector_proj, tangent); + } else { + result = 0.0f; + } + 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); + }; + + // If enabled, compute spot light attenuation value + float spot_atten = 1.0f; + if (!lighting.IsSpotAttenDisabled(num) && + LightingRegs::IsLightingSamplerSupported( + lighting.config0.config, LightingRegs::LightingSampler::SpotlightAttenuation)) { + auto lut = LightingRegs::SpotlightAttenuationSampler(num); + spot_atten = GetLutValue(lighting.lut_input.sp, lighting.abs_lut_input.disable_sp == 0, + lighting.lut_scale.sp, lut); + } + + // 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 + // Note: only the last entry in the light slots applies the Fresnel factor + if (light_index == lighting.max_light_index && 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); + + if (light_config.config.geometric_factor_0 || light_config.config.geometric_factor_1) { + float geo_factor = half_vector.Length2(); + geo_factor = geo_factor == 0.0f ? 0.0f : std::min(dot_product / geo_factor, 1.0f); + if (light_config.config.geometric_factor_0) { + specular_0 *= geo_factor; + } + if (light_config.config.geometric_factor_1) { + specular_1 *= geo_factor; + } + } + + auto diffuse = + light_config.diffuse.ToVec3f() * dot_product + light_config.ambient.ToVec3f(); + diffuse_sum += Math::MakeVec(diffuse * dist_atten * spot_atten, 0.0f); + + specular_sum += Math::MakeVec( + (specular_0 + specular_1) * clamp_highlights * dist_atten * spot_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 std::make_tuple(diffuse, specular); +} + +} // namespace Pica |