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AzaharUWP/src/video_core/swrasterizer/lighting.cpp
wwylele b5763cb952 pica/lighting: split FresnelSelector into bitfields 
The FresnelSelector was already working like a bitfield, so just make it actual bitfield to reduce redundant code. Also, it is already confirmed that this field also affects shadow on alpha. Given that the only two source that can affect alpha components are both controlled by this field, this field should be renamed to a general alpha switch
2018-04-10 20:25:56 +03:00

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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,
const Math::Vec4<u8> (&texture_color)[4]) {
Math::Vec4<float> shadow;
if (lighting.config0.enable_shadow) {
shadow = texture_color[lighting.config0.shadow_selector].Cast<float>() / 255.0f;
if (lighting.config0.shadow_invert) {
shadow = Math::MakeVec(1.0f, 1.0f, 1.0f, 1.0f) - shadow;
}
} else {
shadow = Math::MakeVec(1.0f, 1.0f, 1.0f, 1.0f);
}
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",
static_cast<u32>(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.enable_primary_alpha) {
diffuse_sum.a() = lut_value;
}
// Enabled for the specular lighting alpha component
if (lighting.config0.enable_secondary_alpha) {
specular_sum.a() = lut_value;
}
}
auto dot_product = Math::Dot(light_vector, normal);
if (light_config.config.two_sided_diffuse)
dot_product = std::abs(dot_product);
else
dot_product = std::max(dot_product, 0.0f);
float clamp_highlights = 1.0f;
if (lighting.config0.clamp_highlights) {
clamp_highlights = dot_product == 0.0f ? 0.0f : 1.0f;
}
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()) *
dist_atten * spot_atten;
auto specular = (specular_0 + specular_1) * clamp_highlights * dist_atten * spot_atten;
if (!lighting.IsShadowDisabled(num)) {
if (lighting.config0.shadow_primary) {
diffuse = diffuse * shadow.xyz();
}
if (lighting.config0.shadow_secondary) {
specular = specular * shadow.xyz();
}
}
diffuse_sum += Math::MakeVec(diffuse, 0.0f);
specular_sum += Math::MakeVec(specular, 0.0f);
}
if (lighting.config0.shadow_alpha) {
// Alpha shadow also uses the Fresnel selecotr to determine which alpha to apply
// Enabled for diffuse lighting alpha component
if (lighting.config0.enable_primary_alpha) {
diffuse_sum.a() *= shadow.w;
}
// Enabled for the specular lighting alpha component
if (lighting.config0.enable_secondary_alpha) {
specular_sum.a() *= shadow.w;
}
}
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
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