// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <array>
#include <cmath>
#include "common/math_util.h"
#include "video_core/swrasterizer/proctex.h"
namespace Pica {
namespace Rasterizer {
using ProcTexClamp = TexturingRegs::ProcTexClamp;
using ProcTexShift = TexturingRegs::ProcTexShift;
using ProcTexCombiner = TexturingRegs::ProcTexCombiner;
using ProcTexFilter = TexturingRegs::ProcTexFilter;
static float LookupLUT(const std::array<State::ProcTex::ValueEntry, 128>& lut, float coord) {
// For NoiseLUT/ColorMap/AlphaMap, coord=0.0 is lut[0], coord=127.0/128.0 is lut[127] and
// coord=1.0 is lut[127]+lut_diff[127]. For other indices, the result is interpolated using
// value entries and difference entries.
coord *= 128;
const int index_int = std::min(static_cast<int>(coord), 127);
const float frac = coord - index_int;
return lut[index_int].ToFloat() + frac * lut[index_int].DiffToFloat();
}
// These function are used to generate random noise for procedural texture. Their results are
// verified against real hardware, but it's not known if the algorithm is the same as hardware.
static unsigned int NoiseRand1D(unsigned int v) {
static constexpr std::array<unsigned int, 16> table{
{0, 4, 10, 8, 4, 9, 7, 12, 5, 15, 13, 14, 11, 15, 2, 11}};
return ((v % 9 + 2) * 3 & 0xF) ^ table[(v / 9) & 0xF];
}
static float NoiseRand2D(unsigned int x, unsigned int y) {
static constexpr std::array<unsigned int, 16> table{
{10, 2, 15, 8, 0, 7, 4, 5, 5, 13, 2, 6, 13, 9, 3, 14}};
unsigned int u2 = NoiseRand1D(x);
unsigned int v2 = NoiseRand1D(y);
v2 += ((u2 & 3) == 1) ? 4 : 0;
v2 ^= (u2 & 1) * 6;
v2 += 10 + u2;
v2 &= 0xF;
v2 ^= table[u2];
return -1.0f + v2 * 2.0f / 15.0f;
}
static float NoiseCoef(float u, float v, TexturingRegs regs, State::ProcTex state) {
const float freq_u = float16::FromRaw(regs.proctex_noise_frequency.u).ToFloat32();
const float freq_v = float16::FromRaw(regs.proctex_noise_frequency.v).ToFloat32();
const float phase_u = float16::FromRaw(regs.proctex_noise_u.phase).ToFloat32();
const float phase_v = float16::FromRaw(regs.proctex_noise_v.phase).ToFloat32();
const float x = 9 * freq_u * std::abs(u + phase_u);
const float y = 9 * freq_v * std::abs(v + phase_v);
const int x_int = static_cast<int>(x);
const int y_int = static_cast<int>(y);
const float x_frac = x - x_int;
const float y_frac = y - y_int;
const float g0 = NoiseRand2D(x_int, y_int) * (x_frac + y_frac);
const float g1 = NoiseRand2D(x_int + 1, y_int) * (x_frac + y_frac - 1);
const float g2 = NoiseRand2D(x_int, y_int + 1) * (x_frac + y_frac - 1);
const float g3 = NoiseRand2D(x_int + 1, y_int + 1) * (x_frac + y_frac - 2);
const float x_noise = LookupLUT(state.noise_table, x_frac);
const float y_noise = LookupLUT(state.noise_table, y_frac);
return Math::BilinearInterp(g0, g1, g2, g3, x_noise, y_noise);
}
static float GetShiftOffset(float v, ProcTexShift mode, ProcTexClamp clamp_mode) {
const float offset = (clamp_mode == ProcTexClamp::MirroredRepeat) ? 1 : 0.5f;
switch (mode) {
case ProcTexShift::None:
return 0;
case ProcTexShift::Odd:
return offset * (((int)v / 2) % 2);
case ProcTexShift::Even:
return offset * ((((int)v + 1) / 2) % 2);
default:
LOG_CRITICAL(HW_GPU, "Unknown shift mode %u", static_cast<u32>(mode));
return 0;
}
};
static void ClampCoord(float& coord, ProcTexClamp mode) {
switch (mode) {
case ProcTexClamp::ToZero:
if (coord > 1.0f)
coord = 0.0f;
break;
case ProcTexClamp::ToEdge:
coord = std::min(coord, 1.0f);
break;
case ProcTexClamp::SymmetricalRepeat:
coord = coord - std::floor(coord);
break;
case ProcTexClamp::MirroredRepeat: {
int integer = static_cast<int>(coord);
float frac = coord - integer;
coord = (integer % 2) == 0 ? frac : (1.0f - frac);
break;
}
case ProcTexClamp::Pulse:
if (coord <= 0.5f)
coord = 0.0f;
else
coord = 1.0f;
break;
default:
LOG_CRITICAL(HW_GPU, "Unknown clamp mode %u", static_cast<u32>(mode));
coord = std::min(coord, 1.0f);
break;
}
}
float CombineAndMap(float u, float v, ProcTexCombiner combiner,
const std::array<State::ProcTex::ValueEntry, 128>& map_table) {
float f;
switch (combiner) {
case ProcTexCombiner::U:
f = u;
break;
case ProcTexCombiner::U2:
f = u * u;
break;
case TexturingRegs::ProcTexCombiner::V:
f = v;
break;
case TexturingRegs::ProcTexCombiner::V2:
f = v * v;
break;
case TexturingRegs::ProcTexCombiner::Add:
f = (u + v) * 0.5f;
break;
case TexturingRegs::ProcTexCombiner::Add2:
f = (u * u + v * v) * 0.5f;
break;
case TexturingRegs::ProcTexCombiner::SqrtAdd2:
f = std::min(std::sqrt(u * u + v * v), 1.0f);
break;
case TexturingRegs::ProcTexCombiner::Min:
f = std::min(u, v);
break;
case TexturingRegs::ProcTexCombiner::Max:
f = std::max(u, v);
break;
case TexturingRegs::ProcTexCombiner::RMax:
f = std::min(((u + v) * 0.5f + std::sqrt(u * u + v * v)) * 0.5f, 1.0f);
break;
default:
LOG_CRITICAL(HW_GPU, "Unknown combiner %u", static_cast<u32>(combiner));
f = 0.0f;
break;
}
return LookupLUT(map_table, f);
}
Math::Vec4<u8> ProcTex(float u, float v, TexturingRegs regs, State::ProcTex state) {
u = std::abs(u);
v = std::abs(v);
// Get shift offset before noise generation
const float u_shift = GetShiftOffset(v, regs.proctex.u_shift, regs.proctex.u_clamp);
const float v_shift = GetShiftOffset(u, regs.proctex.v_shift, regs.proctex.v_clamp);
// Generate noise
if (regs.proctex.noise_enable) {
float noise = NoiseCoef(u, v, regs, state);
u += noise * regs.proctex_noise_u.amplitude / 4095.0f;
v += noise * regs.proctex_noise_v.amplitude / 4095.0f;
u = std::abs(u);
v = std::abs(v);
}
// Shift
u += u_shift;
v += v_shift;
// Clamp
ClampCoord(u, regs.proctex.u_clamp);
ClampCoord(v, regs.proctex.v_clamp);
// Combine and map
const float lut_coord = CombineAndMap(u, v, regs.proctex.color_combiner, state.color_map_table);
// Look up the color
// For the color lut, coord=0.0 is lut[offset] and coord=1.0 is lut[offset+width-1]
const u32 offset = regs.proctex_lut_offset;
const u32 width = regs.proctex_lut.width;
const float index = offset + (lut_coord * (width - 1));
Math::Vec4<u8> final_color;
// TODO(wwylele): implement mipmap
switch (regs.proctex_lut.filter) {
case ProcTexFilter::Linear:
case ProcTexFilter::LinearMipmapLinear:
case ProcTexFilter::LinearMipmapNearest: {
const int index_int = static_cast<int>(index);
const float frac = index - index_int;
const auto color_value = state.color_table[index_int].ToVector().Cast<float>();
const auto color_diff = state.color_diff_table[index_int].ToVector().Cast<float>();
final_color = (color_value + frac * color_diff).Cast<u8>();
break;
}
case ProcTexFilter::Nearest:
case ProcTexFilter::NearestMipmapLinear:
case ProcTexFilter::NearestMipmapNearest:
final_color = state.color_table[static_cast<int>(std::round(index))].ToVector();
break;
}
if (regs.proctex.separate_alpha) {
// Note: in separate alpha mode, the alpha channel skips the color LUT look up stage. It
// uses the output of CombineAndMap directly instead.
const float final_alpha =
CombineAndMap(u, v, regs.proctex.alpha_combiner, state.alpha_map_table);
return Math::MakeVec<u8>(final_color.rgb(), static_cast<u8>(final_alpha * 255));
} else {
return final_color;
}
}
} // namespace Rasterizer
} // namespace Pica
