Files
FlaxEngine/Source/Engine/Content/Utilities/IESLoader.cpp
2020-12-07 23:40:54 +01:00

517 lines
12 KiB
C++

// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
#include "Engine/Core/Log.h"
#include "Engine/Core/RandomStream.h"
#include "Engine/Core/Enums.h"
#include "Engine/Core/Math/Packed.h"
#include "IESLoader.h"
/// <summary>
/// IES profile format version
/// </summary>
DECLARE_ENUM_4(IESVersion, EIESV_1986, EIESV_1991, EIESV_1995, EIESV_2002);
static void JumpOverWhiteSpace(const uint8*& bufferPos)
{
// Space and return
while (*bufferPos)
{
if (*bufferPos == 13 && *(bufferPos + 1) == 10)
{
bufferPos += 2;
continue;
}
if (*bufferPos == 10)
{
// No valid MSDOS return file
CRASH;
}
else if (*bufferPos <= ' ')
{
// Tab, space, invisible characters
bufferPos++;
continue;
}
break;
}
}
static void GetLineContent(const uint8*& bufferPos, char Line[256], bool bStopOnWhitespace)
{
JumpOverWhiteSpace(bufferPos);
char* linePtr = Line;
uint32 i;
for (i = 0; i < 255; i++)
{
if (*bufferPos == 0)
{
break;
}
if (*bufferPos == 13 && *(bufferPos + 1) == 10)
{
bufferPos += 2;
break;
}
if (*bufferPos == 10)
{
// No valid MSDOS return file
CRASH;
}
else if (bStopOnWhitespace && (*bufferPos <= ' '))
{
// Tab, space, invisible characters
bufferPos++;
break;
}
*linePtr++ = *bufferPos++;
}
Line[i] = 0;
}
static bool GetFloat(const uint8*& bufferPos, float& ret)
{
char line[256];
GetLineContent(bufferPos, line, true);
ret = static_cast<float>(atof(line));
return true;
}
static bool GetInt(const uint8*& bufferPos, int32& ret)
{
char line[256];
GetLineContent(bufferPos, line, true);
ret = atoi(line);
return true;
}
IESLoader::IESLoader()
: _brightness(0)
, _cachedIntegral(-1)
{
}
#define LOG_IES_IMPORT_ERROR(error) LOG(Warning, "Cannot import IES profile. {0}", error)
#define PARSE_FLOAT(x) float x; if (!GetFloat(bufferPos, x)) { LOG_IES_IMPORT_ERROR(error); return true; }
#define PARSE_INT(x) int32 x; if (!GetInt(bufferPos, x)) { LOG_IES_IMPORT_ERROR(error); return true; }
bool IESLoader::Load(const byte* buffer)
{
// File format as described here:
// http://www.ltblight.com/English.lproj/LTBLhelp/pages/iesformat.html
const uint8* bufferPos = buffer;
const Char* error = nullptr;
IESVersion version = IESVersion::EIESV_1986;
{
error = TEXT("VersionError");
char line1[256];
GetLineContent(bufferPos, line1, false);
if (StringUtils::CompareIgnoreCase(line1, "IESNA:LM-63-1995") == 0)
{
version = IESVersion::EIESV_1995;
}
else if (StringUtils::CompareIgnoreCase(line1, "IESNA91") == 0)
{
version = IESVersion::EIESV_1991;
}
else if (StringUtils::CompareIgnoreCase(line1, "IESNA:LM-63-2002") == 0)
{
version = IESVersion::EIESV_2002;
}
else
{
// EIESV_1986
}
}
error = TEXT("HeaderError");
while (*bufferPos)
{
char line[256];
GetLineContent(bufferPos, line, false);
if (strcmp(line, "TILT=NONE") == 0)
{
// At the moment we don't support only profiles with TILT=NONE
break;
}
if (strncmp(line, "TILT=", 5) == 0)
{
// "TILT=NONE", "TILT=INCLUDE", and "TILT={filename}"
// not supported yet, seems rare
LOG(Warning, "Cannot import IES profile. {0}", String(error));
return true;
}
}
error = TEXT("HeaderParameterError");
PARSE_INT(LightCount);
if (LightCount < 1)
{
error = TEXT("Light count needs to be positive.");
LOG(Warning, "Cannot import IES profile. {0}", error);
return true;
}
// if there is any file with that - do we need to parse it differently?
ASSERT(LightCount >= 1);
PARSE_FLOAT(LumensPerLamp);
_brightness = LumensPerLamp / LightCount;
PARSE_FLOAT(CandalaMult);
if (CandalaMult < 0)
{
error = TEXT("CandalaMult is negative");
LOG_IES_IMPORT_ERROR(error);
return true;
}
PARSE_INT(VAnglesNum);
PARSE_INT(HAnglesNum);
if (VAnglesNum < 0)
{
error = TEXT("VAnglesNum is not valid");
LOG_IES_IMPORT_ERROR(error);
return true;
}
if (HAnglesNum < 0)
{
error = TEXT("HAnglesNum is not valid");
LOG_IES_IMPORT_ERROR(error);
return true;
}
PARSE_INT(PhotometricType);
// 1:feet, 2:meter
PARSE_INT(UnitType);
PARSE_FLOAT(Width);
PARSE_FLOAT(Length);
PARSE_FLOAT(Height);
PARSE_FLOAT(BallastFactor);
PARSE_FLOAT(FutureUse);
PARSE_FLOAT(InputWatts);
LOG(Info, "IES profile version: {0}, VAngles: {1}, HAngles: {2}", ::ToString(version), VAnglesNum, HAnglesNum);
error = TEXT("ContentError");
{
float minSoFar = MIN_float;
_vAngles.SetCapacity(VAnglesNum, false);
for (int32 y = 0; y < VAnglesNum; y++)
{
PARSE_FLOAT(Value);
if (Value < minSoFar)
{
// binary search later relies on that
error = TEXT("V Values are not in increasing order");
LOG_IES_IMPORT_ERROR(error);
return true;
}
minSoFar = Value;
_vAngles.Add(Value);
}
}
{
float minSoFar = MIN_float;
_hAngles.SetCapacity(HAnglesNum, false);
for (int32 x = 0; x < HAnglesNum; x++)
{
PARSE_FLOAT(Value);
if (Value < minSoFar)
{
// binary search later relies on that
error = TEXT("H Values are not in increasing order");
LOG_IES_IMPORT_ERROR(error);
return true;
}
minSoFar = Value;
_hAngles.Add(Value);
}
}
_candalaValues.SetCapacity(HAnglesNum * VAnglesNum, false);
for (int32 y = 0; y < HAnglesNum; y++)
{
for (int32 x = 0; x < VAnglesNum; x++)
{
PARSE_FLOAT(Value);
_candalaValues.Add(Value * CandalaMult);
}
}
error = TEXT("Unexpected content after candala values.");
JumpOverWhiteSpace(bufferPos);
if (*bufferPos)
{
// some files are terminated with "END"
char Line[256];
GetLineContent(bufferPos, Line, true);
if (strcmp(Line, "END") == 0)
{
JumpOverWhiteSpace(bufferPos);
}
}
if (*bufferPos)
{
error = TEXT("Unexpected content after END.");
LOG_IES_IMPORT_ERROR(error);
return true;
}
if (_brightness <= 0)
{
// Some samples have -1, then the brightness comes from the samples
// Brightness = ComputeFullIntegral();
// Use some reasonable value
_brightness = 1000;
}
return false;
}
#undef PARSE_FLOAT
#undef PARSE_INT
float IESLoader::ExtractInR16F(Array<byte>& output)
{
uint32 width = GetWidth();
uint32 height = GetHeight();
ASSERT(output.IsEmpty());
output.Resize(width * height * sizeof(Half), false);
Half* out = reinterpret_cast<Half*>(output.Get());
float invWidth = 1.0f / width;
float maxValue = ComputeMax();
float invMaxValue = 1.0f / maxValue;
for (uint32 y = 0; y < height; y++)
{
for (uint32 x = 0; x < width; x++)
{
// 0..1
float fraction = x * invWidth;
// TODO: distort for better quality? eg. Fraction = Square(Fraction);
float value = invMaxValue * Interpolate1D(fraction * 180.0f);
*out++ = ConvertFloatToHalf(value);
}
}
float integral = ComputeFullIntegral();
return maxValue / integral;
}
float IESLoader::InterpolatePoint(int32 X, int32 Y) const
{
int32 HAnglesNum = _hAngles.Count();
int32 VAnglesNum = _vAngles.Count();
ASSERT(X >= 0);
ASSERT(Y >= 0);
X %= HAnglesNum;
Y %= VAnglesNum;
ASSERT(X < HAnglesNum);
ASSERT(Y < VAnglesNum);
return _candalaValues[Y + VAnglesNum * X];
}
float IESLoader::InterpolateBilinear(float fX, float fY) const
{
int32 X = static_cast<int32>(fX);
int32 Y = static_cast<int32>(fY);
float fracX = fX - X;
float fracY = fY - Y;
float p00 = InterpolatePoint(X + 0, Y + 0);
float p10 = InterpolatePoint(X + 1, Y + 0);
float p01 = InterpolatePoint(X + 0, Y + 1);
float p11 = InterpolatePoint(X + 1, Y + 1);
float p0 = Math::Lerp(p00, p01, fracY);
float p1 = Math::Lerp(p10, p11, fracY);
return Math::Lerp(p0, p1, fracX);
}
float IESLoader::Interpolate2D(float HAngle, float VAngle) const
{
float u = ComputeFilterPos(HAngle, _hAngles);
float v = ComputeFilterPos(VAngle, _vAngles);
return InterpolateBilinear(u, v);
}
float IESLoader::Interpolate1D(float VAngle) const
{
float v = ComputeFilterPos(VAngle, _vAngles);
float ret = 0.0f;
uint32 HAnglesNum = static_cast<uint32>(_hAngles.Count());
for (uint32 i = 0; i < HAnglesNum; i++)
{
ret += InterpolateBilinear(static_cast<float>(i), v);
}
return ret / HAnglesNum;
}
float IESLoader::ComputeMax() const
{
float result = 0.0f;
for (int32 i = 0; i < _candalaValues.Count(); i++)
result = Math::Max(result, _candalaValues[i]);
return result;
}
float IESLoader::ComputeFullIntegral()
{
// Compute only if needed
if (_cachedIntegral < 0)
{
// Monte carlo integration
// If quality is a problem we can improve on this algorithm or increase SampleCount
// Larger number costs more time but improves quality
const int32 SamplesCount = 1000000;
RandomStream randomStream(0x1234);
double sum = 0;
for (uint32 i = 0; i < SamplesCount; i++)
{
Vector3 v = randomStream.GetUnitVector();
// http://en.wikipedia.org/wiki/Spherical_coordinate_system
// 0..180
float HAngle = Math::Acos(v.Z) / PI * 180;
// 0..360
float VAngle = Math::Atan2(v.Y, v.X) / PI * 180 + 180;
ASSERT(HAngle >= 0 && HAngle <= 180);
ASSERT(VAngle >= 0 && VAngle <= 360);
sum += Interpolate2D(HAngle, VAngle);
}
_cachedIntegral = static_cast<float>(sum / SamplesCount);
}
return _cachedIntegral;
}
float IESLoader::ComputeFilterPos(float value, const Array<float>& sortedValues)
{
ASSERT(sortedValues.HasItems());
uint32 startPos = 0;
uint32 endPos = sortedValues.Count() - 1;
if (value < sortedValues[startPos])
{
return 0.0f;
}
if (value > sortedValues[endPos])
{
return static_cast<float>(endPos);
}
// Binary search
while (startPos < endPos)
{
uint32 testPos = (startPos + endPos + 1) / 2;
float testValue = sortedValues[testPos];
if (value >= testValue)
{
// Prevent endless loop
ASSERT(startPos != testPos);
startPos = testPos;
}
else
{
// Prevent endless loop
ASSERT(endPos != testPos - 1);
endPos = testPos - 1;
}
}
float leftValue = sortedValues[startPos];
float fraction = 0.0f;
if (startPos + 1 < static_cast<uint32>(sortedValues.Count()))
{
// If not at right border
float rightValue = sortedValues[startPos + 1];
float deltaValue = rightValue - leftValue;
if (deltaValue > 0.0001f)
{
fraction = (value - leftValue) / deltaValue;
}
}
return startPos + fraction;
}