diff options
Diffstat (limited to 'src/gui/painting/qcolorclut_p.h')
| -rw-r--r-- | src/gui/painting/qcolorclut_p.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/src/gui/painting/qcolorclut_p.h b/src/gui/painting/qcolorclut_p.h new file mode 100644 index 0000000000..d95e9701b7 --- /dev/null +++ b/src/gui/painting/qcolorclut_p.h @@ -0,0 +1,127 @@ +// Copyright (C) 2024 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only + +#ifndef QCOLORCLUT_H +#define QCOLORCLUT_H + +// +// W A R N I N G +// ------------- +// +// This file is not part of the Qt API. It exists purely as an +// implementation detail. This header file may change from version to +// version without notice, or even be removed. +// +// We mean it. +// + +#include <QtCore/qlist.h> +#include <QtGui/private/qcolormatrix_p.h> + +QT_BEGIN_NAMESPACE + +// A 3/4-dimensional lookup table compatible with ICC lut8, lut16, mAB, and mBA formats. +class QColorCLUT +{ + inline static QColorVector interpolate(const QColorVector &a, const QColorVector &b, float t) + { + return a + (b - a) * t; // faster than std::lerp by assuming no super large or non-number floats + } + inline static void interpolateIn(QColorVector &a, const QColorVector &b, float t) + { + a += (b - a) * t; + } +public: + uint32_t gridPointsX = 0; + uint32_t gridPointsY = 0; + uint32_t gridPointsZ = 0; + uint32_t gridPointsW = 1; + QList<QColorVector> table; + + bool isEmpty() const { return table.isEmpty(); } + + QColorVector apply(const QColorVector &v) const + { + Q_ASSERT(table.size() == gridPointsX * gridPointsY * gridPointsZ * gridPointsW); + QColorVector frac; + const float x = std::clamp(v.x, 0.0f, 1.0f) * (gridPointsX - 1); + const float y = std::clamp(v.y, 0.0f, 1.0f) * (gridPointsY - 1); + const float z = std::clamp(v.z, 0.0f, 1.0f) * (gridPointsZ - 1); + const float w = std::clamp(v.w, 0.0f, 1.0f) * (gridPointsW - 1); + const uint32_t lox = static_cast<uint32_t>(std::floor(x)); + const uint32_t hix = std::min(lox + 1, gridPointsX - 1); + const uint32_t loy = static_cast<uint32_t>(std::floor(y)); + const uint32_t hiy = std::min(loy + 1, gridPointsY - 1); + const uint32_t loz = static_cast<uint32_t>(std::floor(z)); + const uint32_t hiz = std::min(loz + 1, gridPointsZ - 1); + const uint32_t low = static_cast<uint32_t>(std::floor(w)); + const uint32_t hiw = std::min(low + 1, gridPointsW - 1); + frac.x = x - static_cast<float>(lox); + frac.y = y - static_cast<float>(loy); + frac.z = z - static_cast<float>(loz); + frac.w = w - static_cast<float>(low); + if (gridPointsW > 1) { + auto index = [&](qsizetype x, qsizetype y, qsizetype z, qsizetype w) -> qsizetype { + return x * gridPointsW * gridPointsZ * gridPointsY + + y * gridPointsW * gridPointsZ + + z * gridPointsW + + w; + }; + QColorVector tmp[8]; + // interpolate over w + tmp[0] = interpolate(table[index(lox, loy, loz, low)], + table[index(lox, loy, loz, hiw)], frac.w); + tmp[1] = interpolate(table[index(lox, loy, hiz, low)], + table[index(lox, loy, hiz, hiw)], frac.w); + tmp[2] = interpolate(table[index(lox, hiy, loz, low)], + table[index(lox, hiy, loz, hiw)], frac.w); + tmp[3] = interpolate(table[index(lox, hiy, hiz, low)], + table[index(lox, hiy, hiz, hiw)], frac.w); + tmp[4] = interpolate(table[index(hix, loy, loz, low)], + table[index(hix, loy, loz, hiw)], frac.w); + tmp[5] = interpolate(table[index(hix, loy, hiz, low)], + table[index(hix, loy, hiz, hiw)], frac.w); + tmp[6] = interpolate(table[index(hix, hiy, loz, low)], + table[index(hix, hiy, loz, hiw)], frac.w); + tmp[7] = interpolate(table[index(hix, hiy, hiz, low)], + table[index(hix, hiy, hiz, hiw)], frac.w); + // interpolate over z + for (int i = 0; i < 4; ++i) + interpolateIn(tmp[i * 2], tmp[i * 2 + 1], frac.z); + // interpolate over y + for (int i = 0; i < 2; ++i) + interpolateIn(tmp[i * 4], tmp[i * 4 + 2], frac.y); + // interpolate over x + interpolateIn(tmp[0], tmp[4], frac.x); + return tmp[0]; + } + auto index = [&](qsizetype x, qsizetype y, qsizetype z) -> qsizetype { + return x * gridPointsZ * gridPointsY + + y * gridPointsZ + + z; + }; + QColorVector tmp[8] = { + table[index(lox, loy, loz)], + table[index(lox, loy, hiz)], + table[index(lox, hiy, loz)], + table[index(lox, hiy, hiz)], + table[index(hix, loy, loz)], + table[index(hix, loy, hiz)], + table[index(hix, hiy, loz)], + table[index(hix, hiy, hiz)] + }; + // interpolate over z + for (int i = 0; i < 4; ++i) + interpolateIn(tmp[i * 2], tmp[i * 2 + 1], frac.z); + // interpolate over y + for (int i = 0; i < 2; ++i) + interpolateIn(tmp[i * 4], tmp[i * 4 + 2], frac.y); + // interpolate over x + interpolateIn(tmp[0], tmp[4], frac.x); + return tmp[0]; + } +}; + +QT_END_NAMESPACE + +#endif // QCOLORCLUT_H |