core: introduce icc profile helper

src/CMakeLists.txt

@@ -49,6 +49,7 @@ target_sources(kwin PRIVATE
     core/graphicsbuffer.cpp
     core/graphicsbufferallocator.cpp
     core/graphicsbufferview.cpp
+    core/iccprofile.cpp
     core/inputbackend.cpp
     core/inputdevice.cpp
     core/output.cpp

src/colors/colordevice.cpp

@@ -7,6 +7,7 @@
 #include "colordevice.h"
 #include "core/colorpipelinestage.h"
 #include "core/colortransformation.h"
+#include "core/iccprofile.h"
 #include "core/output.h"
 #include "utils/common.h"
 
@@ -49,7 +50,7 @@ public:
     Output *output;
     DirtyToneCurves dirtyCurves;
     QTimer *updateTimer;
-    QString profile;
+    QString profilePath;
     uint brightness = 100;
     uint temperature = 6500;
 
@@ -57,7 +58,7 @@ public:
     QVector3D temperatureFactors = QVector3D(1, 1, 1);
     std::unique_ptr<ColorPipelineStage> brightnessStage;
     QVector3D brightnessFactors = QVector3D(1, 1, 1);
-    std::unique_ptr<ColorPipelineStage> calibrationStage;
+    std::unique_ptr<IccProfile> iccProfile;
 
     std::shared_ptr<ColorTransformation> transformation;
     // used if only limited per-channel multiplication is available
@@ -78,13 +79,6 @@ void ColorDevicePrivate::rebuildPipeline()
     dirtyCurves = DirtyToneCurves();
 
     std::vector<std::unique_ptr<ColorPipelineStage>> stages;
-    if (calibrationStage) {
-        if (auto s = calibrationStage->dup()) {
-            stages.push_back(std::move(s));
-        } else {
-            return;
-        }
-    }
     if (brightnessStage) {
         if (auto s = brightnessStage->dup()) {
             stages.push_back(std::move(s));
@@ -101,6 +95,9 @@ void ColorDevicePrivate::rebuildPipeline()
     }
 
     const auto tmp = std::make_shared<ColorTransformation>(std::move(stages));
+    if (iccProfile && iccProfile->vcgt()) {
+        tmp->append(iccProfile->vcgt().get());
+    }
     if (tmp->valid()) {
         transformation = tmp;
         simpleTransformation = brightnessFactors * temperatureFactors;
@@ -114,7 +111,7 @@ static qreal interpolate(qreal a, qreal b, qreal blendFactor)
 
 QString ColorDevice::profile() const
 {
-    return d->profile;
+    return d->profilePath;
 }
 
 void ColorDevicePrivate::updateTemperatureToneCurves()
@@ -210,32 +207,7 @@ void ColorDevicePrivate::updateBrightnessToneCurves()
 
 void ColorDevicePrivate::updateCalibrationToneCurves()
 {
-    calibrationStage.reset();
-
-    if (profile.isNull()) {
-        return;
-    }
-
-    cmsHPROFILE handle = cmsOpenProfileFromFile(profile.toUtf8(), "r");
-    if (!handle) {
-        qCWarning(KWIN_CORE) << "Failed to open color profile file:" << profile;
-        return;
-    }
-
-    cmsToneCurve **vcgt = static_cast<cmsToneCurve **>(cmsReadTag(handle, cmsSigVcgtTag));
-    if (!vcgt || !vcgt[0]) {
-        qCWarning(KWIN_CORE) << "Profile" << profile << "has no VCGT tag";
-    } else {
-        // Need to duplicate the VCGT tone curves as they are owned by the profile.
-        cmsToneCurve *toneCurves[] = {
-            cmsDupToneCurve(vcgt[0]),
-            cmsDupToneCurve(vcgt[1]),
-            cmsDupToneCurve(vcgt[2]),
-        };
-        calibrationStage = std::make_unique<ColorPipelineStage>(cmsStageAllocToneCurves(nullptr, 3, toneCurves));
-    }
-
-    cmsCloseProfile(handle);
+    iccProfile = IccProfile::load(profilePath);
 }
 
 ColorDevice::ColorDevice(Output *output, QObject *parent)
@@ -306,10 +278,10 @@ void ColorDevice::setTemperature(uint temperature)
 
 void ColorDevice::setProfile(const QString &profile)
 {
-    if (d->profile == profile) {
+    if (d->profilePath == profile) {
         return;
     }
-    d->profile = profile;
+    d->profilePath = profile;
     d->dirtyCurves |= ColorDevicePrivate::DirtyCalibrationToneCurve;
     scheduleUpdate();
     Q_EMIT profileChanged();

src/core/colortransformation.cpp

@@ -45,6 +45,19 @@ ColorTransformation::~ColorTransformation()
     }
 }
 
+void ColorTransformation::append(ColorTransformation *transformation)
+{
+    for (auto &stage : transformation->m_stages) {
+        auto dup = stage->dup();
+        if (!cmsPipelineInsertStage(m_pipeline, cmsAT_END, dup->stage())) {
+            qCWarning(KWIN_CORE) << "Failed to insert cmsPipeline stage!";
+            m_valid = false;
+            return;
+        }
+        m_stages.push_back(std::move(dup));
+    }
+}
+
 bool ColorTransformation::valid() const
 {
     return m_valid;

src/core/colortransformation.h

@@ -28,13 +28,15 @@ public:
     ColorTransformation(std::vector<std::unique_ptr<ColorPipelineStage>> &&stages);
     ~ColorTransformation();
 
+    void append(ColorTransformation *transformation);
+
     bool valid() const;
 
     std::tuple<uint16_t, uint16_t, uint16_t> transform(uint16_t r, uint16_t g, uint16_t b) const;
 
 private:
     cmsPipeline *const m_pipeline;
-    const std::vector<std::unique_ptr<ColorPipelineStage>> m_stages;
+    std::vector<std::unique_ptr<ColorPipelineStage>> m_stages;
     bool m_valid = true;
 };
 

src/core/iccprofile.cpp

@@ -0,0 +1,75 @@
+/*
+    SPDX-FileCopyrightText: 2023 Xaver Hugl <xaver.hugl@gmail.com>
+
+    SPDX-License-Identifier: GPL-2.0-or-later
+*/
+#include "iccprofile.h"
+#include "colorlut.h"
+#include "colorpipelinestage.h"
+#include "colortransformation.h"
+#include "utils/common.h"
+
+#include <lcms2.h>
+
+namespace KWin
+{
+
+IccProfile::IccProfile(cmsHPROFILE handle, const std::shared_ptr<ColorTransformation> &vcgt)
+    : m_handle(handle)
+    , m_vcgt(vcgt)
+{
+}
+
+IccProfile::~IccProfile()
+{
+    cmsCloseProfile(m_handle);
+}
+
+std::shared_ptr<ColorTransformation> IccProfile::vcgt() const
+{
+    return m_vcgt;
+}
+
+std::unique_ptr<IccProfile> IccProfile::load(const QString &path)
+{
+    if (path.isEmpty()) {
+        return nullptr;
+    }
+    cmsHPROFILE handle = cmsOpenProfileFromFile(path.toUtf8(), "r");
+    if (!handle) {
+        qCWarning(KWIN_CORE) << "Failed to open color profile file:" << path;
+        return nullptr;
+    }
+    if (cmsGetDeviceClass(handle) != cmsSigDisplayClass) {
+        qCWarning(KWIN_CORE) << "Only Display ICC profiles are supported";
+        return nullptr;
+    }
+    if (cmsGetPCS(handle) != cmsColorSpaceSignature::cmsSigXYZData) {
+        qCWarning(KWIN_CORE) << "Only ICC profiles with a XYZ connection space are supported";
+        return nullptr;
+    }
+    if (cmsGetColorSpace(handle) != cmsColorSpaceSignature::cmsSigRgbData) {
+        qCWarning(KWIN_CORE) << "Only ICC profiles with RGB color spaces are supported";
+        return nullptr;
+    }
+
+    std::shared_ptr<ColorTransformation> vcgt;
+    cmsToneCurve **vcgtTag = static_cast<cmsToneCurve **>(cmsReadTag(handle, cmsSigVcgtTag));
+    if (!vcgtTag || !vcgtTag[0]) {
+        qCWarning(KWIN_CORE) << "Profile" << path << "has no VCGT tag";
+    } else {
+        // Need to duplicate the VCGT tone curves as they are owned by the profile.
+        cmsToneCurve *toneCurves[] = {
+            cmsDupToneCurve(vcgtTag[0]),
+            cmsDupToneCurve(vcgtTag[1]),
+            cmsDupToneCurve(vcgtTag[2]),
+        };
+        std::vector<std::unique_ptr<ColorPipelineStage>> stages;
+        stages.push_back(std::make_unique<ColorPipelineStage>(cmsStageAllocToneCurves(nullptr, 3, toneCurves)));
+        vcgt = std::make_shared<ColorTransformation>(std::move(stages));
+    }
+
+    return std::make_unique<IccProfile>(handle, vcgt);
+}
+
+}

src/core/iccprofile.h

@@ -0,0 +1,35 @@
+/*
+    SPDX-FileCopyrightText: 2023 Xaver Hugl <xaver.hugl@gmail.com>
+
+    SPDX-License-Identifier: GPL-2.0-or-later
+*/
+#pragma once
+
+#include "kwin_export.h"
+
+#include <QString>
+#include <memory>
+
+typedef void *cmsHPROFILE;
+
+namespace KWin
+{
+
+class ColorTransformation;
+
+class KWIN_EXPORT IccProfile
+{
+public:
+    explicit IccProfile(cmsHPROFILE handle, const std::shared_ptr<ColorTransformation> &vcgt);
+    ~IccProfile();
+
+    std::shared_ptr<ColorTransformation> vcgt() const;
+
+    static std::unique_ptr<IccProfile> load(const QString &path);
+
+private:
+    cmsHPROFILE const m_handle;
+    const std::shared_ptr<ColorTransformation> m_vcgt;
+};
+
+}