Test prepared qcolortransform

Add test of explicitly prepared qcolortransform, this is a state
a transform can get into if used for an image transform.

Also cleans up the test code.

Change-Id: I9445ed114bed0edc790e14024aaae6a42989220b
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

2 files changed, 90 insertions, 17 deletions

diff --git a/tests/auto/gui/painting/qcolortransform/CMakeLists.txt b/tests/auto/gui/painting/qcolortransform/CMakeLists.txt
index 008ac92905..64901eef9f 100644
--- a/tests/auto/gui/painting/qcolortransform/CMakeLists.txt
+++ b/tests/auto/gui/painting/qcolortransform/CMakeLists.txt
@@ -7,4 +7,5 @@ qt_internal_add_test(tst_qcolortransform
         tst_qcolortransform.cpp
     PUBLIC_LIBRARIES
         Qt::Gui
+        Qt::GuiPrivate
 )
diff --git a/tests/auto/gui/painting/qcolortransform/tst_qcolortransform.cpp b/tests/auto/gui/painting/qcolortransform/tst_qcolortransform.cpp
index c2205a02d1..17f115c308 100644
--- a/tests/auto/gui/painting/qcolortransform/tst_qcolortransform.cpp
+++ b/tests/auto/gui/painting/qcolortransform/tst_qcolortransform.cpp
@@ -31,6 +31,7 @@
 
 #include <qcolorspace.h>
 #include <qcolortransform.h>
+#include <QtGui/private/qcolortransform_p.h>
 
 class tst_QColorTransform : public QObject
 {
@@ -46,6 +47,8 @@ private slots:
     void mapRGB64();
     void mapQColor_data();
     void mapQColor();
+    void mapRGB32Prepared_data();
+    void mapRGB32Prepared();
 
     void transformIsIdentity();
 };
@@ -59,23 +62,22 @@ void tst_QColorTransform::mapRGB32_data()
     QTest::addColumn<QColorTransform>("transform");
     QTest::addColumn<bool>("sharesRed");
 
-    QTest::newRow("default") << QColorTransform() << true;
-    QTest::newRow("sRGB to Linear") << QColorSpace(QColorSpace::SRgb).transformationToColorSpace(QColorSpace::SRgbLinear) << true;
-    QTest::newRow("AdobeRGB to sRGB") << QColorSpace(QColorSpace::AdobeRgb).transformationToColorSpace(QColorSpace::SRgb) << true;
-    QTest::newRow("Linear AdobeRGB to Linear sRGB")
-        << QColorSpace(QColorSpace::AdobeRgb).withTransferFunction(QColorSpace::TransferFunction::Linear).transformationToColorSpace(
-            QColorSpace::SRgb)
-        << true;
-    QTest::newRow("sRgb to AdobeRGB") << QColorSpace(QColorSpace::SRgb).transformationToColorSpace(QColorSpace::AdobeRgb) << true;
-    QTest::newRow("DP3 to sRGB") << QColorSpace(QColorSpace::DisplayP3).transformationToColorSpace(QColorSpace::SRgb) << false;
-    QTest::newRow("DP3 to Linear DP3")
-        << QColorSpace(QColorSpace::DisplayP3).transformationToColorSpace(
-            QColorSpace(QColorSpace::DisplayP3).withTransferFunction(QColorSpace::TransferFunction::Linear))
-        << false;
-    QTest::newRow("Linear DP3 to Linear sRGB")
-        << QColorSpace(QColorSpace::DisplayP3).withTransferFunction(QColorSpace::TransferFunction::Linear).transformationToColorSpace(
-            QColorSpace::SRgb)
-        << false;
+    QColorSpace srgb(QColorSpace::SRgb);
+    QColorSpace srgbLinear(QColorSpace::SRgbLinear);
+    QColorSpace adobeRgb(QColorSpace::AdobeRgb);
+    QColorSpace adobeRgbLinear = adobeRgb.withTransferFunction(QColorSpace::TransferFunction::Linear);
+    QColorSpace dp3(QColorSpace::DisplayP3);
+    QColorSpace dp3Linear = dp3.withTransferFunction(QColorSpace::TransferFunction::Linear);
+
+    QTest::newRow("default")                        << QColorTransform()                                        << true;
+    QTest::newRow("sRGB to Linear sRGB")            << srgb.transformationToColorSpace(srgbLinear)              << true;
+    QTest::newRow("AdobeRGB to sRGB")               << adobeRgb.transformationToColorSpace(srgb)                << true;
+    QTest::newRow("Linear AdobeRGB to AdobeRGB")    << adobeRgbLinear.transformationToColorSpace(adobeRgb)      << true;
+    QTest::newRow("Linear AdobeRGB to Linear sRGB") << adobeRgbLinear.transformationToColorSpace(srgbLinear)    << true;
+    QTest::newRow("sRgb to AdobeRGB")               << srgb.transformationToColorSpace(adobeRgb)                << true;
+    QTest::newRow("DP3 to sRGB")                    << dp3.transformationToColorSpace(srgb)                     << false;
+    QTest::newRow("DP3 to Linear DP3")              << dp3.transformationToColorSpace(dp3Linear)                << false;
+    QTest::newRow("Linear DP3 to Linear sRGB")      << dp3Linear.transformationToColorSpace(srgbLinear)         << false;
 }
 
 void tst_QColorTransform::mapRGB32()
@@ -220,6 +222,76 @@ void tst_QColorTransform::mapQColor()
     QVERIFY(result.blueF() >= 1.0f);
 }
 
+void tst_QColorTransform::mapRGB32Prepared_data()
+{
+    mapRGB32_data();
+}
+
+void tst_QColorTransform::mapRGB32Prepared()
+{
+    QFETCH(QColorTransform, transform);
+    QFETCH(bool, sharesRed);
+
+    // The same tests as mapRGB32 but prepared, to use the LUT code-paths
+    if (!transform.isIdentity())
+        QColorTransformPrivate::get(transform)->prepare();
+
+    QRgb testColor = qRgb(32, 64, 128);
+    QRgb result = transform.map(testColor);
+    QVERIFY(qRed(result) < qGreen(result));
+    QVERIFY(qGreen(result) < qBlue(result));
+    QCOMPARE(qAlpha(result), 255);
+    if (transform.isIdentity())
+        QVERIFY(result == testColor);
+    else
+        QVERIFY(result != testColor);
+
+    testColor = qRgb(128, 64, 32);
+    result = transform.map(testColor);
+    QVERIFY(qRed(result) > qGreen(result));
+    QVERIFY(qGreen(result) > qBlue(result));
+    QCOMPARE(qAlpha(result), 255);
+    if (transform.isIdentity())
+        QVERIFY(result == testColor);
+    else
+        QVERIFY(result != testColor);
+
+    testColor = qRgba(15, 31, 63, 128);
+    result = transform.map(testColor);
+    QVERIFY(qRed(result) < qGreen(result));
+    QVERIFY(qGreen(result) < qBlue(result));
+    QCOMPARE(qAlpha(result), 128);
+    if (transform.isIdentity())
+        QVERIFY(result == testColor);
+    else
+        QVERIFY(result != testColor);
+
+    testColor = qRgb(0, 0, 0);
+    result = transform.map(testColor);
+    QCOMPARE(qRed(result), 0);
+    QCOMPARE(qGreen(result), 0);
+    QCOMPARE(qBlue(result), 0);
+    QCOMPARE(qAlpha(result), 255);
+
+    testColor = qRgb(255, 255, 255);
+    result = transform.map(testColor);
+    QCOMPARE(qRed(result), 255);
+    QCOMPARE(qGreen(result), 255);
+    QCOMPARE(qBlue(result), 255);
+    QCOMPARE(qAlpha(result), 255);
+
+    testColor = qRgb(255, 255, 0);
+    result = transform.map(testColor);
+    QCOMPARE(qAlpha(result), 255);
+    if (sharesRed)
+        QCOMPARE(qRed(result), 255);
+
+    testColor = qRgb(0, 255, 255);
+    result = transform.map(testColor);
+    QCOMPARE(qBlue(result), 255);
+    QCOMPARE(qAlpha(result), 255);
+}
+
 void tst_QColorTransform::transformIsIdentity()
 {
     QColorTransform ct;