Add color space model, making gray color spaces explicit

This also adds image conversion of both format and color space, which
will also  be required later for conversions to CMYK formats and color
spaces.

Change-Id: I578c0a010ffcdb4df4cf9080c0621fac8bc342bf
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

1 files changed, 78 insertions, 0 deletions

diff --git a/tests/auto/gui/image/qimage/tst_qimage.cpp b/tests/auto/gui/image/qimage/tst_qimage.cpp
index 3177fa84b1..1abca9e188 100644
--- a/tests/auto/gui/image/qimage/tst_qimage.cpp
+++ b/tests/auto/gui/image/qimage/tst_qimage.cpp
@@ -169,6 +169,9 @@ private slots:
     void largeInplaceRgbConversion_data();
     void largeInplaceRgbConversion();
 
+    void colorSpaceRgbConversion_data();
+    void colorSpaceRgbConversion();
+
     void deepCopyWhenPaintingActive();
     void scaled_QTBUG19157();
 
@@ -3244,6 +3247,81 @@ void tst_QImage::largeInplaceRgbConversion()
     }
 }
 
+void tst_QImage::colorSpaceRgbConversion_data()
+{
+    QTest::addColumn<QImage::Format>("fromFormat");
+    QTest::addColumn<QImage::Format>("toFormat");
+
+    // The various possible code paths for color space conversions compatible with RGB color spaces:
+    QImage::Format formats[] = {
+        QImage::Format_RGB32,
+        QImage::Format_ARGB32,
+        QImage::Format_ARGB32_Premultiplied,
+        QImage::Format_RGBX64,
+        QImage::Format_RGBA64,
+        QImage::Format_RGBA64_Premultiplied,
+        QImage::Format_RGBX32FPx4,
+        QImage::Format_RGBA32FPx4,
+        QImage::Format_RGBA32FPx4_Premultiplied,
+        QImage::Format_Grayscale8,
+        QImage::Format_Grayscale16,
+    };
+
+    for (auto fromFormat : formats) {
+        const QLatin1String formatI = formatToString(fromFormat);
+        for (auto toFormat : formats) {
+            QTest::addRow("%s -> %s", formatI.data(), formatToString(toFormat).data())
+                    << fromFormat << toFormat;
+        }
+    }
+}
+
+void tst_QImage::colorSpaceRgbConversion()
+{
+    // Test that all color space conversions work
+    QFETCH(QImage::Format, fromFormat);
+    QFETCH(QImage::Format, toFormat);
+
+    bool srcGrayscale = fromFormat == QImage::Format_Grayscale8 || fromFormat == QImage::Format_Grayscale16;
+    bool dstGrayscale = toFormat == QImage::Format_Grayscale8 || toFormat == QImage::Format_Grayscale16;
+
+    QImage image(16, 16, fromFormat);
+    image.setColorSpace(QColorSpace::SRgb);
+
+    for (int i = 0; i < image.height(); ++i) {
+        for (int j = 0; j < image.width(); ++j) {
+            if (srcGrayscale || dstGrayscale)
+                image.setPixel(j, i, qRgb((i + j) * 8, (i + j) * 8, (i + j) * 8));
+            else
+                image.setPixel(j, i, qRgb(j * 16, i * 16, (i + j) * 8));
+        }
+    }
+
+    QImage imageConverted = image.convertedToColorSpace(QColorSpace::DisplayP3, toFormat);
+    QCOMPARE(imageConverted.format(), toFormat);
+    QCOMPARE(imageConverted.size(), image.size());
+    if (dstGrayscale) {
+        int gray = 0;
+        for (int x = 0; x < image.width(); ++x) {
+            int newGray = qGray(imageConverted.pixel(x, 6));
+            QCOMPARE_GE(newGray, gray);
+            gray = newGray;
+        }
+    } else {
+        int red = 0;
+        int blue = 0;
+        for (int x = 0; x < image.width(); ++x) {
+            int newRed = qRed(imageConverted.pixel(x, 5));
+            int newBlue = qBlue(imageConverted.pixel(x, 7));
+            QCOMPARE_GE(newBlue, blue);
+            QCOMPARE_GE(newRed, red);
+            blue = newBlue;
+            red = newRed;
+        }
+    }
+}
+
+
 void tst_QImage::deepCopyWhenPaintingActive()
 {
     QImage image(64, 64, QImage::Format_ARGB32_Premultiplied);