Sharper canvas, PSD adjustments and masks, Photoshop's Saturation, Levels and Hue/Saturation on every core, a growing blur's preview kept, the hierarchy kept (13.8)

tests/SharpCanvasTests.cpp

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+#include "Document/BrushStroke.h"
+#include "Rendering/TiledLayerRenderer.h"
+#include <QPainter>
+#include <QtTest>
+
+// Compositor 1.4's sharper canvas: upright layers at 1:1 copy across.
+namespace {
+// Black and white columns, opaque, 100 by 4.
+QImage columns()
+{
+    QImage image = BrushRaster::context(100, 4, false);
+    for (int y = 0; y < 4; ++y) {
+        for (int x = 0; x < 100; ++x)
+            image.setPixel(x, y, x % 2 ? qRgba(255, 255, 255, 255) : qRgba(0, 0, 0, 255));
+    }
+    return image;
+}
+
+using Draw = std::function<void(const LayerTransform &, QPainter &)>;
+
+// Pixels under the layer neither black nor white.
+int blurred(double width, const Draw &draw)
+{
+    QImage surface = BrushRaster::context(120, 4, false);
+    QPainter painter(&surface);
+    draw(LayerTransform{.origin = {0, 0}, .size = {width, 4}}, painter);
+    painter.end();
+    int count = 0;
+    for (int y = 0; y < 4; ++y) {
+        for (int x = 0; x < 100; ++x)
+            count += qRed(surface.pixel(x, y)) % 255 != 0;
+    }
+    return count;
+}
+}
+
+class SharpCanvasTests : public QObject {
+    Q_OBJECT
+private slots:
+    void anUprightLayerPixelForPixelTakesNoFilter();
+    void plainMaskedAndTiledLayersCopyAcross();
+};
+
+void SharpCanvasTests::anUprightLayerPixelForPixelTakesNoFilter()
+{
+    for (LayerSampling sampling : {LayerSampling::smooth, LayerSampling::high}) {
+        QCOMPARE(LayerRenderer::interpolation(sampling, 1.0009, true), InterpolationQuality::none);
+        QCOMPARE(LayerRenderer::interpolation(sampling, 0.9991, true), InterpolationQuality::none);
+        QCOMPARE(LayerRenderer::interpolation(sampling, 0.9989, true), InterpolationQuality::low);
+        QCOMPARE(LayerRenderer::interpolation(sampling, 1, false), InterpolationQuality::low);
+    }
+    QCOMPARE(LayerRenderer::interpolation(LayerSampling::high, 1.0011, true), InterpolationQuality::high);
+    QCOMPARE(LayerRenderer::interpolation(LayerSampling::high, 1.0009, false), InterpolationQuality::high);
+    QCOMPARE(LayerRenderer::interpolation(LayerSampling::nearest, 1.5, true), InterpolationQuality::none);
+}
+
+void SharpCanvasTests::plainMaskedAndTiledLayersCopyAcross()
+{
+    const QImage image = columns();
+    QImage white = BrushRaster::context(100, 4, true);
+    white.fill(255);
+    const auto raster = std::make_shared<const RasterSnapshot>(100, 4, image, QRectF(0, 0, 100, 4), std::vector<BrushPatch>{});
+    const std::vector<Draw> draws{
+        [&](const LayerTransform &transform, QPainter &painter) { LayerRenderer::draw(image, transform, transform.center(), painter); },
+        [&](const LayerTransform &transform, QPainter &painter) {
+            LayerRenderer::draw(image, transform, transform.center(), painter, {.mask = white});
+        },
+        [&](const LayerTransform &transform, QPainter &painter) {
+            TiledLayerRenderer::drawRaster(raster, transform, transform.center(), painter);
+        },
+    };
+    for (const Draw &draw : draws) {
+        // A twentieth of a pixel over 100: within tolerance, crisp.
+        QCOMPARE(blurred(100.05, draw), 0);
+        // A fifth: filtered as before.
+        QVERIFY(blurred(100.2, draw) > 0);
+    }
+}
+
+QTEST_GUILESS_MAIN(SharpCanvasTests)
+#include "SharpCanvasTests.moc"