vcl: unit tests for Bitmap::Crop() and Bitmap::GetDownsampledBitmap()

Bitmap::Crop() test:

- If crop rectangle is fully outside of the bitmap, then return false
and don't change the bitmap.
- If crop rectangle is same size as bitmap, then return false
- If crop rectangle is larger than the bitmap, then return false
- If crop rectangle partially overlaps the bitmap, return true and crop
the bitmap
- If crop rectangle is fully within the bitmap, then return true and
crop the bitmap

Bitmap::GetDownsampledBitmap() tested to check when empty or not.

Change-Id: Id2a6f739fdb1961748ce218862e628dfa8512122
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/121546
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

2 files changed, 112 insertions, 0 deletions

diff --git a/vcl/qa/cppunit/BitmapTest.cxx b/vcl/qa/cppunit/BitmapTest.cxx
index 45e1bdfa1d73..25630ea9cabb 100644
--- a/vcl/qa/cppunit/BitmapTest.cxx
+++ b/vcl/qa/cppunit/BitmapTest.cxx
@@ -45,6 +45,7 @@ class BitmapTest : public CppUnit::TestFixture
     void testEmptyAccess();
     void testDitherSize();
     void testMirror();
+    void testCrop();
 
     CPPUNIT_TEST_SUITE(BitmapTest);
     CPPUNIT_TEST(testCreation);
@@ -61,6 +62,7 @@ class BitmapTest : public CppUnit::TestFixture
     CPPUNIT_TEST(testEmptyAccess);
     CPPUNIT_TEST(testDitherSize);
     CPPUNIT_TEST(testMirror);
+    CPPUNIT_TEST(testCrop);
     CPPUNIT_TEST_SUITE_END();
 };
 
@@ -685,6 +687,45 @@ void BitmapTest::testMirror()
     }
 }
 
+void BitmapTest::testCrop()
+{
+    Bitmap aBitmap(Bitmap(Size(16, 16), vcl::PixelFormat::N24_BPP));
+
+    {
+        Bitmap aCroppedBmp(aBitmap);
+        CPPUNIT_ASSERT_MESSAGE("Crop was fully outside of bitmap bounds",
+                               !aCroppedBmp.Crop(tools::Rectangle(Point(20, 20), Size(5, 5))));
+        CPPUNIT_ASSERT_EQUAL(Size(16, 16), aCroppedBmp.GetSizePixel());
+    }
+
+    {
+        Bitmap aCroppedBmp(aBitmap);
+        CPPUNIT_ASSERT_MESSAGE("Crop same size as bitmap",
+                               !aCroppedBmp.Crop(tools::Rectangle(Point(0, 0), Size(16, 16))));
+        CPPUNIT_ASSERT_EQUAL(Size(16, 16), aCroppedBmp.GetSizePixel());
+    }
+
+    {
+        Bitmap aCroppedBmp(aBitmap);
+        CPPUNIT_ASSERT_MESSAGE("Crop larger than bitmap",
+                               !aCroppedBmp.Crop(tools::Rectangle(Point(0, 0), Size(100, 100))));
+        CPPUNIT_ASSERT_EQUAL(Size(16, 16), aCroppedBmp.GetSizePixel());
+    }
+
+    {
+        Bitmap aCroppedBmp(aBitmap);
+        CPPUNIT_ASSERT_MESSAGE("Crop partially overcrops bitmap",
+                               aCroppedBmp.Crop(tools::Rectangle(Point(10, 10), Size(100, 100))));
+        CPPUNIT_ASSERT_EQUAL(Size(6, 6), aCroppedBmp.GetSizePixel());
+    }
+
+    {
+        Bitmap aCroppedBmp(aBitmap);
+        CPPUNIT_ASSERT_MESSAGE("Crop inside bitmap",
+                               aCroppedBmp.Crop(tools::Rectangle(Point(5, 5), Size(10, 10))));
+        CPPUNIT_ASSERT_EQUAL(Size(10, 10), aCroppedBmp.GetSizePixel());
+    }
+}
 } // namespace
 
 CPPUNIT_TEST_SUITE_REGISTRATION(BitmapTest);
diff --git a/vcl/qa/cppunit/outdev.cxx b/vcl/qa/cppunit/outdev.cxx
index 1857b4555c8a..2df0df7d8a69 100644
--- a/vcl/qa/cppunit/outdev.cxx
+++ b/vcl/qa/cppunit/outdev.cxx
@@ -44,6 +44,7 @@ public:
     void testDrawScalePartBitmap();
     void testDrawTransformedBitmapEx();
     void testDrawTransformedBitmapExFlip();
+    void testCroppedDownsampledBitmap();
     void testRTL();
     void testRTLGuard();
     void testDefaultFillColor();
@@ -76,6 +77,7 @@ public:
     CPPUNIT_TEST(testGetReadableFontColorWindow);
     CPPUNIT_TEST(testDrawTransformedBitmapEx);
     CPPUNIT_TEST(testDrawTransformedBitmapExFlip);
+    CPPUNIT_TEST(testCroppedDownsampledBitmap);
     CPPUNIT_TEST(testRTL);
     CPPUNIT_TEST(testRTLGuard);
     CPPUNIT_TEST(testDefaultFillColor);
@@ -510,6 +512,75 @@ void VclOutdevTest::testDrawTransformedBitmapExFlip()
     CPPUNIT_ASSERT_EQUAL_MESSAGE(ss.str(), COL_BLACK, Color(aColor));
 }
 
+namespace
+{
+class DownsampleBitmapTester : public OutputDevice
+{
+public:
+    DownsampleBitmapTester()
+        : OutputDevice(OUTDEV_VIRDEV)
+        , maBitmap(Bitmap(Size(16, 16), vcl::PixelFormat::N24_BPP))
+    {
+        SetDPIX(96);
+        SetDPIY(96);
+    }
+
+    bool AcquireGraphics() const { return true; }
+    void ReleaseGraphics(bool) {}
+    bool UsePolyPolygonForComplexGradient() { return false; }
+
+    Bitmap testCropFullyOutsideBounds()
+    {
+        return GetDownsampledBitmap(Size(10, 10), Point(20, 20), Size(5, 5), maBitmap, 72, 72);
+    }
+
+    Bitmap testCropSameSize()
+    {
+        return GetDownsampledBitmap(Size(10, 10), Point(0, 0), maBitmap.GetSizePixel(), maBitmap,
+                                    72, 72);
+    }
+
+    Bitmap testFullyOvercrop()
+    {
+        return GetDownsampledBitmap(Size(10, 10), Point(0, 0), Size(100, 100), maBitmap, 72, 72);
+    }
+
+    Bitmap testPartiallyOvercrop()
+    {
+        return GetDownsampledBitmap(Size(10, 10), Point(10, 10), Size(100, 100), maBitmap, 72, 72);
+    }
+
+private:
+    Bitmap maBitmap;
+};
+}
+
+void VclOutdevTest::testCroppedDownsampledBitmap()
+{
+    ScopedVclPtrInstance<DownsampleBitmapTester> pTester;
+
+    {
+        Bitmap aDownsampledBmp(pTester->testCropFullyOutsideBounds());
+        CPPUNIT_ASSERT_MESSAGE("Crop was fully outside of bitmap bounds",
+                               aDownsampledBmp.IsEmpty());
+    }
+
+    {
+        Bitmap aDownsampledBmp(pTester->testCropSameSize());
+        CPPUNIT_ASSERT_MESSAGE("Crop same size as bitmap", !aDownsampledBmp.IsEmpty());
+    }
+
+    {
+        Bitmap aDownsampledBmp(pTester->testFullyOvercrop());
+        CPPUNIT_ASSERT_MESSAGE("Crop larger than bitmap", !aDownsampledBmp.IsEmpty());
+    }
+
+    {
+        Bitmap aDownsampledBmp(pTester->testPartiallyOvercrop());
+        CPPUNIT_ASSERT_MESSAGE("Crop partially overcrops bitmap", !aDownsampledBmp.IsEmpty());
+    }
+}
+
 void VclOutdevTest::testRTL()
 {
     ScopedVclPtrInstance<vcl::Window> pWindow(nullptr, WB_APP | WB_STDWORK);