drawinglayer/qa/unit/vclpixelprocessor2d.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  */
  10
  11 #include <test/bootstrapfixture.hxx>
  12
  13 #include <vcl/virdev.hxx>
  14 #include <vcl/BitmapReadAccess.hxx>
  15 #include <vcl/graphicfilter.hxx>
  16 #include <tools/stream.hxx>
  17 #include <drawinglayer/geometry/viewinformation2d.hxx>
  18 #include <drawinglayer/primitive2d/fillgradientprimitive2d.hxx>
  19 #include <drawinglayer/primitive2d/maskprimitive2d.hxx>
  20 #include <drawinglayer/processor2d/baseprocessor2d.hxx>
  21 #include <drawinglayer/processor2d/processor2dtools.hxx>
  22 #include <basegfx/polygon/b2dpolygontools.hxx>
  23 #include <basegfx/utils/gradienttools.hxx>
  24
  25 using namespace drawinglayer;
  26
  27 class VclPixelProcessor2DTest : public test::BootstrapFixture
  28 {
  29     // if enabled - check the result images with:
  30     // "xdg-open ./workdir/CppunitTest/drawinglayer_processors.test.core/"
  31     static constexpr const bool mbExportBitmap = false;
  32
  33     void exportDevice(const OUString& filename, const VclPtr<VirtualDevice>& device)
  34     {
  35         if (mbExportBitmap)
  36         {
  37             BitmapEx aBitmapEx(device->GetBitmapEx(Point(0, 0), device->GetOutputSizePixel()));
  38             SvFileStream aStream(filename, StreamMode::WRITE | StreamMode::TRUNC);
  39             GraphicFilter::GetGraphicFilter().compressAsPNG(aBitmapEx, aStream);
  40         }
  41     }
  42
  43 public:
  44     VclPixelProcessor2DTest()
  45         : BootstrapFixture(true, false)
  46     {
  47     }
  48
  49     // Test that drawing only a part of a gradient draws the proper part of it.
  50     void testTdf139000()
  51     {
  52         ScopedVclPtr<VirtualDevice> device
  53             = VclPtr<VirtualDevice>::Create(DeviceFormat::WITHOUT_ALPHA);
  54         device->SetOutputSizePixel(Size(100, 200));
  55         device->SetBackground(Wallpaper(COL_RED));
  56         device->Erase();
  57
  58         drawinglayer::geometry::ViewInformation2D view;
  59         std::unique_ptr<processor2d::BaseProcessor2D> processor(
  60             processor2d::createProcessor2DFromOutputDevice(*device, view));
  61         CPPUNIT_ASSERT(processor);
  62
  63         // I stumbled over this when hunting another problem, but I have to correct
  64         // this: This test does test something that is not supported. It seems to be
  65         // based on the *misunderstanding* that in the version of the constructor of
  66         // FillGradientPrimitive2D (and similar others) with two ranges the 2nd
  67         // B2DRange parameter 'OutputRange' is a 'clipping' parameter. This is *not*
  68         // the case --- it is in fact the *contrary*, it is there to *extend* the
  69         // usual definition/paintRange of a gradient:
  70         // It was originally needed to correctly display TextFrames (TF) in Writer: If you
  71         // have a TF in SW filled with a gradient and that TF has sub-frames, it inherits
  72         // the gradient fill. Since you can freely move those sub-TFs even outside the
  73         // parent TF there has to be a way to not only paint gradients in their definition
  74         // range (classical, all DrawObjects do that), but extended from that. This is
  75         // needed e.g. for linear gradients, but - dependent of e.g. the center settings -
  76         // also for all other ones, all can have geometry 'outside' the DefinitionRange.
  77         // This is now also used in various other locations which is proof that this is
  78         // useful and needed. It is possible to see that basic history/reason for this
  79         // parameter by following the git history and why and under which circumstances
  80         // that parameter was originally added. Other hints are: It is *not* named
  81         // 'ClipRange'. Using a B2DRange to define a ClipRange topology would be bad due
  82         // to not being transformable, a PolyPolygon would be used in that case. Using as
  83         // clipping mechanism would offer a 2nd principle to add clipping for primitives
  84         // besides MaskPrimitive2D - always bad style in a sub-system. A quick look
  85         // on it's usages gives hints, too.
  86         // This means that when defining an outputRange that resides completely *inside*
  87         // the definitionRange *no change* at all is done by definition since this does
  88         // not *extend* the target area of the gradient paint region at all. If an
  89         // implementation does clip and limit output to 'outputRange' that should do no
  90         // harm, but is not the expected/reliable way to paint primitives clipped.
  91         // That's why all DrawObjects with gradient fill (and other fills do the same)
  92         // embed the fill that is defined for a range (usually the BoundRange of a
  93         // PolyPolygon) in a MaskPrimitive2D defined by the outline PolyPolygon of the
  94         // shape. Nothing speaks against renderers detecting that combination and do
  95         // something optimized if they want to, especially SDPRs, but this is not
  96         // required. The standard embedded clipping of the implementations of the
  97         // MaskPrimitive2D do the right thing.
  98         // This test intends to paint the lower part of a gradient, so define the
  99         // gradient for the full target range and embed it to a MaskPrimitive2D
 100         // defining the lower part of that area to do that.
 101
 102         basegfx::B2DRange definitionRange(0, 0, 100, 200);
 103         basegfx::B2DRange outputRange(0, 100, 100, 200); // Paint only lower half of the gradient.
 104
 105         const primitive2d::Primitive2DContainer primitives{
 106             rtl::Reference<primitive2d::MaskPrimitive2D>(new primitive2d::MaskPrimitive2D(
 107                 basegfx::B2DPolyPolygon(basegfx::utils::createPolygonFromRect(outputRange)),
 108                 primitive2d::Primitive2DContainer{
 109                     rtl::Reference<primitive2d::FillGradientPrimitive2D>(
 110                         new primitive2d::FillGradientPrimitive2D(
 111                             definitionRange, attribute::FillGradientAttribute(
 112                                                  css::awt::GradientStyle_LINEAR, 0, 0, 0, 0,
 113                                                  basegfx::BColorStops(COL_WHITE.getBColor(),
 114                                                                       COL_BLACK.getBColor())))) }))
 115         };
 116         processor->process(primitives);
 117
 118         exportDevice("test-tdf139000.png", device);
 119         Bitmap bitmap = device->GetBitmap(Point(), device->GetOutputSizePixel());
 120         Bitmap::ScopedReadAccess access(bitmap);
 121         // The upper half should keep its red background color.
 122         CPPUNIT_ASSERT_EQUAL(BitmapColor(COL_RED), access->GetColor(Point(0, 99)));
 123         // First line of the gradient should not be the start color, but something halfway.
 124         CPPUNIT_ASSERT_LESS(static_cast<sal_uInt16>(16),
 125                             access->GetColor(Point(0, 100)).GetColorError(COL_GRAY));
 126         // Last line of the gradient should be the end color, or close.
 127         CPPUNIT_ASSERT_LESS(static_cast<sal_uInt16>(16),
 128                             access->GetColor(Point(0, 199)).GetColorError(COL_BLACK));
 129     }
 130
 131     CPPUNIT_TEST_SUITE(VclPixelProcessor2DTest);
 132     CPPUNIT_TEST(testTdf139000);
 133     CPPUNIT_TEST_SUITE_END();
 134 };
 135
 136 CPPUNIT_TEST_SUITE_REGISTRATION(VclPixelProcessor2DTest);
 137
 138 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */