Implement antialiasing as an option for vector layers

Being able to disable anti-aliasing on Vector layer is something frequently asked on KA

• Vector Layer should have the option of disabling anti-aliasing
• Disabling anti-aliasing effects of exported vector layers into raster images
• Disable anti-aliasing on vector layer as a new option?
• Jagged and Antialiasing Lines
• You want Krita’s text to be crispy, pixel and not Anti-Aliased? Try this tutorial!
• How to disable antialias in vector layer when drawing curve?
• How to make vector stroke pixelated?

This is an implementation of an option to activate/deactivate anti-aliasing on Vector Layer

• The option is available from layer properties

  

• The option is available from layers docker

  

Example:

vector_antialiasing

From a technical point of view:

• Layer properties UI use standard implementation through sectionModelProperties(), setSectionModelProperties(), KisLayerPropertiesIcons
  • I've used the icon curve-preset-s because it give a 'smooth' look I've tried to search on google what a 'anti-alias' icon could look but didn't find anything convincing me I'm open to ideas about this icon if the chosen one is not Ok 😄
• The option is saved/loaded from Krita document (impact on impex/libkra)
• Are concerned by activation/deactivation of anti-aliasing all shapes on vector layer, including text. This is made through:

  • KisShapeLayerCanvasBase::repaint() that set QPainter::Antialiasing only if vector option is set to True

  • KoSvgTextShape::paintPaths(), when given QPainter renderHint(QPainter::Antialiasing) is True

  • This works with "On canvas" text editing but may be its better @woltherav check I didn't broke or miss anything here with new text tool

    vector_antialiasing2

• Also, VectorLayer class from python API has been updated to let plugin developers being able to use this new option.

Notes concerning impact on class KisShapeLayer

• I use if(m_d->canvas) m_d->canvas->resetCache(); to refresh canvas content when option is modified, not sure it's the best method
• There's many KisShapeLayer constructors and I'm not sure I've updated them in the best way...

Test Plan

Test 1

• Create a document, add one or more vector layer
• Add shapes & text in vector layer, zoom on layer to have a better view of pixels (zoom 400% for example)
• Open layer properties, check/uncheck "Antialiasing" option, see how layer is rendered according to option status; close properties
• Change status from Layer docker, see how layer is rendered according to option status; close properties
• Save document, close it
• Open document, option status (activated/deactivated) should match what was defined when saved

Test 2

• Open a document with vector layer, created from a previous version of Krita
• Document must open and vector layers are antialiased

Test 3

• Open a document created from Test 1 in a previous version of Krita
• Document must open and all vector layers are antialiased (option is ignored, and will be lost is saved from a previous version)

Test 4

• Open a document created from Test 1 in version of Krita with this MR implemented

• Open scripter

• Execute the following script

    from krita import (Document, Notifier)
    from PyQt5.Qt import *
  
    class TestVectorLayer():
        def __init__(self):
            doc = Krita.instance().activeDocument()
            if doc:
                node = doc.rootNode()
                
                for childNode in node.childNodes():                
                    if childNode.type() == "vectorlayer":
                        qDebug(f"{childNode.name()}: {childNode.isAntialiased()}")
                        childNode.setAntialiased(not childNode.isAntialiased())
                    
    test = TestVectorLayer()

• Check that status of option on vector layer has been switched

Test 5

Execute tests unit build with Krita

• /krita-build/plugins/impex/libkra/tests/kis_kra_saver_test
• /krita-build/plugins/impex/libkra/tests/kis_kra_loader_test

Note: the kis_kra_saver_test currently return 1 failure on master branch... the failure is still here in my MR

QWARN  : KisKraSaverTest::testRoundTrip() krita.core: BUG: The walker hasn't reached the root layer!
QWARN  : KisKraSaverTest::testRoundTrip() krita.core:      Start node: KisGroupLayer(0x557dbba0d950, name = "group1") Requested rect: QRect(-76,0 76x304)
QWARN  : KisKraSaverTest::testRoundTrip() krita.core:      An inconsistency in the walkers occurred!
QWARN  : KisKraSaverTest::testRoundTrip() krita.core:      Please report a bug describing how you got this message.
FAIL!  : KisKraSaverTest::testRoundTrip() 'result' returned FALSE. ()
  Loc: [/home/appimage/persistent/krita/plugins/impex/libkra/tests/kis_kra_saver_test.cpp(91)]

Formalities Checklist

• I confirmed this builds.
• I confirmed Krita ran and the relevant functions work.
• I tested the relevant unit tests and can confirm they are not broken. (If not possible, don't hesitate to ask for help!)
• I made sure my commits build individually and have good descriptions as per KDE guidelines.
• I made sure my code conforms to the standards set in the HACKING file.
• I can confirm the code is licensed and attributed appropriately, and that unattributed code is mine, as per KDE Licensing Policy.

Reminder: the reviewer is responsible for merging the patch, this is to ensure at the least two people can build the patch. In case a patch breaks the build, both the author and the reviewer should be contacted to fix the build. If this is not possible, the commits shall be reverted, and a notification with the reasoning and any relevant logs shall be sent to the mailing list, kimageshop@kde.org.