Fix HTML button sizing and HiDPI SVG rendering

Use border-box sizing for HTML buttons to match browser user-agent styles and
prevent padding from increasing explicitly declared button heights.

Keep inline SVG textures rasterized at full physical resolution while assigning
density-independent sprite destination sizes, avoiding double scaling on HiDPI
displays.

Add SS64 and pixel-density regressions for button alignment, percentage-sized
SVG layout, and drawable dimensions.

src/eepp/ui/uisvg.cpp

@@ -107,7 +107,9 @@ void UISvg::rasterizeSvg( const std::string& svgXml, const Sizef& targetSize ) {
 		return;
 
 	SpritePtr sprite = Sprite::New();
-	sprite->createStatic( std::move( texture ) );
+	// TextureRegion destination sizes are density-independent and get converted back to pixels by
+	// the drawable. The SVG texture is already rasterized at the widget's physical pixel size.
+	sprite->createStatic( std::move( texture ), PixelDensity::pxToDp( targetSize ) );
 
 	runOnMainThread( [this, sprite = std::move( sprite )]() mutable {
 		if ( sprite )

src/eepp/ui/uiwidgetcreator.cpp

@@ -124,6 +124,7 @@ input[type="submit"],
 input[type="button"],
 input[type="reset"] {
 	display: inline-block;
+	box-sizing: border-box;
 	border-width: 1dp;
 	border-color: #767676;
 	background-color: #f0f0f0;

src/tests/unit_tests/htmlsvg_tests.cpp

@@ -2,6 +2,7 @@
 
 #include <eepp/graphics/fontfamily.hpp>
 #include <eepp/graphics/fonttruetype.hpp>
+#include <eepp/graphics/pixeldensity.hpp>
 #include <eepp/scene/scenemanager.hpp>
 #include <eepp/system/filesystem.hpp>
 #include <eepp/system/sys.hpp>
@@ -263,15 +264,49 @@ UTEST( UISvg, percentageHeightResolvesAfterContainingBlockLayout ) {
 	ASSERT_TRUE( svgWidget != nullptr );
 	EXPECT_EQ( svgWidget->getLayoutHeightPolicy(), SizePolicy::Fixed );
 	EXPECT_GT( svgWidget->getPixelsSize().getHeight(), 0.f );
-	EXPECT_NEAR( svgWidget->getPixelsSize().getHeight(), 34.5f, 1.f );
+	EXPECT_NEAR( button->getPixelsSize().getHeight(), 34.5f, 1.f );
+	EXPECT_NEAR( svgWidget->getPixelsSize().getHeight(), 27.5f, 1.f );
 
 	button->setStyleSheetProperty( StyleSheetProperty( "height", "50px" ) );
 	sceneNode->updateDirtyLayouts();
-	EXPECT_NEAR( svgWidget->getPixelsSize().getHeight(), 50.f, 1.f );
+	EXPECT_NEAR( svgWidget->getPixelsSize().getHeight(), 43.f, 1.f );
 
 	destroyScene( sceneNode );
 }
 
+UTEST( UISvg, percentageSizeUsesPhysicalContainingBlockAtPixelDensity2 ) {
+	auto sceneNode = createScene();
+	ASSERT_TRUE( sceneNode != nullptr );
+	PixelDensity::setPixelDensity( 2.f );
+
+	std::string html = R"html(<!doctype html>
+<html>
+<body>
+<div id="box" style="box-sizing:border-box;width:64px;height:34.5px;padding:2px 6px 3px">
+  <svg id="icon" viewBox="0 0 26 26" style="width:100%;height:100%">
+    <circle cx="13" cy="13" r="10"/>
+  </svg>
+</div>
+</body>
+</html>)html";
+
+	auto rootWidget = sceneNode->loadLayoutFromString( HTMLFormatter::HTMLtoXML( html ) );
+	ASSERT_TRUE( rootWidget != nullptr );
+	sceneNode->updateDirtyLayouts();
+
+	auto* box = rootWidget->querySelector( "#box" );
+	auto* svgWidget = rootWidget->querySelector( "#icon" )->asType<UISvg>();
+	ASSERT_TRUE( box != nullptr );
+	ASSERT_TRUE( svgWidget != nullptr );
+	EXPECT_NEAR( box->getPixelsSize().getWidth(), 128.f, 1.f );
+	EXPECT_NEAR( box->getPixelsSize().getHeight(), 69.f, 1.f );
+	EXPECT_NEAR( svgWidget->getPixelsSize().getWidth(), 104.f, 1.f );
+	EXPECT_NEAR( svgWidget->getPixelsSize().getHeight(), 59.f, 1.f );
+
+	destroyScene( sceneNode );
+	PixelDensity::setPixelDensity( 1.f );
+}
+
 UTEST( UISvg, svgWithMemoryAsset ) {
 	auto sceneNode = createScene();
 	ASSERT_TRUE( sceneNode != nullptr );

src/tests/unit_tests/uihtml_float_tests.cpp

@@ -615,8 +615,9 @@ UTEST( UIHTMLFloat, floatedListItemsShrinkToFitBlockAnchors ) {
 	Engine::destroySingleton();
 }
 
-UTEST( UIHTMLFloat, ss64BlockAnchorsFillButtons ) {
+UTEST( UIHTMLFloat, ss64BlockAnchorsAndSvgAtPixelDensity2 ) {
 	init_float_test();
+	PixelDensity::setPixelDensity( 2.f );
 	UISceneNode* sceneNode = SceneManager::instance()->getUISceneNode();
 	std::string html;
 	ASSERT_TRUE( FileSystem::fileGet( "assets/html/ss64.html", html ) );
@@ -629,16 +630,34 @@ UTEST( UIHTMLFloat, ss64BlockAnchorsFillButtons ) {
 	ASSERT_EQ( anchors.size(), buttons.size() );
 	for ( size_t i = 0; i < buttons.size(); ++i ) {
 		auto* anchor = anchors[i]->asType<UIRichText>();
-		EXPECT_NEAR( anchor->getLineHeightPx(), 40.f, 1.f );
-		EXPECT_NEAR( anchor->getPixelsSize().getHeight(), 40.f, 1.f );
-		EXPECT_NEAR( anchor->getPixelsSize().getHeight() + 2.f,
+		EXPECT_NEAR( anchor->getLineHeightPx(), 80.f, 1.f );
+		EXPECT_NEAR( anchor->getPixelsSize().getHeight(), 80.f, 1.f );
+		EXPECT_NEAR( anchor->getPixelsSize().getHeight() + 4.f,
 					 buttons[i]->getPixelsSize().getHeight(), 1.f );
 	}
 	auto* svg = sceneNode->getRoot()->querySelector( "#sherlock svg" )->asType<UISvg>();
+	auto* input = sceneNode->getRoot()->querySelector( "#qu" );
+	auto* searchButton = sceneNode->getRoot()->querySelector( "#sherlock" );
+	ASSERT_TRUE( input != nullptr );
+	ASSERT_TRUE( searchButton != nullptr );
 	ASSERT_TRUE( svg != nullptr );
+	EXPECT_NEAR( input->getPixelsSize().getHeight(), 74.5f, 1.f );
+	EXPECT_NEAR( searchButton->getPixelsSize().getHeight(), 69.f, 1.f );
+	EXPECT_LE( searchButton->getPixelsPosition().y + searchButton->getPixelsSize().getHeight(),
+			   input->getPixelsPosition().y + input->getPixelsSize().getHeight() );
 	EXPECT_EQ( svg->getLayoutHeightPolicy(), SizePolicy::Fixed );
-	EXPECT_GT( svg->getPixelsSize().getHeight(), 0.f );
+	EXPECT_NEAR( svg->getPixelsSize().getHeight(), 59.f, 1.f );
+	for ( int i = 0; i < 500 && svg->getDrawable() == nullptr; ++i ) {
+		SceneManager::instance()->update();
+		Sys::sleep( Milliseconds( 1 ) );
+	}
+	ASSERT_TRUE( svg->getDrawable() != nullptr );
+	EXPECT_NEAR( svg->getDrawable()->getPixelsSize().getWidth(), svg->getPixelsSize().getWidth(),
+				 1.f );
+	EXPECT_NEAR( svg->getDrawable()->getPixelsSize().getHeight(), svg->getPixelsSize().getHeight(),
+				 1.f );
 	Engine::destroySingleton();
+	PixelDensity::setPixelDensity( 1.f );
 }
 
 UTEST( UIHTMLFloat, autoHorizontalMarginsCenterBlockInsideFloat ) {