Bug 201361 – [WinCairo, FTW] Properly handle device scale factor

• Component: WebKit Misc.
• Status: REOPENED

[Brent Fulgham]

The Modern WebKit implementation does not handle device scale factor properly. The WebContent process runs without DPI awareness and draws everything into 1x buffers, even when the system is running at higher DPI. This leads to Windows scaling the content and lower resolution output.

This patch makes a few corrections:

1. It calls "SetProcessDPIAware" at launch in the WebContent process so that it can make appropriate measurements of the screen resolution.
2. We update the WebPage the proper "setIntrinsicDeviceScaleFactor" value based on screen resolution so that it can pass it to the WebContent process for rendering calculations.
3. We do call WKPageSetPageZoomFactor with the screen DPI scale factor, since this is meant to be a logical screen zoom, not a correction for high DPI.

[Brent Fulgham]

The attached patch gets things working properly so that Windows controls are drawn properly. It does not handle changes in DPI (such as adjusting the Windows settings, or dragging a WebView from a high DPI monitor to a low-DPI monitor.

[Brent Fulgham]

Created attachment 377787 [details]
Patch

[WebKit Commit Bot]

Comment on attachment 377787 [details]
Patch

Rejecting attachment 377787 [details] from commit-queue.

Failed to run "['/Volumes/Data/EWS/WebKit/Tools/Scripts/webkit-patch', '--status-host=webkit-queues.webkit.org', '--bot-id=webkit-cq-03', 'validate-changelog', '--check-oops', '--non-interactive', 377787, '--port=mac']" exit_code: 1 cwd: /Volumes/Data/EWS/WebKit

ChangeLog entry in Source/WebKit/ChangeLog contains OOPS!.

Full output: https://webkit-queues.webkit.org/results/12989465

[Brent Fulgham]

Committed r249366: <https://trac.webkit.org/changeset/249366>

[Radar WebKit Bug Importer]

<rdar://problem/54932919>

[Fujii Hironori]

device scale factor is not correct in WinCairo WK2
WinCairo WK2 crashes in some web sites, for example https://webkit.org and https://www.youtube.com

Callstack:

> cairo.dll!_pixman_implementation_create_sse2()	C
> cairo.dll!_pixman_gradient_walker_write_wide()	C
> cairo.dll!pixman_image_composite32()	C
> cairo.dll!_inplace_src_spans(void * abstract_renderer, int y, int h, const _cairo_half_open_span * spans, unsigned int num_spans) Line 2716	C
> cairo.dll!generate_row(_cairo_span_renderer * renderer, const _rectangle * r, int y, int h, unsigned short coverage) Line 626	C
> cairo.dll!_cairo_rectangular_scan_converter_generate(void * converter, _cairo_span_renderer * renderer) Line 673	C
> cairo.dll!composite_boxes(const cairo_spans_compositor * compositor, _cairo_composite_rectangles * extents, _cairo_boxes_t * boxes) Line 741	C
> cairo.dll!clip_and_composite_boxes(const cairo_spans_compositor * compositor, _cairo_composite_rectangles * extents, _cairo_boxes_t * boxes) Line 888	C
> cairo.dll!_cairo_spans_compositor_mask(const cairo_compositor * _compositor, _cairo_composite_rectangles * extents) Line 1000	C
> cairo.dll!_cairo_compositor_paint(const cairo_compositor * compositor, _cairo_surface * surface, _cairo_operator op, const _cairo_pattern * source, const _cairo_clip * clip) Line 67	C
> cairo.dll!_cairo_image_surface_paint(void * abstract_surface, _cairo_operator op, const _cairo_pattern * source, const _cairo_clip * clip) Line 931	C
> cairo.dll!_cairo_surface_paint(_cairo_surface * surface, _cairo_operator op, const _cairo_pattern * source, const _cairo_clip * clip) Line 2199	C
> cairo.dll!_cairo_gstate_paint(_cairo_gstate * gstate) Line 1061	C
> cairo.dll!_cairo_default_context_paint_with_alpha(void * abstract_cr, double alpha) Line 971	C
> cairo.dll!cairo_paint_with_alpha(_cairo * cr, double alpha) Line 2248	C
> WebKit2.dll!WebCore::Cairo::drawPatternToCairoContext(_cairo * cr, _cairo_pattern * pattern, const WebCore::FloatRect & destRect, float alpha) Line 156	C++
> WebKit2.dll!WebCore::Cairo::drawSurface(WebCore::PlatformContextCairo & platformContext, _cairo_surface * surface, const WebCore::FloatRect & destRect, const WebCore::FloatRect & originalSrcRect, WebCore::InterpolationQuality imageInterpolationQuality, float globalAlpha, const WebCore::Cairo::ShadowState & shadowState) Line 988	C++
> WebKit2.dll!WebKit::ShareableBitmap::paint(WebCore::GraphicsContext & context, float scaleFactor, const WebCore::IntPoint & dstPoint, const WebCore::IntRect & srcRect) Line 80	C++
> WebKit2.dll!WebKit::BackingStore::incorporateUpdate(WebKit::ShareableBitmap * bitmap, const WebKit::UpdateInfo & updateInfo) Line 93	C++
> WebKit2.dll!WebKit::BackingStore::incorporateUpdate(const WebKit::UpdateInfo & updateInfo) Line 67	C++
> WebKit2.dll!WebKit::DrawingAreaProxyCoordinatedGraphics::incorporateUpdate(const WebKit::UpdateInfo & updateInfo) Line 254	C++
> WebKit2.dll!WebKit::DrawingAreaProxyCoordinatedGraphics::update(unsigned __int64 backingStoreStateID, const WebKit::UpdateInfo & updateInfo) Line 164	C++
> WebKit2.dll!IPC::callMemberFunctionImpl<WebKit::DrawingAreaProxy,void (WebKit::DrawingAreaProxy::*)(unsigned long long, const WebKit::UpdateInfo &),std::tuple<unsigned long long,WebKit::UpdateInfo>,0,1>(WebKit::DrawingAreaProxy * object, void(WebKit::DrawingAreaProxy::*)(unsigned __int64, const WebKit::UpdateInfo &) function, std::tuple<unsigned long long,WebKit::UpdateInfo> && args, std::integer_sequence<unsigned long long,0,1>) Line 42	C++
> WebKit2.dll!IPC::callMemberFunction<WebKit::DrawingAreaProxy,void (WebKit::DrawingAreaProxy::*)(unsigned long long, const WebKit::UpdateInfo &),std::tuple<unsigned long long,WebKit::UpdateInfo>,std::integer_sequence<unsigned long long,0,1> >(std::tuple<unsigned long long,WebKit::UpdateInfo> && args, WebKit::DrawingAreaProxy * object, void(WebKit::DrawingAreaProxy::*)(unsigned __int64, const WebKit::UpdateInfo &) function) Line 47	C++
> WebKit2.dll!IPC::handleMessage<Messages::DrawingAreaProxy::Update,WebKit::DrawingAreaProxy,void (WebKit::DrawingAreaProxy::*)(unsigned long long, const WebKit::UpdateInfo &)>(IPC::Decoder & decoder, WebKit::DrawingAreaProxy * object, void(WebKit::DrawingAreaProxy::*)(unsigned __int64, const WebKit::UpdateInfo &) function) Line 121	C++
> WebKit2.dll!WebKit::DrawingAreaProxy::didReceiveMessage(IPC::Connection & connection, IPC::Decoder & decoder) Line 44	C++
> WebKit2.dll!IPC::MessageReceiverMap::dispatchMessage(IPC::Connection & connection, IPC::Decoder & decoder) Line 124	C++
> WebKit2.dll!WebKit::AuxiliaryProcessProxy::dispatchMessage(IPC::Connection & connection, IPC::Decoder & decoder) Line 155	C++
> WebKit2.dll!WebKit::WebProcessProxy::didReceiveMessage(IPC::Connection & connection, IPC::Decoder & decoder) Line 662	C++
> WebKit2.dll!IPC::Connection::dispatchMessage(IPC::Decoder & decoder) Line 940	C++
> WebKit2.dll!IPC::Connection::dispatchMessage(std::unique_ptr<IPC::Decoder,std::default_delete<IPC::Decoder> > message) Line 993	C++
> WebKit2.dll!IPC::Connection::dispatchIncomingMessages() Line 1097	C++
> WebKit2.dll!IPC::Connection::enqueueIncomingMessage::<unnamed-tag>::operator()() Line 914	C++
> WebKit2.dll!WTF::Detail::CallableWrapper<`lambda at ..\..\Source\WebKit\Platform\IPC\Connection.cpp:912:30',void>::call() Line 52	C++
> WTF.dll!WTF::Function<void ()>::operator()() Line 79	C++
> WTF.dll!WTF::RunLoop::performWork() Line 108	C++
> WTF.dll!WTF::RunLoop::wndProc(HWND__ * hWnd, unsigned int message, unsigned __int64 wParam, __int64 lParam) Line 57	C++
> WTF.dll!WTF::RunLoop::RunLoopWndProc(HWND__ * hWnd, unsigned int message, unsigned __int64 wParam, __int64 lParam) Line 39	C++
> [External Code]	
> WebKit.dll!WebKitMessageLoop::run(HACCEL__ * hAccelTable) Line 94	C++
> MiniBrowserLib.dll!wWinMain(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, wchar_t * lpstrCmdLine, int nCmdShow) Line 97	C++
> MiniBrowserLib.dll!dllLauncherEntryPoint(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, wchar_t * lpstrCmdLine, int nCmdShow) Line 115	C++
> MiniBrowser.exe!wWinMain(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, wchar_t * lpstrCmdLine, int nCmdShow) Line 232	C++
> [External Code]

[Fujii Hironori]

Reverted r249366 for reason:

WinCairo WebKit2 crashes in some websites and the device scale factor is not correct in high DPI.

Committed r249371: <https://trac.webkit.org/changeset/249371>

[Fujii Hironori]

Callstack in Comment 6 have incorrect pixman function names for https://github.com/WebKitForWindows/WinCairoRequirements/issues/26
Here is the correct callstack:

> [Inline Frame] cairo.dll!combine4(const __m128i *) Line 550	C
> cairo.dll!sse2_combine_add_u(pixman_implementation_t * imp, pixman_op_t op, unsigned int * dst, const unsigned int * src, const unsigned int * mask, int width) Line 1380	C
> cairo.dll!general_composite_rect(pixman_implementation_t * imp, pixman_composite_info_t * info) Line 225	C
> cairo.dll!pixman_image_composite32(pixman_op_t op, pixman_image * src, pixman_image * mask, pixman_image * dest, int src_x, int src_y, int mask_x, int mask_y, int dest_x, int dest_y, int width, int height) Line 700	C
> cairo.dll!_inplace_src_spans(void * abstract_renderer, int y, int h, const _cairo_half_open_span * spans, unsigned int num_spans) Line 2716	C
> cairo.dll!generate_row(_cairo_span_renderer * renderer, const _rectangle * r, int y, int h, unsigned short coverage) Line 626	C
> cairo.dll!_cairo_rectangular_scan_converter_generate(void * converter, _cairo_span_renderer * renderer) Line 673	C
> cairo.dll!composite_boxes(const cairo_spans_compositor * compositor, _cairo_composite_rectangles * extents, _cairo_boxes_t * boxes) Line 741	C
> cairo.dll!clip_and_composite_boxes(const cairo_spans_compositor * compositor, _cairo_composite_rectangles * extents, _cairo_boxes_t * boxes) Line 888	C
> cairo.dll!_cairo_spans_compositor_mask(const cairo_compositor * _compositor, _cairo_composite_rectangles * extents) Line 1000	C
> cairo.dll!_cairo_compositor_paint(const cairo_compositor * compositor, _cairo_surface * surface, _cairo_operator op, const _cairo_pattern * source, const _cairo_clip * clip) Line 67	C
> cairo.dll!_cairo_image_surface_paint(void * abstract_surface, _cairo_operator op, const _cairo_pattern * source, const _cairo_clip * clip) Line 931	C
> cairo.dll!_cairo_surface_paint(_cairo_surface * surface, _cairo_operator op, const _cairo_pattern * source, const _cairo_clip * clip) Line 2199	C
> cairo.dll!_cairo_gstate_paint(_cairo_gstate * gstate) Line 1061	C
> cairo.dll!_cairo_default_context_paint_with_alpha(void * abstract_cr, double alpha) Line 971	C
> cairo.dll!cairo_paint_with_alpha(_cairo * cr, double alpha) Line 2248	C
> WebKit2.dll!WebCore::Cairo::drawPatternToCairoContext(_cairo * cr, _cairo_pattern * pattern, const WebCore::FloatRect & destRect, float alpha) Line 156	C++
> WebKit2.dll!WebCore::Cairo::drawSurface(WebCore::PlatformContextCairo & platformContext, _cairo_surface * surface, const WebCore::FloatRect & destRect, const WebCore::FloatRect & originalSrcRect, WebCore::InterpolationQuality imageInterpolationQuality, float globalAlpha, const WebCore::Cairo::ShadowState & shadowState) Line 988	C++
> WebKit2.dll!WebKit::ShareableBitmap::paint(WebCore::GraphicsContext & context, float scaleFactor, const WebCore::IntPoint & dstPoint, const WebCore::IntRect & srcRect) Line 80	C++
> WebKit2.dll!WebKit::BackingStore::incorporateUpdate(WebKit::ShareableBitmap * bitmap, const WebKit::UpdateInfo & updateInfo) Line 93	C++
> WebKit2.dll!WebKit::BackingStore::incorporateUpdate(const WebKit::UpdateInfo & updateInfo) Line 67	C++
> WebKit2.dll!WebKit::DrawingAreaProxyCoordinatedGraphics::incorporateUpdate(const WebKit::UpdateInfo & updateInfo) Line 254	C++
> WebKit2.dll!WebKit::DrawingAreaProxyCoordinatedGraphics::update(unsigned __int64 backingStoreStateID, const WebKit::UpdateInfo & updateInfo) Line 164	C++
> WebKit2.dll!IPC::callMemberFunctionImpl<WebKit::DrawingAreaProxy,void (WebKit::DrawingAreaProxy::*)(unsigned long long, const WebKit::UpdateInfo &),std::tuple<unsigned long long,WebKit::UpdateInfo>,0,1>(WebKit::DrawingAreaProxy * object, void(WebKit::DrawingAreaProxy::*)(unsigned __int64, const WebKit::UpdateInfo &) function, std::tuple<unsigned long long,WebKit::UpdateInfo> && args, std::integer_sequence<unsigned long long,0,1>) Line 42	C++
> WebKit2.dll!IPC::callMemberFunction<WebKit::DrawingAreaProxy,void (WebKit::DrawingAreaProxy::*)(unsigned long long, const WebKit::UpdateInfo &),std::tuple<unsigned long long,WebKit::UpdateInfo>,std::integer_sequence<unsigned long long,0,1> >(std::tuple<unsigned long long,WebKit::UpdateInfo> && args, WebKit::DrawingAreaProxy * object, void(WebKit::DrawingAreaProxy::*)(unsigned __int64, const WebKit::UpdateInfo &) function) Line 47	C++
> WebKit2.dll!IPC::handleMessage<Messages::DrawingAreaProxy::Update,WebKit::DrawingAreaProxy,void (WebKit::DrawingAreaProxy::*)(unsigned long long, const WebKit::UpdateInfo &)>(IPC::Decoder & decoder, WebKit::DrawingAreaProxy * object, void(WebKit::DrawingAreaProxy::*)(unsigned __int64, const WebKit::UpdateInfo &) function) Line 121	C++
> WebKit2.dll!WebKit::DrawingAreaProxy::didReceiveMessage(IPC::Connection & connection, IPC::Decoder & decoder) Line 44	C++
> WebKit2.dll!IPC::MessageReceiverMap::dispatchMessage(IPC::Connection & connection, IPC::Decoder & decoder) Line 124	C++
> WebKit2.dll!WebKit::AuxiliaryProcessProxy::dispatchMessage(IPC::Connection & connection, IPC::Decoder & decoder) Line 155	C++
> WebKit2.dll!WebKit::WebProcessProxy::didReceiveMessage(IPC::Connection & connection, IPC::Decoder & decoder) Line 662	C++
> WebKit2.dll!IPC::Connection::dispatchMessage(IPC::Decoder & decoder) Line 940	C++
> WebKit2.dll!IPC::Connection::dispatchMessage(std::unique_ptr<IPC::Decoder,std::default_delete<IPC::Decoder> > message) Line 993	C++
> WebKit2.dll!IPC::Connection::dispatchIncomingMessages() Line 1097	C++
> WebKit2.dll!IPC::Connection::enqueueIncomingMessage::<unnamed-tag>::operator()() Line 914	C++
> WebKit2.dll!WTF::Detail::CallableWrapper<`lambda at ..\..\Source\WebKit\Platform\IPC\Connection.cpp:912:30',void>::call() Line 52	C++
> WTF.dll!WTF::Function<void ()>::operator()() Line 79	C++
> WTF.dll!WTF::RunLoop::performWork() Line 108	C++
> WTF.dll!WTF::RunLoop::wndProc(HWND__ * hWnd, unsigned int message, unsigned __int64 wParam, __int64 lParam) Line 57	C++
> WTF.dll!WTF::RunLoop::RunLoopWndProc(HWND__ * hWnd, unsigned int message, unsigned __int64 wParam, __int64 lParam) Line 39	C++
> [External Code]	
> WebKit.dll!WebKitMessageLoop::run(HACCEL__ * hAccelTable) Line 94	C++
> MiniBrowserLib.dll!wWinMain(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, wchar_t * lpstrCmdLine, int nCmdShow) Line 97	C++
> MiniBrowserLib.dll!dllLauncherEntryPoint(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, wchar_t * lpstrCmdLine, int nCmdShow) Line 115	C++
> MiniBrowser.exe!wWinMain(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, wchar_t * lpstrCmdLine, int nCmdShow) Line 232	C++
> [External Code]

[Fujii Hironori]

Created attachment 377836 [details]
Wrong Patch

[Fujii Hironori]

(In reply to Fujii Hironori from comment #6)
> device scale factor is not correct in WinCairo WK2

Bug 196339 for this.

> WinCairo WK2 crashes in some web sites

Bug 196340 for this.

[Brent Fulgham]

(In reply to Fujii Hironori from comment #10)
> (In reply to Fujii Hironori from comment #6)
> > device scale factor is not correct in WinCairo WK2
> 
> Bug 196339 for this.
> 
> > WinCairo WK2 crashes in some web sites
> 
> Bug 196340 for this.

Hi Fujii -- do you intend to re-land this change when you have resolved the regressions you found? Or do you think this patch will not be necessary after that work is done?

[Fujii Hironori]

I'll re-land this patch after finishing Bug 196339.

[Brent Fulgham]

(In reply to Fujii Hironori from comment #12)
> I'll re-land this patch after finishing Bug 196339.

Excellent, thank you!