Add new image type for CSS painting API, and hook it up to draw something.
Created attachment 352681 [details] Patch
Created attachment 352710 [details] Patch
Comment on attachment 352710 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=352710&action=review > Source/WebCore/platform/graphics/CustomPaintImage.cpp:76 > + auto canvas = OffscreenCanvas::create(*scriptExecutionContext, destSize.width(), destSize.height()); > + ExceptionOr<OffscreenRenderingContext> contextOrException = canvas->getContext(*execState, OffscreenCanvas::RenderingContextType::Webgl, { }); > + > + if (contextOrException.hasException()) > + return ImageDrawResult::DidNothing; > + auto context = contextOrException.releaseReturnValue(); > + > + context->clearColor(0, 0, 0, 1.0); > + context->clear(GL_COLOR_BUFFER_BIT); > + > + auto result = m_paintCallback->handleEvent(*context); > + if (result.type() != CallbackResultType::Success) > + return ImageDrawResult::DidNothing; > + > + auto bitmap = canvas->transferToImageBitmap(); > + if (!bitmap) > + return ImageDrawResult::DidNothing; > + > + destContext.drawImage(*bitmap->buffer()->copyImage(), FloatPoint()); This will work fine but will be too slow in practice, since transferToImageBitmap is a GPU readback. However, it's a good place to start. Ultimately I don't expect we'll want to support WebGL initially - only 2d contexts. It's a bit scary to think that any element on a page could require a WebGL canvas/context.
(In reply to Dean Jackson from comment #3) > Comment on attachment 352710 [details] > Patch > > View in context: > https://bugs.webkit.org/attachment.cgi?id=352710&action=review > > > Source/WebCore/platform/graphics/CustomPaintImage.cpp:76 > > + auto canvas = OffscreenCanvas::create(*scriptExecutionContext, destSize.width(), destSize.height()); > > + ExceptionOr<OffscreenRenderingContext> contextOrException = canvas->getContext(*execState, OffscreenCanvas::RenderingContextType::Webgl, { }); > > + > > + if (contextOrException.hasException()) > > + return ImageDrawResult::DidNothing; > > + auto context = contextOrException.releaseReturnValue(); > > + > > + context->clearColor(0, 0, 0, 1.0); > > + context->clear(GL_COLOR_BUFFER_BIT); > > + > > + auto result = m_paintCallback->handleEvent(*context); > > + if (result.type() != CallbackResultType::Success) > > + return ImageDrawResult::DidNothing; > > + > > + auto bitmap = canvas->transferToImageBitmap(); > > + if (!bitmap) > > + return ImageDrawResult::DidNothing; > > + > > + destContext.drawImage(*bitmap->buffer()->copyImage(), FloatPoint()); > > This will work fine but will be too slow in practice, since > transferToImageBitmap is a GPU readback. However, it's a good place to start. > > Ultimately I don't expect we'll want to support WebGL initially - only 2d > contexts. It's a bit scary to think that any element on a page could require > a WebGL canvas/context. I did that because it was the only offscreen canvas I could get easily. The spec actually only supports 2d.
Comment on attachment 352710 [details] Patch Clearing flags on attachment: 352710 Committed r237276: <https://trac.webkit.org/changeset/237276>
All reviewed patches have been landed. Closing bug.
<rdar://problem/45390166>
Comment on attachment 352710 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=352710&action=review In general this approach doesn't seem right. We should not be firing the callback synchronously at paint time. We should be firing the call back at requestAnimationFrame time; the context drawn into should be backed by a display list, and in this doCustomPaint code we should just be playing back that display list. > Source/WebCore/css/CSSPaintCallback.h:41 > + virtual CallbackResult<void> handleEvent(WebGLRenderingContext&) = 0; Why is this using WebGLRenderingContext? The custom paint API is al 2d. > Source/WebCore/platform/graphics/CustomPaintImage.cpp:59 > + ExceptionOr<OffscreenRenderingContext> contextOrException = canvas->getContext(*execState, OffscreenCanvas::RenderingContextType::Webgl, { }); Shouldn't be WebGL.