On Fri, 21 Aug 2026 22:42:36 GMT, Andy Goryachev <[email protected]> wrote:

>> This PR adds a `getDrawingContext` method to `WritableImage`, which works 
>> similar to `Canvas::getGraphicsContext` and shares the same signatures. Key 
>> features include:
>> 
>> - **Shape rendering**: `strokeRect`, `fillRect`, `strokeOval`, `fillOval`, 
>> `strokeArc`, `fillArc`, `strokePolyline`, `fillPolygon`, etc.
>> - **Stroke and fill attributes**: `lineWidth`, `lineCap`, `lineJoin`, 
>> `miterLimit`, `fillRule`, `stroke` and `fill` paints.
>> - **Global graphics settings**: `globalAlpha` and `globalBlendMode`.
>> - **Image drawing**: draw other `Image` instances with scaling and 
>> source/destination rectangles.
>> - **Text rendering**: render text
>> - **Save/Restore**: store current stroke, font, dashes, etc and restore them 
>> later
>> - **Paths**: begin a path, with lines, curves, etc, then stroke or fill it
>> - **Clips**: support rectangular clips in the SW renderer
>> 
>> This feature enables direct software rendering to `WritableImage` without 
>> requiring a `Canvas` + snapshot.
>> 
>> **Additional notes**:
>> 
>> - The implementation leverages the software stack consisting of the Marlin 
>> rasterizer and Pisces compositor/painter.
>> 
>> **Example usage**:
>> 
>> 
>> WritableImage img = new WritableImage(400, 400);
>> DrawingContext ctx = img.getDrawingContext();
>> ctx.setFill(Color.RED);
>> ctx.fillRect(50, 50, 100, 100);
>> 
>> 
>> See the sample program `RandomShapesDemo` to see a `WritableImage` and 
>> `Canvas` side by side performing the same operations:
>> 
>> <img width="1249" height="741" alt="image" 
>> src="https://github.com/user-attachments/assets/4a0b9dcc-8f96-4faa-99cf-83c66d2c851e";
>>  />
>> 
>> Newer version:
>> 
>> <img width="1249" height="741" alt="image" 
>> src="https://github.com/user-attachments/assets/c0502620-3d02-4fbd-8c33-43bd5138b42c";
>>  />
>> 
>> ---------
>> - [x] I confirm that I make this contribution in accordance with the 
>> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai).
>
> The size argument is a good one.
> 
> One last question: would it make more sense to update the `Canvas` instead to 
> remove the size limitation, instead of creating some parallel way of doing 
> the same thing, possibly introducing subtle and not so subtle differences?
> 
> Another aspect: let's say we decide to go with two parallel APIs - should we 
> then make sure they mirror each other exactly?  If so, would it create 
> another maintenance burden?

@andy-goryachev-oracle @mstr2  I think this is ready for a re-review; I did do 
some substantial changes (like adding sliced/direct buffer support) to cover 
the gaps rather than rejecting these, so this PR has become a bit bigger, but I 
think most of it is still in scope of this PR and makes the feature more 
polished.

-------------

PR Comment: https://git.openjdk.org/jfx/pull/1969#issuecomment-5556156455

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