如何在 DirectWrite 中使用 Direct2D 在图像或抽象形状周围环绕文本？

Question

I couldn't find an example of a block of text not rendered to a rectangular area.

Ideally, it would be nice if ID2D1HwndRenderTarget.DrawText() would let me provide a polygon Geometry instead of a rectangle.

I've tried adding a Direct2D Layer with contentBounds , thinking it might skip rendering text within those layers. It didn't work as expected, it just blocked render to the area still emulating text underneath.

I've also tried applying a rectangular area to hwnd window itself. It too blocked render but didn't shift text.

Answer 1

IDWriteTextLayout only supports rectangular layouts, but DirectWrite supports any shape you can think of by using the lower level functions (text analysis, glyph measurement, glyph shaping). It's no easy task to write your own text layout from scratch, but I wrote a Windows 7 SDK sample containing a "FlowLayout" that demonstrates a circle and a few other simple shapes. It doesn't take arbitrary geometry, but you may be able to adapt it to your needs (see FlowLayoutSource::GetNextRect for computing the width of each line).

https://github.com/pauldotknopf/WindowsSDK7-Samples/tree/master/multimedia/DirectWrite/CustomLayout

Answer 2

DirectWrite only supports rectangular layouts, so you can't get anything more complicated automatically. You'll have to implement layout functionality yourself if you want it to work differently. Clipping arguments, like you already observed, have nothing to do with text layout.