ribir_gpu

ribir_gpu is a gpu painter backend for ribir_painter. ribir_gpu accept PaintCommand as input and convert them to triangles and texture then submit to the graphics library to draw.

Tessellator: generate triangles and texture

There are some awesome library we use to generate triangles.

• use ttf-parser to parse font
• use rustybuzz to shape text.
• use lyon to generate triangles for path.

  Replace graphics library

wgpu is provide as the default graphics library to render the result of Tessellator. Enable is across the wgpu_gl feature.

Cache mechanism

Vertex generation is cached pre PaintCommand and retain if it cache hit by next frame.

For text, a high level cache may have, the glyph is may cached as an alpha mode bitmap in atlas texture. For all cache miss glyphs, tessellator will count the duplicate glyphs pre frame, and generate their vertexes once and draw them in atlas texture convert to new vertexes.

Parallel and not serial guarantee

Notice ribir_gpu is design as parallel render with ribir, so PaintCommand submit to ribir_gpu will not be processed immediately.

ribir_painter will processed the PaintCommand parallel and try to merge the result as much as possible in a max allowed memory before submit to gpu.