Is skia never going to touch opengl until flush is called?

[Red Artist]

Skia paragraphs are really expensive, so I decided to push the UI work into the background. I will draw those paragraphs to Canvas of GrBackendTexture and then on the main (gl) thread, I will render those textures into the main openGL framebuffer.

So, I was hoping someone could tell me which operations were safe to do on not-opengl-current threads and which skia functions need a current opengl context.

1. Creating a surface out of openGL GrBackendTexture?

2. Using a canvas to draw things to that canvas created out of GrBackendTexture based surface?

3. layout and draw paragraphs into the canvas? ( I remember that skia uses a scratch texture to hold glyphs)

4. draw those GrBackendTexture canvases into a surface backed by GrBackendRenderTarget (main framebuffer).

5. Now, on opengl main thread, I can simply call flush before swapping buffers.