Hello.
I want to draw 2D curvy path with beizer curves and color fill.
Is it possible to do that in kha?
What is the best method to do that? Use some drawing methods of g2, or use some shaders with g4?

g2's drawLine or fancy shaders on g4 are both suited for the job. Unless you really know what you're doing I'd go for drawLine - it's auto-batched so it's pretty fast.

Just noticed Kha has that already in kha.graphics2.GraphicsExtension.hx

Yes. There is drawCubicBezierPath method in GraphicsExtension. But how to fill that path with color?

You'd have to change the algorithm somewhat to triangulate the area.

Bezier curve is also triangles? If i draw curves and triangulate the shape, can i use shaders for that shape?

I found method calculateCubicBezierPoint in GraphicsExtension. May be it's better calculate all points of path with this method, and then use method fillTriangle for all points? But method calculateCubicBezierPoint is static private.

Please feel free to change that.

calculateCubicBezierPoint is a helper method for drawCubicBezier / drawCubicBezierPath to work. It returns a point in a section of a simple curve. To get all the points in a curve with many sections, you could modify drawCubicBezierPath to return the points instead of draw, but actually I was already experimenting with this some time ago, you can see here:
https://github.com/RafaelOliveira/KhaGfx/blob/master/Sources/gfx/Geom.hx#L76
With the points of the shape you can try a triangulate algorithm, or draw lines getting the points horizontally. That is something I'm interested but didn't test yet.