Adding clipping to doodle [Draft]

[VOSID8]

I'm done with the Algebra, Syntax, Constructor and now working on Java2d Backend. Clipit is the end implementation, taking clipping area as Closed Path as argument as it was intended to.

@main def hello(): Unit =
  val closed = ClosedPath.empty
                  .moveTo(80, -60)
                  .lineTo(10, 10).lineTo(10, 60).lineTo(80, 60).lineTo(80, -60)
  val blackSquare = Picture.triangle(200, 100).fillColor(Color.red).clipit(closed)
  blackSquare.draw()

Right now with the Java2dClip.scala file where after the setClip is done, when doing Clip, java.awt.Shape is required as argument where I have Drawing[A], and need to return vice versa.

[error] 20 |    gg.clip(image) //Graphics2D.clip() requires java.awt.Shape as argument 
[error]    |            ^^^^^
[error]    |            Found:    (image : Java2dClip.this.Drawing[A])
[error]    |            Required: java.awt.Shape

[noelwelsh]

This file lists the syntax in alphabetic order. You should follow this convention.

[noelwelsh]

Should just be clip. Use alphabetic ordering.

[noelwelsh]

This doesn't follow the existing naming convention. Just Clip will do.

[noelwelsh]

Suggested change

	def clipit[A](image: Drawing[A], clip_path: ClosedPath): Drawing[A]
	def clip[A](image: Drawing[A], clipPath: ClosedPath): Drawing[A]

[noelwelsh]

The clip method is not a constructor. It does not create a Picture from things that are not a Picture. See the description here.

Only constructors go here.

[noelwelsh]

Suggested change

	def clipit(clip_path: ClosedPath): Picture[Alg, A] =
	def clip(clipPath: ClosedPath): Picture[Alg, A] =

Scala does not use _ as a separator in names. It uses camelCase naming, not snake_case.

[noelwelsh]

This implementation strategy will not work.

If you look at the other Java2D algebras you will see they are all implemented in the reified package. The Reified data structure represents all the drawing instructions, and the render method on Reified carries out those instructions. To implement clipping you need to do the same: represent the clipping as an instruction in Reified and then carry out the instruction in render.