Made similar changes to the Pattern interface and all of artist

artist/pattern.go

@@ -7,61 +7,55 @@ import "git.tebibyte.media/sashakoshka/tomo/shatter"
 // Pattern is capable of drawing to a canvas within the bounds of a given
 // clipping rectangle.
 type Pattern interface {
-	// Draw draws to destination, using the bounds of destination as a width
-	// and height for things like gradients, bevels, etc. The pattern may
-	// not draw outside the union of destination.Bounds() and clip. The
-	// clipping rectangle effectively takes a subset of the pattern. To
-	// change the bounds of the pattern itself, use canvas.Cut() on the
-	// destination before passing it to Draw().
-	Draw (destination canvas.Canvas, clip image.Rectangle)
+	// Draw draws the pattern onto the destination canvas, using the
+	// specified bounds. The given bounds can be smaller or larger than the
+	// bounds of the destination canvas. The destination canvas can be cut
+	// using canvas.Cut() to draw only a specific subset of a pattern.
+	Draw (destination canvas.Canvas, bounds image.Rectangle)
 }
 
-// Draw lets you use several clipping rectangles to draw a pattern.
-func Draw (
+// Fill fills the destination canvas with the given pattern.
+func Fill (destination canvas.Canvas, source Pattern) (updated image.Rectangle) {
+	source.Draw(destination, destination.Bounds())
+	return destination.Bounds()
+}
+
+// Draw lets you draw several subsets of 
+func DrawClip (
 	destination canvas.Canvas,
 	source      Pattern,
-	clips       ...image.Rectangle,
+	bounds      image.Rectangle,
+	subsets     ...image.Rectangle,
 ) (
 	updatedRegion image.Rectangle,
 ) {
-	for _, clip := range clips {
-		source.Draw(destination, clip)
-		updatedRegion = updatedRegion.Union(clip)
+	for _, subset := range subsets {
+		source.Draw(canvas.Cut(destination, subset), bounds)
+		updatedRegion = updatedRegion.Union(subset)
 	}
 	return
 }
 
-// DrawBounds lets you specify an overall bounding rectangle for drawing a
-// pattern. The destination is cut to this rectangle.
-func DrawBounds (
-	destination canvas.Canvas,
-	source      Pattern,
-	bounds      image.Rectangle,
-) (
-	updatedRegion image.Rectangle,
-) {
-	return Draw(canvas.Cut(destination, bounds), source, bounds)
-}
-
-// DrawShatter is like an inverse of Draw, drawing nothing in the areas
-// specified in "rocks".
+// DrawShatter is like an inverse of DrawClip, drawing nothing in the areas
+// specified by "rocks".
 func DrawShatter (
 	destination canvas.Canvas,
 	source      Pattern,
+	bounds      image.Rectangle,
 	rocks       ...image.Rectangle,
 ) (
 	updatedRegion image.Rectangle,
 ) {
-	tiles := shatter.Shatter(destination.Bounds(), rocks...)
-	return Draw(destination, source, tiles...)
+	tiles := shatter.Shatter(bounds, rocks...)
+	return DrawClip(destination, source, bounds, tiles...)
 }
 
 // AllocateSample returns a new canvas containing the result of a pattern. The
 // resulting canvas can be sourced from shape drawing functions. I beg of you
 // please do not call this every time you need to draw a shape with a pattern on
 // it because that is horrible and cruel to the computer.
-func AllocateSample (source Pattern, width, height int) (allocated canvas.Canvas) {
-	allocated = canvas.NewBasicCanvas(width, height)
-	source.Draw(allocated, allocated.Bounds())
-	return
+func AllocateSample (source Pattern, width, height int) canvas.Canvas {
+	allocated := canvas.NewBasicCanvas(width, height)
+	Fill(allocated, source)
+	return allocated
 }