package artist import "image" import "git.tebibyte.media/sashakoshka/tomo/canvas" 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 lets you use several clipping rectangles to draw a pattern. func Draw ( destination canvas.Canvas, source Pattern, clips ...image.Rectangle, ) ( updatedRegion image.Rectangle, ) { for _, clip := range clips { source.Draw(destination, clip) updatedRegion = updatedRegion.Union(clip) } 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". func DrawShatter ( destination canvas.Canvas, source Pattern, rocks ...image.Rectangle, ) ( updatedRegion image.Rectangle, ) { tiles := shatter.Shatter(destination.Bounds(), rocks...) return Draw(destination, source, 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 }