62 lines
2.0 KiB
Go
62 lines
2.0 KiB
Go
package artist
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import "image"
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import "git.tebibyte.media/sashakoshka/tomo/canvas"
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import "git.tebibyte.media/sashakoshka/tomo/shatter"
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// Pattern is capable of drawing to a canvas within the bounds of a given
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// clipping rectangle.
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type Pattern interface {
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// Draw draws the pattern onto the destination canvas, using the
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// specified bounds. The given bounds can be smaller or larger than the
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// bounds of the destination canvas. The destination canvas can be cut
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// using canvas.Cut() to draw only a specific subset of a pattern.
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Draw (destination canvas.Canvas, bounds image.Rectangle)
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}
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// Fill fills the destination canvas with the given pattern.
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func Fill (destination canvas.Canvas, source Pattern) (updated image.Rectangle) {
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source.Draw(destination, destination.Bounds())
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return destination.Bounds()
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}
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// DrawClip lets you draw several subsets of a pattern at once.
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func DrawClip (
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destination canvas.Canvas,
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source Pattern,
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bounds image.Rectangle,
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subsets ...image.Rectangle,
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) (
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updatedRegion image.Rectangle,
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) {
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for _, subset := range subsets {
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source.Draw(canvas.Cut(destination, subset), bounds)
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updatedRegion = updatedRegion.Union(subset)
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}
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return
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}
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// DrawShatter is like an inverse of DrawClip, drawing nothing in the areas
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// specified by "rocks".
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func DrawShatter (
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destination canvas.Canvas,
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source Pattern,
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bounds image.Rectangle,
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rocks ...image.Rectangle,
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) (
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updatedRegion image.Rectangle,
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) {
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tiles := shatter.Shatter(bounds, rocks...)
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return DrawClip(destination, source, bounds, tiles...)
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}
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// AllocateSample returns a new canvas containing the result of a pattern. The
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// resulting canvas can be sourced from shape drawing functions. I beg of you
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// please do not call this every time you need to draw a shape with a pattern on
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// it because that is horrible and cruel to the computer.
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func AllocateSample (source Pattern, width, height int) canvas.Canvas {
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allocated := canvas.NewBasicCanvas(width, height)
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Fill(allocated, source)
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return allocated
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}
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