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tomo-old/artist/artutil/util.go

65 lines
2.0 KiB
Go

// Package artutil provides utility functions for working with graphical types
// defined in artist, canvas, and image.
package artutil
import "image"
import "image/color"
import "git.tebibyte.media/sashakoshka/tomo/artist"
import "git.tebibyte.media/sashakoshka/tomo/canvas"
import "git.tebibyte.media/sashakoshka/tomo/shatter"
// Fill fills the destination canvas with the given pattern.
func Fill (destination canvas.Canvas, source artist.Pattern) (updated image.Rectangle) {
source.Draw(destination, destination.Bounds())
return destination.Bounds()
}
// DrawClip lets you draw several subsets of a pattern at once.
func DrawClip (
destination canvas.Canvas,
source artist.Pattern,
bounds image.Rectangle,
subsets ...image.Rectangle,
) (
updatedRegion image.Rectangle,
) {
for _, subset := range subsets {
source.Draw(canvas.Cut(destination, subset), bounds)
updatedRegion = updatedRegion.Union(subset)
}
return
}
// DrawShatter is like an inverse of DrawClip, drawing nothing in the areas
// specified by "rocks".
func DrawShatter (
destination canvas.Canvas,
source artist.Pattern,
bounds image.Rectangle,
rocks ...image.Rectangle,
) (
updatedRegion image.Rectangle,
) {
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 artist.Pattern, width, height int) canvas.Canvas {
allocated := canvas.NewBasicCanvas(width, height)
Fill(allocated, source)
return allocated
}
// Hex creates a color.RGBA value from an RGBA integer value.
func Hex (color uint32) (c color.RGBA) {
c.A = uint8(color)
c.B = uint8(color >> 8)
c.G = uint8(color >> 16)
c.R = uint8(color >> 24)
return
}