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tomo-old/artist/bordered.go

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2023-01-20 17:24:21 -07:00
package artist
import "image"
import "image/color"
// Bordered is a pattern with a border and a fill.
type Bordered struct {
Fill Pattern
Stroke
}
// AtWhen satisfies the Pattern interface.
func (pattern Bordered) AtWhen (x, y, width, height int) (c color.RGBA) {
outerBounds := image.Rectangle { Max: image.Point { width, height }}
innerBounds := outerBounds.Inset(pattern.Weight)
if (image.Point { x, y }).In (innerBounds) {
return pattern.Fill.AtWhen (
x - pattern.Weight,
y - pattern.Weight,
innerBounds.Dx(), innerBounds.Dy())
} else {
return pattern.Stroke.AtWhen(x, y, width, height)
}
}
2023-01-23 22:09:19 -07:00
// Stroke represents a stoke that has a weight and a pattern.
type Stroke struct {
Weight int
Pattern
}
type borderInternal struct {
weight int
stroke Pattern
bounds image.Rectangle
dx, dy int
}
// MultiBordered is a pattern that allows multiple borders of different lengths
// to be inset within one another. The final border is treated as a fill color,
// and its weight does not matter.
type MultiBordered struct {
borders []borderInternal
lastWidth, lastHeight int
maxBorder int
}
// NewMultiBordered creates a new MultiBordered pattern from the given list of
// borders.
func NewMultiBordered (borders ...Stroke) (multi *MultiBordered) {
internalBorders := make([]borderInternal, len(borders))
for index, border := range borders {
internalBorders[index].weight = border.Weight
internalBorders[index].stroke = border.Pattern
}
return &MultiBordered { borders: internalBorders }
}
// AtWhen satisfies the Pattern interface.
func (multi *MultiBordered) AtWhen (x, y, width, height int) (c color.RGBA) {
if multi.lastWidth != width || multi.lastHeight != height {
multi.recalculate(width, height)
}
point := image.Point { x, y }
for index := multi.maxBorder; index >= 0; index -- {
border := multi.borders[index]
if point.In(border.bounds) {
return border.stroke.AtWhen (
point.X - border.bounds.Min.X,
point.Y - border.bounds.Min.Y,
border.dx, border.dy)
}
}
return
}
func (multi *MultiBordered) recalculate (width, height int) {
bounds := image.Rect (0, 0, width, height)
multi.maxBorder = 0
for index, border := range multi.borders {
multi.maxBorder = index
multi.borders[index].bounds = bounds
multi.borders[index].dx = bounds.Dx()
multi.borders[index].dy = bounds.Dy()
bounds = bounds.Inset(border.weight)
if bounds.Empty() { break }
}
}