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tomo-old/artist/rectangle.go

113 lines
2.9 KiB
Go

package artist
import "image"
import "git.tebibyte.media/sashakoshka/tomo/canvas"
// Paste transfers one canvas onto another, offset by the specified point.
func Paste (
destination canvas.Canvas,
source canvas.Canvas,
offset image.Point,
) (
updatedRegion image.Rectangle,
) {
dstData, dstStride := destination.Buffer()
srcData, srcStride := source.Buffer()
sourceBounds :=
source.Bounds().Canon().
Intersect(destination.Bounds().Sub(offset))
if sourceBounds.Empty() { return }
updatedRegion = sourceBounds.Add(offset)
for y := sourceBounds.Min.Y; y < sourceBounds.Max.Y; y ++ {
for x := sourceBounds.Min.X; x < sourceBounds.Max.X; x ++ {
dstData[x + offset.X + (y + offset.Y) * dstStride] =
srcData[x + y * srcStride]
}}
return
}
// FillRectangle draws a filled rectangle with the specified pattern.
func FillRectangle (
destination canvas.Canvas,
source Pattern,
bounds image.Rectangle,
) (
updatedRegion image.Rectangle,
) {
return FillRectangleClip(destination, source, bounds, bounds)
}
// FillRectangleClip is similar to FillRectangle, but it clips the pattern to
// a specified rectangle mask. That is—the pattern will be queried as if it
// were drawn without the mask, but only the area specified by the intersection
// of bounds and mask will be drawn to.
func FillRectangleClip (
destination canvas.Canvas,
source Pattern,
bounds image.Rectangle,
mask image.Rectangle,
) (
updatedRegion image.Rectangle,
) {
data, stride := destination.Buffer()
realBounds := bounds
bounds =
bounds.Canon().
Intersect(mask.Canon()).
Intersect(destination.Bounds())
if bounds.Empty() { return }
updatedRegion = bounds
realWidth, realHeight := realBounds.Dx(), realBounds.Dy()
patternOffset := realBounds.Min.Sub(bounds.Min)
width, height := bounds.Dx(), bounds.Dy()
for y := 0; y < height; y ++ {
for x := 0; x < width; x ++ {
data[x + bounds.Min.X + (y + bounds.Min.Y) * stride] =
source.AtWhen (
x - patternOffset.X, y - patternOffset.Y,
realWidth, realHeight)
}}
return
}
// StrokeRectangle draws the outline of a rectangle with the specified line
// weight and pattern.
func StrokeRectangle (
destination canvas.Canvas,
source Pattern,
weight int,
bounds image.Rectangle,
) {
bounds = bounds.Canon()
insetBounds := bounds.Inset(weight)
if insetBounds.Empty() {
FillRectangle(destination, source, bounds)
return
}
// top
FillRectangle (destination, source, image.Rect (
bounds.Min.X, bounds.Min.Y,
bounds.Max.X, insetBounds.Min.Y))
// bottom
FillRectangle (destination, source, image.Rect (
bounds.Min.X, insetBounds.Max.Y,
bounds.Max.X, bounds.Max.Y))
// left
FillRectangle (destination, source, image.Rect (
bounds.Min.X, insetBounds.Min.Y,
insetBounds.Min.X, insetBounds.Max.Y))
// right
FillRectangle (destination, source, image.Rect (
insetBounds.Max.X, insetBounds.Min.Y,
bounds.Max.X, insetBounds.Max.Y))
}