mirror of https://github.com/mum4k/termdash.git
71 lines
2.0 KiB
Go
71 lines
2.0 KiB
Go
// Package area provides functions working with image areas.
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package area
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import (
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"fmt"
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"image"
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)
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// Size returns the size of the provided area.
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func Size(area image.Rectangle) image.Point {
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return image.Point{
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area.Dx(),
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area.Dy(),
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}
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}
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// FromSize returns the corresponding area for the provided size.
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func FromSize(size image.Point) (image.Rectangle, error) {
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if size.X < 0 || size.Y < 0 {
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return image.Rectangle{}, fmt.Errorf("cannot convert zero or negative size to an area, got: %+v", size)
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}
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return image.Rect(0, 0, size.X, size.Y), nil
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}
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// HSplit returns two new areas created by splitting the provided area in the
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// middle along the horizontal axis. Can return zero size areas.
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func HSplit(area image.Rectangle) (image.Rectangle, image.Rectangle) {
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height := area.Dy() / 2
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if height == 0 {
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return image.ZR, image.ZR
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}
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return image.Rect(area.Min.X, area.Min.Y, area.Max.X, area.Min.Y+height),
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image.Rect(area.Min.X, area.Min.Y+height, area.Max.X, area.Max.Y)
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}
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// VSplit returns two new areas created by splitting the provided area in the
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// middle along the vertical axis. Can return zero size areas.
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func VSplit(area image.Rectangle) (image.Rectangle, image.Rectangle) {
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width := area.Dx() / 2
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if width == 0 {
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return image.ZR, image.ZR
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}
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return image.Rect(area.Min.X, area.Min.Y, area.Min.X+width, area.Max.Y),
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image.Rect(area.Min.X+width, area.Min.Y, area.Max.X, area.Max.Y)
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}
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// abs returns the absolute value of x.
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func abs(x int) int {
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if x < 0 {
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return -x
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}
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return x
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}
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// ExcludeBorder returns a new area created by subtracting a border around the
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// provided area. Can return a zero area.
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func ExcludeBorder(area image.Rectangle) image.Rectangle {
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// If the area dimensions are smaller than this, subtracting a point for the
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// border on each of its sides results in a zero area.
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const minDim = 3
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if area.Dx() < minDim || area.Dy() < minDim {
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return image.ZR
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}
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return image.Rect(
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abs(area.Min.X+1),
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abs(area.Min.Y+1),
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abs(area.Max.X-1),
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abs(area.Max.Y-1),
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)
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}
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