85 lines
1.7 KiB
Go
85 lines
1.7 KiB
Go
package imgrow
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import (
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"image"
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"image/color"
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"image/draw"
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)
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// DrawImage returns an image that is 'img' where (only) drawing is scalad by 'scalar'.
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// The actual image stays the same size.
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// Only the drawing is scaled.
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//
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// So, for example:
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//
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// var newImage draw.Image = imgrow.Image(2, oldImage)
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//
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// ... would return a new image that is just like 'oldImage' except any drawing on it is 2 times as big.
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//
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// Note that if you are trying to try a complex object and want the top-left corner to be at the original (unscaled) (x,y)
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// rather (rather than the scaled position) then you need to move the top-left corner to:
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//
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// xAdjusted := x / scalar
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// yAdjusted := y / scalar
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func DrawImage(scalar int, img draw.Image) draw.Image {
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return internalDrawImage {
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img:img,
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scalar:scalar,
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}
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}
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var _ draw.Image = &internalDrawImage{}
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type internalDrawImage struct {
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img draw.Image
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scalar int
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}
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func (receiver internalDrawImage) At(x, y int) color.Color {
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var img image.Image = receiver.img
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if nil == img {
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return nil
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}
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return img.At(x, y)
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}
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func (receiver internalDrawImage) Bounds() image.Rectangle {
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var img image.Image = receiver.img
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if nil == img {
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return image.Rectangle{}
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}
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return img.Bounds()
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}
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func (receiver internalDrawImage) ColorModel() color.Model {
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var img image.Image = receiver.img
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if nil == img {
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return nil
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}
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return img.ColorModel()
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}
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func (receiver internalDrawImage) Set(x int, y int, c color.Color) {
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var img draw.Image = receiver.img
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if nil == img {
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return
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}
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var scalar int = receiver.scalar
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xScaled, yScaled := scaleXY(scalar, x, y)
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for yi := yScaled; yi < (yScaled + scalar); yi++ {
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for xi := xScaled; xi < (xScaled + scalar); xi++ {
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img.Set(xi, yi, c)
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}
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}
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}
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