47 lines
821 B
Go
47 lines
821 B
Go
package raster
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// Line draws line by Bresenham's algorithm.
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func (b *Bitmap) Line(x0, y0, x1, y1 int, p Pixel) {
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// implemented straight from WP pseudocode
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dx := x1 - x0
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if dx < 0 {
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dx = -dx
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}
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dy := y1 - y0
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if dy < 0 {
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dy = -dy
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}
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var sx, sy int
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if x0 < x1 {
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sx = 1
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} else {
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sx = -1
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}
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if y0 < y1 {
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sy = 1
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} else {
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sy = -1
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}
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err := dx - dy
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for {
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b.SetPx(x0, y0, p)
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if x0 == x1 && y0 == y1 {
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break
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}
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e2 := 2 * err
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if e2 > -dy {
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err -= dy
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x0 += sx
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}
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if e2 < dx {
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err += dx
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y0 += sy
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}
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}
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}
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func (b *Bitmap) LineRgb(x0, y0, x1, y1 int, c Rgb) {
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b.Line(x0, y0, x1, y1, c.Pixel())
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}
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