35 lines
868 B
Go
35 lines
868 B
Go
package pixelflut
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import (
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"fmt"
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"image"
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"image/color"
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)
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// CommandsFromImage converts an image to the respective pixelflut commands
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func CommandsFromImage(img image.Image, offset image.Point) (commands Commands) {
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b := img.Bounds()
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commands = make([][]byte, b.Size().X*b.Size().Y)
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numCmds := 0
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for x := b.Min.X; x < b.Max.X; x++ {
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for y := b.Min.Y; y < b.Max.Y; y++ {
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// ensure we're working with RGBA colors (non-alpha-pre-multiplied)
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c := color.NRGBAModel.Convert(img.At(x, y)).(color.NRGBA)
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// ignore transparent pixels
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if c.A == 0 {
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continue
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}
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// @incomplete: also send alpha? -> bandwidth tradeoff
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// @speed: this sprintf call is quite slow..
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cmd := fmt.Sprintf("PX %d %d %.2x%.2x%.2x\n",
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x + offset.X, y + offset.Y, c.R, c.G, c.B)
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commands[numCmds] = []byte(cmd)
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numCmds++
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}
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}
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return commands[:numCmds]
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}
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