68 lines
1.3 KiB
Go
68 lines
1.3 KiB
Go
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package patterns
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import "math"
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type RGBcolor = [3]byte
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func plasmaRGBFromVal(val byte) (byte, byte, byte) {
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var r byte
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var g byte
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var b byte
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if val < 85 {
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r = val * 3
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g = 255 - r
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b = 0
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} else if val < 170 {
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b = (val - 85) * 3
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r = 255 - b
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g = 0
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} else {
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g = (val - 170) * 3
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b = 255 - g
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r = 0
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}
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return r, g, b
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}
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func LinearPlasma(l int) []byte {
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line := make([]byte, l*3)
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for i := 0; i < l*3; i += 3 {
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val := byte(i % 256)
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r, g, b := plasmaRGBFromVal(val)
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line[i] = r
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line[i+1] = g
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line[i+2] = b
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}
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return line
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}
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var offset float64 = 0.5
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func PlasmaPanel(w int, h int, speed uint16) [][]RGBcolor {
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grid := make([][]RGBcolor, w)
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for i := 0; i < w; i++ {
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grid[i] = make([]RGBcolor, h)
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}
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scale := math.Pi * 2.0 / float64(w)
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step := float64(5 * speed / 40)
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offset -= step
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if offset < 0 {
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offset += 1.0
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}
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for y := 0; y < h; y++ {
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for x := 0; x < w; x++ {
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u := math.Cos((float64(x) + offset) * scale)
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v := math.Cos((float64(y) + offset) * scale)
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w := math.Cos((float64(w) + offset) * scale)
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e := (u + v + w + 3.0) / 6.0
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r, g, b := plasmaRGBFromVal(byte((offset + e) * 255))
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var rgb [3]byte
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rgb[0] = r
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rgb[1] = g
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rgb[2] = b
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grid[x][y] = rgb
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}
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}
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return grid
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}
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