From 5f8e68662f1165f92248ee5c6f9905278fee7b0f Mon Sep 17 00:00:00 2001 From: Martyn Ranyard Date: Tue, 19 May 2020 12:48:47 +0200 Subject: [PATCH] Working plasma pattern Signed-off-by: Martyn Ranyard --- internal/patterns/plasma.go | 69 ++++++++++++++++++++++++++++++------- 1 file changed, 57 insertions(+), 12 deletions(-) diff --git a/internal/patterns/plasma.go b/internal/patterns/plasma.go index 442b5ba..dd95d37 100755 --- a/internal/patterns/plasma.go +++ b/internal/patterns/plasma.go @@ -1,9 +1,15 @@ package patterns -import "math" +import ( + "math" +) type RGBcolor = [3]byte +func floatColorToIntColor(val float64) byte { + return byte(val*256 - 0.5) +} + func plasmaRGBFromVal(val byte) (byte, byte, byte) { var r byte var g byte @@ -24,7 +30,6 @@ func plasmaRGBFromVal(val byte) (byte, byte, byte) { return r, g, b } - func LinearPlasma(l int) []byte { line := make([]byte, l*3) for i := 0; i < l*3; i += 3 { @@ -37,26 +42,66 @@ func LinearPlasma(l int) []byte { return line } -var offset float64 = 0.5 +func linearFromVal(val byte) (byte, byte, byte) { + var r byte = val + var g byte = 0 + var b byte = 0 + return r, g, b +} + +func positiveModF(val float64) float64 { + _, val = math.Modf(val) + if val < 0 { + return val + 1.0 + } + return val +} + +func colorPlasmaFromFloatVal(val float64) (byte, byte, byte) { + var r byte + var g byte + var b byte + val = positiveModF(val) * 3.0 + if val < 1.0 { + r = floatColorToIntColor(val) + g = floatColorToIntColor(1.0 - val) + b = 0 + } else if val < 2.0 { + b = floatColorToIntColor(val - 1.0) + r = floatColorToIntColor(1.0 - (val - 1.0)) + g = 0.0 + } else { + g = floatColorToIntColor(val - 2.0) + b = floatColorToIntColor(1.0 - (val - 2.0)) + r = 0.0 + } + return r, g, b +} + +var palletteOffset float64 = 0.0 func PlasmaPanel(w int, h int, speed uint16) [][]RGBcolor { grid := make([][]RGBcolor, w) for i := 0; i < w; i++ { grid[i] = make([]RGBcolor, h) } - scale := math.Pi * 2.0 / float64(w) - step := float64(5 * speed / 40) - offset -= step - if offset < 0 { - offset += 1.0 + + // pbrook didn't say what DT is for... so it resolves to 0.05 + palletteOffset -= 0.05 / 1.0 + if palletteOffset < 0 { + palletteOffset += 1.0 } + + offset := 0.5 // center offset + scale := math.Pi * 2.0 / float64(w) + for y := 0; y < h; y++ { for x := 0; x < w; x++ { u := math.Cos((float64(x) + offset) * scale) v := math.Cos((float64(y) + offset) * scale) - w := math.Cos((float64(w) + offset) * scale) - e := (u + v + w + 3.0) / 6.0 - r, g, b := plasmaRGBFromVal(byte((offset + e) * 255)) + j := math.Cos(offset * scale) // 2D - No Z + e := (u + v + j + 3.0) / 6.0 + r, g, b := colorPlasmaFromFloatVal(palletteOffset + e) var rgb [3]byte rgb[0] = r rgb[1] = g @@ -65,4 +110,4 @@ func PlasmaPanel(w int, h int, speed uint16) [][]RGBcolor { } } return grid -} \ No newline at end of file +}