Working plasma pattern

Signed-off-by: Martyn Ranyard <m@rtyn.berlin>
This commit is contained in:
Martyn 2020-05-19 12:48:47 +02:00
parent 34bb137e7b
commit 5f8e68662f
1 changed files with 57 additions and 12 deletions

View File

@ -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