implemented Breathing effect, TODO: rework animation speed

rgbanimations/utilFuncs.go

@@ -36,3 +36,45 @@ func HSVToRGB(h, s, v uint8) (r, g, b, a uint8) {
 func Scale8(i uint8, scale uint8) uint8 {
 	return uint8((uint16(i) * uint16(scale)) >> 8)
 }
+
+func Scale16by8(i uint16, scale uint8) uint16 {
+	return (i * (1 + uint16(scale))) >> 8
+}
+
+func Abs8(i int8) uint8 {
+	if i < 0 {
+		return uint8(-i)
+	}
+	return uint8(i)
+}
+
+func Sin8(theta uint8) uint8 {
+	offset := theta
+	if theta&0x40 != 0 {
+		offset = 0xFF - offset
+	}
+	offset &= 0x3F
+
+	secoffset := offset & 0x0F
+	if theta&0x40 != 0 {
+		secoffset++
+	}
+
+	section := offset >> 4
+	s2 := section * 2
+	var p = []uint8{0, 49, 49, 41, 90, 27, 117, 10}
+	b := p[s2]
+	m16 := p[s2+1]
+
+	mx := (m16 * secoffset) >> 4
+
+	y := int8(mx + b)
+	if theta&0x80 != 0 {
+		y = -y
+	}
+
+	y += 127
+	y++
+
+	return uint8(y)
+}

rgbanimations/vialrgbBreathing.go

@@ -0,0 +1,24 @@
+package rgbanimations
+
+import keyboard "github.com/percyjw-2/tinygo-keyboard"
+
+func GetBreathingAnim() keyboard.RgbAnimation {
+	return keyboard.RgbAnimation{
+		AnimationFunc: vialRGBBreathing,
+		AnimationType: keyboard.VIALRGB_EFFECT_BREATHING,
+	}
+}
+
+var time = uint16(0)
+
+func vialRGBBreathing(matrix *keyboard.RGBMatrix) {
+	v := Scale8(Abs8(int8(Sin8(uint8(time))-128))*8, matrix.CurrentValue)
+	r, g, b, a := HSVToRGB(matrix.CurrentHue, matrix.CurrentSaturation, v)
+	for _, val := range matrix.LedMatrixVals {
+		val.R = r
+		val.G = g
+		val.B = b
+		val.A = a
+	}
+	time++
+}