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New App: Perlin Noise generator #368

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9 changes: 9 additions & 0 deletions apps/perlinnoise/manifest.yaml
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Original file line number Diff line number Diff line change
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---
id: perlin-noise
name: Perlin Noise
summary: Perlin noise for your Tronbyt
desc: Set the vibe with beautiful, complex, colorful animated noise produced with math!
author: rektdeckard
fileName: perlin_noise.star
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medium

The fileName does not match the app's directory name. This violates the repository's file naming conventions.

fileName: perlinnoise.star
References
  1. The Starlark file containing the main() function should have the same base name as its containing directory. (link)

packageName: perlinnoise

218 changes: 218 additions & 0 deletions apps/perlinnoise/perlin_noise.star
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"""
Applet: Perlin Noise
Summary: Perlin noise for your Tronbyt
Description: Set the vibe with beautiful, complex, colorful animated noise produced with math!
Author: rektdeckard
"""

load("render.star", "render")
load("animation.star", "animation")
load("schema.star", "schema")
load("math.star", "math")
load("humanize.star", "humanize")

SCALE = 40
SCALE_T = "40"
SPEED = 1 / 30
HUE = "#EB6E21"
FRAMES = 160
FRAMES_PER_VIEW = 1

def get_schema():
return schema.Schema(
version = "1",
fields = [
schema.Color(
id = "color",
name = "Color",
desc = "Hue of the noise.",
icon = "brush",
default = HUE,
),
schema.Text(
id = "scale",
name = "Scale",
desc = "Scale of the noise.",
icon = "ruler",
default = SCALE_T,
)
],
)

PERMUTATION = [151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7, 225,140, 36, 103, 30, 69, 142, 8, 99, 37, 240, 21, 10, 23, 190, 6, 148, 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117, 35, 11, 32, 57, 177, 33, 88, 237, 149, 56, 87, 174, 20, 125, 136, 171, 168, 68, 175, 74, 165, 71, 134, 139, 48, 27, 166, 77, 146, 158, 231, 83, 111, 229, 122, 60, 211, 133, 230, 220, 105, 92, 41, 55, 46, 245, 40, 244, 102, 143, 54, 65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208, 89, 18, 169, 200, 196, 135, 130, 116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3, 64, 52, 217, 226, 250, 124, 123, 5, 202, 38, 147, 118, 126, 255, 82, 85, 212, 207, 206, 59, 227, 47, 16, 58, 17, 182, 189, 28, 42, 223, 183, 170, 213, 119, 248, 152, 2, 44, 154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9, 129, 22, 39, 253, 19, 98, 108, 110, 79, 113, 224, 232, 178, 185, 112, 104, 218, 246, 97, 228, 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241, 81, 51, 145, 235, 249, 14, 239, 107, 49, 192, 214, 31, 181, 199, 106, 157, 184, 84, 204, 176, 115, 121, 50, 45, 127, 4, 150, 254, 138, 236, 205, 93, 222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 215, 61, 156, 180]
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medium

To improve readability and maintainability, large constant data structures like PERMUTATION (and GRAD_3) should be moved to a separate file (e.g., perlin_data.star) and loaded using a load() statement. This follows general best practices for this repository.

References
  1. To improve readability and maintainability, move large data structures into a separate file and load them into the main application logic.


GRAD_3 = [[1.0, 1.0, 0.0], [-1.0, 1.0, 0.0], [1.0, -1.0, 0.0], [-1.0, -1.0, 0.0], [1.0, 0.0, 1.0], [-1.0, 0.0, 1.0], [1.0, 0.0, -1.0], [-1.0, 0.0, -1.0], [0.0, 1.0, 1.0], [0.0, -1.0, 1.0], [0.0, 1.0, -1.0], [0.0, -1.0, -1.0]]

def grad_dot2(grad, a, b):
return grad[0] * a + grad[1] * b

def grad_dot3(grad, a, b, c):
return grad[0] * a + grad[1] * b + grad[2] * c

def lerp(mn, mx, v):
return (mn + (mx - mn) * v)

perm = [0 for x in range(512)]
grads = [0 for x in range(512)]
F2 = 0.5 * (math.sqrt(3) - 1)
G2 = (3 - math.sqrt(3)) / 6
F3 = 1 / 3
G3 = 1 / 6

def reseed(seed):
if seed > 0 and seed < 1:
seed *= 655536
se = math.floor(seed)
if se < 256:
se |= se << 8
for i in range(256):
v = 0
if i & 1:
v = PERMUTATION[i] ^ (se & 255)
else:
v = PERMUTATION[i] * ((se >> 8) & 255)
perm[i + 256] = v
perm[i] = v
grads[i + 256] = GRAD_3[v % 12]
grads[i] = grads[i + 256]

def simp(x, y, z):
s = (x + y + z) * F3
i = math.floor(x + s)
j = math.floor(y + s)
k = math.floor(z + s)
t = (i + j + k) * G3
x0 = x - i + t
y0 = y - j + t
z0 = z - k + t
i1 = 0
j1 = 0
k1 = 0
i2 = 0
j2 = 0
k2 = 0
if x0 > y0:
if y0 > z0:
i1 = 1
j1 = 0
k1 = 0
i2 = 1
j2 = 1
k2 = 0
elif x0 > z0:
i1 = 1
j1 = 0
k1 = 0
i2 = 1
j2 = 0
k2 = 1
else:
i1 = 0
j1 = 0
k1 = 1
i2 = 1
j2 = 0
k2 = 1
else:
if y0 < z0:
i1 = 0
j1 = 0
k1 = 1
i2 = 0
j2 = 1
k2 = 1
elif x0 < z0:
i1 = 0
j1 = 1
k1 = 0
i2 = 0
j2 = 1
k2 = 1
else:
i1 = 0
j1 = 1
k1 = 0
i2 = 1
j2 = 1
k2 = 0
x1 = x0 - i1 + G3
y1 = y0 - j1 + G3
z1 = z0 - k1 + G3
x2 = x0 - i2 + 2 * G3
y2 = y0 - j2 + 2 * G3
z2 = z0 - k2 + 2 * G3
x3 = x0 - 1 + 3 * G3
y3 = y0 - 1 + 3 * G3
z3 = z0 - 1 + 3 * G3
ii = math.floor(i) & 255
jj = math.floor(j) & 255
kk = math.floor(k) & 255
gi0 = grads[ii + perm[jj + perm[kk]]]
gi1 = grads[ii + i1 + perm[jj + j1 + perm[kk + k1]]]
gi2 = grads[ii + i2 + perm[jj + j2 + perm[kk + k2]]]
gi3 = grads[ii + 1 + perm[jj + 1 + perm[kk + 1]]]
t0 = 0.6 - x0 * x0 - y0 * y0 - z0 * z0
if t0 < 0.0:
n0 = 0.0
else:
t0 *= t0
n0 = t0 * t0 * grad_dot3(gi0, x0, y0, z0)
t1 = 0.6 - x1 * x1 - y1 * y1 - z1 * z1
if t1 < 0.0:
n1 = 0.0
else:
t1 *= t1
n1 = t1 * t1 * grad_dot3(gi1, x1, y1, z1)
t2 = 0.6 - x2 * x2 - y2 * y2 - z2 * z2
if t2 < 0.0:
n2 = 0.0
else:
t2 *= t2
n2 = t2 * t2 * grad_dot3(gi2, x2, y2, z2)
t3 = 0.6 - x3 * x3 - y3 * y3 - z3 * z3
if t3 < 0.0:
n3 = 0.0
else:
t3 *= t3
n3 = t3 * t3 * grad_dot3(gi3, x3, y3, z3)
return 32 * (n0 + n1 + n2 + n3)

reseed(0)

def flatten(iter):
list = []
if type(iter) != "list":
list.append(iter)
else:
for it in iter:
if type(it) != "list":
list.append(it)
else:
list.extend(flatten(it))
return list

def color_for_pixel(x, y, t, c, s):
b = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F"]
val = simp(x / s, y / s, t * SPEED)
val = math.floor((val + 1) * 128)
h = (val & 0xF0) >> 4
l = val & 0x0F
# print([h, l])
return c + b[h] + b[l]
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critical

The color string concatenation is incorrect. The color value from the configuration is a full hex string (e.g., #RRGGBB). Appending two more hex characters results in an invalid color string that will prevent the app from rendering correctly. To modulate a component of the color (e.g., the blue part), you should slice the original string.

return c[:5] + b[h] + b[l]


def main(config):
color = config.str("color");
if not color:
color = HUE
scale = config.str("scale");
if not scale:
scale = SCALE
scale = int(scale)

return render.Root(
child = render.Animation(
children = flatten([[render.Column([
render.Row([
render.Box(color = color_for_pixel(x, y, t, color, scale), width = 1, height = 1) for x in range(64)]) for y in range(32)])] * FRAMES_PER_VIEW for t in range(FRAMES)])
)
)
Comment on lines +203 to +218
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high

The main function has several areas for improvement regarding robustness, style, and features:

  • 2x Support: The app lacks 2x support, using hardcoded 64x32 dimensions. The style guide encourages 2x support, and it seems intended based on your PR description. This can be added by using render.get_render_dimensions().
  • Input Validation: The scale configuration is not validated. A non-numeric input will crash the app. This should be handled with a try/except block.
  • Code Simplification: The children list for render.Animation is generated using a complex flatten helper. This can be simplified to a direct list comprehension, making the flatten function and FRAMES_PER_VIEW constant unnecessary.
  • Style: Lines 204 and 207 contain unnecessary semicolons.

Here is a revised main function that addresses these points. You will also need to add canvas to your load statement at the top of the file: load("render.star", "render", "canvas").

def main(config):
	color = config.get("color") or HUE

	scale = SCALE
	scale_str = config.get("scale")
	if scale_str:
		try:
			scale = int(scale_str)
		except ValueError:
			pass # Fallback to default scale

	dims = render.get_render_dimensions()

	return render.Root(
		child = render.Animation(
			children = [render.Column([
				render.Row([
					render.Box(color = color_for_pixel(x, y, t, color, scale), width = 1, height = 1) for x in range(dims.width)]) for y in range(dims.height)]) for t in range(FRAMES)]
		)
	)
References
  1. We encourage app developers to add 2x support for their apps. Please refer to the Pixlet documentation on 2x apps for detailed guidelines. A file with a main() function that doesn't import the "canvas" object from "render.star" is likely an app without 2x support. (link)

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