A few shader samples

shaders/background.py

@@ -0,0 +1,8 @@
+import math
+from pixel import Pixel
+
+def main(pixel: Pixel, resolution: tuple, frag_coord: tuple, time: float):
+	uv = (frag_coord[0] / resolution[0], frag_coord[1] / resolution[1])
+
+	h = math.sin(uv[0] * math.pi + uv[1] * 10.0 + time + math.cos(uv[0] * uv[1] + uv[1] * 7.1823) * math.sin(uv[0] * 14.2))
+	pixel.background_color.set(h, h, h)

shaders/default.py

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+import math
+from pixel import Pixel
+
+def main(pixel: Pixel, resolution: tuple, frag_coord: tuple, time: float):
+	uv = (frag_coord[0] / resolution[0], frag_coord[1] / resolution[1])
+
+	pixel.background_color.set(
+		0.5 + 0.5 * math.cos(time + uv[0]),
+		0.5 + 0.5 * math.cos(time + uv[1] + 2),
+		0.5 + 0.5 * math.cos(time + uv[0] + 4)
+	)

shaders/eyeblower.py

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+import math
+from pixel import Pixel
+
+FREQUENCY = 20.0
+COLOR_A = (1.0, 0.5, 0.9)
+COLOR_B = (0.5, 0.1, 0.3)
+
+def distance(a: tuple, b: tuple) -> float:
+	if len(a) != len(b):
+		raise TypeError("Mismatching dimentional vector passed")
+
+	dist = 0
+	for i in range(len(a)):
+		d = b[i] - a[i]
+		dist += d * d
+
+	return dist ** 0.5
+
+def sign(v: float) -> float:
+	return 1.0 if v >= 0 else 0.0
+
+def main(pixel: Pixel, resolution: tuple, frag_coord: tuple, time: float): # https://www.shadertoy.com/view/ldX3DN
+	uv = tuple(-1.0 + 2.0 * x for x in (frag_coord[0] / resolution[0], frag_coord[1] / resolution[1]))
+
+	homo_coords = (uv[0], 2.0 * frag_coord[1] / resolution[0])
+
+	moving_origin1 = (math.sin(time * 0.7), math.sin(time * 1.7))
+	moving_origin2 = (-math.cos(time * 2.0), -math.sin(time * 3.0))
+
+	wave_point1 = math.sin( distance(moving_origin1, homo_coords) * FREQUENCY )
+	wave_point2 = math.sin( distance(moving_origin2, homo_coords) * FREQUENCY )
+
+	black_or_white1 = sign(wave_point1)
+	black_or_white2 = sign(wave_point2)
+
+	composite = black_or_white1 * black_or_white2
+
+	col = tuple(max(COLOR_A[i] * composite, COLOR_B[i]) for i in range(3))
+
+	pixel.background_color.set( *col )

shaders/ripples.py

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+import math
+from pixel import Pixel
+
+def main(pixel: Pixel, resolution: tuple, frag_coord: tuple, time: float): # https://www.shadertoy.com/view/ldX3zr
+	invAr = resolution[1] / resolution[0]
+
+	uv = (frag_coord[0] / resolution[0], frag_coord[1] / resolution[1])
+
+	col = [*uv, 0.5 + 0.5 * math.sin(time)]
+
+	x = 0.5 - uv[0]
+	y = (0.5 - uv[1]) * invAr
+
+	r = -(x * x + y * y)
+	z = 1.0 + 0.5 * math.sin((r + time * 0.035) / 0.013)
+
+	for i in range(3):
+		col[i] *= z
+
+	pixel.background_color.set( *col )

shaders/wave.py

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+import math
+from pixel import Pixel
+
+def main(pixel: Pixel, resolution: tuple, frag_coord: tuple, time: float):
+	uv = (frag_coord[0] / resolution[0], frag_coord[1] / resolution[1])
+
+	def hsv2rgb(h, s, v) -> tuple:
+		r,g,b = 0,0,0
+
+		i = int(h * 6)
+		f = h * 6 - i
+		p = v * (1 - s)
+		q = v * (1 - f * s)
+		t = v * (1 - (1 - f) * s)
+
+		o = i % 6
+
+		if o == 0:
+			r,g,b = v,t,p
+		elif o == 1:
+			r,g,b = q,v,p
+		elif o == 2:
+			r,g,b = p,v,t
+		elif o == 3:
+			r,g,b = p,q,v
+		elif o == 4:
+			r,g,b = t,p,v
+		else:
+			r,g,b = v,p,q
+
+		return r, g, b
+
+	def step(edge: float, value: float) -> float:
+		return 1.0 if value > edge else 0.0
+
+	def strip(h: float, thickness: float, y: float) -> float:
+		return step(y + h - thickness, step(1., y + h + thickness))
+
+	col = [0.0, 0.0, 0.0]
+
+	f = 0.0
+	while f < math.pi * 2:
+		a = strip(.5 + math.cos(uv[0] * 2. + time * 3.) * .15,
+						.005,
+						uv[1] + math.cos(uv[0] * 3. + time * 2. + f) * .25)
+
+		_col = hsv2rgb(f / math.pi / 2., 1., 1.)
+		for i in range(3):
+			col[i] += a * _col[i]
+
+		f += math.pi / 4.
+	
+	pixel.background_color.set(*col)