import cairo
import math
import matplotlib.pyplot as plt
import numpy as np

WIDTH, HEIGHT = 256, 256

# Create a surface whith is what we draw on, image surface renders to memory
surface = cairo.ImageSurface(cairo.Format.ARGB32, WIDTH, HEIGHT)
ctx = cairo.Context(surface)

# normlize the context
ctx.scale(WIDTH, HEIGHT)
ctx.rotate(0.3)

pat = cairo.SolidPattern(1.0, 0.0, 0.0, 1.0)
#pat = cairo.LinearGradient(0.0, 0.0, 0.0, 1.0)
#pat.add_color_stop_rgba(1, 0.7, 0, 0, 0.5)  # First stop, 50% opacity
#pat.add_color_stop_rgba(0, 0.9, 0.7, 0.2, 1)  # Last stop, 100% opacity

ctx.rectangle(0, 0, 1, 1)  # Rectangle(x0, y0, x1, y1)
ctx.set_source(pat)
ctx.fill()

ctx.translate(0.1, 0.1)  # Changing the current transformation matrix

ctx.move_to(0, 0)
# Arc(cx, cy, radius, start_angle, stop_angle)
ctx.arc(0.2, 0.1, 0.1, -math.pi / 2, 0)
ctx.line_to(0.5, 0.1)  # Line to (x,y)
# Curve(x1, y1, x2, y2, x3, y3)
ctx.curve_to(0.5, 0.2, 0.5, 0.4, 0.2, 0.8)
ctx.close_path()

ctx.set_source_rgb(0.3, 0.2, 0.5)  # Solid color
ctx.set_line_width(0.02)
ctx.stroke()

surface.write_to_png("example.png")  # Output to PNG


buf = surface.get_data()
data = np.ndarray(
    shape=(WIDTH, HEIGHT, 4),
    dtype=np.uint8,
    buffer=buf
)
# transform back
data = data[:, :, [2, 1, 0, 3]]
print(data[-1])

plt.imshow(data)
plt.show()
