def TRIANGLE_DEMO():
""" Draw a set of axes and a triangle. Perform a series of random transformations
on the triangle and display the results.
"""
A = Point(143, 52)
B = Point(17, 96.5)
C = Point(0, 0)
for i in range(10):
# Create random transformation
angle = random.random() * 2 * math.pi
scale = random.random() * 3
delX = (random.random() - 0.5) * 200
delY = (random.random() - 0.5) * 200
translate = Point(delX, delY)
transform = Transform(translate, angle, scale)
# Transform the triangle
A_ = transform.transform(A)
B_ = transform.transform(B)
C_ = transform.transform(C)
# From the line A-B and the transformed line A'-B', determine what the transformation was
# This should be the same as the original transformation
trans_calc = Transform.line_mapping(A, B, A_, B_)
print("Angle: {:.2f}; {:.2f}".format(rad_to_deg(angle), rad_to_deg(trans_calc.rot)))
print("Trans: ({}); ({})".format(translate, trans_calc.trans))
print("Zoom: {:.2f}; {:.2f}".format(scale, trans_calc.zoom))
# Display on image
image = Image.blank(1000, 800)
image.draw_offset = IMG_CENTER
draw_axes(image, 300)
# Draw original triangle
image.draw_line(A, B, Color.Red(), 5)
image.draw_line(C, B, Color.Red(), 5)
image.draw_line(A, C, Color.Red(), 5)
#Draw transformed triangle
image.draw_line(A_, B_, Color.Green())
image.draw_line(A_, C_, Color.Green())
image.draw_line(C_, B_, Color.Green())
# Check that the reverse transformation works properly
A__ = transform.reverse(A_)
B__ = transform.reverse(B_)
C__ = transform.reverse(C_)
# Draw the reverse transformation - this should overlap the origianl triangle
image.draw_line(A__, B__, Color.Green(), 1)
image.draw_line(A__, C__, Color.Green(), 1)
image.draw_line(C__, B__, Color.Green(), 1)
# Write the transformation on the image
image.draw_text(transform.__str__(), Point(-450, 350), Color.White(), centered=False, scale=0.5, thickness=1)
# Show the image
image.popup()
