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"""2D drawing examples."""
import sys
from random import randint
import sdl2
import sdl2.ext
# Draws random lines on the passed surface
def draw_lines(surface, width, height):
# Fill the whole surface with a black color.
sdl2.ext.fill(surface, 0)
for x in range(15):
# Create a set of four random points for drawing the line.
x1, x2 = randint(0, width), randint(0, width)
y1, y2 = randint(0, height), randint(0, height)
# Create a random color.
color = sdl2.ext.Color(randint(0, 255),
randint(0, 255),
randint(0, 255))
# Draw the line with the specified color on the surface.
# We also could create a set of points to be passed to the function
# in the form
#
# line(surface, color, (x1, y1, x2, y2, x3, y3, x4, y4, ...))
# ^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^
# first line second line
sdl2.ext.line(surface, color, (x1, y1, x2, y2))
# Draws random, filled rectangles on the passed surface
def draw_rects(surface, width, height):
# Fill the whole surface with a black color.
sdl2.ext.fill(surface, 0)
for k in range(15):
# Create a set of four random points for the edges of the rectangle.
x, y = randint(0, width), randint(0, height)
w, h = randint(1, width // 2), randint(1, height // 2)
# Create a random color.
color = sdl2.ext.Color(randint(0, 255),
randint(0, 255),
randint(0, 255))
# Draw the filled rect with the specified color on the surface.
# We also could create a set of points to be passed to the function
# in the form
#
# fill(surface, color, ((x1, y1, x2, y2), (x3, y3, x4, y4), ...))
# ^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^
# first rect second rect
sdl2.ext.fill(surface, color, (x, y, w, h))
def run():
# You know those from the helloworld.py example.
# Initialize the video subsystem, create a window and make it visible.
sdl2.ext.init()
window = sdl2.ext.Window("2D drawing primitives", size=(800, 600))
window.show()
# As in colorpalettes.py, explicitly acquire the window's surface to
# draw on.
windowsurface = window.get_surface()
# We implement the functionality as it was done in colorpalettes.py and
# utilise a mapping table to look up the function to be executed, together
# with the arguments they should receive
functions = ((draw_lines, (windowsurface, 800, 600)),
(draw_rects, (windowsurface, 800, 600))
)
# A storage variable for the function we are currently on, so that we know
# which function to execute next.
curindex = 0
draw_lines(windowsurface, 800, 600)
# The event loop is nearly the same as we used in colorpalettes.py. If you
# do not know, what happens here, take a look at colorpalettes.py for a
# detailled description.
running = True
while running:
events = sdl2.ext.get_events()
for event in events:
if event.type == sdl2.SDL_QUIT:
running = False
break
if event.type == sdl2.SDL_MOUSEBUTTONDOWN:
curindex += 1
if curindex >= len(functions):
curindex = 0
# In contrast to colorpalettes.py, our mapping table consists
# of functions and their arguments. Thus, we get the currently
# requested function and argument tuple and execute the
# function with the arguments.
func, args = functions[curindex]
func(*args)
break
window.refresh()
sdl2.ext.quit()
return 0
if __name__ == "__main__":
sys.exit(run())
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