Develop Reference

How to make sprite move to point along a curve in pygame

I'm doing a pygame project for practice and I need a sprite to move to some point on screen and I did it, but it moves in a straight line and I would like to learn how to make it move to the same point in a curve.
def move_to_point(self, dest_rect, speed, delta_time):
# Calculates relative rect of dest
rel_x = self.rect.x - dest_rect[0]
rel_y = self.rect.y - dest_rect[1]
# Calculates diagonal distance and angle from entity rect to destination rect
dist = math.sqrt(rel_x**2 + rel_y**2)
angle = math.atan2( - rel_y, - rel_x)
# Divides distance to value that later gives apropriate delta x and y for the given speed
# there needs to be at least +2 at the end for it to work with all speeds
delta_dist = dist / (speed * delta_time) + 5
print(speed * delta_time)
# If delta_dist is greater than dist entety movement is jittery
if delta_dist > dist:
delta_dist = dist
# Calculates delta x and y
delta_x = math.cos(angle) * (delta_dist)
delta_y = math.sin(angle) * (delta_dist)
if dist > 0:
self.rect.x += delta_x
self.rect.y += delta_y
This movement looks like
and I would like it to be like

There are many many ways to achieve what you want. One possibility is a Bézier curve:
def bezier(p0, p1, p2, t):
px = p0[0]*(1-t)**2 + 2*(1-t)*t*p1[0] + p2[0]*t**2
py = p0[1]*(1-t)**2 + 2*(1-t)*t*p1[1] + p2[1]*t**2
return px, py
p0, p1 and p2 are the control points and t is a value in the range [0,0, 1,0] indicating the position along the curve. p0 is the start of the curve and p2 is the end of the curve. If t = 0, the point returned by the bezier function is equal to p0. If t=1, the point returned is equal to p2.
Also see PyGameExamplesAndAnswers - Shape and contour - Bezier
Minimal example:
import pygame
pygame.init()
window = pygame.display.set_mode((500, 500))
clock = pygame.time.Clock()
def bezier(p0, p1, p2, t):
px = p0[0]*(1-t)**2 + 2*(1-t)*t*p1[0] + p2[0]*t**2
py = p0[1]*(1-t)**2 + 2*(1-t)*t*p1[1] + p2[1]*t**2
return px, py
dx = 0
run = True
while run:
clock.tick(100)
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
pts = [(100, 100), (100, 400), (400, 400)]
window.fill(0)
for p in pts:
pygame.draw.circle(window, (255, 255, 255), p, 5)
for i in range(101):
x, y = bezier(*pts, i / 100)
pygame.draw.rect(window, (255, 255, 0), (x, y, 1, 1))
p = bezier(*pts, dx / 100)
dx = (dx + 1) % 101
pygame.draw.circle(window, (255, 0, 0), p, 5)
pygame.display.update()
pygame.quit()
exit()

How to give a warning when a moving object deviates from a path by a specific margin?

In my pygame-code, I have a drone that is supposed to follow a flight path.
I used pygame.draw.lines to draw lines between specified points. Now, I have a flight path with 10 points where after each point the path angle changes (a bit like a zigzag). The player can move the drone by pressing the keys.
My goal is to print a warning once the drone deviates from the path, e.g. by +/-30. I have been racking my brain for two days but can't come up with a condition to detect a deviation. I just can't figure out how to approach this.
I can determine the drone's x-coordinate at any time but how do I determine the offset from the path? I have attached an image to visualize my problem.
Edit:
As I am a beginner my code is a mess but when copy-pasting it, I guess only the lines 35-91 are interesting. Thank you for any kind of advice in advance!!
import pygame
import pygame.gfxdraw
import random
import sys
import math
pygame.init()
# Define some colors
black = (0,0,0)
white = (255,255,255)
red = (255,0,0)
red_transp = (255,0,0, 150)
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
BLUE = (0, 0, 255)
GREEN = (0, 255, 0)
RED = (255, 0, 0)
X = 0
Y = 250
#Display
display_width, display_height = 1200, 700
h_width, h_height = display_width/2, display_height/2
gameDisplay = pygame.display.set_mode((display_width,display_height))
pygame.display.set_caption('Game Display')
#Drone Sprite Image Load Function
droneImg_interim = pygame.image.load('drone.png')
droneImg = pygame.transform.scale(droneImg_interim, [50,50])
drone_width, drone_height = droneImg.get_rect().size
#Create 11 Waypoints with the same coordinates
p1=[X, Y]
p2=[X, Y]
p3=[X, Y]
p4=[X, Y]
p5=[X, Y]
p6=[X, Y]
p7=[X, Y]
p8=[X, Y]
p9=[X, Y]
p10=[X, Y]
p11=[X, Y]
pointlist = [p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11]
x_min=drone_width
x_max=100
#Setting new x-coordinate for each point
for i in pointlist:
i[0] = random.randrange(x_min, x_max)
x_min+=250
x_max+=250
#Setting new y-coordinate for each point
for i in range(len(pointlist)):
if i == 0:
pointlist[i][1] = random.randrange(200, 400)
else:
prev = pointlist[i-1][1]
pointlist[i][1] = random.randrange(200, prev+100)
#Plotting pointlist on gameDisplay and connecting dots
def flightpath(pointlist):
pygame.draw.lines(gameDisplay, (255, 0, 0), False, pointlist, 2)
def margin(x):
for i in range(len(pointlist)-1):
p1_x = pointlist[i][0]
p2_x = pointlist[i+1][0]
p1_y = pointlist[i][1]
p2_y = pointlist[i+1][1]
distance_x = p2_x - p1_x
distance = math.sqrt((p2_x-p1_x)**2+(p2_y-p1_y)**2)
halfwaypoint_x = math.sqrt((p2_x - p1_x)**2)/2 + p1_x
halfwaypoint_y = math.sqrt((p2_y - p1_y)**2)/2 + p1_y
if p2_y < p1_y:
angle_rad = math.acos(distance_x/distance)
elif p2_y > p1_y:
angle_rad = 0 - math.acos(distance_x/distance)
angle_deg = math.degrees(angle_rad)
rect_width = distance
rect_height = 60
"""
This part of the code is meant for displaying the margins (the rectangles) around the flight path on the display.
marginSize = (rect_width, rect_height)
surface = pygame.Surface(marginSize, pygame.SRCALPHA)
surface.fill((255,0,0,25))
rotated_surface = pygame.transform.rotate(surface, angle_deg)
#new_rect = rotated_surface.get_rect(center = surface.get_rect(center = ((pointlist[i][0], pointlist[i][1]))).center)
new_rect = rotated_surface.get_rect(center = surface.get_rect(center = ((halfwaypoint_x, halfwaypoint_y))).center)
#gameDisplay.blit(rotated_surface, new_rect)
"""
#Placing drone on the screen
def drone(x,y):
rect = droneImg.get_rect ()
rect.center=(x, y)
gameDisplay.blit(droneImg,rect)
def displayMSG(value,ttext,posx,posy):
myFont = pygame.font.SysFont("Verdana", 12)
Label = myFont.render(ttext, 1, black)
Value = myFont.render(str(value), 1, black)
gameDisplay.blit(Label, (posx, posy))
gameDisplay.blit(Value, (posx + 100, posy))
#Main Loop Object
def game_loop():
global X, Y, FThrustX, FThrustY, FDragY, Time
FThrustY = 0
gameExit = False
while not gameExit:
#Event Checker (Keyboard, Mouse, etc.)
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_ESCAPE:
pygame.quit()
sys.exit()
keys = pygame.key.get_pressed() #checking pressed keys
if keys[pygame.K_LEFT]:
X -= 1
if keys[pygame.K_RIGHT]:
X +=1
if keys[pygame.K_DOWN]:
Y += 1
if keys[pygame.K_UP]:
Y -=1
#Display Background Fill
gameDisplay.fill(white)
#Plot flightpath
flightpath(pointlist)
#YS: Determine the position of the mouse
current_pos_x, current_pos_y = pygame.mouse.get_pos()
displayMSG(current_pos_x,'x:',20,665)
displayMSG(current_pos_y,'y:',20,680)
#Plot margin
margin(5)
#Move Drone Object
drone(X,Y)
#Determine the position of the mouse
current_pos_x, current_pos_y = pygame.mouse.get_pos()
#No exceeding of display edge
if X > display_width - drone_width: X = display_width - drone_width
if Y > display_height - drone_height: Y = display_height - drone_height
if X < drone_width: X = drone_width
if Y < drone_height: Y = drone_height
pygame.display.update()
#MAIN
game_loop()
pygame.quit()
sys.exit()

One approach is to find the minimum distance between the center of the drone and the line.
Write the function that calculates the minimum distance from a point to a line segment. To do this, use pygame.math.Vector2 and the Dot product:
def distance_point_linesegment(pt, l1, l2):
LV = pygame.math.Vector2(l2[0] - l1[0], l2[1] - l1[1])
PV = pygame.math.Vector2(pt[0] - l1[0], pt[1]- l1[1])
dotLP = LV.dot(PV)
if dotLP < 0:
return PV.length()
if dotLP > LV.length_squared():
return pygame.math.Vector2(pt[0] - l2[0], pt[1]- l2[1]).length()
NV = pygame.math.Vector2(l1[1] - l2[1], l2[0] - l1[0])
return abs(NV.normalize().dot(PV))
Find the line segment with the shortest distance in a loop:
def minimum_distance(pt, pointlist):
min_dist = -1
for i in range(len(pointlist)-1):
dist = distance_point_linesegment(pt, pointlist[i], pointlist[i+1])
if i == 0 or dist < min_dist:
min_dist = dist
return min_dist
Create an alert when the distance exceeds a certain threshold:
def game_loop():
# [...]
while not gameExit:
# [...]
dist_to_path = minimum_distance((X, Y), pointlist)
if dist_to_path > 25:
pygame.draw.circle(gameDisplay, (255, 0, 0), (X, Y), 25, 4)
drone(X,Y
# [...]
Another possible solution is to use pygame.Rect.clipline and detect the collision of the line segments and the rectangle surrounding the drone:
def intersect_rect(rect, pointlist):
for i in range(len(pointlist)-1):
if rect.clipline(pointlist[i], pointlist[i+1]):
return True
return False
def game_loop():
# [...]
while not gameExit:
# [...]
if not intersect_rect(droneImg.get_rect(center = (X, Y)), pointlist):
pygame.draw.circle(gameDisplay, (255, 0, 0), (X, Y), 25, 4)
drone(X,Y
# [...]

The interesting part of the question is of course finding the nearest point on the desired path to the actual position; distance is easy. The hard part of that is in turn identifying the nearest element (line segment) of the path; projecting onto it is also straightforward.
If the path is simple enough (in particular, if it doesn’t branch and it’s impossible/disallowed to skip sections at a self-intersection), you can finesse that part by just maintaining that current element in a variable and updating it to the previous or next element when the projection onto one of them is closer than the projection onto the current one. This is a typical algorithm used by racing games to determine the instantaneous order of racers.

Switching the displayed surface in PyGame allows the user to scroll off the borders of the surface

I am creating a randomly generated map in with PyGame. However, I've run into an issue, where, if the user scrolls away from the top-left corner of the map and changes the PyGame surface that's displayed, an issue happens.
The problem is, PyGame still starts them on the upper-left of the surface, and will then allow them to scroll off the edges of the surface because the list that keeps track of that, camera_pos, now has incorrect values.
All of the surfaces are the same dimensions and I want to make it so the user is in the same position when they change the displayed surface. However, I'm not sure how to set the position of the user's view when pygame switches surfaces.
How can I switch the position of the user's view back to what it used to be when the surface is switched?
I have made a MCV Example below I hope will help. Instead of displaying maps, it just draws a border around a solid color. I apologize for how long it is. I'm not sure how to make it much shorter.
In this example, scrolling is done with the arrow keys. You can press r, g, or b on the keyboard to display the different colored surfaces.
import pygame
import numpy as np
import sys
def scroll_y(display_surface, offset):
"""
Handles vertical scrolling.
:param display_surface: A pyGame surface object.
:param offset: The speed of the scroll
"""
width, height = display_surface.get_size()
map_copy = display_surface.copy()
display_surface.blit(map_copy, (0, offset))
# handle scrolling down
if offset < 0:
display_surface.blit(map_copy,
(0, height + offset),
(0, 0, width, -offset))
# handle scrolling up
else:
display_surface.blit(map_copy,
(0, 0),
(0, height - offset, width, offset))
def scroll_x(display_surface, offset):
"""
Handles horizontal scrolling.
:param display_surface: A pyGame surface object.
:param offset: The speed of the scroll
"""
width, height = display_surface.get_size()
map_copy = display_surface.copy()
display_surface.blit(map_copy, (offset, 0))
# handle scrolling right
if offset < 0:
display_surface.blit(map_copy,
(width + offset, 0),
(0, 0, -offset, height))
# handle scrolling left
else:
display_surface.blit(map_copy,
(0, 0),
(width - offset, 0, offset, height))
def main():
"""
This function displays the three surfaces.
Press r to show the red surface (which is displayed by default).
Press g to show the green surface.
Press b to show the blue surface.
"""
pygame.init()
window = pygame.display.set_mode((1600, 900))
red_surface = pygame.Surface([3200, 1800]).convert(window)
green_surface = pygame.Surface([3200, 1800]).convert(window)
blue_surface = pygame.Surface([3200, 1800]).convert(window)
red_surface.fill((255, 145, 145))
green_surface.fill((145, 255, 145))
blue_surface.fill((145, 145, 255))
# draw thick black lines on surface borders
pygame.draw.rect(red_surface, (0, 0, 0), (0, 0, 3200, 1800), 40)
pygame.draw.rect(green_surface, (0, 0, 0), (0, 0, 3200, 1800), 40)
pygame.draw.rect(blue_surface, (0, 0, 0), (0, 0, 3200, 1800), 40)
display_surface = red_surface.copy()
camera_pos = np.array([0, 0])
while True: # <-- the pyGame loop
event = pygame.event.poll()
pressed = pygame.key.get_pressed()
# handle closing the window
if event.type == pygame.QUIT:
break
window.blit(display_surface, (0, 0))
# handle switching display modes
if pressed[pygame.K_g]:
display_surface = green_surface
elif pressed[pygame.K_b]:
display_surface = blue_surface
elif pressed[pygame.K_r]:
display_surface = red_surface
# handle scrolling, make sure you can't scroll past the borders
if pressed[pygame.K_UP] and camera_pos[1] > 0:
scroll_y(display_surface, 5)
camera_pos[1] -= 5
elif pressed[pygame.K_DOWN] and camera_pos[1] < (1800 / 2):
scroll_y(display_surface, -5)
camera_pos[1] += 5
elif pressed[pygame.K_LEFT] and camera_pos[0] > 0:
scroll_x(display_surface, 5)
camera_pos[0] -= 5
elif pressed[pygame.K_RIGHT] and camera_pos[0] < (3200 / 2):
scroll_x(display_surface, -5)
camera_pos[0] += 5
# updates what the window displays
pygame.display.update()
pygame.quit()
sys.exit(0)
if __name__ == "__main__":
# runs the pyGame loop
main()

Here's what I think is a fairly elegant solution that doesn't require the two scrolling functions, scroll_x() and scroll_y() you have. Because it was so fast not using them, the main loop was detecting the same scrolling key as being pressed multiple times — necessitating the addition of a pygame.time.Clock to slow the frame-rate down to something reasonable.
Instead of scrolling the display surfaces themselves via those scrolling functions, as your code was doing, this version just updates the current "camera" position, then blits the corresponding region of the current display_surface to the window whenever it's modified. The camera's position is constrained by making sure its x and y components stay within some boundary limit constants — MINX,MINY and MAXX,MAXY — which get computed based the values of some other previously defined constants.
The use of symbolic constants rather than hardcoding literal values multiple places in the code is considered a very good programming practice because it makes changing them easier, since doing so only requires a source code change to be done one place.
import pygame
import sys
def main():
"""
This function displays the three surfaces.
Press r to show the red surface (which is displayed by default).
Press g to show the green surface.
Press b to show the blue surface.
"""
FPS = 60 # Frames per second
SURF_WIDTH, SURF_HEIGHT = 3200, 1800
WIN_WIDTH, WIN_HEIGHT = 1600, 900
DX, DY = 5, 5 # Scroll amounts.
MINX, MAXX = DX, SURF_WIDTH - WIN_WIDTH + DX - 1
MINY, MAXY = DY, SURF_HEIGHT - WIN_HEIGHT + DY - 1
pygame.init()
pygame.font.init()
fonts = pygame.font.get_fonts()
clock = pygame.time.Clock()
window = pygame.display.set_mode((WIN_WIDTH, WIN_HEIGHT))
red_surface = pygame.Surface([SURF_WIDTH, SURF_HEIGHT]).convert(window)
green_surface = pygame.Surface([SURF_WIDTH, SURF_HEIGHT]).convert(window)
blue_surface = pygame.Surface([SURF_WIDTH, SURF_HEIGHT]).convert(window)
red_surface.fill((255, 145, 145))
green_surface.fill((145, 255, 145))
blue_surface.fill((145, 145, 255))
# Draw thick black lines on surface borders
pygame.draw.rect(red_surface, (0, 0, 0), (0, 0, SURF_WIDTH, SURF_HEIGHT), 40)
pygame.draw.rect(green_surface, (0, 0, 0), (0, 0, SURF_WIDTH, SURF_HEIGHT), 40)
pygame.draw.rect(blue_surface, (0, 0, 0), (0, 0, SURF_WIDTH, SURF_HEIGHT), 40)
# Draw label on each of the surfaces for testing. (ADDED)
font = pygame.font.SysFont(None, 35)
rtext = font.render('red surface', True, (255, 0, 0))
textpos = rtext.get_rect(centerx=300, centery=200) # Reused.
red_surface.blit(rtext, textpos)
rtext = font.render('green surface', True, (0, 192, 0))
green_surface.blit(rtext, textpos)
rtext = font.render('blue surface', True, (0, 0, 255))
blue_surface.blit(rtext, textpos)
display_surface = red_surface
camera_pos = pygame.math.Vector2(0, 0)
update_surface = True
while True: # Game loop
if update_surface:
window.blit(display_surface, (0, 0), (camera_pos[0], camera_pos[1],
WIN_WIDTH, WIN_HEIGHT))
update_surface = False
event = pygame.event.poll()
pressed = pygame.key.get_pressed()
# Close window?
if event.type == pygame.QUIT or pressed[pygame.K_ESCAPE]:
break
# Switch display surface?
if pressed[pygame.K_g]:
display_surface = green_surface
update_surface = True
elif pressed[pygame.K_b]:
display_surface = blue_surface
update_surface = True
elif pressed[pygame.K_r]:
display_surface = red_surface
update_surface = True
# Constrain scrolling to within borders
if pressed[pygame.K_LEFT] and camera_pos[0] >= MINX:
camera_pos[0] -= DX
update_surface = True
elif pressed[pygame.K_RIGHT] and camera_pos[0] <= MAXX:
camera_pos[0] += DX
update_surface = True
elif pressed[pygame.K_UP] and camera_pos[1] >= MINY:
camera_pos[1] -= DY
update_surface = True
elif pressed[pygame.K_DOWN] and camera_pos[1] <= MAXY:
camera_pos[1] += DY
update_surface = True
# updates what the window displays
pygame.display.update()
clock.tick(FPS)
pygame.quit()
sys.exit(0)
if __name__ == "__main__":
main() # runs the pyGame loop

How to make ball bounce off triangle in pygame?

Hello I'm a pretty new programmer and I'm trying to make a ball bounce off a 45 degree triangle. Here is my code:
This program makes the ball bounce when it hits the sides of the window, but I don't know how to make it bounce off a triangle.
import pygame # importing the pygame
import sys # importing the system libraries
import time # importing timer
import random
from pygame.locals import * # importing the locals functions from the pygame library set
pygame.init() # the function from pygame that initializes all relevant variable
# setting length and width
width = 500
length = 300
# colour variables
WHITE = (255,255,255)
BLUE = (0,0,255)
# importing ball image
ball = pygame.image.load('ball.png')
ballRect = ball.get_rect()
ballRect.left = 300
ballRect.right = 300
# setting speed
x_speed = 2
y_speed = 2
# setting window size
WINDOW = pygame.display.set_mode((width, length))# setting the size of the window
pygame.display.update()
# loop
while True:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
ballRect = ballRect.move(x_speed,y_speed)
WINDOW.fill(WHITE) # changing screen colour to white
WINDOW.blit(ball,ballRect) # printing the ball to screen
pygame.display.update()
pygame.display.flip()
time.sleep(0.002) # to slow down the speed of bouncing
pygame.display.update()
# if the left side of ballRect is in a position less than 0, or the right side of ballRect is greater than 500
if ballRect.left < 0 or ballRect.right > (width):
x_speed = x_speed * -1
# if the top of ballRect is in a position less than 0, or the bottom of ballRect is greater than the length
elif ballRect.top < 0 or ballRect.bottom > (length):
y_speed = y_speed * -1
pygame.display.update()
I haven't drawn in the triangle because I don't know where to, but I expect the ball to bounce off the triangle like it does when it hits the sides of the window. Any help would be great!

Interesting task. A triangle can be defined by a simple list:
triangle = [(250, 220), (400, 300), (100, 300)]
The triangle can be drawn by pygame.draw.polygon()
pygame.draw.polygon(WINDOW, RED, triangle, 0)
Use pygame.math.Vector2 to define the position and the motion vector of the ball:
ballvec = pygame.math.Vector2(1, 1)
ballpos = pygame.math.Vector2(150, 250)
balldiameter = 64
Create a function, which does the collision detection. The function has to detect if the ball hits a line. If the line is hit, then the motion vector of the ball is reflected on the line.
The line is represented by 2 points (lp0, lp1), which are pygame.math.Vector2 objects.
The position of the ball (pt) and the motion vector (dir) are pygame.math.Vector2 objects, too:
def isect(lp0, lp1, pt, dir, radius):
# direction vector of the line
l_dir = (lp1 - lp0).normalize()
# normal vector to the line
nv = pygame.math.Vector2(-l_dir[1], l_dir[0])
# distance to line
d = (lp0-pt).dot(nv)
# intersection point on endless line
ptX = pt + nv * d
# test if the ball hits the line
if abs(d) > radius or dir.dot(ptX-pt) <= 0:
return dir
if (ptX-lp0).dot(l_dir) < 0 or (ptX-lp1).dot(l_dir) > 0:
return dir
# reflect the direction vector on the line (like a billiard ball)
r_dir = dir.reflect(nv)
return r_dir
Append the window rectangle and the triangle to a list of lines. Ech line is represented by a tuple of 2 pygame.math.Vector2 objects:
# add screen rect
screen_rect = [(0, 0), (0, 300), (500, 300), (500, 0)]
for i in range(len(screen_rect)):
p0, p1 = screen_rect[i], screen_rect[(i+1) % len(screen_rect)]
line_list.append((pygame.math.Vector2(p0[0], p0[1]), pygame.math.Vector2(p1[0], p1[1])))
# add red trianlge
triangle = [(250, 220), (400, 300), (100, 300)]
for i in range(len(triangle)):
p0, p1 = triangle[i], triangle[(i+1) % len(triangle)]
line_list.append((pygame.math.Vector2(p0[0], p0[1]), pygame.math.Vector2(p1[0], p1[1])))
Do the collision detection in a loop, which traverse the lines. If the ball hits a line, then the motion vector is replaced by the reflected motion vector:
for line in line_list:
ballvec = isect(*line, ballpos, ballvec, balldiameter/2)
Finally update the position of the ball an the ball rectangle:
ballpos = ballpos + ballvec
ballRect.x, ballRect.y = ballpos[0]-ballRect.width/2, ballpos[1]-ballRect.height/2
See the example code, where I applied the suggested changes to your original code. My ball image has a size of 64x64. The ball diameter has to be set to this size (balldiameter = 64):
Minimal example
import pygame
pygame.init()
window = pygame.display.set_mode((500, 300))
try:
ball = pygame.image.load("Ball64.png")
except:
ball = pygame.Surface((64, 64), pygame.SRCALPHA)
pygame.draw.circle(ball, (255, 255, 0), (32, 32), 32)
ballvec = pygame.math.Vector2(1.5, 1.5)
ballpos = pygame.math.Vector2(150, 250)
balldiameter = ball.get_width()
def reflect_circle_on_line(lp0, lp1, pt, dir, radius):
l_dir = (lp1 - lp0).normalize() # direction vector of the line
nv = pygame.math.Vector2(-l_dir[1], l_dir[0]) # normal vector to the line
d = (lp0-pt).dot(nv) # distance to line
ptX = pt + nv * d # intersection point on endless line
if (abs(d) > radius or dir.dot(ptX-pt) <= 0 or # test if the ball hits the line
(ptX-lp0).dot(l_dir) < 0 or (ptX-lp1).dot(l_dir) > 0):
return dir
r_dir = dir.reflect(nv) # reflect the direction vector on the line (like a billiard ball)
return r_dir
triangle1 = [(250, 220), (400, 300), (100, 300)]
triangle2 = [(250, 80), (400, 0), (100, 0)]
screen_rect = [(0, 0), (0, window.get_height()), window.get_size(), (window.get_width(), 0)]
line_list = []
for p0, p1 in zip(triangle1, triangle1[1:] + triangle1[:1]):
line_list.append((pygame.math.Vector2(p0), pygame.math.Vector2(p1)))
for p0, p1 in zip(triangle2, triangle2[1:] + triangle2[:1]):
line_list.append((pygame.math.Vector2(p0), pygame.math.Vector2(p1)))
for p0, p1 in zip(screen_rect, screen_rect[1:] + screen_rect[:1]):
line_list.append((pygame.math.Vector2(p0), pygame.math.Vector2(p1)))
clock = pygame.time.Clock()
run = True
while run:
clock.tick(250)
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
for line in line_list:
ballvec = reflect_circle_on_line(*line, ballpos, ballvec, balldiameter/2)
ballpos = ballpos + ballvec
window.fill((64, 64, 64))
pygame.draw.polygon(window, (255, 0, 0), triangle1, 0)
pygame.draw.polygon(window, (0, 0, 255), triangle2, 0)
window.blit(ball, (round(ballpos[0]-balldiameter/2), round(ballpos[1]-balldiameter/2)))
pygame.display.flip()
pygame.quit()

Moving object across screen in Pygame

So I am trying to move this random jumble of two polygons, a circle, and a line across the screen, any direction, and when it reaches the end of the screen is is placed back on the screen and moves again. Simply put, I want to move those shapes across the screen. I cannot really figure out how, I am new to pygame so all this is a bit confusing but this is what I have so far.
import pygame, sys, time, random
from pygame.locals import *
pygame.init()
windowSurface = pygame.display.set_mode((500, 400), 0, 32)
pygame.display.set_caption("Paint")
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
windowSurface.fill(WHITE)
info = pygame.display.Info()
sw = info.current_w
sh = info.current_h
x = y = 0
dx = 5
dy = 2
while True:
pygame.draw.polygon(windowSurface,BLUE,((0+x,250+y),(120+x,120+y),(55+x,55+y)))
pygame.draw.polygon(windowSurface,RED,((0+x,150+y),(85+x,85+y),(100+x,175+y),(0+x,150+y)))
pygame.draw.line(windowSurface,BLACK,(60+x,85+y), (120+x, 110+x), 6)
pygame.draw.circle(windowSurface, GREEN , (75+x,100+y), 13, 0)
x += dx
y += dy
if x - dx < 0 or x + dx > sw:
dx = -dx
if y - dy < 0 or y + dy > sh:
dy = -dy
pygame.display.update()
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()

You probably want to clear the screen each time you redraw.
while True:
windowSurface.fill(WHITE) #This clears the screen on each redraw
pygame.draw.polygon(windowSurface,BLUE,((0+x,250+y),(120+x,120+y),(55+x,55+y)))
pygame.draw.polygon(windowSurface,RED,((0+x,150+y),(85+x,85+y),(100+x,175+y),(0+x,150+y)))
pygame.draw.line(windowSurface,BLACK,(60+x,85+y), (120+x, 110+y), 6)
pygame.draw.circle(windowSurface, GREEN , (75+x,100+y), 13, 0)
Also, look at the coordinates for the line. I have changed the endpoint to
(120+x, 110+y)
And if you change your edge detection to this your shapes will mostly stay in the window
if x < 0 or x > sw-120:
dx = -dx
x += dx
if y < -85 or y > sh-175:
dy = -dy
y += dy