# Flare

Tinkering around with vectors, I created this fancy program. By left-clicking you spawn a white circle at your current mouse position. This circle then will emit a specific quantity of red pixels $(\text{which is }c = 2 \pi r \text{ with } r = 50)$. Those red pixels then get pushed across the screen until they eventually die out.

#### Controls

• Left click spawns in a circle
• Space saves a screenshot

# Python 2.7.7 Code
# Pygame 1.9.1 (for Python 2.7.7)
# Jonathan Frech 14th of October, 2015
#         edited 15th of October, 2015

# importing needed modules
import pygame, sys, time, math, os, random, datetime

""" CLASSES """
# dummy class for global variables
class dummy():
pass

class charge():
def __init__(self, _pos):
self.pos = _pos
self.entities = []

for _ in range(0, n):
p = getCirclePos(self.pos, self.radius, 360. / n * _)
self.entities.append(p)

def tick(self):
_n = -1
for _ in self.entities:
main.SURF.set_at(intpos(_), [255, 0, 0])

_n += 1
vec = vecConvert(_, self.pos)
vecl = vecLen(vec)
if vecl != 0 and vecl < 1000:
vec0 = vecMultiply(vec, 1. / vecl)
vecn = vecMultiply(vec0, vecl*1.1)
self.entities[_n] = vecGetPoint(self.pos, vecn)
else:
self.entities.remove(_)

def render(self, _surface):
pygame.draw.circle(_surface, [255, 255, 255], self.pos, self.radius)

""" FUNCTIONS """
# gets the position on a circle
# circle center                           : '_pos'
# angle from center to point on the circle: '_angle'
return [
]

# returns an integer version of given positon
def intpos(_pos):
return [int(_pos[0]), int(_pos[1])]

# basic vector functions
def vecConvert(p1, p2):
return [p2[0] - p1[0], p2[1] - p1[1]]
def vecLen(vec):
return math.sqrt( (vec[0]**2) + (vec[1]**2) )
def vecMultiply(vec, n):
return [vec[0] * n, vec[1] * n]
def vecGetPoint(vec, point):
return [point[0] + vec[0], point[1] + vec[1]]

# saves the current surface
def saveSurface():
try:
path = os.getcwd() + "/out/"
if not os.path.isdir(path):
os.mkdir(path)

name = path + "img" + str(len(os.listdir(path))) + ".png"
pygame.image.save(main.SURF, name)
except:
pass

# quits the program
def quit():
sys.exit()

""" TICK; RENDER """
# tick function
def tick():
# handle events
for event in pygame.event.get():
if event.type == pygame.QUIT:
quit()

if event.type == pygame.KEYDOWN:
if event.key == pygame.K_SPACE:
saveSurface()

if event.type == pygame.MOUSEBUTTONDOWN:
if event.button == 3:
main.CHARGES.append(charge(list(pygame.mouse.get_pos())))

for _ in main.CHARGES:
_.tick()

# render function
def render():
# render white bobbles
for _ in main.CHARGES:
_.render(main.SURF)

# blit and flip
main.SCREEN.blit(main.SURF, [0, 0])

pygame.display.flip()

""" INIT """
# initialize program
def init():
main.WIDTH, main.HEIGHT = 1080, 720
main.SIZE = [main.WIDTH, main.HEIGHT]
main.CENTER = [main.WIDTH / 2., main.HEIGHT / 2.]
main.SCREEN = pygame.display.set_mode(main.SIZE)
main.SURF = pygame.Surface(main.SIZE)

main.CAPTION = "Flare"
main.COLOR = [0, 0, 0]
main.TICKS = 0

main.CHARGES = []

# functions
pygame.display.set_caption(main.CAPTION)

""" RUN """
# run function (uses tick() and render())
def run():
ticksPerSecond = 60
lastTime = time.time() * 1000000000
nsPerTick =  1000000000.0 / float(ticksPerSecond)

ticks = 0
frames = 0

lastTimer = time.time() * 1000
delta = 0.0

while True:
now = time.time() * 1000000000
delta += float(now - lastTime) / float(nsPerTick)
lastTime = now
shouldRender = False

while delta >= 1:
ticks += 1
main.TICKS += 1
tick()
delta -= 1
shouldRender = True

if shouldRender:
frames += 1
render()

if time.time() * 1000 - lastTimer >= 1000:
lastTimer += 1000

# debug
# print("Frames: " + str(frames) + ", ticks: " + str(ticks))

frames = 0
ticks = 0

# main variable
main = dummy()
init()

# start program
run()