Develop Reference

Exclude results in find_closest (Tkinter, Python)

I am writing a script to store movements over a hexgrid using Tkinter. As part of this I want to use a mouse-click on a Tkinter canvas to first identify the click location, and then draw a line between this point and the location previously clicked.
Generally this works, except that after I've drawn a line, it become an object that qualifies for future calls off the find_closest method. This means I can still draw lines between points, but selecting the underlying Hex in the Hexgrid over times becomes nearly impossible. I was wondering if someone could help me find a solution to exclude particular objects (lines) from the find_closest method.
edit: I hope this code example is minimal enough.
import tkinter
from tkinter import *
from math import radians, cos, sin, sqrt
class App:
def __init__(self, parent):
self.parent = parent
self.c1 = Canvas(self.parent, width=int(1.5*340), height=int(1.5*270), bg='white')
self.c1.grid(column=0, row=0, sticky='nsew')
self.clickcount = 0
self.clicks = [(0,0)]
self.startx = int(20*1.5)
self.starty = int(20*1.5)
self.radius = int(20*1.5) # length of a side
self.hexagons = []
self.columns = 10
self.initGrid(self.startx, self.starty, self.radius, self.columns)
self.c1.bind("<Button-1>", self.click)
def initGrid(self, x, y, radius, cols):
"""
2d grid of hexagons
"""
radius = radius
column = 0
for j in range(cols):
startx = x
starty = y
for i in range(6):
breadth = column * (1.5 * radius)
if column % 2 == 0:
offset = 0
else:
offset = radius * sqrt(3) / 2
self.draw(startx + breadth, starty + offset, radius)
starty = starty + 2 * (radius * sqrt(3) / 2)
column = column + 1
def draw(self, x, y, radius):
start_x = x
start_y = y
angle = 60
coords = []
for i in range(6):
end_x = start_x + radius * cos(radians(angle * i))
end_y = start_y + radius * sin(radians(angle * i))
coords.append([start_x, start_y])
start_x = end_x
start_y = end_y
hex = self.c1.create_polygon(coords[0][0], coords[0][1], coords[1][0], coords[1][1], coords[2][0],
coords[2][1], coords[3][0], coords[3][1], coords[4][0], coords[4][1],
coords[5][0], coords[5][1], fill='black')
self.hexagons.append(hex)
def click(self, evt):
self.clickcount = self.clickcount + 1
x, y = evt.x, evt.y
tuple_alfa = (evt.x, evt.y)
self.clicks.append(tuple_alfa)
if self.clickcount >= 2:
start = self.clicks[self.clickcount - 1]
startx = start[0]
starty = start[1]
self.c1.create_line(evt.x, evt.y, startx, starty, fill='white')
clicked = self.c1.find_closest(x, y)[0]
print(clicked)
root = tkinter.Tk()
App(root)
root.mainloop()

Creating Custom Time Picker Widget

I need to create a widget that is used to pick a time. QTimeEdit widget doesn't seem intuitive or a good design. So I decided to create a time picker similar to the time picker in smartphones.
I managed to create the clock and click that makes the pointer (something similar to the pointer in the image) move to the currently clicked position (note: it's not perfect, it still looks bad). I would like to have help with making the inner clock
Here is my code:
from PyQt5 import QtWidgets, QtGui, QtCore
import math, sys
class ClockWidget(QtWidgets.QWidget): # I want to be able to reuse this class for other programs also, so please don't hard code values of the list, start and end
def __init__(self, start, end, lst=[], *args, **kwargs):
super(ClockWidget, self).__init__(*args, **kwargs)
self.lst = lst
if not self.lst:
self.lst = [*range(start, end)]
self.index_start = 0 # tune this to move the letters in the circle
self.pointer_angles_multiplier = 9 # just setting the default values
self.current = None
self.rects = []
#property
def index_start(self):
return self._index_start
#index_start.setter
def index_start(self, index):
self._index_start = index
def paintEvent(self, event):
self.rects = []
painter = QtGui.QPainter(self)
pen = QtGui.QPen()
pen.setColor(QtCore.Qt.red)
pen.setWidth(2)
painter.setPen(pen)
x, y = self.rect().x(), self.rect().y()
width, height = self.rect().width(), self.rect().height()
painter.drawEllipse(x, y, x + width, x + height)
s, t, equal_angles, radius = self.angle_calc()
radius -= 30
pen.setColor(QtCore.Qt.green)
pen.setWidth(2)
painter.setPen(pen)
""" pointer angle helps in determining to which position the pointer should be drawn"""
self.pointer_x, self.pointer_y = s + ((radius-30) * math.cos(self.pointer_angles_multiplier * equal_angles)), t \
+ ((radius-30) * math.sin(self.pointer_angles_multiplier * equal_angles))
""" The pendulum like pointer """
painter.drawLine(QtCore.QPointF(s, t), QtCore.QPointF(self.pointer_x, self.pointer_y))
painter.drawEllipse(QtCore.QRectF(QtCore.QPointF(self.pointer_x - 20, self.pointer_y - 40),
QtCore.QPointF(self.pointer_x + 30, self.pointer_y + 10)))
pen.setColor(QtCore.Qt.blue)
pen.setWidth(3)
font = self.font()
font.setPointSize(14)
painter.setFont(font)
painter.setPen(pen)
""" Drawing the number around the circle formula y = t + radius * cos(a)
y = s + radius * sin(a) where angle is in radians (s, t) are the mid point of the circle """
for index, char in enumerate(self.lst, start=self.index_start):
angle = equal_angles * index
y = t + radius * math.sin(angle)
x = s + radius * math.cos(angle)
# print(f"Add: {add_x}, index: {index}; char: {char}")
rect = QtCore.QRectF(x - 30, y - 40, x + 60, y) # clickable point
self.rects.append([index, char, rect]) # appends index, letter, rect
painter.setPen(QtCore.Qt.blue)
painter.drawRect(rect) # helps in visualizing the points where the click can received
print(f"Rect: {rect}; char: {char}")
painter.setPen(QtCore.Qt.red)
points = QtCore.QPointF(x, y)
painter.drawText(points, str(char))
def mousePressEvent(self, event):
for x in self.rects:
index, char, rect = x
if event.button() & QtCore.Qt.LeftButton and rect.contains(event.pos()):
self.pointer_angles_multiplier = index
self.current = char
self.update()
break
def angle_calc(self):
"""
This will simply return (midpoints of circle, divides a circle into the len(list) and return the
angle in radians, radius)
"""
return ((self.rect().width() - self.rect().x()) / 2, (self.rect().height() - self.rect().y()) / 2,
(360 / len(self.lst)) * (math.pi / 180), (self.rect().width() / 2))
def resizeEvent(self, event: QtGui.QResizeEvent):
"""This is supposed to maintain a Square aspect ratio on widget resizing but doesn't work
correctly as you will see when executing"""
if event.size().width() > event.size().height():
self.resize(event.size().height(), event.size().width())
else:
self.resize(event.size().width(), event.size().width())
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
message = ClockWidget(1, 13)
message.index_start = 10
message.show()
sys.exit(app.exec())
The Output:
The blue rectangles represent the clickable region. I would be glad if you could also, make the pointer move to the closest number when clicked inside the clock (Not just move the pointer when the clicked inside the blue region)
There is one more problem in my code, that is the numbers are not evenly spaced from the outer circle. (like the number 12 is closer to the outer circle than the number 6)

Disclaimer: I will not explain the cause of the error but the code I provide I think should give a clear explanation of the errors.
The logic is to calculate the position of the centers of each small circle, and use the exinscribed rectangle to take it as a base to draw the text and check if the point where you click is close to the texts.
from functools import cached_property
import math
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
class ClockWidget(QtWidgets.QWidget):
L = 12
r = 40.0
DELTA_ANGLE = 2 * math.pi / L
current_index = 9
def paintEvent(self, event):
painter = QtGui.QPainter(self)
painter.setRenderHint(QtGui.QPainter.Antialiasing)
R = min(self.rect().width(), self.rect().height()) / 2
margin = 4
Rect = QtCore.QRectF(0, 0, 2 * R - margin, 2 * R - margin)
Rect.moveCenter(self.rect().center())
painter.setBrush(QtGui.QColor("gray"))
painter.drawEllipse(Rect)
rect = QtCore.QRectF(0, 0, self.r, self.r)
if 0 <= self.current_index < 12:
c = self.center_by_index(self.current_index)
rect.moveCenter(c)
pen = QtGui.QPen(QtGui.QColor("red"))
pen.setWidth(5)
painter.setPen(pen)
painter.drawLine(c, self.rect().center())
painter.setBrush(QtGui.QColor("red"))
painter.drawEllipse(rect)
for i in range(self.L):
j = (i + 2) % self.L + 1
c = self.center_by_index(i)
rect.moveCenter(c)
painter.setPen(QtGui.QColor("white"))
painter.drawText(rect, QtCore.Qt.AlignCenter, str(j))
def center_by_index(self, index):
R = min(self.rect().width(), self.rect().height()) / 2
angle = self.DELTA_ANGLE * index
center = self.rect().center()
return center + (R - self.r) * QtCore.QPointF(math.cos(angle), math.sin(angle))
def index_by_click(self, pos):
for i in range(self.L):
c = self.center_by_index(i)
delta = QtGui.QVector2D(pos).distanceToPoint(QtGui.QVector2D(c))
if delta < self.r:
return i
return -1
def mousePressEvent(self, event):
i = self.index_by_click(event.pos())
if i >= 0:
self.current_index = i
self.update()
#property
def hour(self):
return (self.current_index + 2) % self.L + 1
def minumumSizeHint(self):
return QtCore.QSize(100, 100)
def main():
app = QtWidgets.QApplication(sys.argv)
view = ClockWidget()
view.resize(400, 400)
view.show()
sys.exit(app.exec_())
if __name__ == "__main__":
main()

Python - spherical coordinates have Z axis bias

Long story short I need to get a bunch of balls moving in random directions in space. I am using a python script with VRED (3D rendering software) to display the balls on screen.
I am trying to use spherical coordinates but somehow the distribution of the balls in space is biased to the Z axis. I really cannot figure out where I got it wrong.
I am proceeding like this:
I generate a random yaw starting direction (-180, 180) and a random starting pitch (0, 180)
At each new frame I change the yaw and pitch by a small amount and move the ball in that new direction.
Here is my Python code (I hope it's not too hard to read; vrAEBase is a class related to VRED which allows the loop() to be updated each frame):
import random
import math
populationsize = 1000
balllist = []
#________________________________________BALL CLASS______________________________________________
class Ball(vrAEBase):
def __init__(self):
vrAEBase.__init__(self)
self.addLoop()
self.body = createSphere(2,100,1,1,1) # create sphere
self.isplaying = false
self.steplength = 20 #step length between each frame
self.yaw = random.uniform(-180, 180) #set starting yaw
self.pitch = random.uniform(0, 180) #set starting pitch
self.maxsteering = 1 # max angular change for yaw/pitch for each frame
self.x = 0 #startting X location
self.y = 0 #startting Y location
self.z = 0 #startting Z location
def loop(self): #loop is executed every frame
if self.isplaying:
self.yaw = self.yaw + random.uniform(-1*self.maxsteering, self.maxsteering) #set new yaw
self.pitch = self.pitch + random.uniform(-1*self.maxsteering, self.maxsteering) #set new pitch
localX = self.steplength * (math.sin(self.pitch)) * (math.cos(self.yaw)) #calculate X step length
localY = self.steplength * (math.sin(self.pitch)) * (math.sin(self.yaw)) #calculate Y step length
localZ = self.steplength * (math.cos(self.pitch)) #calculate Z step length
self.x += localX
self.y += localY
self.z += localZ
setTransformNodeTranslation(self.body, self.x,self.y,self.z,true)
def rewind(self):
self.isplaying = false
self.x = 0
self.y = 0
self.z = 0
setTransformNodeTranslation(self.body, self.x,self.y,self.z,true)
#__________________________________PLAY__________________________________
def play():
global balllist
for ball in balllist:
if ball.isplaying == false:
ball.isplaying = true
else:
ball.isplaying = false
#__________________________________REWIND_________________________________
def rewind():
global balllist
for ball in balllist:
ball.rewind()
#_______________________________SPAWN BALLS________________________________
for x in range(0, populationsize):
newball = Ball() #create ball
balllist.append(newball) #add ball to list
play()
print("end")
Here is an image of the final distribution:

The problem is that in order to generate a uniform distribution of points around a sphere you cannot do phi = [0,pi] and theta=[-pi,pi] as this would lead to a surface elment dA= dphi*dtheta instead of the correct one dA= sin(phi)*dphi*dtheta.
In order to achieve the correct volume elment change
def __init__( self):
...
self.yaw = random.uniform(-180, 180) #set starting yaw
self.pitch = random.uniform(0, 180) #set starting pitch
...
to
def __init__( self):
...
u = random.uniform(0,1)
v = random.uniform(0,1)
self.yaw = 2 * math.pi * u #set starting yaw
self.pitch = math.acos( 2*v -1) #set starting pitch
...
For more documentation see http://mathworld.wolfram.com/SpherePointPicking.html.
Also be careful of the behavior of your timestep routine, as of now it seems that the dots will tend to collapse more toward this distribution. I don't know if this is your intended behavior

Why is my pyglet program slow while rendering 128 particles?

Why is my program slow while rendering 128 particles? I think that's not enough to get less than 30 fps.
All I do is rendering 128 particles and giving them some basic gravitation
on_draw function
def on_draw(self, time=None):
glClearColor(0.0, 0.0, 0.0, 1.0)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glLoadIdentity()
self.particles.append(Particle())
for particle in self.particles:
particle.draw()
if particle.is_dead:
self.particles.remove(particle)
Particle class
class Particle:
def __init__(self, **kwargs):
self.acceleration = Vector2(0, 0.05)
self.velocity = Vector2(random.uniform(-1, 1), random.uniform(-1, 0))
self.position = Vector2()
self.time_to_live = 255
self.numpoints = 50
self._vertices = []
for i in range(self.numpoints):
angle = math.radians(float(i) / self.numpoints * 360.0)
x = 10 * math.cos(angle) + self.velocity[0] + 300
y = 10 * math.sin(angle) + self.velocity[1] + 400
self._vertices += [x, y]
def update(self, time=None):
self.velocity += self.acceleration
self.position -= self.velocity
self.time_to_live -= 2
def draw(self):
glEnable(GL_BLEND)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
glPushMatrix()
glTranslatef(self.position[0], self.position[1], 0)
pyglet.graphics.draw(self.numpoints, GL_TRIANGLE_FAN, ('v2f', self._vertices), ('c4B', self.color))
glPopMatrix()
self.update()
#property
def is_dead(self):
if self.time_to_live <= 0:
return True
return False
#property
def color(self):
return tuple(color for i in range(self.numpoints) for color in (255, 255, 255, self.time_to_live))

I'm not overly happy about using GL_TRIANGLE_FAN because it's caused a lot of odd shapes when using batched rendering. So consider moving over to GL_TRIANGLES instead and simply add all the points to the object rather than leaning on GL to close the shape for you.
That way, you can easily move over to doing batched rendering:
import pyglet
from pyglet.gl import *
from collections import OrderedDict
from time import time, sleep
from math import *
from random import randint
key = pyglet.window.key
class CustomGroup(pyglet.graphics.Group):
def set_state(self):
#pyglet.gl.glLineWidth(5)
#glPolygonMode(GL_FRONT_AND_BACK, GL_LINE)
#glColor4f(1, 0, 0, 1) #FFFFFF
#glLineWidth(1)
#glEnable(texture.target)
#glBindTexture(texture.target, texture.id)
pass
def unset_state(self):
glLineWidth(1)
#glDisable(texture.target)
class Particle():
def __init__(self, x, y, batch, particles):
self.batch = batch
self.particles = particles
self.group = CustomGroup()
self.add_point(x, y)
def add_point(self, x, y):
colors = ()#255,0,0
sides = 50
radius = 25
deg = 360/sides
points = ()#x, y # Starting point is x, y?
prev = None
for i in range(sides):
n = ((deg*i)/180)*pi # Convert degrees to radians
point = int(radius * cos(n)) + x, int(radius * sin(n)) + y
if prev:
points += x, y
points += prev
points += point
colors += (255, i*int(255/sides), 0)*3 # Add a color pair for each point (r,g,b) * points[3 points added]
prev = point
points += x, y
points += prev
points += points[2:4]
colors += (255, 0, 255)*3
self.particles[len(self.particles)] = self.batch.add(int(len(points)/2), pyglet.gl.GL_TRIANGLES, self.group, ('v2i/stream', points), ('c3B', colors))
class main(pyglet.window.Window):
def __init__ (self, demo=False):
super(main, self).__init__(800, 600, fullscreen = False, vsync = True)
#print(self.context.config.sample_buffers)
self.x, self.y = 0, 0
self.sprites = OrderedDict()
self.batches = OrderedDict()
self.batches['default'] = pyglet.graphics.Batch()
self.active_batch = 'default'
for i in range(1000):
self.sprites[len(self.sprites)] = Particle(randint(0, 800), randint(0, 600), self.batches[self.active_batch], self.sprites)
self.alive = True
self.fps = 0
self.last_fps = time()
self.fps_label = pyglet.text.Label(str(self.fps) + ' fps', font_size=12, x=3, y=self.height-15)
def on_draw(self):
self.render()
def on_close(self):
self.alive = 0
def on_key_press(self, symbol, modifiers):
if symbol == key.ESCAPE: # [ESC]
self.alive = 0
def render(self):
self.clear()
#self.bg.draw()
self.batches[self.active_batch].draw()
self.fps += 1
if time()-self.last_fps > 1:
self.fps_label.text = str(self.fps) + ' fps'
self.fps = 0
self.last_fps = time()
self.fps_label.draw()
self.flip()
def run(self):
while self.alive == 1:
self.render()
# -----------> This is key <----------
# This is what replaces pyglet.app.run()
# but is required for the GUI to not freeze
#
event = self.dispatch_events()
if __name__ == '__main__':
x = main(demo=True)
x.run()
Bare in mind, on my nVidia 1070 I managed to get roughly 35fps out of this code, which isn't mind blowing. But it is 1000 objects * sides, give or take.
What I've changed is essentially this:
self.batch.add(int(len(points)/2), pyglet.gl.GL_TRIANGLES, self.group, ('v2i/stream', points), ('c3B', colors))
and in your draw loop, you'll do:
self.batch.draw()
Instead of calling Particle.draw() for each particle object.
What this does is that it'll send all the objects to the graphics card in one gigantic batch rather than having to tell the graphics card what to render object by object.
As #thokra pointed out, your code is more CPU intensive than GPU intensive.
Hopefully this fixes it or gives you a few pointers.
Most of this code is taking from a LAN project I did with a good friend of mine a while back:
https://github.com/Torxed/pyslither/blob/master/main.py
Because I didn't have all your code, mainly the main loop. I applied your problem to my own code and "solved " it by tweaking it a bit. Again, hope it helps and steal ideas from that github project if you need to. Happy new year!

How to make an object move in a circular path by constantly adding a rate of chage to its rect.x and rect.y?

Below is the code I wrote.
The object moves along a circular path when I constantly calculate its position and give the coordinates to the obj.rect.x and object.rect.y.
What I need to know is how to rotate the object by something like below.
obj.rect.x += incrementx
obj.rect.y += incrementy
I implemented this in my code bu then the motion becomes anything but circluar.
Please help.
The two images used are here.
http://s5.postimg.org/fs4adqqib/crate_B.png
http://s5.postimg.org/vevjr44ab/plt0.png
import sys, os, pygame
from math import sin,cos,pi, radians
from pygame.locals import *
from standard_object_creator import *
SCREENW = 800
SCREENH = 700
BLUE = (0, 50, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
PURPLE = (145, 0, 100)
YELLOW = (220,220, 0)
pygame.init()
FPSCLOCK = pygame.time.Clock()
FONT1= "data\Cookie-Regular.ttf"
if sys.platform == 'win32' or sys.platform == 'win64':
#os.environ['SDL_VIDEO_CENTERED'] = '2'# center of screen
os.environ['SDL_VIDEO_WINDOW_POS'] = "%d,%d" % (10,30)#top left corner
SCREEN = pygame.display.set_mode((SCREENW, SCREENH))
## self, imagelist, posx, posy, speedx = 0, speedy = 0, value = 0
plat = pygame.image.load("grfx\plt0.png").convert_alpha()
box = pygame.image.load("grfx\crateB.png").convert_alpha()
FPS = 160 # frames per second
platforms = pygame.sprite.Group()
boxes = pygame.sprite.Group()
def maketext(msg,fontsize, colour = YELLOW, font = FONT1):
mafont = pygame.font.Font(font, fontsize)
matext = mafont.render(msg, True, colour)
matext = matext.convert_alpha()
return matext
box = object_factory ([box], 340, 50, 0, 1)
boxes.add(box)
center_x = 450 # x pos in relation to screen width
center_y = 400 # y pos in relation to screen height
radius = 200
angle = -90 #pi / 4 # starting angle 45 degrees
omega = .001 #Angular velocity
for x in xrange(6):
xpos = radius * cos(angle) #+ center_x #Starting position x
ypos = radius * sin(angle) #+ center_x #Startinh position y
obj = object_factory([plat], xpos, ypos)
obj.angle = angle
obj.omega = omega #angula velocity
obj.radius = radius
platforms.add(obj)
angle += 60
mouseposlist = []
all2gether = [platforms, boxes]
while True:
SCREEN.fill(BLACK)
## MOVE THE SPRITE IN A CIRCLE. Each object is placed by varying the step)
for obj in platforms:
obj.angle = obj.angle + obj.omega
## THE CODE BELOW WORKS
obj.rect.x = center_x + (cos(obj.angle) * obj.radius)
obj.rect.y = center_y + (sin(obj.angle) * obj.radius)
## How can I get the same thing to work in this way? by adding the rate of change to the box objects rect.x and rec.t? Why does this not work?
#obj.rect.x += obj.radius * obj.omega * cos(obj.angle)
#obj.rect.y -= obj.radius * obj.omega * sin(obj.angle)
pygame.draw.line(SCREEN, BLUE, (center_x, center_y), (obj.rect.x, obj.rect.y), 2)
for hp in boxes:
hp.rect.x += hp.speedx
hp.rect.y += hp.speedy
hp.move()
hp.collide(platforms)
for thing in all2gether:
thing.update()
thing.draw(SCREEN)
pygame.draw.line(SCREEN, BLUE, (0, SCREENH / 2), (SCREENW, SCREENH / 2), 2)
pygame.draw.line(SCREEN, BLUE, (SCREENW / 2, 0), (SCREENW / 2, SCREENH), 2)
pygame.display.update()
FPSCLOCK.tick(FPS)
##--------------------------------------------------------------
pygame.event.pump()
keys = pygame.key.get_pressed()
for event in pygame.event.get():
if event.type == MOUSEBUTTONDOWN:
if event.button == 1:
pos = pygame.mouse.get_pos()
val = [pos[0], pos[1], 0, 0]
print val
mouseposlist.append(val)
elif event.button == 3 and mouseposlist != []:
mouseposlist.pop(-1)
if event.type == KEYDOWN and event.key == K_ESCAPE:
print mouseposlist
pygame.quit()
sys.exit()
pygame.time.wait(0)

Your solution for moving the sprite in a circle is the time evaluation of the positional equation. You need to calculate the angle as a function of time. x = r * cos (omega * time). your first solution is a loop on time, incrementing omega by the fractional angle that is provided by the angular velocity. To evaluate a position take the amount of time multiplied by the angular velocity....

I manged to solve my problem and would like to share it. The new code is given below.
This works with Python / Pygame
center_of_rotation_x = SCREENW/2
center_of_rotation_y = SCREENH/2
radius = 200
angle = radians(45) #pi/4 # starting angle 45 degrees
omega = 0.1 #Angular velocity
x = center_of_rotation_x + radius * cos(angle) #Starting position x
y = center_of_rotation_y - radius * sin(angle) #Starting position y
SCREEN.blit(star, (x, y)) # Draw current x,y
angle = angle + omega # New angle, we add angular velocity
x = x + radius * omega * cos(angle + pi / 2) # New x
y = y - radius * omega * sin(angle + pi / 2) # New y
The above code works as it is. But when applied as a class it works differently. I will ask that in another question