pyglet drawing primitive GL_POINT. A buffer issue? - python

Beginner in pyglet. I have an issue when drawing GL_POINT using pyglet.graphicss.draw(). I want this GL_POINT to be drawn after another on the next pixel buffer, but it seems the function does not keep the last GL_POINT to be drawn on the next pixel buffer.
import pyglet
from pyglet.gl import *
from pyglet.window import key # for key input, on_key_press
window = pyglet.window.Window(800, 600) # create a window object with the resolution of 800x600
window.set_caption('window title')
glClear(GL_COLOR_BUFFER_BIT)
#window.event
def on_key_press(symbol, modifiers): # keyboard input handler
if symbol == key.L: # Drawing a center point
print("DRAWING TEST A POINT (400, 300)")
pyglet.graphics.draw(
1, pyglet.gl.GL_POINTS,
('v2i', (400, 300))
)
elif symbol == key.K: # Drawing a bit further 100 more horizontally from center point
print("DRAWING TEST A POINT (500, 300)")
pyglet.graphics.draw(
1, pyglet.gl.GL_POINTS,
('v2i', (500, 300))
)
pyglet.app.run()
Pressing L would draw a center point.
Then pressing K would draw 100 more horizontally from the center point with the last center point gone.
Where is the bug? is there something wrong with my code? if not,
my guess would be, does pyglet.graphicss.draw() function actually redraw one after another primitive shape? How do I code to draw one after another?

The issue is caused by Double buffering. You can solve the issue by drawing the point to both buffers. Draw the point twice and swap the OpenGL front and back buffers in between by (flip).
pyglet.graphics.draw(
1, pyglet.gl.GL_POINTS,
('v2i', (400, 300))
)
window.flip()
pyglet.graphics.draw(
1, pyglet.gl.GL_POINTS,
('v2i', (400, 300))
)
But I recommend to add the points to a list and to draw the list. e.g.:
import pyglet
from pyglet.gl import *
from pyglet.window import key # for key input, on_key_press
points = []
window = pyglet.window.Window(800, 600) # create a window object with the resolution of 800x600
window.set_caption('window title')
glClear(GL_COLOR_BUFFER_BIT)
#window.event
def on_key_press(symbol, modifiers): # keyboard input handler
global points
if symbol == key.L: # Drawing a center point
print("DRAWING TEST A POINT (400, 300)")
points += [400, 300]
elif symbol == key.K: # Drawing a bit further 100 more horizontally from center point
print("DRAWING TEST A POINT (500, 300)")
points += [500, 300]
pyglet.graphics.draw(len(points) // 2, pyglet.gl.GL_POINTS, ('v2i', points))
pyglet.app.run()

Related

Pygame and PyOpenGL: No shapes appear on screen

I have created a complete snake game using C++ and OpenGL before, and I want to do the same using Python, pygame, and PyOpenGL. The current problem I have is that after I spawn a fruit, it does not appear on the screen. Here's the code for my main function:
def main(): # Main function
# Initialize game components
game = Game(800, 600)
test_fruit = game.spawn_fruit(Point(100, 100))
# Initialize pygame module
pygame.init()
pygame.display.set_mode(game.get_window_size(), DOUBLEBUF | OPENGL)
pygame.display.set_caption("Python Game")
# Define variable to control main loop
running = True
# Main loop
while running:
# event handling, gets all event from the event queue
for event in pygame.event.get():
# only do something if the event is of type QUIT
if event.type == pygame.QUIT:
# change the value to False, to exit the main loop
running = False
# Modify game properties
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
game.draw_shapes()
pygame.display.flip()
pygame.time.wait(5)
It's possible I'm missing a pygame or pyopengl function, but I'm not sure. I've also tried changing pygame.display.flip() to pygame.display.update(), yet it gives me an error ("cannot update an OpenGL display") instead.
Here's the code for the shape I am attempting to display:
class Circle:
def __init__(self, pivot: Point, radius: int, sides: int, fill: bool, color: Color):
self.pivot = pivot
self.radius = radius
self.sides = sides
self.fill = fill
self.color = color
# Draw the shape of the circle
def draw(self):
glColor3f(self.color.r, self.color.g, self.color.b)
if self.fill:
glBegin(GL_POLYGON)
else:
glBegin(GL_LINE_LOOP)
for i in range(100):
cosine = self.radius * cos(i*2*pi/self.sides) + self.pivot.x
sine = self.radius * sin(i*2*pi/self.sides) + self.pivot.y
glVertex2f(cosine, sine)
glEnd()
OpenGL coordinates are in range [-1.0, 1.0] (Normalized Device Space). The Normalized device space is a unique cube from the left, bottom, near (-1, -1, -1) to the right, top, far (1, 1, 1).
If you want to use "window" coordinates, you must specify an Orthographic projection using glOrtho:
glOrtho(0, 800, 600, 0, -1, 1)
Choose the matrix mode with glMatrixMode and load the Identity matrix with glLoadIdentity.
Example:
def main(): # Main function
# Initialize game components
game = Game(800, 600)
test_fruit = game.spawn_fruit(Point(100, 100))
# Initialize pygame module
pygame.init()
pygame.display.set_mode(game.get_window_size(), DOUBLEBUF | OPENGL)
pygame.display.set_caption("Python Game")
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
glOrtho(0, 800, 600, 0, -1, 1)
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
# Define variable to control main loop
running = True
# [...]

Surface display able to properly represent opacity, but any other surface cannot

I am trying to make a tic-tac-toe game with pygame. An important thing I want is being able to make my images (eg. X and O) slightly translucent for when my user is only hovering over a grid tile. I also use opacity to visually show whose turn it is.
This is what I have tried:
x_tile = pygame.image.load('x_tile').convert()
x_tile.set_alpha(100)
This works fine when I'm blitting x_tile directly onto the display like this:
# This is for simplicity's sake. The actual blit process is all being done in an infinite loop
screen = pygame.display.set_mode((300, 300))
screen.blit(x_file, x_file.get_rect())
But my game is using another image that represents the grid, and that is what I'm blitting onto. So I'm blitting this board onto the display, then blitting the actual X and O tiles on the board.
screen = pygame.display.set_mode((300, 300))
screen.blit(board, board_rect)
board.blit(x_tile, x_tile.get_rect(center=grid[0].center)) # I have a list of Rects that make a grid on the board image. grid[0] is the top left
When I do it that way, x_tile.set_alpha(100) seems to have no effect and I don't know what to do.
Edit: I am using pygame 2.0.1. I'm on Windows 10.
Here is the entire code
import os
import pygame
from pygame.locals import *
# Game constants
WIN_SIZE = WIN_WIDTH, WIN_HEIGHT = 800, 600
BLACK = 0, 0, 0
WHITE = 255, 255, 255
RED = 255, 0, 0
BLUE = 0, 0, 255
# Game functions
class NoneSound:
"""dummy class for when pygame.mixer did not init
and there is no sound available"""
def play(self): pass
def load_sound(file):
"""loads a sound file, prepares it for play"""
if not pygame.mixer:
return NoneSound()
music_to_load = os.path.join('sounds', file)
try:
sound = pygame.mixer.Sound(music_to_load)
except pygame.error as message:
print('Cannot load following sound:', music_to_load)
raise SystemExit(message)
return sound
def load_image(file, colorkey=None, size=None):
"""loads image into game"""
image_to_load = os.path.join('images', file)
try:
image = pygame.image.load(image_to_load).convert()
except pygame.error as message:
print('Cannot load following image:', image_to_load)
raise SystemExit(message)
if colorkey is not None:
if colorkey == -1:
colorkey = image.get_at((0, 0))
image.set_colorkey(colorkey, RLEACCEL)
if size is not None:
image = pygame.transform.scale(image, size)
return image
# Game class
class TTTVisual:
"""Controls game visuals"""
def __init__(self, win: pygame.Surface):
self.win = win
# Load in game images
self.board = load_image('board.png', size=(600, 450), colorkey=WHITE)
self.x_tile = load_image('X_tile.png', size=(100, 100), colorkey=BLACK)
self.o_tile = load_image('O_tile.png', size=(100, 100), colorkey=BLACK)
# Translucent for disabled looking tile
self.x_tile_trans = self.x_tile.copy()
self.o_tile_trans = self.o_tile.copy()
self.x_tile_trans.set_alpha(100)
self.o_tile_trans.set_alpha(100)
# Used to let user know whose turn it is
self.x_turn = pygame.transform.scale(self.x_tile, (50, 50))
self.o_turn = pygame.transform.scale(self.o_tile, (50, 50))
self.x_turn_trans = pygame.transform.scale(self.x_tile_trans, (50, 50))
self.o_turn_trans = pygame.transform.scale(self.o_tile_trans, (50, 50))
self.get_rects()
self.grid = self.setup_grid()
def get_rects(self):
"""Creates coords for some visual game assets"""
self.board_rect = self.board.get_rect(
center=self.win.get_rect().center)
self.x_turn_rect = self.x_turn.get_rect(top=10, left=10)
self.o_turn_rect = self.o_turn.get_rect(top=10, left=WIN_WIDTH-60)
def setup_grid(self):
grid = []
left = 0
top = 150
row = 0
for i in range(9):
if (i != 0) and (i % 3 == 0):
row += 1
left = 0
grid.append(pygame.Rect(left, row*top, 200, 150))
left += 200
return grid
def update_turn_status(self):
"""Updates the X and O tiles on the top left and right to
let user know whose turn it is"""
self.win.blits((
(self.x_turn_trans, self.x_turn_rect),
(self.o_turn, self.o_turn_rect)
))
def update_grid(self):
"""Updates board"""
self.win.blit(self.board, self.board_rect)
# Here is where you could change board to win and see that the tile changes in opacity
self.board.blit(self.x_tile_trans, self.x_tile_trans.get_rect(center=self.grid[0].center))
def update(self):
self.win.fill(WHITE)
self.update_turn_status()
self.update_grid()
pygame.display.flip()
def main():
pygame.init()
win = pygame.display.set_mode(WIN_SIZE)
tttvisual = TTTVisual(win)
tttfunc = TTTFunc(tttvisual)
clock = pygame.time.Clock()
running = True
while running:
clock.tick(60)
for event in pygame.event.get():
if event.type == QUIT:
running = False
tttvisual.update()
pygame.quit()
if __name__ == "__main__":
main()
The issue is caused by the line:
self.board.blit(self.x_tile_trans, self.x_tile_trans.get_rect(center=self.grid[0].center))
You don't blit the image on the display Surface, but on the self.board Surface. When a Surface is blit, it is blended with the target. When you draw on a Surface, it changes permanently. Since you do that over and over again, in every frame, the source Surface appears to by opaque. When you decrease the alpha value (e.g. self.x_tile_trans.set_alpha(5)), a fade in effect will appear.
Never draw on an image Surface. Always draw on the display Surface. Cleat the display at begin of a frame. Draw the entire scene in each frame and update the display once at the end of the frame.
class TTTVisual:
# [...]
def update_grid(self):
"""Updates board"""
self.win.blit(self.board, self.board_rect)
# Here is where you could change board to win and see that the tile changes in opacity
x, y = self.grid[0].center
x += self.board_rect.x
y += self.board_rect.y
self.win.blit(self.x_tile_trans, self.x_tile_trans.get_rect(center=(x, y)))
The typical PyGame application loop has to:
handle the events by either pygame.event.pump() or pygame.event.get().
update the game states and positions of objects dependent on the input events and time (respectively frames)
clear the entire display or draw the background
draw the entire scene (blit all the objects)
update the display by either pygame.display.update() or pygame.display.flip()

How can i build this zoom screen at the side?

So, i am building a physics simulation. And whenever the left mouse button is pressed, the player can control the height the ball is at(by dragging). What i want to build is: whenever the player is dragging the ball to reposition it, a screen will appear at the side, and inside it i want a real time zoom of where the ball is(sorry if i didnt explain it too well, i think the picture explains it better).
Just to clarify, I want it all in one window only
Can anyone help me? :)
It's not that complicated. Just draw your stuff on a seperate Surface, then use subsurface and the transform module. Here's an example:
import pygame
pygame.init()
def main():
# we'll not draw an the display surface directly
screen = pygame.display.set_mode((800, 600))
# but we'll draw everything on this surface
main = screen.copy()
# this surface is the zoom window
zoom = pygame.Surface((400, 300))
# the ball and its movement vector
ball = pygame.Rect(550, 100, 40, 40)
ball_v = pygame.Vector2(0, 0)
dt = 0
clock = pygame.time.Clock()
while True:
pressed = pygame.mouse.get_pressed()
for e in pygame.event.get():
if e.type == pygame.QUIT:
return
if pressed[0]:
# dragging the ball if mouse button is pressed
ball_v = pygame.Vector2(0, 0)
ball.center = pygame.mouse.get_pos()
else:
# if not, we apply the gravity
ball_v += pygame.Vector2(0, 0.2)
# move the ball
ball.move_ip(ball_v)
# but keep it on the screen
ball.clamp_ip(main.get_rect())
# draw the main surface
main.fill(pygame.Color('white'))
w = 10
for y in range(main.get_rect().height):
pygame.draw.rect(main, pygame.Color('lightgray'), pygame.Rect(500, y, w, 1))
w = (w - 1) % 20
pygame.draw.circle(main, pygame.Color('orange'), ball.center, 20)
screen.blit(main, (0, 0))
# if the mouse button is pressed, draw the zoom window
if pressed[0]:
# the area of the main surface that should be drawn in the zoom window
rect = pygame.Rect(0, 0, 200, 150)
# center it on the ball
rect.center = ball.center
# ensure it's on the screen
rect.clamp_ip(main.get_rect())
# grab the part from the main surface
sub = main.subsurface(rect)
# scale it
zoom.blit(pygame.transform.scale2x(sub), (0, 0))
pygame.draw.rect(zoom, pygame.Color('black'), zoom.get_rect(), 4)
screen.blit(zoom, (25, 25))
pygame.display.flip()
clock.tick(120)
main()

Pygame surface location seems to be different than what it is on the screen?

I am trying to make a virtual phone kind of program with pygame, just to experiment with it, but i ran into a problem. I have loaded an image and then blitted it to the bottom left of the screen. But when i do print(imagename.get_rect()) it prints out a location at 0, 0 of the screen.
also the mouse collides with it there. what am i not understanding?
def aloitus(): #goes back to the home screen
cls() #clears the screen
tausta = pygame.image.load("./pyhelin.png") #load background
tausta = pygame.transform.scale(tausta, (360, 640)) #scale it
screen.blit(tausta, (0, 0)) #blit it
alapalkki = pygame.Surface((600, 100)) #ignore
alapalkki.set_alpha(120)
alapalkki.fill(blonk)
screen.blit(alapalkki, (0, 560))
global messenger #this is the thing!
messenger = pygame.image.load("./mese.png").convert_alpha() #load image
print(messenger.get_rect()) #print its location
messenger = pygame.transform.scale(messenger, (60,65)) #scale it to the correct size
screen.blit(messenger, (10, 570)) # blit on the screen
update() #update screen
aloitus() # at the start of the program, go to the home screen
while loop: #main loop
for event in pygame.event.get():
if event.type == pygame.MOUSEBUTTONDOWN:
# Set the x, y postions of the mouse click
x, y = event.pos
if messenger.get_rect().collidepoint(x, y): #messenger is the image defined earlier
#do things
print("hi")
Expected result would be, when clicking on the image "hi" would be printed.
actual result is that when topleft corner is clicked hi is printed.
get_rect returns a pygame.Rect with the default top left coordinates (0, 0). You need to set the coordinates afterwards or pass them as a keyword argument to get_rect.
I suggest assigning the rect to another variable and set the coords in one of these ways:
messenger_rect = messenger.get_rect()
messenger_rect.x = 100
messenger_rect.y = 200
# or
messenger_rect.topleft = (100, 200)
# or pass the coords as an argument to `get_rect`
messenger_rect = messenger.get_rect(topleft=(100, 200))
There are even more rect attributes to which you can assign the coordinates:
x,y
top, left, bottom, right
topleft, bottomleft, topright, bottomright
midtop, midleft, midbottom, midright
center, centerx, centery

Pygame - " display.set_mode() " creates a smaller window, than requested ( Surfaces are outside of the window )

I´m trying to draw a ship on the bottom-right of the screen, but it´s not appearing on the window! Coordinates seem to be off on X, Y by approximately 50 points. No matter what kind of resolution is set through pygame.display.set_mode(), the window is always smaller than the defined dimensions ( by 50 ).
External FULL HD screen is connected to the laptop through HDMI, but disconnecting it had no effect. Using Windows 10, Python 3.6.2 and Pygame 1.9.3.
Using "centerx", "bottom" to display the ship
Same as above, but substracting both "centerx" and "bottom" by 50.
import sys
import pygame
def main():
#Initialize the screen.
pygame.init()
screen = pygame.display.set_mode( ( 1024, 768 ) )
screen_rect = screen.get_rect()
bg_color = ( 235, 235, 235 )
# Load the ship surface, get its rect.
ship_image = pygame.image.load( "images/ship.bmp" )
ship_rect = ship_image.get_rect()
# TRYING TO POSITION THE SHIP TO THE BOTTOM-RIGHT OF THE SCREEN.
screen_bottom_right = screen_rect.centerx, screen_rect.bottom
while True:
for event in pygame.event.get():
if ( event == "QUIT" ):
sys.exit()
# Redraw the screen.
screen.fill( bg_color )
# Blit the ship´s image.
screen.blit( ship_image, ( screen_bottom_right ) )
pygame.display.flip()
main()
Tried searching for answers, but none of them had worked / explicitly mentioned this issue. Tutorials, which used the code didn´t substract the X/Y coordinates to obtain exactly positioned image. "0, 0" as rect drawing position works flawlessly. The bottom-right suffers from the above-mentioned issue.
Pygame blits the image so that its top left corner is positioned at the coordinates that you passed. So by passing the screen bottom as the y-coord you're telling pygame to draw the ship below the screen. To fix this you can assign the bottomright attribute of the screen_rect to the bottomright of the ship_rect and then just blit the image at the ship_rect.
import sys
import pygame
def main():
pygame.init()
screen = pygame.display.set_mode((1024, 768))
screen_rect = screen.get_rect()
bg_color = (235, 235, 235)
ship_image = pygame.Surface((40, 50))
ship_image.fill((20, 10, 100))
ship_rect = ship_image.get_rect()
ship_rect.bottomright = screen_rect.bottomright
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
screen.fill(bg_color)
screen.blit(ship_image, ship_rect)
pygame.display.flip()
main()
pygame.Rects have a lot of other attributes that you can use as well, but keep in mind that only the topleft coords are used as the blit position:
x,y
top, left, bottom, right
topleft, bottomleft, topright, bottomright
midtop, midleft, midbottom, midright
center, centerx, centery
size, width, height
w,h

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