Pygame and PyOpenGL: No shapes appear on screen - python

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
# [...]

Related

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()

pyglet drawing primitive GL_POINT. A buffer issue?

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()

How do I save a section of a pygame screen and blit it to another location?

I am making a program with a graph that scrolls and I just need to move a section of the screen.
If I do something like this:
import pygame
screen = pygame.display.set_mode((300, 300))
sub = screen.subsurface((0,0,20,20))
screen.blit(sub, (30,40))
pygame.display.update()
It gives the error message: pygame.error: Surfaces must not be locked during blit
I assume it means the child is locked to its parent surface or something but how else could I go about doing this?
screen.subsurface creates a surface, which reference to the original surface. From documentation:
Returns a new Surface that shares its pixels with its new parent.
To avoid undefined behaviour, the surfaces get locked. You've to .copy the surface, before you can .blit it to its source:
sub = screen.subsurface((0,0,20,20)).copy()
screen.blit(sub, (30,40))
Just don't draw to the screen surface directly. Create a Surface for each part of your game/UI, and blit each of those to the screen.
import pygame
def main():
pygame.init()
screen = pygame.display.set_mode((640, 480))
# create two parts: a left part and a right part
left_screen = pygame.Surface((400, 480))
left_screen.fill((100, 0, 0))
right_screen = pygame.Surface((240, 480))
right_screen.fill((200, 200, 0))
x = 100
while True:
events = pygame.event.get()
for e in events:
if e.type == pygame.QUIT:
return
# don't draw to the screen surface directly
# draw stuff either on the left_screen or right_screen
x += 1
left_screen.fill(((x / 10) % 255, 0, 0))
# then just blit both parts to the screen surface
screen.blit(left_screen, (0, 0))
screen.blit(right_screen, (400, 0))
pygame.display.flip()
if __name__ == '__main__':
main()

How to get the coordinates of the place where the sprites are colliding?

is it possible to get the coordinates of the place where the sprites are colliding?, and if it more than one is it possible to get both?
Thanks a lot for the solvers
You can use the Pymunk physics library to get the contact points. Of course that means you'll have to familiarize yourself with this library first (it can be a bit difficult for beginners). You especially need to know how collision handlers, arbiters and callback functions work.
So you create a collision handler which checks if there were collisions between shapes of two specified collision types, e.g. handler = space.add_collision_handler(1, 1). When a collsion occurs the handler calls some callback functions (in the example I set handler.post_solve to the callback function) which receive an arbiter object as an argument that holds the collision data. Then you can extract the needed information from this arbiter, add it to a list or other data structure and use it in your main loop.
import sys
import random
import pygame as pg
import pymunk as pm
from pymunk import Vec2d
def flipy(p):
"""Convert chipmunk coordinates to pygame coordinates."""
return Vec2d(p[0], -p[1]+600)
class Ball(pg.sprite.Sprite):
def __init__(self, space, pos, mass=5, radius=30, elasticity=0.9):
super().__init__()
self.image = pg.Surface((60, 60), pg.SRCALPHA)
pg.draw.circle(self.image, pg.Color('royalblue'), (30, 30), radius)
self.rect = self.image.get_rect(center=pos)
# Set up the body and shape of this object and add them to the space.
inertia = pm.moment_for_circle(mass, 0, radius, (0, 0))
self.body = pm.Body(mass, inertia)
self.body.position = flipy(pos)
self.shape = pm.Circle(self.body, radius, (0, 0))
self.shape.elasticity = elasticity
# This type will be used by the collision handler.
self.shape.collision_type = 1
self.space = space
self.space.add(self.body, self.shape)
def update(self):
pos = flipy(self.body.position)
self.rect.center = pos
if pos.y > 600:
self.space.remove(self.body, self.shape)
self.kill()
def main():
screen = pg.display.set_mode((800, 600))
clock = pg.time.Clock()
all_sprites = pg.sprite.Group()
done = False
contact_points = []
def contact_callback(arbiter, space, data):
"""Append the contact point to the contact_points list."""
if arbiter.is_first_contact:
for contact in arbiter.contact_point_set.points:
contact_points.append(contact.point_a)
# Pymunk stuff.
space = pm.Space()
space.gravity = Vec2d(0, -900)
# This collision handler will be used to get the contact points.
# It checks if shapes with `collision_type` 1 collide with others
# that also have type 1.
handler = space.add_collision_handler(1, 1)
# After a collision is solved, the callback funtion will be called
# which appends the contact point to the `contact_points` list.
handler.post_solve = contact_callback
# Create some static lines.
static_lines = [
pm.Segment(space.static_body, (170, 200), (0, 300), .1),
pm.Segment(space.static_body, (170, 200), (500, 200), .1),
pm.Segment(space.static_body, (500, 200), (600, 260), .1),
]
for line in static_lines:
line.elasticity = 0.9
space.add(static_lines)
while not done:
for event in pg.event.get():
if event.type == pg.QUIT:
done = True
elif event.type == pg.MOUSEBUTTONDOWN:
all_sprites.add(Ball(space, event.pos))
contact_points = []
space.step(1/60) # Update the physics space.
all_sprites.update()
screen.fill((60, 70, 80))
all_sprites.draw(screen) # Draw the sprite group.
# Draw static_lines.
for line in static_lines:
body = line.body
p1 = flipy(body.position + line.a.rotated(body.angle))
p2 = flipy(body.position + line.b.rotated(body.angle))
pg.draw.line(screen, pg.Color('gray68'), p1, p2, 5)
# Draw contact_points.
for point in contact_points:
x, y = flipy(point)
x, y = int(x), int(y)
pg.draw.circle(screen, pg.Color('orange'), (x, y), 8)
pg.display.flip()
clock.tick(60)
if __name__ == '__main__':
pg.init()
main()
pg.quit()
sys.exit()

Can somebady help me why errors exist in my pygame code about `ball moving`?

I will show my code below. I think when I def moveDot, something wrong I can feel it. However, I just code as my instructor's presentation. She's code can work and mine cannot. I don't know the reason. I think the order of moveDot's variances may have some problems. Is that right? I will appreciate anyone who can help me! Thanks a lot!
# Poke The Dots
# There are two dots that are moving on a 500 by 400 window
# There is a score board that displays the time in seconds
# since the game started
# If the player clicks inside the window, the dots disappear
# and reappear at some random location
# If the dots collide, the dots stop moving, the score stops
# changing and Game Over is displayed.
# Version 1
import pygame, sys, time
from pygame.locals import *
# User-defined classes
# User-defined functions
def main():
# Initialize pygame
pygame.init()
# Set window size and title, and frame delay
surfaceSize = (500, 400) # window size
windowTitle = 'Poke The Dots' #window title
frameDelay = 0.02 # smaller is faster game
# Create the window
surface = pygame.display.set_mode(surfaceSize, 0, 0)
pygame.display.set_caption(windowTitle)
# create and initialize red dot and blue dot
gameOver = False
color1=pygame.Color('red')
center1 = [50, 75]
radius1=30
speed1=[1,2]
color2=pygame.Color('blue')
center2=[200,100]
radius2=40
speed2=[2,1]
# Draw objects
pygame.draw.circle(surface, color1, center1, radius1, 0)
pygame.draw.circle(surface, color2,center2,radius2,0)
gameOver = update(surface, color1, center1, radius1, speed1, color2, center2, radius2, speed2)
# Refresh the display
pygame.display.update()
# Loop forever
while True:
# Handle events
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
# Handle additional events
# Update and draw objects for the next frame
#gameOver = update(center, surface)
# Refresh the display
pygame.display.update()
# Set the frame speed by pausing between frames
time.sleep(frameDelay)
def update(surface, color1, center1, radius1, speed1, color2, center2, radius2, speed2):
#Check if the game is over. If so, end the game and
#returnTrue. Otherwise, update the game objects, draw
#them, and return False.
#This is an example update function - replace it.
#- center is a list containing the x and y int coords
#of the center of a circle
#- surface is the pygame.Surface object for the window
erasecolor=pygame.Color('black')
if False: # check if the game is over
return True
else: # continue the game
surface.fill(erasecolor)
moveDot(surface, color1, center1, radius1)
moveDot(surface, color2, center2, radius2)
pygame.draw.circle(surface,color1,center1,radius1,0,0)
pygame.draw.circle(surface,color2,center2,radius2,0,0)
return False
def moveDot(surface,center,radius,speed):
size=surface.get_size()
for coord in range(0,2):
center[coord]=center[coord]+speed[coord]
if center [coord]<radius:
speed[coord]=-speed[coord]
if center[coord]+radius>size(coord):
speed[coord]=-speed[coord]
main()
The order of your arguments being passed when you call moveDot is incorrect. It should be
moveDot(surface, center1, radius1, speed)
For both statements. Speed should be the speed of movement of the circle.

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