You blit an image onto your surface to use as your background. Then you press button X to blit an image on the same surface, how do you erase the image? I have this so far, but then I end up with a white rectangle in the middle of my background.
screen = pygame.display.set_mode(1280, 512)
screen.blit(background, (0,0))
while True:
pygame.display.flip() #flip is same as update
for event in pygame.event.get():
if (event.type == pygame.KEYDOWN):
if event.key == pygame.K_SPACE:
screen.blit(player, (x, y))
if event.key == pygame.K_BACKSPACE:
pygame.draw.rect(screen, [255,255,255], (x, y, 62,62))
There are basically two things you can do here. You can go the simple route and just draw the background again...
if event.key == pygame.K_BACKSPACE:
screen.blit(background, (0,0))
Or, if you want it to be a little more efficient, you can have the blit method only draw the part of the background that the player image is covering up. You can do that like this...
screen.blit(background, (x, y), pygame.Rect(x, y, 62, 62))
The Rect in the third argument will cause the blit to only draw the 62x62 pixel section of 'background' located at position x,y on the image.
Of course this assumes that the player image is always inside the background. If the player image only partially overlaps the background I'm not entirely sure what will happen. It'll probably throw an exception, or it'll just wrap around to the other side of the image.
Really the first option should be just fine if this is a fairly small project, but if you're concerned about performance for some reason try the second option.
Normally the blit workflow is just to blit the original background to screen.
In your code you would use screen.blit(background, (0,0))
When you start combining lots of surfaces you will probably want either a variable or a list of variables to keep track of screen state.
E.g.
Initialise Background
objectsonscreen = []
objectsonscreen.append(background)
screen.blit(background, (0,0))
Add Sprite
objectsonscreen.append(player)
screen.blit(player, (x, y))
Clear Sprite
objectsonscreen = [background]
screen.blit(background, (0,0))
See here for more information on sprites in Pygame. Note that if your background isn't an image background and is just a solid color you could also use screen.fill([0, 0, 0]) instead.
I personally use
pygame.draw.rect(screen, (RgbColorHere), (x, y, width, height))
Related
I am trying to make a game where if someone press left-click, pygame draws a circle, then a line connecting the circle to the upper left corner. If he/she press right-click, it removes everything created from the screen. I thought about just covering everything with a big black square, but that is not really clearing the screen, just covering it. My code is as follow:
from pygame import *
init()
size = width, height = 650, 650
screen = display.set_mode(size)
button = 0
BLACK = (0, 0, 0)
GREEN = (0, 255, 0)
def drawScene(screen, button):
# Draw circle if the left mouse button is down.
if button==1:
draw.circle(screen,GREEN,(mx,my), 10)
draw.line(screen,GREEN, (0,0),(mx,my))
if button == 3:
mouse.set_visible(False)
display.flip()
running = True
myClock = time.Clock()
# Game Loop
while running:
for e in event.get(): # checks all events that happen
if e.type == QUIT:
running = False
if e.type == MOUSEBUTTONDOWN:
mx, my = e.pos
button = e.button
drawScene(screen, button)
myClock.tick(60) # waits long enough to have 60 fps
quit()
Kindly guide me in this situation. Thanks in advance.
I thought about just covering everything with a big black square, but that is not really clearing the screen, just covering it.
There is not any difference between cover and clear. The screen consist of pixels. Drawing an object just changes the color of the pixels. Drawing a black square changes the color of the pixel again.
Note, operations like pygame.draw.circle() and pygame.draw.line() do not create any object. They just change the colors of some pixels of the surface which is passed to the operation.
The easiest way to clear the entire window is pygame.Surface.fill():
screen.fill((0, 0, 0))
respectively
screen.fill(BLACK)
In computer graphics, there is no such thing as "clearing" a screen. you can only overwrite the previous drawing with new pixels. your idea of drawing a big black rectangle would work perfectly but I may be more efficient to use screen.fill(0)
I'm looking for method that allow me to draw single pixel on display screen. For example when I click mouse, I want the position of clicked pixel to change color. I know how to read mouse pos, but I could not find simple pixel draw ( there is screen.fill method but it's not working as I want).
You can do this with surface.set_at():
surface.set_at((x, y), color)
You can also use pygame.gfxdraw.pixel():
from pygame import gfxdraw
gfxdraw.pixel(surface, x, y, color)
Do note, however, the warning:
EXPERIMENTAL!: meaning this api may change, or dissapear in later
pygame releases. If you use this, your code will break with the next
pygame release.
You could use surface.fill() to do the job too:
def pixel(surface, color, pos):
surface.fill(color, (pos, (1, 1)))
You can also simply draw a line with the start and end points as the same:
def pixel(surface, color, pos):
pygame.draw.line(surface, color, pos, pos)
The usual method of drawing a point on a Surface or the display is to use [`pygame.Surface.set_at']:
window_surface.set_at((x, y), my_color)
However, this function is very slow and leads to a massive lack of performance if more than 1 point is to be drawn.
Minimal example where each pixel is set separately: repl.it/#Rabbid76/PyGame-DrawPixel-1
import pygame
pygame.init()
window = pygame.display.set_mode((300, 300))
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
window.fill(0)
rect = pygame.Rect(window.get_rect().center, (0, 0)).inflate(*([min(window.get_size())//2]*2))
for x in range(rect.width):
u = x / (rect.width - 1)
color = (round(u*255), 0, round((1-u)*255))
for y in range(rect.height):
window.set_at((rect.left + x, rect.top + y), color)
pygame.display.flip()
pygame.quit()
exit()
Another option is to use a "pygame.PixelArray" object. This object enables direct pixel access to Surface objects. A PixelArray pixel item can be assigned directly. The pixel can be accessed by subscription. The PixelArray locks the Surface, You have to close() it when you have changed the pixel:
pixel_array = pygame.PixelArray(window_surface)
pixel_array[x, y] = my_color
pixel_array[start_x:end_x, start_y:end_y] = my_color
pixel_array.close()
Minimal example that set one line of pixels at once: repl.it/#Rabbid76/PyGame-DrawPixel-2
import pygame
pygame.init()
window = pygame.display.set_mode((300, 300))
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
window.fill(0)
rect = pygame.Rect(window.get_rect().center, (0, 0)).inflate(*([min(window.get_size())//2]*2))
pixel_array = pygame.PixelArray(window)
for x in range(rect.width):
u = x / (rect.width - 1)
color = (round(u*255), 0, round((1-u)*255))
pixel_array[rect.left + x, rect.top:rect.bottom] = color
pixel_array.close()
pygame.display.flip()
pygame.quit()
exit()
For those who are interested in a more modern answer to the question you can use pygame.draw.circle() to draw a single pixel at a given position (or center).
pygame.draw.circle(surface, color, center, 0)
The documentation specifically says:
radius (int or float) -- radius of the circle, measured from the center parameter, a radius of 0 will only draw the center pixel
One way of doing that is to draw a line staring and ending at the same point.
pygame.draw.line(surface, (255,255,255), (x,y), (x,y))
draw a single coloured pixel
def drawPoint(x,y,color):
s = pygame.Surface((1,1)) # the object surface 1 x 1 pixel (a point!)
s.fill(color) # color as (r,g,b); e.g. (100,20,30)
# now get an object 'rectangle' from the object surface and place it at position x,y
r,r.x,r.y = s.get_rect(),x,y
screen.blit(s,r) # link the object rectangle to the object surface
of course you have to call: pygame.display.update() once you have
drawn all the points you need, don't call update at every single point.
# with this function, you can draw points and change the yer size
def point(surface, color, x, y, size):
'''the surface need the information of the pygame window'''
for i in range(0, size):
pygame.draw.line(surface, color, (x, y-1), (x, y+2), abs(size))
When I use blit function, it does not delete the previous loaded sprite to make sprites move until I call the "display.fill(bgcolor)" function. The problem is that I have a multicolored background. so how do I update the image without affecting my background?
NOTE - already tried "pygame.display.update()" and "pygame.display.flip()" - it doesn't help :(
class states():
def __init__(self, goku1,goku2, x, y):
self.image=goku1
keys=pygame.key.get_pressed()
if keys[K_RIGHT]:
self.image=goku2
if keys[K_LEFT]:
self.image=goku2
while True:
pygame.display.flip()
pygame.display.update()
obj=states(goku1, goku2, x, y)
call=position()
DISPLAYSURF.blit(obj.image, (x, y))
am stuck for long :(
You would blit the background first, and then blit the new location for the sprite that is moving. It would look something like this:
window= pygame.display.set_mode(WINDOWSIZE, 0, 32)
while True:
#update events
window.blit(your_multi_colored_background, (0, 0))
window.blit(obj.image, (x, y))
pygame.display.update()
Hope this helps.
Blit never delete previous element - it can't - all blitted elements create one bitmap.
You have to blit all elements again in all loop.
Or you have to keep part of background before you blit sprite and use it later to blit this part in place of sprite to remove it.
You can also use pygame.display.update() with arguments to blit only some parts of background.
I am asking if it is possible to draw a list of sprites in Pygame, and if so how?
I am attempting to draw from a two dimensional list, that will draw the map
import pygame
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
RED = (255, 0, 0)
screen_width = 700
screen_height = 400
screen = pygame.display.set_mode([screen_width, screen_height])
pygame.init()
image = pygame.image.load("Textures(Final)\Grass_Tile.bmp").convert()
imagerect = image.get_rect()
tilemap = [
[image, image, image],
[image, image, image]
]
done = False
clock = pygame.time.Clock()
while not done:
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
screen.fill(BLACK)
screen.blit(tilemap, imagerect)
clock.tick(20)
pygame.display.flip()
pygame.quit()
I know I can do something much simpler, like drawing each image. But, I am wondering if I can do this, so in the future when I have more sprites I can just add to the list, and create the map.
Thank you!
I don't believe this is quite possible as you describe it, but if these images aren't going to change often I would suggest pre-blitting all your map images to a pygame Surface which can later be used, using something like:
map_surface = pygame.Surface(( len(tilemap[0])*TILE_WIDTH, len(tilemap)*TILE_HEIGHT ))
for y,row in enumerate(tilemap):
for x,tile_surface in enumerate(row):
map_surface.blit(tile_surface,(x*TILE_WIDTH,y*TILE_HEIGHT))
and then later you can simply use:
screen.blit(map_surface)
One thing to note is that even if your map does change, you will only have to blit the changed tiles onto the map_surface surface, and not have to recreate the whole thing.
I am using pygame and python for a project I am building, and I am building a splashscreen for when the game first opens. I have a .png that I want to show for the splashscreen, and decided to fade it in and out from black. the best way I found to do this was by blitting the image with a set alpha. I made this code, but it runs really slowly (the program hangs for 30 seconds) and doesn't give an alpha. Only displays the picture onscreen. What am i doing wrong?
screen = pygame.display.set_mode([1066,600])
#Drawable surface
background = pygame.Surface(screen.get_size())
#Used for converting color maps
background = background.convert()
#Splashscreen
#image fades in
for i in range (225):
background.fill((0,0,0))
image = pygame.image.load("logo.png")
image.set_alpha(i)
logoimage = screen.blit(image,(0,0))
pygame.display.flip()
pygame.time.delay(2000)
#image fades out
#goes on to display main menu
Another problem that you might be having (besides what monkey said) is that you might need to use surface.convert() which converts the image into a form where the alpha can be changed. You can do either of the following.
image = pygame.image.load("logo.png")
image = image.convert()
or
image = pygame.image.load("logo.png").convert()
I have found that, although surface.convert_alpha() should do pretty much the same thing, it doesn't usually work. Try this test code to check.
import pygame, sys
pygame.init()
window=pygame.display.set_mode((1500, 800))
background=pygame.Surface((window.get_rect().width, window.get_rect().height))
background.fill((0, 0, 0))
image=pygame.image.load('InsertImageHere.png')
image=image.convert()
image2=pygame.image.load('InsertImage2Here.png')
image2=image2.convert_alpha()
rect=image.get_rect()
rect2=image2.get_rect()
rect2.left=rect.width+1
i=1
while True:
for event in pygame.event.get():
if event.type==12:
pygame.quit()
sys.exit()
image.set_alpha(i)
image2.set_alpha(i)
window.fill((255, 255, 255))
window.blit(background, background.get_rect())
window.blit(image, rect)
window.blit(image2, rect2)
pygame.time.delay(20)
i+=1
if i==255:
i=1
pygame.display.update()
In my testings, image 1 faded in properly, but image 2 stayed dark the whole time. You should try it for yourself; your computer might work differently.
If surface.convert_alpha() does work for you, you should use it, otherwise, do what I said before. This should solve your problem.
You should also note that I used pygame.time.delay(20) rather than 2000 like you had before. 2000 would be a bit too long if you are increasing the alpha in incraments of one.
[1] You don't want to load the image every iteration. Because creating a new surface is a slow operation. [2] Your loop draws 225 times, then afterward the final iteration, waits 2000ms.
You want:
image = pygame.image.load("logo.png")
for i in range (225):
background.fill((0,0,0))
image.set_alpha(i)
screen.blit(image,(0,0))
pygame.display.flip()
pygame.time.delay(20)
To fade in and out, you need to keep looping until the player clicks/hits a button. Like this:
import pygame
from pygame.locals import *
# ...
def title_loop():
# title screen main loop
image = pygame.image.load("logo.png")
done = False
alpha = 0
alpha_vel = 1
# fade alpha in-out while waiting
while not done:
# get key input
for event in pygame.event.get():
if event.type == QUIT:
done = true
if event.type == KEYDOWN:
if event.key = K_ESCAPE:
done = true
# draw
if alpha >= 255 or alpha <= 0:
alpha_vel *= -1
alpha += alpha_vel
background.fill((0,0,0))
image.set_alpha(i)
screen.blit(image,(0,0))
pygame.display.flip()
pygame.time.delay(20)
PygameNerd your example is close, but it doesn't really work.
The image.convert() will fade properly, but it doesn't support alpha channel. Try it on a non black background & it shows.
The image.convert_alpha() will not fade, but the alpha channel does work properly.
I'm surprised that pygame doesn't support this out of the box, but anyway. Here is an answer:
http://www.nerdparadise.com/tech/python/pygame/blitopacity/
Its a bit complex, but works fine. Transparent background & fading all in one package.