Re: [pygame] Surfaces with Transparent Backgrounds
Hi, I don't know Pygame that well and have never used subsurfaces but it it looks kinda interesting. Would you do the subsurface approach in the following way? def load_strip(filename, width): imgs = [] img = load_image(filename) for x in range(img.get_width()/width): i = img.subsurface(pygame.Rect(-x*width, 0, width, img.get_height())) imgs.append(i) return imgs Patrick Mullen schrieb: Lenard: his problems was that he was blitting that per-pixel alpha surface onto a newly created surface which also had to be per-pixel alpha, and wasn't sure how to create that. But he figured it out :) Pymike, that's one way to do it, another way would be to use subsurfaces. They are a bit nicer because you don't have to go through the hassle of making a separate surface for each frame. I think they might take less memory as well. On Thu, Aug 20, 2009 at 8:47 PM, Lenard Lindstromle...@telus.net wrote: Hi pymike, I don't understand what you are doing here. If you load an image with per-pixel alpha, the returned surface will also have per-pixel alpha. All convert_alpha() may do here is improve performance by formating the surface to match the display. Of course this is with Pygame 1.9.1. Earlier Pygames may have a problem with 32bit to 32bit surface blits. Lenard Lindstrom pymike wrote: Aha! Figured it out! def load_strip(filename, width): imgs = [] img = load_image(filename) for x in range(img.get_width()/width): *i = pygame.Surface((width, img.get_height())).convert_alpha() i = i.convert_alpha() i.fill((255,255,255,0))* i.blit(img, (-x*width, 0)) imgs.append(i) return imgs Everything's working awesome now. -- - pymike
[pygame] Surfaces with Transparent Backgrounds
Hi, I have a function that loads image stripshttp://pymike.pynguins.com/downloads/player-run.pngand returns the images in lists. To do this, I create new surfaces and blit the strips to them at an offset. My question is: Is there a way to create surfaces with transparent backgrounds? The images have quite a bit of semi-transparent pixels in them, so I can't use colorkeys. Thanks, -- - pymike
Re: [pygame] Surfaces with Transparent Backgrounds
Transparency is often a problem because image editors and viewers not always display the same sorts of transparency. To create a transparent background, load it from an image with transparency. Png supports it, but not all png editors do. I managed to get transparency done by using GIMP (http://www.gimp.org/). In this editor, you need to add a transparency channel to the image, select the part that you want to be transparent and delete it (with the Delete key). This usually does the trick, but people more experient with image editing might have better ways. Pygame can also do transparency by using color keys, which means defining a specific RGB color that will represent transparent pixel. In your example, that would be white (0, 0, 0). Use http://www.pygame.org/docs/ref/surface.html#Surface.set_colorkey for this kind of transparency. On Thu, Aug 20, 2009 at 22:46, pymike pymik...@gmail.com wrote: Hi, I have a function that loads image stripshttp://pymike.pynguins.com/downloads/player-run.pngand returns the images in lists. To do this, I create new surfaces and blit the strips to them at an offset. My question is: Is there a way to create surfaces with transparent backgrounds? The images have quite a bit of semi-transparent pixels in them, so I can't use colorkeys. Thanks, -- - pymike
Re: [pygame] Surfaces with Transparent Backgrounds
I *did* create the images with Gimp, and they do have transparent
backgrounds. (Did you view the image link I posted?)
I have used colorkeys in the past, but the problem here is that there are
semi-transparent (not fully opaque) pixels in the images (again see the
image I linked to), and when you draw these images to newly created surfaces
(ie new = pygame.Surface(); new.blit(loadedimage)) the pixels are no longer
transparent. Hence why I need to create surfaces with completely transparent
backgrounds, instead of the default black.
Here's my code for reference:
import os
import pygame
from pygame.locals import *
IMAGE_CACHE = {}
def load_image(filename):
if filename not in IMAGE_CACHE:
img = pygame.image.load(os.path.join(data,
filename)).convert_alpha()
IMAGE_CACHE[filename] = img
return IMAGE_CACHE[filename]
def load_strip(filename, width):
imgs = []
img = load_image(filename)
for x in range(img.get_width()/width):
*i = pygame.Surface((width, img.get_height()))***
*i.blit(img, (-x*width, 0))*
imgs.append(i)
return imgs
Cheers,
On Thu, Aug 20, 2009 at 9:05 PM, Henrique Nakashima
henrique.nakash...@gmail.com wrote:
Transparency is often a problem because image editors and viewers not
always display the same sorts of transparency.
To create a transparent background, load it from an image with
transparency. Png supports it, but not all png editors do. I managed to get
transparency done by using GIMP (http://www.gimp.org/). In this editor,
you need to add a transparency channel to the image, select the part that
you want to be transparent and delete it (with the Delete key). This usually
does the trick, but people more experient with image editing might have
better ways.
Pygame can also do transparency by using color keys, which means defining a
specific RGB color that will represent transparent pixel. In your example,
that would be white (0, 0, 0). Use
http://www.pygame.org/docs/ref/surface.html#Surface.set_colorkey for this
kind of transparency.
On Thu, Aug 20, 2009 at 22:46, pymike pymik...@gmail.com wrote:
Hi,
I have a function that loads image
stripshttp://pymike.pynguins.com/downloads/player-run.pngand returns the
images in lists. To do this, I create new surfaces and blit
the strips to them at an offset.
My question is: Is there a way to create surfaces with transparent
backgrounds? The images have quite a bit of semi-transparent pixels in them,
so I can't use colorkeys.
Thanks,
--
- pymike
--
- pymike
Re: [pygame] Surfaces with Transparent Backgrounds
You need to convert the surface i with .convert_alpha(), as well.
Re: [pygame] Surfaces with Transparent Backgrounds
On Thu, Aug 20, 2009 at 10:15 PM, Ian Mallett geometr...@gmail.com wrote: You need to convert the surface i with .convert_alpha(), as well. i = pygame.Surface((width, img.get_height())).convert_alpha() ...I still get a black background. -- - pymike
Re: [pygame] Surfaces with Transparent Backgrounds
Aha! Figured it out! def load_strip(filename, width): imgs = [] img = load_image(filename) for x in range(img.get_width()/width): *i = pygame.Surface((width, img.get_height())).convert_alpha() i = i.convert_alpha() i.fill((255,255,255,0))* i.blit(img, (-x*width, 0)) imgs.append(i) return imgs Everything's working awesome now. -- - pymike
Re: [pygame] Surfaces with Transparent Backgrounds
Aha. There might be something weird about the image as well, because when I used another one with a transparent background it worked as well - without modifications to the code. Despite that, I couldn't find anything strange in the png. On Fri, Aug 21, 2009 at 00:23, pymike pymik...@gmail.com wrote: Aha! Figured it out! def load_strip(filename, width): imgs = [] img = load_image(filename) for x in range(img.get_width()/width): *i = pygame.Surface((width, img.get_height())).convert_alpha() i = i.convert_alpha() i.fill((255,255,255,0))* i.blit(img, (-x*width, 0)) imgs.append(i) return imgs Everything's working awesome now. -- - pymike
Re: [pygame] Surfaces with Transparent Backgrounds
Hi pymike, I don't understand what you are doing here. If you load an image with per-pixel alpha, the returned surface will also have per-pixel alpha. All convert_alpha() may do here is improve performance by formating the surface to match the display. Of course this is with Pygame 1.9.1. Earlier Pygames may have a problem with 32bit to 32bit surface blits. Lenard Lindstrom pymike wrote: Aha! Figured it out! def load_strip(filename, width): imgs = [] img = load_image(filename) for x in range(img.get_width()/width): *i = pygame.Surface((width, img.get_height())).convert_alpha() i = i.convert_alpha() i.fill((255,255,255,0))* i.blit(img, (-x*width, 0)) imgs.append(i) return imgs Everything's working awesome now. -- - pymike
