#Pygame image convert alpha full
#Pygame image convert alpha code

Orange = (os.path.join('media', 'orange.png')).convert_alpha()īulletorange = (os.path.join('media', 'bulletorange.png')).convert_alpha() NOTE* You may want to make a copy of the image before you change its alpha like this without the risk of the image having a 'spillover' affect from previous uses.I've been working on a fighting game using python and pygame and its quite finished, currently I'm looking for some constructive feedback about any issues/functions I should change in my code. I hope this is what you are looking for and hoped my answer helped here. The alpha has been stripped and reset, and the colorkey has been set to white because it was the background

#Pygame image convert alpha code

This is the finished look of the image with the whole code applied. The white part was transparent until loaded with '.convert()' This is what it looks like blitted onto a green background without the added alpha. The image does have transparency around the edges of it. I threw this test picture together for testing the code. #Set colorkey To Eliminate Background Color The colorkey does not care about per pixel alpha so you can change the alpha of an image and use colorkey at the same time. Be carful with colorkey because any color in the image that is set as the colorkey will become transparent. Then all you have to do is use 'set_colorkey(background color)' to eliminate the background image. If you load your image using 'convert()', and then setting alpha you can get your image to become transparent. However, you can get around this limitation by doing the following. Based on the docs setting alpha will have no effect. Pygame's 'convert_alpha()' function does not support per pixel alpha. def change_alpha(img, alpha=255):Ĭhan = _alpha(img)Ĭhan2 = numpy.minimum(chan, numpy.ones(chan.shape, dtype=chan.dtype)) * alpha Before you can blit the image to the screen, the array reference to the alpha array must be cleared, releasing the lock on the image surface.

#Pygame image convert alpha full

Then take the minimum (pixel-wise) of your original alpha and an array full of ones (that will leave you with an array of only ones and zeros), multiply that (pixel-wise) by your desired alpha and copy the result back to the image's alpha channel (still represented by that array reference).

This will create a lock on the image surface let's remember that for later. Start out by referencing the image's alpha channel into a numpy array. What's really slow about calculating the alpha value pixel-wise is iterating in Python, while numpy does it all in C.

The fastest solution is probably to use numpy array manipulation, it should be fast enough to avoid the need for caching. Load image: image=image_with_alpha('test.png')īlit with 60 for alpha: screen.blit(image.get_img(60),(0,0)) With some caching methodology: class image_with_alpha(object): = EDIT =Īdd some optimisation because asking in comment Img.set_at((x,y),(r,g,b,(alpha*old_alpha)/255))Īnd in this case, never modify the original image, but work on a copy to never lose your original alpha. If your png has multiple level of transparency, you should manage the transparency with a better formula, like this: r,g,b,old_alpha=img.get_at((x,y))

Work with png with no/yes transparency only): def change_alpha(img,alpha=255):īe carefull, it's 'slow', because you manage each pixel which is not at 0 (transparent from your png). For example, you can do that (not the best code, but easy to understand. %In your case, with a png image, it's a per pixel alphas. If the Surface format contains per pixel alphas, then this alpha value will be ignored. When you read the documentation for set_alpha you can read this :