Want to copy part of an image fully to another part of an image, but write alphas with it.

Discostew

Any idea on how to do this? From what I can tell, the draw functions take alpha into account for how they write pixels. Any pixels with an alpha of 0 simply don't get written, when what I want to do is write all pixels, along with their alpha values. Only function I saw that could possibly do that is copyImage, but that simply makes a new image when I don't want to make a new image, but copy part of an image into a section of another image I designate, alphas and all.

Nisse5

If the image is set to image_rgba, this should work:

setDrawTarget(img1)
clear({0, 0, 0, 0})
drawImage(img2, 0, 0)

Discostew

@Nisse5 said in Want to copy part of an image fully to another part of an image, but write alphas with it.:

If the image is set to image_rgba, this should work:
setDrawTarget(img1)
clear({0, 0, 0, 0})
drawImage(img2, 0, 0)

But I'm looking to write to a part of an image, leaving the rest intact. Unless clear() can be limited to an area rather than the whole, it would clear the entire image.

Nisse5

@Discostew ~~In that case, use box() instead of clear(). Haven't tried it but it should work?~~ EDIT: On second though that would probably just paint nothing.

Dave

I'm not sure if this is the help that you need @Discostew because in truth this isn't something I've had little experience with, but you can use this form of drawImage():

drawImage( img, {sourceX, sourceY, sourceW, sourceH}, {destX, destY, destW, destH} )

To select a portion of a created image and draw at any scale. I hope this helps, even if a little!

doumdoum

Did you try to modify the drawing mode, with setBlend() ?

Discostew

@doumdoum Ah, that's it! I never checked it because I thought that worked differently. Thank you!