Image Filtering and Image.MidHandle
Monkey Forums/Monkey Programming/Image Filtering and Image.MidHandle
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| I have been doing some tests regarding image filtering after getting blurry and distorted images, and wondered if anyone could shed any light. [EDIT] Screenshots taken from GLFW target, as HTML5 doesn't work (well) with the image filtering stuff.
#MOJO_IMAGE_FILTERING_ENABLED = True
' Image 1
img1 = LoadImage("image.png",1,Image.MidHandle)
' Image 2
img2 = LoadImage("image.png)
img2.SetHandle(img2.Width() / 2, img2.Height() / 2
Gives this...  and this...
#MOJO_IMAGE_FILTERING_ENABLED = False
' Image 1
img1 = LoadImage("image.png",1,Image.MidHandle)
' Image 2
img2 = LoadImage("image.png)
img2.SetHandle(img2.Width() / 2, img2.Height() / 2
gives this....  It seems like Image.MidHandle is broken, or doing something that makes the image blurry or distorted depending on the #MOJO_IMAGE_FILTERING_ENABLED flag. Any ideas? |
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| Could it be that one image is being drawn at float coords, and the other at integer coords? |
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Not unless it's being sneaky behind my back?DrawImage img1, 300, 400 ' img1 loaded with Image.MidHandle flag DrawImage img2, 540, 400 ' img2.SetHandle()I actually thought it was a problem with the Spine module, but after testing with normal images and removing Spine from the equation found the problem to be with the Image.MidHandle flag. |
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| What's the size of the image? SetHandle takes floats, and your mid calculations are doing an int division. Internally, if you set the handle using the MidHandle flag, mojo uses a float divide to calculate the offset. The blurring is presumably because the offset isn't working out to an integer pixel position. |
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| What muddy_shoes said, basically, is the image size an odd number? Like 303x303? If so, make it 304x304 (for example) and you will probably see this issue go away. I had this same problem when I first started with Monkey and was using GrabImage to get images that weren't perfectly divisible by 2. |
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| But having an odd number would mean that it would perfectly fit using MidHandle! So an image with a size of 4x4 pixel does NOT have a correct middle, where an image of 3x3 pixel clearly has?! |
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| OK, the image in question is 243x223. I've just padded and extra pixel on x/y to make it 244x224 and muddy and ben are right, it now draw perfectly with the image filtering off. Thanks both for the fix! :) Does this mean I have to go through every single odd sized image and pack an extra pixel in, or is there something I can do code-wise? I have hundreds of images, not looking forward to adding a pixel to every odd sized one! :( |
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| You can pad or you can use your integer SetHandle calc or you can allow for the half pixel when positioning. You could alter mojo to force integer positioning, I guess. Which suits you will depend on how you use the graphics. |
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I am playing with that now muddy, but I've noticed that even when setting a variable as a Float, unless you divide by a float number (2.0 instead of 2) then the answer comes back as an Int regardless of if the result will have .5 at the end or not.' This will equal 121 xf:Float = 243 / 2 ' This will equal 121.5 xy:Float = 243.0 / 2.0 Just doing some more testing... |
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| >But the image distortion still happens even if I Int() the Width()/Height() calls, or even if I explicitly set the SetHandle using Ints (SetHandle 121,111). I don't follow. If that's true then your initial post isn't true, because you were asking why the image wasn't distorted when you used SetHandle with your own calculations. |
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| Yep - see my strikethrough :) OK yep muddy and benmc were right with their sugggestions re: Float/Int pixel positions - thank you! ...Spine is fixed also by adding .5 to the SetPosition(), or by placing the image within Spine to a full Int position :) Cheers guys, much appreciated :) |
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