Acorn Arcade forums: Programming: 32K plotter
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32K plotter |
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andreww (15:04 27/3/2002)
Phlamethrower (22:04 27/3/2002)
andreww (09:44 28/3/2002)
andreww (09:49 29/3/2002)
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Andrew |
Message #86229, posted by andreww at 15:04, 27/3/2002 |
AA refugee
Posts: 555
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I'm plotting a 32K sprite using a routine I've used before but I'm getting a double image effect (the sprite is appearing twice: once where it should be on the rhs and once in the middle of the x-axis of the screen)
i can't see a problem with the code and I'm using a mode selector block to get the 640x480 32K mode which also works with the original plotter program.What could be wrong?
regards Andrew |
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Jeffrey Lee |
Message #86230, posted by Phlamethrower at 22:04, 27/3/2002, in reply to message #86229 |
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Posts: 15100
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The most obvious problem would be adding on 1 times the screen width instead of 2 times at the end of each row... Try fiddling round with drawing the sprite at the mouse coordinates to see if you can work out how the two images are related. Either that or if it is the full image being duplicated (i.e. not squished to half height), then it might be a branching problem in the code causing it to draw twice. Check that all branches go to the right place, and that all registers are stored and loaded as they should be. |
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Andrew |
Message #86231, posted by andreww at 09:44, 28/3/2002, in reply to message #86230 |
AA refugee
Posts: 555
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Yes, I think you've got it Jeffrey! I don't know why it worked with the original 32K plotter program though.
I'll check this and get back.
Thanks again.
Andrew
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Andrew |
Message #86232, posted by andreww at 09:49, 29/3/2002, in reply to message #86231 |
AA refugee
Posts: 555
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Yes that's right, forgot to add 1280 at the end of each scanline plot! |
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Acorn Arcade forums: Programming: 32K plotter |
