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+-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html)
+--- Forum: HP Prime (/forum-5.html)
+--- Thread: Letters Rotate? (/thread-7917.html)
Letters Rotate? - Onieh - 03-10-2017 07:30 PM
With what order can I turn the writing about 90 degrees with the HP Prime?
RE: Letters Rotate? - StephenG1CMZ - 03-10-2017 09:37 PM
IIRC the best way is to place the text into another graphic screen, rotate it, then overlay that onto the desired graphic.
Or,
http://www.hpmuseum.org/forum/thread-7135.html?highlight=Rotate
RE: Letters Rotate? - Han - 03-10-2017 09:48 PM
(03-10-2017 09:37 PM)StephenG1CMZ Wrote: IIRC the best way is to place the text into another graphic screen, rotate it, then overlay that onto the desired graphic.
http://www.hpmuseum.org/forum/thread-7135.html?highlight=Rotate
Erwin's program to rotate a graphics object is really nice. There is an alternative method that might produce slightly different results (perhaps better quality?). Rather than taking a pixel from the source graphics object and rotating it into the destination graphics object, you might get better quality by taking a destination position, applying an inverse rotation, sample the the color there, and then color the destination position with the sample color. This will enable you to have a finer handle on how to color a pixel (in the destination location) that would have presumably come from in between two pixels in the source position.
The mathematics is more or less the same, just in a slightly different order.