fix fill_triangle bug issue #33

[peter-l5]

This fix for issue #33 replaces the for loop at lines 283 to 291 with a while loop so that the y variable is properly incremented between the loops to fill the top and bottom parts of the triangle. This avoids screen row at y0 being drawn twice, and corrects the shape of the triangle. The changes to lines 278 to 282 (as numbered after the fix) initiate the two loops in a way that addresses issue #22 where a triangle with a flat bottom edge was not drawn correctly.

This fix has been implemented in the derived repository framebuf2 which applies the algorithm here and has been tested with the following code. (Note that f=True parameter draws a filled triangle in this implementation.)

    for z in range(3,123+1,20):
        for x in range(10,120+1,20):
            for y in range(0,128):
                display.fill(0)
                display.triangle(x,y,30,z,90,63,c=1,f=True)
                display.show()

[tekktrik]

Looks like this is failing the CI. You can use pre-commit to reformat the code to get it to pass. You can find information on installing and using pre-commit here: https://learn.adafruit.com/creating-and-sharing-a-circuitpython-library/check-your-code

[peter-l5]

Thanks. I wasn’t sure what to do next so will try out pre commit. To be aware be a few days before I can tackle it, but will do as soon as I can. On 5 May 2023, at 20:12, Alec Delaney ***@***.***> wrote:  Looks like this is failing the CI. You can use pre-commit to reformat the code to get it to pass. You can find information on installing and using pre-commit here: https://learn.adafruit.com/creating-and-sharing-a-circuitpython-library/check-your-code — Reply to this email directly, view it on GitHub<#34 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AZGBNNHA4URLR5KPCS75QLTXEVGIFANCNFSM6AAAAAAXXCQTDI>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[peter-l5]

@tekktrik: I couldn't get pre-commit to work on my Raspberry Pi (perhaps because I'm working without local git) but have downloaded and applied black formatting. This removed a superfluous space in my changes and adjusted some legacy code formatting.

[tekktrik]

Yup, that fixed the issue! I'll add the review team so the first person who has the bandwidth can take a look :)

[dhalbert]

Thank you!