Framebuffer "portrait" orientation problem.

[Tomasz]

Hi All,

I have a problem with my 7'' 800x480 TFT and framebuffer driver. The "landscape" orientation works OK but when I'm trying to rotate the screen to the "portrait" mode, all the shapes and images are slightly distorted. They look "squeezed" (circle changes to oval shape). I'm not sure if this is a hardware or software related problem.

Thank you in advance,

Tomasz

[inmarket]

uGFX, like all modern graphics systems, assume 1:1 pixel ratio ie the width of the pixel is the same as the height of the pixel.

Historically this hasn't always been true e.g. I think EGA had non-square pixels. The big advantage of VGA when it came out was its high resolution (comparitively) and it's square pixels.

Unfortunately it looks like your display is a display without square pixels. I am guessing it is a lower quality cheaper display - certainly it has a design problem and shapes will be warped in whatever orientation you draw, it is probably just more obvious in portrait mode.

The only way around this is to take the distortion into account when you draw e.g. use an appropriately sized ellipse rather than a circle.

[Tomasz]

Hi,

Thank you for the prompt reply.

Best regards,