[Bug] Rounded Form borders have "Triangles" in corners

[Smurf-IV]

Originally posted by @Smurf-IV in https://github.com/Krypton-Suite/Standard-Toolkit/issues/1271#issuecomment-2304977265

Expected (V85)

Actual (V90 alpha):

[Smurf-IV]

It is more "Noticeable" when rounding is increased:

Notes:

• seems to be always a single pixel around the border
• The corner "triangles" are drawn in the equivalent of transparent, which then renders through to the desktop back theme (Not the desktop image!)

[Smurf-IV]

I have been chasing my tail on this: and it appears that my statement that it has been there a while is true. Because settings borders to be visible (i.e.not default) also causes the triangles and the "single pixel line" to appear in V80 as well:

Edit: It's just not as bad as it is in V90 !!

[giduac]

@Smurf-IV Does it differ between themes / gets more or less worse / stays the same? Which color does Windows use for transparency?

[Smurf-IV]

Does it differ between themes

Yes, as some do not have the default rounding

gets more or less worse / stays the same?

In v90 2They" all have the obvious small triangle without the need to force the coloured border. Coloured borders (i.e. setting thickness and roundness to be a "Big" value" cause it to be exaggerated (As per V80 image)

Which color does Windows use for transparency?

for NC area, it is supposed to be black, and then state it is not in clipping; If within a form, then it can be set to a specific colour or via opaqueness.

[giduac]

This is alpha on W11

[giduac]

This is with this.TransparencyKey = Color.Black;

[giduac]

Setting the TransparencyKey to Magenta or Transparent results in the black corner again

[Smurf-IV]

This is with this.TransparencyKey = Color.Black;

Good find, That's a great ;-) But, does it mean that each Theme will have to a Transparency key, otherwise dark themes will become transparent ??

[Smurf-IV]

Anything that is not a Krypton object is then obliterated:

And even some of the KButton text made wibbly-wobbly ;-(

[giduac]

Also has adverse effects on the Kpropgrid

[giduac]

DrawString versus DrawText ?

[giduac]

Maybe a different colour might work.

This is what ChatGPT coughs up on this:

[Smurf-IV]

Yay fixed. Rather simpler when the "big file" is done ! Thanks @giduac for the pointer.. Just had to put it in the correct place ;-)

And

[giduac]

@Smurf-IV Rounding looks good now. But, forms now have a thin magenta border...

[giduac]

@Smurf-IV

The thin border always shows when the width is set to any value but zero.

https://github.com/user-attachments/assets/a3b2b581-e862-4a00-a23e-e0c8086129a7

[Smurf-IV]

@Smurf-IV

The thin border always shows when the width is set to any value but zero.

Please raise another bug ;-(