Use a src rect for copying from screen with CanvasGroup in the mobile backend

[clayjohn]

Fixes: #75956, fixes #76104, fixes #85063, fixes #89689, fixes #90793

To fix this I had to extend copy_to_fb_rect to allow for reading from a section of a texture instead of always copying the entire texture.

before

after

[kleonc]

Fixes: #75956

What about #76104, #85063, #89689, #90793 (are they duplicates of #75956)?

[clayjohn]

Fixes: #75956

What about #76104, #85063, #89689, #90793 (are they duplicates of #75956)?

Woah, great work finding all those. Indeed they all have the same root cause as #75956 and are all fixed by this PR :)

[akien-mga]

Thanks!

[NafunaAfrica]

I dont get the fix? I am experiencing the same issue but not sure what copy_to_fb_rect is

[clayjohn]

I dont get the fix? I am experiencing the same issue but not sure what copy_to_fb_rect is

What version of Godot are you using?

[Nicholas3413]

Please fix this for Godot 4.1.5 next. I had to manually change the code and rebuild custom editor&export template to be able to fix the masking. Cherry pick may cause issue. the Godot 4.1.4 doesnt have the p_normal parameter
here's my change to fix it on 4.1.4:

[akien-mga]

@Nicholas3413 Any reason you need to stay on 4.1 instead of upgrading to 4.3?

We can't maintain all branches forever, and now with both 4.2 and 4.3 to support, the 4.1 branch will soon be EOL. The only changes suitable to include for 4.1.5 if we ever release it are critical bug fixes for platform compatibility.

[Nicholas3413]

@akien-mga, Sorry for late reply, it was because there was a shader visual bug that's not fixed on 4.2 and 4.3 on certain PC driver that's not yet updated, but Godot 4.1.4 doesn't have that issue, only when upgraded to 4.2 and 4.3 we had that issue. so we are forced to stay at 4.1.4. Now i can't test it if the bug still exists on 4.3, because the driver for the device that has bugged shader visual was updated/changed. The Shader Visual Bug is a big deal, because it's part of the game UI and we used it on several area including main area.

I see, but isn't this kind of critical bug? Mobile Renderer build can't have a proper masking.
for now yes, we are using the custom build both export templates (MacOS, Android, iOS) and editor (windows 64).

EDIT:
i can confirm the shader bug still exist on Godot 4.3 stable after uninstalling the driver update. The driver is AMD Ryzen 3 2200G With Radeon Graphics. the compatibility renderer mode shader looks broken. Doesn't broke on Mobile/Forward+ renderer.