Transparent parts in the sprite sheet displayed as random color dots instead of transparent？

[rxing365]

Hello,

I created a buffer,and emptied it with clear(), then used sprite() to draw the game's map into it, and then used blit() to display the buffer on the screen.
All the opaque parts are good, but the parts that should be transparent are displayed as random color dots. I tried to use clear() on the buffer SCREEN before drawing on it, but it didn't work. Drawing the sprite directly in SCREEN without blit() seems to work correctly, but I really need multiple layers.

I used this web page to convert my PNG image: https://wiki.picosystem.com/en/tools/image-converter

Here is my code and the sprite sheet I used.
main.txt

Thank you！

[rxing365]

I did some testing and it seems that using blit() doesn't properly copy the alpha channel of any buffer, not just the sprite. The transparent part shows some random data.

[rxing365]

Problem resolved by assigning a transparent image array to the buffer before using it. I think this issue may be closed. I wish the usage of each functions could be documented in more detail, with examples. I often need to open its header files to see how each function works in order to use them.

[Gadgetoid]

I'm going to leave this open because:

1. This darn issue gets me every time, and I still didn't spot that it was the cause of your problem
2. I agree- we need better documentation for stuff like this, specially the weird edge cases

[ahnlak]

I have a feeling this PR partially addresses this issue