I'm learning ez80 assembly with EZStudio and want to add sprites and palette data to my code but it's difficult to add directly to the source on-calc.
I want to read the palette and sprite data that convimg outputs from an appvar, I have read the documentation and made a function for it but it doesn't seem to work right.

To get a pointer to an appvar, load HL with a pointer to an appvar header. Then, call Mov9ToOP1 and ChkFindSym. DE will now point to the appvar. Here is what that would look like:


Code:

It's a little more complex than that to get to the appvar's actual data if it may be archived. You have to account for the variable header in archive when that's the case. Here's some code to handle archived variables:


Code:


As for convimg details, it should have an option to output an asm include file along with the appvar (using source-format: asm), though I don't know enough about EZStudio to know if that's directly compatible or might need some formatting changes. This contains equates for the offsets in the appvar for each palette and converted image, as well as the size of the convimg appvar header (which I believe the palette/image offsets are relative to, but it may not include the appvar size bytes, so you might need to add an additional 2 bytes to the address returned from the previous routine).

Thanks for the help.
I tried almost the same code and added a check to see if the file was found and copied the first 24 bytes (palette data exported by convimg) to the palette ram area for the LCD but the colors aren't right.
As for the include file, ezstudio does support this, but I want to do as much as I can on-calc so I will be adding images with Design.
Here's my graphics code:
Code:

Unfortunately I don't have the yaml file I used but I was able to load the first 24 bytes as palette data into Design and the colors were right

I'm not sure how big the convimg appvar header is by default (the include file I mentioned would tell you) but you're currently copying the palette from the data pointer directly returned by ChkFindSym, which would include the 2-byte appvar size header and/or the archived variable header (if it's archived), plus whatever is in the convimg header.

This code is definitely a problem, meaning the sprite is not going to be drawn correctly:

Code:


You forgot to load the pointer first before offsetting, it should actually be:

Code:


Though if your palette is only 12 colors, I'm not sure where the 258 here is coming from.

Also, the parts where you're attempting to load HL into BC aren't working (which I feel like you noticed) because pointers are 24-bit on eZ80. You would actually need to do:

Code:


Another problem related to the 24-bit pointers is that you need to use dl here instead of dw, otherwise you'd be corrupting whatever byte is after this line in the loaded program:

Code:

Thanks, its working now! 🙂
Edit: the problem was all of the above, but mostly the two byte header.