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I think DrawTile sounds good

I understand why you have drawtile and drawtile8x8 so it can be changed easily per platform

but what is the difference between drawtile and drawtilemono?
and what does DEFDATAREL do?

DrawTile gets color attributes from a specified tile data, and needs 8 + 1 bytes of data for tile 8x8 (8 bytes for pixels and 1 for color attribute). For non-ZX platform the such tiles may be colored (has many colors, greater than 2) and be able to has non-Spectrum formats (BMP, PNG, etc, even vector formats). That's why for portable code is better not to place the tiles data directly into the user-level code (by DATA), and make a separate module Rsrc that will defines different graphic (and other) resources for different platforms.

DrawMonoTile gets color attributes from internal variable that specified by procedure SetColors. For non-ZX platform such tiles are always monochrome (two-colored), as for ZX. And a color is specified by the same constants named identically, i.e. YellowOnBlue tile looks the same as on ZX, as under DOS, etc.

DEFDATAREL defines a block of data (relative, relocatable). First parameter after running the procedure has the data address. Second parameter must be = data size, and it is needed for correct jump over the data to next machine code placed after the data.

I must optimize this procedure, and I have to write the non-relocatable variant that will be named DEFDATA.

READ just reads bytes. Perhaps we need procedures READINT, READSET, READSINT, READLINT, READCHAR, READBOOL, etc. Just like we need DATAINT*, DATASET*, DATACHAR*, DATABOOL*, etc. I intend to add these features as they become necessary.

thanks

the tile variable like 'square' has to be declared a global to work

so it cant be declared in a procedure

Yeap. A resource variable is like a constant - for example, it may be assigned when module Rsrc initialized. As:

Here we have a good incapsulation - after initializing the module all the exported variables are assigned to appropriate tiles.


P.S. I think, except tiles (that are small squares with fixed size) we also need sprites (squares or rectangles with different sizes, specified directly in a sprite's data). For it, we'll start a new module GrSprite (or GrSprt?).