Commit Graph

2 Commits

Author SHA1 Message Date
nmlgc 38f17af25d [Reverse-engineering] [th04/th05] Micro-optimized 32×32 sprite display
Which *looks* like a master.lib function, but only because ZUN adapted
his own micro-optimized super_roll_put_tiny() for 32×32. Good thing we
covered that one first!

Part of P0073, funded by [Anonymous] and -Tom-.
2020-02-16 21:38:38 +01:00
nmlgc e4f1718e93 [Maintenance] [th04/th05] Improve the z_super_roll_put*() naming convention
So, master.lib has:
• super_put_tiny() for tiny-format 16×n sprites
• super_roll_put_tiny() for vertically wrapped tiny-format 16×16
  sprites
• super_put_tiny_small() for tiny-format 8×n sprites
• yet *no* super_roll_put_tiny_small() function

And now we have ZUN adding micro-optimized versions of:
1) vertically-wrapped tiny-format 16×16, clearly based on master.lib's
   super_roll_put_tiny(), RE'd in 35f9bd7
2) vertically-wrapped tiny-format 32×32
3) vertically-wrapped non-tiny monochrome 16×16 (TH05 only)

Conclusion: Even though 1) does duplicate a master.lib function, trying
to continue following master.lib's inconsistent naming convention only
leads to more confusion here. master.lib also already designates the _8
suffix to mean "x will be byte-aligned, ⌊x/8⌋*8"…
So let's:
• spell out both coordinates of the sprite size directly in the
  function
• keep the z_ prefix to encode ZUN's optimized calling convention
  (left/top coordinates in registers, ES already set to the beginning
  of a VRAM plane, GRCG already on) for all of these, not just 1).
• and prefix the actual functions with _raw, since C land will want
  to handle the coordinate parameter registers in a macro.

Part of P0073, funded by [Anonymous] and -Tom-.
2020-02-16 21:36:56 +01:00