04-07-2012, 12:58 PM
I'm also wondering which one is faster! 
Except for the inc b/dec b (used to update pixel coords in BC for later use), which sub is faster?
e.g. Here is DRAW incY:
Notes: Line 292 (inc b) can be removed out, this is a DRAW requirement and can be done outside the sub
The routine sets Carry on F', to signal the ATTR position must be also updated.
Except for the inc b/dec b (used to update pixel coords in BC for later use), which sub is faster?
e.g. Here is DRAW incY:
Notes: Line 292 (inc b) can be removed out, this is a DRAW requirement and can be done outside the sub
The routine sets Carry on F', to signal the ATTR position must be also updated.
Code:
288 ;; Given an HL screen position, calculates
289 ;; the above position
290 ;; Also updates BC coords
291 __INCY:
292 inc b
293 ld a, h
294 dec h
295 and 7
296 ret nz
297 ex af, af' ; Sets carry on F'
298 scf ; which flags ATTR must be updated
299 ex af, af'
300 ld a, 8
301 add a, h
302 ld h, a
303 ld a, l
304 sub 32
305 ld l, a
306 ret nc
307 ld a, h
308 sub 8
309 ld h, a
310 ret