optimise circle draw by redusing instructions

This commit is contained in:
hugova 2025-06-30 23:41:55 +02:00
parent ba2db967c4
commit 6c962befa2

View file

@ -5,7 +5,7 @@
;;We have named the parts of the circle as such. ;;We have named the parts of the circle as such.
;; * | ;; |
;; qbb | qab ;; qbb | qab
;; | ;; |
;; qba | qaa ;; qba | qaa
@ -13,7 +13,7 @@
;; qca | qda ;; qca | qda
;; | ;; |
;; qcb | qdb ;; qcb | qdb
;; | * ;; |
;; v Y ;; v Y
;; The q stands for quarter, whe have 4 quarter, and each quarter is split into 2 ;; The q stands for quarter, whe have 4 quarter, and each quarter is split into 2
@ -53,20 +53,19 @@ draw_qaa:
ORA (btp_mem_pos), Y ORA (btp_mem_pos), Y
STA (btp_mem_pos), Y STA (btp_mem_pos), Y
draw_qcb:; xy swaped draw_qcb:; xy swoped
STY temp STY temp
LDA byte_to_paint LDA byte_to_paint
STA temp__ STA temp__
;;modify Y_pos ;;modify Y_pos
LDY #$00 LDY #$00
jmp goto_loop JMP goto_loop
loop: loop:
INY INY
goto_loop: goto_loop:
ASL byte_to_paint; lsr asl ASL byte_to_paint
BCC loop BCC loop
STY temp___
revert_byte_to_paint: revert_byte_to_paint:
LDA temp__ LDA temp__
STA byte_to_paint STA byte_to_paint
@ -76,39 +75,35 @@ revert_byte_to_paint:
LDA binary_factor, X; (see END.s) LDA binary_factor, X; (see END.s)
LDY temp___
ORA (btp_mem_pos_qcb), Y ORA (btp_mem_pos_qcb), Y
STA (btp_mem_pos_qcb), Y; STA (btp_mem_pos_qcb), Y
draw_qdb:; xy swaped and y is inverted. draw_qdb:; xy swaped and y is inverted.
;;modify X ;;modify X
LDX temp
LDA binary_factor, X; (see END.s)
TAX
LDA inverse_factor_value, X;; (see END.s)
;;Uses modifyed Y from above
ORA (btp_mem_pos_qdb), Y
STA (btp_mem_pos_qdb), Y;
draw_qab:; xy swoped + mirroring
;SEC
LDA #$07
SBC temp___
TAY
LDA #$07 LDA #$07
SBC temp SBC temp
TAX TAX
LDA binary_factor, X; (see END.s) LDA binary_factor, X; (see END.s)
TAX
;;Uses modifyed Y from above
ORA (btp_mem_pos_qdb), Y
STA (btp_mem_pos_qdb), Y
draw_qab:; xy swoped + mirroring
STY temp___
LDA #$07
SBC temp___
TAY
TXA
ORA (btp_mem_pos_qab), Y ORA (btp_mem_pos_qab), Y
STA (btp_mem_pos_qab), Y STA (btp_mem_pos_qab), Y
LDY temp
draw_qda:; y is inverted draw_qda:; y is inverted
;; invert Y, this is shared with qca ;; invert Y, this is shared with qca
LDA #$07 LDA #$07
SBC temp SBC temp
@ -122,7 +117,6 @@ draw_qca: ;;mirror technique
;; calculate byte_to_paint_inv 00000001 --> 10000000, 00000010 --> 01000000 ... etc ;; calculate byte_to_paint_inv 00000001 --> 10000000, 00000010 --> 01000000 ... etc
;; uses a table! ;; uses a table!
STX temp_
LDX byte_to_paint LDX byte_to_paint
LDA inverse_factor_value, X;; (see END.s) LDA inverse_factor_value, X;; (see END.s)
TAX ;; A is saved to x because qba use this as well TAX ;; A is saved to x because qba use this as well
@ -140,6 +134,9 @@ draw_qba: ;;mirror_technique
ORA (btp_mem_pos_qba), Y ORA (btp_mem_pos_qba), Y
STA (btp_mem_pos_qba), Y STA (btp_mem_pos_qba), Y
increment_y_pos: increment_y_pos:
INC Y_rel ; y++ INC Y_rel ; y++
DEY DEY