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remove duplicate code for circle_draw

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hugova 2025-06-29 15:22:30 +02:00
parent c4add9a62c
commit 7a50de832e
1 changed files with 34 additions and 37 deletions
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71
wip-hugo/routines/circle/circle_help.s
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@ -4,56 +4,38 @@
;;We have named the parts of the circle as such.
;; |
;; q22 | q12
;; qbb | qab
;; |
;; q21 | q11
;; qba | qaa
;;---------------X-----------------> X
;; q31 | q41
;; qca | qda
;; |
;; q32 | q42
;; qcb | qdb
;; |
;; v Y
;; The q stands for quarter, whe have 4 quarter, and each quarter is split into 2
draw_pixel:;;q11
draw_qaa:
LDA byte_to_paint ;A byte containing a single 1. Coresponds to X position in the chunk.
ORA (btp_mem_pos), Y
STA (btp_mem_pos), Y
draw_pixel_inv_y:;;q41
draw_qda:
;; inverted Y, this is shared with qca
STY temp
LDA #$07
SEC
SBC temp
TAY
LDA byte_to_paint
ORA (btp_mem_pos_inv_y), Y
STA (btp_mem_pos_inv_y), Y
;hihi:
;jmp hihi
LDY temp
;LDY temp
draw_pixel_inv_y_mirror:
SEC
LDA btp_mem_pos_center_two
SBC btp_mem_pos_inv_y
STA btp_mem_pos_inv
LDA btp_mem_pos_center_two + 1
SBC btp_mem_pos_inv_y + 1
STA btp_mem_pos_inv + 1
STX temp_
LDX byte_to_paint
LDA inverse_factor_value, X;; (see END.s)
LDX temp_
; A = byte_to_paint_inv
ORA (btp_mem_pos_inv), Y
STA (btp_mem_pos_inv), Y
draw_pixel_mirror:;;q31
draw_qca: ;;mirror technique
SEC
;;C = 1 beacause the branching to while_x_bigger_then_y and SEC on first ittteration.
LDA btp_mem_pos_center_two
@ -63,19 +45,12 @@ draw_pixel_mirror:;;q31
SBC btp_mem_pos + 1
STA btp_mem_pos_inv + 1
;; calculate the inverted y value Y = 7-Y
STY temp
LDA #$07
;; C = 1 because arithmatic above
SBC temp
TAY
;; calculate byte_to_paint_inv 00000001 --> 10000000, 00000010 --> 01000000 ... etc
;; uses a table!
STX temp_
LDX byte_to_paint
LDA inverse_factor_value, X;; (see END.s)
LDX temp_
TAX ;; A is saved to x because qba use this as well
; A = byte_to_paint_inv
ORA (btp_mem_pos_inv), Y
@ -83,5 +58,27 @@ draw_pixel_mirror:;;q31
;;Recover the Y value (we changed it because evrything is inverted)
LDY temp
draw_qba: ;;mirror_technique
SEC
LDA btp_mem_pos_center_two
SBC btp_mem_pos_inv_y
STA btp_mem_pos_inv
LDA btp_mem_pos_center_two + 1
SBC btp_mem_pos_inv_y + 1
STA btp_mem_pos_inv + 1
;STX temp_
;LDX byte_to_paint
;LDA inverse_factor_value, X;; (see END.s)
TXA
LDX temp_
; A = byte_to_paint_inv
ORA (btp_mem_pos_inv), Y
STA (btp_mem_pos_inv), Y
RTS
.endproc