From d5d3a1c3b29c94a2ddbf35686adb7659ca09be40 Mon Sep 17 00:00:00 2001 From: FeralChild64 Date: Tue, 17 Dec 2019 18:46:52 +0100 Subject: [PATCH] small cleanup in screen code --- c64/kernal/screen/screen_add_40_to_pntr.s | 10 ++++++++++ c64/kernal/screen/screen_normalize_xy.s | 13 +++---------- 2 files changed, 13 insertions(+), 10 deletions(-) create mode 100644 c64/kernal/screen/screen_add_40_to_pntr.s diff --git a/c64/kernal/screen/screen_add_40_to_pntr.s b/c64/kernal/screen/screen_add_40_to_pntr.s new file mode 100644 index 00000000..ff5d9f36 --- /dev/null +++ b/c64/kernal/screen/screen_add_40_to_pntr.s @@ -0,0 +1,10 @@ + + +screen_add_40_to_PNTR: + + lda PNTR + clc + adc #40 + sta PNTR + + rts diff --git a/c64/kernal/screen/screen_normalize_xy.s b/c64/kernal/screen/screen_normalize_xy.s index 147895a4..b4dc6ecd 100644 --- a/c64/kernal/screen/screen_normalize_xy.s +++ b/c64/kernal/screen/screen_normalize_xy.s @@ -14,13 +14,13 @@ screen_normalize_xy: lda #0 sta TBLX -!: jsr add_40_to_screen_x +!: jsr screen_add_40_to_PNTR // Check if line is linked, if so, add 40 again ldy TBLX lda LDTBL,y bpl !+ - jsr add_40_to_screen_x + jsr screen_add_40_to_PNTR !: x_not_negative: @@ -29,7 +29,7 @@ x_not_negative: lda LDTBL,y bpl !+ lda #79 - .byte $2C // BIT $nnnn, used to skip next instruction + skip_2_bytes_trash_nvz !: lda #39 cmp PNTR bcs x_not_too_big @@ -73,10 +73,3 @@ link_count_loop: sta TBLX y_ok: rts - -add_40_to_screen_x: - lda PNTR - clc - adc #40 - sta PNTR - rts