From 3ccfe725cfd1672e04dcf5caa555ceaaf3f27159 Mon Sep 17 00:00:00 2001
From: "B. Watson" <yalhcru@gmail.com>
Date: Thu, 4 Feb 2016 17:33:17 -0500
Subject: rewrite cspace() in asm, save a few more bytes

---
 clrtobot.s | 66 --------------------------------------------------------------
 1 file changed, 66 deletions(-)
 delete mode 100644 clrtobot.s

(limited to 'clrtobot.s')

diff --git a/clrtobot.s b/clrtobot.s
deleted file mode 100644
index 72f97e5..0000000
--- a/clrtobot.s
+++ /dev/null
@@ -1,66 +0,0 @@
-
-
- .include "atari.inc"
- .export _clrtobot, _clrtoeol, _clrtoline
-
- .import mul40        ; from cc65's runtime
- .importzp tmp3       ; ditto
- .import bump_destptr ; these two are
- .importzp destptr    ; from draw_lorcha.s
-
-; void clrtobot(void);
-; void clrtoeol(void);
-; void clrtoline(unsigned char line);
-
-; this stuff doesn't disturb conio's (and the OS's) idea of the
-; current cursor position. It's *way* faster than writing them in
-; C in terms of cclear() (which uses one cputc() call per blank).
-
-_clrtobot: ; same as clrtoline(24);
- lda #24
- bne _clrtoline
-
-_clrtoeol:
- lda ROWCRS
- ; fall through to _clrtoline
-
-_clrtoline:
- sta tmp3 ; stash our arg
- lda #0
- sta OLDCHR ; stop conio from redrawing stuff after we clear it
-
- ; setup destptr to start of current line, NOT
- ; current cursor position.
- lda ROWCRS
- jsr mul40  ; AX = A*40 (addr of start-of-row)
- clc
- adc SAVMSC ; add to screen pointer
- sta destptr
- txa
- adc SAVMSC+1
- sta destptr+1
-
- ; X = current row, Y = current column. Stop clearing a line when Y == 40,
- ; we're done when X == 24. Apologies, the names X and Y are backwards
- ; compared to proper Cartesian coordinates.
- ldx ROWCRS
- ldy COLCRS
- lda #0
-
-clrloop:
- sta (destptr),y ; blank a character (A == 0, screen code for a space)
- iny
- cpy #40
- bne clrloop
- ldy #0
- inx
- cpx tmp3
- bcs done
-
- jsr bump_destptr
- lda #0
- tay
- beq clrloop
-
-done:
- rts
-- 
cgit v1.2.3