From 0697de373a5d070333806e28cf9d1d75708036e5 Mon Sep 17 00:00:00 2001
From: Kelvin Sherlock <ksherlock@gmail.com>
Date: Wed, 25 Apr 2018 20:00:49 -0400
Subject: [PATCH] add a cursor.

---
 ansi.asm | 150 ++++++++++++++++++++++++++++++++-----------------------
 vt100.c  |   8 +++
 2 files changed, 96 insertions(+), 62 deletions(-)

diff --git a/ansi.asm b/ansi.asm
index 714a8d1..1d9777a 100644
--- a/ansi.asm
+++ b/ansi.asm
@@ -40,9 +40,14 @@ rows	anop
 ; columns are simply x * 2
 ;
 
-
-
 	end
+
+cursor_data	privdata
+
+cursor_offset	dc i2'0'
+cursor_bits	dc i2'0'
+	end
+
 ;
 ;ReverseScrollRegion(line1, line2)
 ;
@@ -477,66 +482,6 @@ exit	anop
 	END
 
 
-;
-; void DrawCursor(int Xpos, int Ypos, int state);
-;
-;
-DrawCursor	START
-
-
-state	equ	13
-Ypos	equ	11
-Xpos	equ	9
-_rtlb	equ	5
-tmp	equ	3
-_d	equ	1
-
-	phb
-	pha		;tmp
-	phd
-	tsc
-	tcd
-
-
-	lda <Ypos
-	and #$00ff
-	xba		; x 256
-	sta <tmp
-	asl a		; x 512
-	asl a		; x 1024
-	clc
-	adc <tmp	; a = Y * 1280
-	
-	adc #11*160	; last row of it
-	sta <tmp
-	adc <Xpos	; + X * 2
-	adc <Xpos
-	tax
-
-	lda #$ffff	; assume to draw it
-	ldy <state
-	bne draw
-        lda #0		; nope!
-	
-draw	anop
-
-	sta >$e12000,x
-
-
-
-	pld
-	pla		;tmp
-	pla
-	sta 5,s
-	pla
-	sta 5,s
-	pla
-	plb
-	rtl
-
-	END
-
-
 
 ;
 ; clear the screen to black (or whatnot)
@@ -695,6 +640,87 @@ exit	anop
 	rtl
 	end
 	
+
+HideCursor	start
+	using cursor_data
+
+	ldx cursor_offset
+	beq exit
+
+	lda cursor_bits
+	sta >$e10000,x
+	stz cursor_offset
+
+exit	rtl
+
+	end
+
+ShowCursor	start
+	using cursor_data
+	using tables
+
+
+yy	equ 9
+xx	equ 7
+_rtlb	equ 3
+_d	equ 1
+
+
+	phb
+
+	phd
+	tsc
+	tcd
+
+
+	ldx cursor_offset
+	beq off
+
+* hide old cursor.
+	lda cursor_bits
+	sta >$e10000,x
+	stz cursor_offset
+
+off	anop
+
+	lda <xx
+	cmp #80
+	bcs exit
+	lda <yy
+	cmp #24
+	bcs exit
+
+	asl xx
+	asl yy
+
+	ldx yy
+	lda rows,x
+	clc
+	adc xx
+	adc #160*7
+	sta cursor_offset
+	tax
+	lda >$e10000,x
+	sta cursor_bits
+	lda #-1
+	sta >$e10000,x
+
+exit	anop
+
+
+	lda _rtlb+2
+	sta yy
+	lda _rtlb
+	sta xx
+
+	pld
+	pla
+	pla
+	plb
+	rtl
+
+	end
+
 ;Cursor	START
 
 ;StartCursor	ENTRY
diff --git a/vt100.c b/vt100.c
index 704b2f9..a42f408 100644
--- a/vt100.c
+++ b/vt100.c
@@ -28,6 +28,9 @@ extern void ClearLine2(unsigned line, unsigned start, unsigned end);
 
 extern void SetCursor(unsigned x, unsigned y);
 
+extern void HideCursor(void);
+extern void ShowCursor(unsigned x, unsigned y);
+
 extern pascal void SysBeep2(Word) inline(0x3803,dispatcher);
 
 
@@ -90,6 +93,8 @@ void vt100_init(void)
 	parm_count = 0;
 	private = 0;
 	state = 0;
+
+	HideCursor();
 }
 
 #if 0
@@ -476,6 +481,7 @@ static void do_control(char c) {
 void vt100_process(const unsigned char *buffer, unsigned buffer_size) {
 
 	unsigned i;
+	HideCursor();
 	for (i = 0; i < buffer_size; ++i) {
 		unsigned char c = buffer[i] & 0x7f;
 		if (c == 0 || c == 0x7f) continue;
@@ -612,6 +618,8 @@ void vt100_process(const unsigned char *buffer, unsigned buffer_size) {
 
 		}
 	}
+
+	ShowCursor(__x, __y);
 }