From e72a9bc297e2d09595e46e0a6889cad9fa1bedde Mon Sep 17 00:00:00 2001
From: David Schmenk <dschmenk@gmail.com>
Date: Tue, 20 May 2014 20:08:32 -0700
Subject: [PATCH] Draw ground grid

---
 PLASMA/src/hgr1test.pla | 131 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 121 insertions(+), 10 deletions(-)

diff --git a/PLASMA/src/hgr1test.pla b/PLASMA/src/hgr1test.pla
index ab509ad2..86adc87d 100644
--- a/PLASMA/src/hgr1test.pla
+++ b/PLASMA/src/hgr1test.pla
@@ -1,16 +1,127 @@
 import STDLIB
-    predef memset, memcpy, cin
+    predef memset, memcpy, getc, heapalloc, heapmark, heaprelease
 end
 import HGR1
 end
 
-byte i = 0
-word hcolor[] = $0000, $552A, $2A55, $7F7F, $8080, $D5AA, $AAD5, $FFFF
-repeat
-    memset($2000, $2000, hcolor[i])
-    i = (i + 1) & 7
-until ^$C000 >= 128
-^$C010
-^$C054
-^$C051
+const view_height = 64 ; scan count of ground view
+const fix_bits    = 8   ; number of fixed point bits
+;
+; Hardware addresses
+;
+const speaker=$C030
+const showgraphics=$C050
+const showtext=$C051
+const showfull=$C052
+const showmix=$C053
+const showpage1=$C054
+const showpage2=$C055
+const showlores=$C056
+const showhires=$C057
+const keyboard=$C000
+const keystrobe=$C010
+const hgr1=$2000
+const hgr2=$4000
+const page1=0
+const page2=1
+word hgrpage[] = hgr1, hgr2
+word hgrscan[] = $0000,$0400,$0800,$0C00,$1000,$1400,$1800,$1C00
+word           = $0080,$0480,$0880,$0C80,$1080,$1480,$1880,$1C80
+word           = $0100,$0500,$0900,$0D00,$1100,$1500,$1900,$1D00
+word           = $0180,$0580,$0980,$0D80,$1180,$1580,$1980,$1D80
+word           = $0200,$0600,$0A00,$0E00,$1200,$1600,$1A00,$1E00
+word           = $0280,$0680,$0A80,$0E80,$1280,$1680,$1A80,$1E80
+word           = $0300,$0700,$0B00,$0F00,$1300,$1700,$1B00,$1F00
+word           = $0380,$0780,$0B80,$0F80,$1380,$1780,$1B80,$1F80
+word           = $0028,$0428,$0828,$0C28,$1028,$1428,$1828,$1C28
+word           = $00A8,$04A8,$08A8,$0CA8,$10A8,$14A8,$18A8,$1CA8
+word           = $0128,$0528,$0928,$0D28,$1128,$1528,$1928,$1D28
+word           = $01A8,$05A8,$09A8,$0DA8,$11A8,$15A8,$19A8,$1DA8
+word           = $0228,$0628,$0A28,$0E28,$1228,$1628,$1A28,$1E28
+word           = $02A8,$06A8,$0AA8,$0EA8,$12A8,$16A8,$1AA8,$1EA8
+word           = $0328,$0728,$0B28,$0F28,$1328,$1728,$1B28,$1F28
+word           = $03A8,$07A8,$0BA8,$0FA8,$13A8,$17A8,$1BA8,$1FA8
+word           = $0050,$0450,$0850,$0C50,$1050,$1450,$1850,$1C50
+word           = $00D0,$04D0,$08D0,$0CD0,$10D0,$14D0,$18D0,$1CD0
+word           = $0150,$0550,$0950,$0D50,$1150,$1550,$1950,$1D50
+word           = $01D0,$05D0,$09D0,$0DD0,$11D0,$15D0,$19D0,$1DD0
+word           = $0250,$0650,$0A50,$0E50,$1250,$1650,$1A50,$1E50
+word           = $02D0,$06D0,$0AD0,$0ED0,$12D0,$16D0,$1AD0,$1ED0
+word           = $0350,$0750,$0B50,$0F50,$1350,$1750,$1B50,$1F50
+word           = $03D0,$07D0,$0BD0,$0FD0,$13D0,$17D0,$1BD0,$1FD0
+word hcolor[]  = $0000,$552A,$2A55,$7F7F,$8080,$D5AA,$AAD5,$FFFF
+;
+; def draw_scan(d8p8, scanptr)
+;
+asm draw_scan
+	!SOURCE	"plvm02zp.inc"
+WFIXL	=	$80
+WFIXH	=	$81
+WINT	=	$82
+PIX	=	$83
+	LDA	ESTKL,X
+	STA	TMPL
+	LDA	ESTKH,X
+	STA	TMPH
+  	LDA	ESTKL+1,X
+	STA	WFIXL
+	STA	WFIXH
+	LDA	ESTKH+1,X
+	LSR
+	STA	WINT
+	ROR	WFIXH
+	ROR	WFIXL
+	LDA	#$FF
+	SEC
+	SBC	WFIXL
+	STA	WFIXL
+	LDA	#$FF
+	SBC	WFIXH
+	STA	WFIXH
+	LDA	#$FF
+	SBC	WINT
+	STA	WINT
+	LDY	#$01
+	STY	PIX
+	DEY
+-	EOR	ESTKH+1,X
+	LSR
+	BCC	+
+	LDA	PIX
+	ORA	(TMP),Y
+	STA	(TMP),Y
++	ASL	PIX
+	BPL	+
+	LDA	#$01
+	STA	PIX
+	INY
+	CPY	#36
+	BEQ	++
++	LDA	ESTKL+1,X
+	CLC
+	ADC	WFIXL
+	STA	WFIXL
+	LDA	ESTKH+1,X
+	ADC	WFIXH
+	STA	WFIXH
+	LDA	#$00
+	ADC	WINT
+	STA	WINT
+	BNE	-
+	BEQ	-
+++	INX
+	RTS
+end
+def draw_ground(page)
+    byte ip
+
+    for ip = 1 to view_height
+        draw_scan((127 << fix_bits) / ip, hgrpage[page] + hgrscan[ip + 191 - view_height] + 2)
+    next
+end
+
+draw_ground(page1)
+getc
+^showpage1
+^showtext
 done
\ No newline at end of file