uxn

commit 1b04e0814bbe1a1837e5f61a407a5af0ef3ff141
parent 11c9ec8b49ae650005a3b7bd74269ff58ab09635
Author: Andrew Alderwick <andrew@alderwick.co.uk>
Date:   Sun,  6 Mar 2022 13:36:47 +0000

(draft) Add looping functionality to Screen/auto.

Diffstat:
A
projects/examples/devices/screen.auto.tal
 | 
30
++++++++++++++++++++++++++++++
M
src/devices/screen.c
 | 
16
++++++++++++----

2 files changed, 42 insertions(+), 4 deletions(-)
diff --git a/projects/examples/devices/screen.auto.tal b/projects/examples/devices/screen.auto.tal
@@ -0,0 +1,30 @@
+( devices )
+
+|00 @System     &vector $2 &wst      $1 &rst    $1 &swsz   $1 &swap   $1 &pad     $2 &r       $2 &g      $2 &b     $2 &debug  $1 &halt $1
+|20 @Screen     &vector $2 &width    $2 &height $2 &auto   $1 &pad    $1 &x       $2 &y       $2 &addr   $2 &pixel $1 &sprite $1
+
+( variables )
+
+|0000
+
+( program )
+
+|0100 ( -> )
+	( theme ) 
+	#0fe5 .System/r DEO2 
+	#0fc5 .System/g DEO2 
+	#0f25 .System/b DEO2
+
+	#35 .Screen/auto DEO
+
+	;font #0210 ADD2 .Screen/addr DEO2
+	#3400 &loop
+		#04 .Screen/sprite DEO
+		INC
+		GTHk ,&loop JCN
+
+BRK
+
+~projects/assets/msx01x02.tal
+
+
diff --git a/src/devices/screen.c b/src/devices/screen.c
@@ -157,7 +157,7 @@ screen_deo(Device *d, Uint8 port)
 		break;
 	}
 	case 0xf: {
-		Uint16 x, y, addr;
+		Uint16 x, y, addr, auto_i;
 		Uint8 twobpp = !!(d->dat[0xf] & 0x80);
 		Layer *layer = (d->dat[0xf] & 0x40) ? &uxn_screen.fg : &uxn_screen.bg;
 		DEVPEEK16(x, 0x8);
@@ -166,9 +166,17 @@ screen_deo(Device *d, Uint8 port)
 		if(addr > 0xfff8 - twobpp * 8)
 			return;
 		screen_blit(&uxn_screen, layer, x, y, &d->u->ram[addr], d->dat[0xf] & 0xf, d->dat[0xf] & 0x10, d->dat[0xf] & 0x20, twobpp);
-		if(d->dat[0x6] & 0x04) DEVPOKE16(0xc, addr + 8 + twobpp * 8); /* auto addr+length */
-		if(d->dat[0x6] & 0x01) DEVPOKE16(0x8, x + 8);                 /* auto x+8 */
-		if(d->dat[0x6] & 0x02) DEVPOKE16(0xa, y + 8);                 /* auto y+8 */
+		auto_i = d->dat[0x6] + 0x40;
+		if((auto_i >> 6) > ((auto_i & 0x30) >> 4)) {
+			d->dat[0x6] = auto_i & 0x3f;
+			DEVPOKE16(0x8, x + ((auto_i & 0x01) << 3) - ((auto_i & 0x02) * (auto_i & 0x30) >> 2));
+			DEVPOKE16(0xa, y + ((auto_i & 0x02) << 2) - ((auto_i & 0x01) * (auto_i & 0x30) >> 1));
+		} else {
+			d->dat[0x6] = auto_i;
+			DEVPOKE16(0x8, x + ((auto_i & 0x02) << 2));
+			DEVPOKE16(0xa, y + ((auto_i & 0x01) << 3));
+		}
+		if(auto_i & 0x04) DEVPOKE16(0xc, addr + 8 + twobpp * 8); /* auto addr+length */
 		break;
 	}
 	}