@@ -2,6 +2,26 @@

 A [stack-based VM](https://wiki.xxiivv.com/site/uxn.html), written in ANSI C.

+## Setup

+

+If you wish to build your own emulator, you can create a new instance of Uxn like:

+

+```

+#include "uxn.h"

+

+Uxn u;

+

+if(!bootuxn(&u))

+	return error("Boot", "Failed");

+if(!loaduxn(&u, argv[1]))

+	return error("Load", "Failed");

+if(!init())

+	return error("Init", "Failed");

+

+evaluxn(u, u->vreset); /* Once on start */

+evaluxn(u, u->vframe); /* Each frame

+```

+

 ## Assembly Syntax

 ### Write

@@ -67,6 +87,10 @@ BRK

 - Auto-advance ldr?

 - Getting rid of IOR/IOW would be nice..

 - Sending from the wst to the rst, balance mode/flag?

+- Device that works like an extra memory bank

+- Line routine

+- LineRect routine

+- Draw a chr sprite.

 ## Refs

@@ -190,6 +190,12 @@ consolew(Device *d, Uint8 b)

 Uint8

 screenr(Device *d, Uint8 b)

 {

+	switch(b) {

+	case 0: return (WIDTH >> 8) & 0xff;

+	case 1: return WIDTH & 0xff;

+	case 2: return (HEIGHT >> 8) & 0xff;

+	case 3: return HEIGHT & 0xff;

+	}

 	return d->mem[b];

 }

@@ -293,11 +299,6 @@ main(int argc, char **argv)

 	devmouse = portuxn(&u, "mouse", mouser, mousew);

 	devkey = portuxn(&u, "key", keyr, keyw);

-	devscreen->mem[0] = (WIDTH >> 8) & 0xff;

-	devscreen->mem[1] = WIDTH & 0xff;

-	devscreen->mem[2] = (HEIGHT >> 8) & 0xff;

-	devscreen->mem[3] = HEIGHT & 0xff;

-

 	start(&u);

 	echos(&u.wst, 0x40, "stack");

@@ -22,11 +22,22 @@

 	( fill rect x y w h )

 	,0040 ,0040 ,0060 ,0040 ,fillrect JSR

-

 	,01 ,color STR

 	( fill rect x y w h )

 	,00a0 ,0010 ,0020 ,0020 ,fillrect JSR

+	,02 ,color STR

+	( fill rect x y w h )

+	,00b0 ,0040 ,0020 ,0020 ,linerect JSR

+

+	,03 ,color STR

+	( fill rect x y w h )

+	,0058 ,0028 ,0050 ,0050 ,linerect JSR

+

+	,01 ,color STR

+	( fill rect x y w h )

+	,0028 ,0038 ,0050 ,0030 ,linerect JSR

+

 	,redraw JSR

 BRK

@@ -37,13 +48,28 @@ BRK

 	@fillrectrow

 		,x LDR^ ,x_ STR^

 		@fillrectcol

-			,x_ LDR^ ,y_ LDR^ ,putpixel JSR

+			( draw ) ,x_ LDR^ ,y_ LDR^ ,putpixel JSR

 			,x_ LDR^ ,0001 ADD^ ,x_ STR^ 

 			,x_ LDR^ ,w LDR^ ,x LDR^ ADD^ LTH^ ,fillrectcol ROT JMP? POP^

 		,y_ LDR^ ,0001 ADD^ ,y_ STR^ 

 		,y_ LDR^ ,h LDR^ ,y LDR^ ADD^ LTH^ ,fillrectrow ROT JMP? POP^

 	RTS

+@linerect

+	,h STR^ ,w STR^ ,y STR^ ,x STR^

+	,x LDR^ ,x_ STR^ ,y LDR^ ,y_ STR^

+	@linerectcol

+		( draw ) ,x LDR^ ,y_ LDR^ ,putpixel JSR

+		( draw ) ,x LDR^ ,w LDR^ ADD^ ,y_ LDR^ ,putpixel JSR

+		,y_ LDR^ ,0001 ADD^ ,y_ STR^ 

+		,y_ LDR^ ,h LDR^ ,y LDR^ ADD^ LTH^ ,linerectcol ROT JMP? POP^

+	@linerectrow

+		( draw ) ,x_ LDR^ ,y LDR^ ,putpixel JSR

+		( draw ) ,x_ LDR^ ,y LDR^ ,h LDR^ ADD^ ,putpixel JSR

+		,x_ LDR^ ,0001 ADD^ ,x_ STR^ 

+		,x_ LDR^ ,w LDR^ ,x LDR^ ADD^ ,0001 ADD^ LTH^ ,linerectrow ROT JMP? POP^

+	RTS

+

 @redraw

 	,0000 IOW^

 	,0000 IOW^

@@ -199,8 +199,6 @@ loaduxn(Uxn *u, char *filepath)

 	return 1;

 }

-/* to start: evaluxn(u, u->vreset); */

-

 Device *

 portuxn(Uxn *u, char *name, Uint8 (*rfn)(Device *, Uint8), Uint8 (*wfn)(Device *, Uint8))

 {