fix flickering by not redrawing everything all the timeHEADtrunk

1 files changed, 48 insertions, 19 deletions

diff --git a/main.ha b/main.ha
index 967e92c..b5410c8 100644
--- a/main.ha
+++ b/main.ha
@@ -30,14 +30,17 @@ fn set_tile_at(r: room, x: size, y: size, t: tile) void = {
 	r.tiles[ix] = t;
 };
 
+fn tile_repr(t: tile) str = match(t) {
+	case floor => yield "\x1b[33m.";
+	case wall => yield  "\x1b[32m\u2588";
+};
+
+
 fn draw_room(t: *vt::term, r: room) void = {
 	for (let y = 0z; y < r.h; y+=1) {
 		vt::move(t, (y+1):uint, 0)!;
 		for (let x = 0z; x < r.w; x+=1) {
-			fmt::fprint(t, match (tile_at(r,x,y)) {
-				case floor => yield '.';
-				case wall => yield  '\u2588';
-			})!;
+			fmt::fprint(t, tile_repr(tile_at(r,x,y)))!;
 		};
 	};
 };
@@ -51,15 +54,8 @@ fn get_key() u8 = {
 def W = 50;
 def H = 40;
 
-
-export fn main() void = {
-	const term = vt::open();
-	defer vt::close(term);
-
-	vt::enablealt(term)!;
-	vt::disablecur(term)!;
-
-	const tiles: [W*H]tile = [floor...];
+fn get_room() room = {
+	static const tiles: [W*H]tile = [floor...];
 	const room = room { w=W, h=H, tiles=tiles };
 
 	for (let i = 0z; i < W; i+=1) {
@@ -78,9 +74,34 @@ export fn main() void = {
 		set_tile_at(room, x,y, wall);
 	};
 
+	return room;
+};
+
+fn can_move(r: room, x: size, y: size) bool =
+	tile_at(r,x,y) is floor;
+
+	
+fn clear_ent(t: *vt::term, r: room, x:size, y:size) void = {
+	vt::move(t,y:uint+1,x:uint+1)!;
+	vt::print(t,tile_repr(tile_at(r,x,y)))!;
+};
+fn draw_ent(t: *vt::term, r: room, x:size, y:size, s:str) void = {
+	vt::move(t,y:uint+1,x:uint+1)!;
+	vt::print(t,s)!;
+};
+
+
+export fn main() void = {
+	const term = vt::open();
+	defer vt::close(term);
+
+	vt::enablealt(term)!;
+	vt::disablecur(term)!;
+
 	let player = player { x=1, y=1 };
-	const playerpen = vt::newpen(vt::color::BLACK, vt::color::RED);
-	const playerstr = vt::tag(playerpen, "@");
+	const playerstr = "\x1b[31m@";
+
+	const room = get_room();
 
 	let entities: []entity = [];
 	for (let i = 0u; i < 1; i += 1) {
@@ -88,16 +109,17 @@ export fn main() void = {
 		entities[i].x=i*2;
 	};
 
+	vt::clear(term)!;
+	draw_room(term, room);
+
+
 	for (true) {
-		vt::clear(term)!;
-		draw_room(term, room);
 		for (let i = 0z; i < len(entities); i +=1)
 			entity_draw(&entities[i], term);
 
 		vt::move(term, player.y:uint+1, player.x:uint+1)!;
 		vt::print(term, playerstr)!;
 
-
 		match (get_input(term)) {
 		case let m: move => {
 			let nx = player.x;
@@ -109,7 +131,9 @@ export fn main() void = {
 			case move::RIGHT => nx += 1;
 			};
 
-			if (tile_at(room, nx: size, ny: size) is floor) {
+			if (can_move(room,nx,ny)) {
+				clear_ent(term,room,player.x,player.y);
+				draw_ent(term,room,nx,ny,playerstr);
 				player.x = nx;
 				player.y = ny;
 			};
@@ -118,6 +142,11 @@ export fn main() void = {
 		case => yield;
 		};
 
+		for (let i = 0z; i < len(entities); i += 1) {
+			const ent = entities[i];
+			clear_ent(term,room,ent.x,ent.y);
+		};
+
 		for (let i = 0z; i < len(entities); i += 1)
 			entity_tick(&entities[i],&room);