Remove the other sources of off-by-one

src/circuit.zig

@@ -123,12 +123,12 @@ fn get_plugs(tile: u8) Plugs {
 
 pub fn get_cell(this: @This(), cell: Cell) ?u8 {
     const i = this.indexOf(cell) orelse return null;
-    return if (this.map[i] != 0) this.map[i] - 1 else null;
+    return if (this.map[i] != 0) this.map[i] else null;
 }
 
 pub fn set_cell(this: *@This(), cell: Cell, tile: u8) void {
     const i = this.indexOf(cell) orelse return;
-    this.map[i] = tile + 1;
+    this.map[i] = tile;
     this.levels[i] = 0;
 }
 

src/extract.zig

@@ -188,8 +188,8 @@ pub fn extractLevel(opt: Options) !void {
                 .Switch_On => opt.switch_on.find(autotile),
                 .Switch_Off => opt.switch_off.find(autotile),
                 .Plug => opt.plug.find(autotile),
-                .And => 21,
+                .And => world.Tiles.LogicAnd,
-                .Xor => 23,
+                .Xor => world.Tiles.LogicXor,
                 else => 0,
             };
             circuit.map[i] = tile;

src/game.zig

@@ -228,19 +228,11 @@ pub fn start() !void {
         .level = level,
         .map = &map,
         .circuit = &circuit,
-        .tileset = world.AutoTileset.initOffsetFull(113),
+        .tileset = world.Tiles.Walls,
-        .conduit = world.AutoTileset.initOffsetFull(97),
+        .conduit = world.Tiles.Conduit,
-        .plug = world.AutoTileset.initOffsetCardinal(17),
+        .plug = world.Tiles.Plugs,
-        .switch_off = world.AutoTileset.initSwitches(&.{
+        .switch_off = world.Tiles.SwitchesOff,
-            29, // South-North
+        .switch_on = world.Tiles.SwitchesOn,
-            25, // South-West-North
-            27, // South-East-North
-        }, 2),
-        .switch_on = world.AutoTileset.initSwitches(&.{
-            30, // South-North
-            26, // South-West-North
-            28, // South-East-West
-        }, 2),
     });
 
     var entity_buf = try alloc.alloc(world.Entity, level.entity_count);

src/map.zig

@@ -82,9 +82,8 @@ pub fn draw(this: @This(), offset: Vec2) void {
         while (x < width) : (x += 1) {
             const cell = Vec2{ @intCast(i32, x), @intCast(i32, y) } + offset;
             const pos = Vec2{ @intCast(i32, x), @intCast(i32, y) } * tile_size;
-            const tilePlus = this.get_cell(cell) orelse continue;
+            const tile = this.get_cell(cell) orelse continue;
-            if (tilePlus == 0) continue;
+            if (tile == world.Tiles.Empty) continue;
-            const tile = tilePlus - 1;
             const t = Vec2{
                 @intCast(i32, (tile % tilemap_width) * tile_width),
                 @intCast(i32, (tile / tilemap_width) * tile_width),
@@ -134,14 +133,14 @@ pub fn collide(this: @This(), body: BodyInfo) CollisionInfo {
             const bottom = @floatToInt(i32, bot_right[1]);
             const foot = body.rect.pos[1] + body.rect.size[1];
 
-            if (isOneWay(tile)) {
+            if (world.Tiles.is_oneway(tile)) {
                 if (!body.is_passing and a == bottom and body.last[1] <= body.next[1] and foot < tiley + 2) {
                     collisions.append(util.AABB{
                         .pos = Vec2f{ tilex, tiley },
                         .size = tile_sizef,
                     });
                 }
-            } else if (isSolid(tile)) {
+            } else if (world.Tiles.is_solid(tile)) {
                 collisions.append(util.AABB{
                     .pos = Vec2f{ tilex, tiley },
                     .size = tile_sizef,
@@ -171,14 +170,6 @@ pub const CollisionInfo = struct {
     }
 };
 
-pub fn isSolid(tile: u8) bool {
-    return if (tile == 0) false else world.Tiles.is_solid(tile - 1);
-}
-
-pub fn isOneWay(tile: u8) bool {
-    return if (tile == 0) false else world.Tiles.is_oneway(tile - 1);
-}
-
 // Debug functions
 
 pub fn trace(this: @This()) void {
@@ -190,8 +181,7 @@ pub fn trace(this: @This()) void {
 }
 
 pub fn traceDraw(this: @This()) void {
-    for (this.tiles) |tilePlus, i| {
+    for (this.tiles) |tile, i| {
-        const tile = tilePlus - 1;
         const t = Vec2{
             @intCast(i32, (tile % tilemap_width) * tile_width),
             @intCast(i32, (tile / tilemap_width) * tile_width),

src/world.zig

@@ -22,15 +22,18 @@ pub const Tiles = struct {
     // Switches
     pub const SwitchTeeWestOff = 24;
     pub const SwitchTeeWestOn = 25;
+
     pub const SwitchTeeEastOff = 26;
     pub const SwitchTeeEastOn = 27;
+
     pub const SwitchVerticalOff = 28;
     pub const SwitchVerticalOn = 29;
+
     pub const SwitchHorizontalOff = 30;
     pub const SwitchHorizontalOn = 31;
 
     pub fn is_switch(tile: u8) bool {
-        return tile >= 24 and tile <= 31;
+        return tile >= SwitchTeeWestOff and tile <= SwitchHorizontalOn;
     }
 
     // Plugs, sorted by autotile order
@@ -51,8 +54,8 @@ pub const Tiles = struct {
         return tile >= 21 and tile <= 24;
     }
 
-    pub const ConduitCross = 97;
+    pub const ConduitCross = 96;
-    pub const ConduitSingle = 113;
+    pub const ConduitSingle = 112;
 
     pub fn is_conduit(tile: u8) bool {
         return tile >= ConduitCross and tile <= ConduitSingle;
@@ -62,15 +65,15 @@ pub const Tiles = struct {
         return is_plug(tile) or is_conduit(tile) or is_switch(tile) or is_logic(tile);
     }
 
-    pub const WallSingle = 113;
+    pub const WallSingle = 112;
     pub const WallSurrounded = 127;
 
     pub fn is_wall(tile: u8) bool {
         return tile >= WallSingle and tile <= WallSurrounded;
     }
 
-    pub const Door = 3;
+    pub const Door = 2;
-    pub const Trapdoor = 4;
+    pub const Trapdoor = 3;
 
     pub fn is_door(tile: u8) bool {
         return tile == 3 or tile == 4;
@@ -89,6 +92,20 @@ pub const Tiles = struct {
     }
 
     pub const Empty = 0;
+
+    pub const Walls = AutoTileset.initOffsetFull(WallSingle);
+    pub const Conduit = AutoTileset.initOffsetFull(ConduitCross);
+    pub const Plugs = AutoTileset.initOffsetCardinal(PlugNorth);
+    pub const SwitchesOff = AutoTileset.initSwitches(&.{
+        SwitchVerticalOff, // South-North
+        SwitchTeeWestOff, // South-West-North
+        SwitchTeeEastOff, // South-East-North
+    }, 2);
+    pub const SwitchesOn = AutoTileset.initSwitches(&.{
+        SwitchVerticalOn, // South-North
+        SwitchTeeWestOn, // South-West-North
+        SwitchTeeEastOn, // South-East-North
+    }, 2);
 };
 
 pub const TileData = union(enum) {

tools/LDtkImport.zig

@@ -180,7 +180,7 @@ fn make(step: *std.build.Step) !void {
                 const i = @intCast(usize, x + y * width);
                 const sx = @divExact(autotile.src[0], collision.__gridSize);
                 const sy = @divExact(autotile.src[1], collision.__gridSize);
-                const t = sx + sy * 16 + 1;
+                const t = sx + sy * 16;
                 tiles[i] = world.TileData{ .tile = @intCast(u7, t) };
             }