Enabled tile randomization.

src/engine.zig

@@ -3,6 +3,7 @@ const assets = @import("engine/assets.zig");
 pub const Fonts = assets.Fonts;
 pub const FPS = @import("engine/fps.zig").FPS;
 pub const Keys = @import("engine/keys.zig").Keys;
+pub const Object = @import("engine/object.zig").Object;
 pub const OpaquePtr = @import("engine/opaque_ptr.zig").OpaquePtr;
 pub const Point = @import("engine/point.zig").Point;
 pub const PointF = @import("engine/point_f.zig").PointF;

src/engine/object.zig

@@ -0,0 +1,19 @@
+const std = @import("std");
+
+pub fn Object(comptime T: type) type {
+    return struct {
+        const Self = @This();
+
+        allocator: std.mem.Allocator,
+        ptr: *T,
+
+        pub fn create(allocator: std.mem.Allocator) !Self {
+            const ptr = try allocator.create(T);
+            return Self{ .allocator = allocator, .ptr = ptr };
+        }
+
+        pub fn destroy(self: Self) void {
+            self.allocator.destroy(self.ptr);
+        }
+    };
+}

src/game/game.zig

@@ -2,8 +2,9 @@ const std = @import("std");
 const allegro = @import("allegro");
 const engine = @import("../engine.zig");
 const Animation = @import("animation.zig").Animation;
-const Renderer = @import("../renderer.zig").Renderer;
 const Level = @import("level.zig").Level;
+const Renderer = @import("../renderer.zig").Renderer;
+const TileMap = @import("tile_map.zig").TileMap;
 
 pub const Game = struct {
     pub const Direction = enum {
@@ -13,6 +14,8 @@ pub const Game = struct {
 
     pub const TileSize = 32;
 
+    prng: std.rand.DefaultPrng = std.rand.DefaultPrng.init(0),
+
     level: Level,
     health: i64 = 4,
 
@@ -25,10 +28,11 @@ pub const Game = struct {
     starAnimation: Animation,
 
     renderer: *Renderer,
+    randomTile: TileMap(usize),
     // current viewport translated to tiles.
     boundsInTiles: engine.RectangleF,
 
-    pub fn init(level: Level, renderer: *Renderer) Game {
+    pub fn init(allocator: std.mem.Allocator, level: Level, renderer: *Renderer) Game {
         const playerPosition = level.character.float();
         return Game{
             .level = level,
@@ -39,10 +43,16 @@ pub const Game = struct {
             .isPlayerWalking = false,
             .starAnimation = Animation.init(renderer.sprites.get("item_star_32").?, 0.15),
             .renderer = renderer,
+            .randomTile = TileMap(usize).init(allocator),
             .boundsInTiles = Game.calculateBoundsInTiles(playerPosition),
         };
     }
 
+    pub fn deinit(self: *Game) void {
+        self.level.deinit();
+        self.randomTile.deinit();
+    }
+
     fn calculateBoundsInTiles(position: engine.PointF) engine.RectangleF {
         return engine.RectangleF.initRelative(
             position.x - 15,
@@ -77,6 +87,15 @@ pub const Game = struct {
         self.boundsInTiles = Game.calculateBoundsInTiles(self.playerPosition);
     }
 
+    pub fn randomTileOffset(self: *Game, x: i64, y: i64, maxOffset: usize) usize {
+        if (self.randomTile.get(x, y)) |offset| {
+            return offset;
+        }
+        const offset = self.prng.random().intRangeLessThan(usize, 0, maxOffset);
+        self.randomTile.set(x, y, offset) catch {};
+        return offset;
+    }
+
     // return values are in view coordinates
     pub fn tile(self: Game, x: f32, y: f32) engine.PointF {
         return self.tileP(engine.PointF.init(x, y));

src/game/level.zig

@@ -15,7 +15,7 @@ pub const Level = struct {
     tiles: TileMap(Tile),
     collectables: TileMap(Collectable),
 
-    pub fn load(allocator: std.mem.Allocator, path: []const u8) !Level {
+    pub fn init(allocator: std.mem.Allocator, path: []const u8) !Level {
         const path_ = try std.fs.realpathAlloc(allocator, path);
         defer allocator.free(path_);
 
@@ -25,10 +25,10 @@ pub const Level = struct {
         const data = try file.readToEndAlloc(allocator, 1024 * 1024);
         defer allocator.free(data);
 
-        return try Level.loadFromMemory(allocator, data);
+        return try Level.initFromMemory(allocator, data);
     }
 
-    pub fn loadFromMemory(allocator: std.mem.Allocator, data: []const u8) !Level {
+    pub fn initFromMemory(allocator: std.mem.Allocator, data: []const u8) !Level {
         const n = std.mem.count(u8, data, "\n");
         _ = n;
 
@@ -41,9 +41,6 @@ pub const Level = struct {
         while (lines.next()) |line| {
             defer y += 1;
 
-            try tiles.ensureColumns(line.len);
-            try collectables.ensureColumns(line.len);
-
             for (line, 0..) |tile, column| {
                 var x = @intCast(i64, column);
                 switch (tile) {
@@ -61,4 +58,9 @@ pub const Level = struct {
             .collectables = collectables,
         };
     }
+
+    pub fn deinit(self: *Level) void {
+        self.tiles.deinit();
+        self.collectables.deinit();
+    }
 };

src/game/tile_map.zig

@@ -1,4 +1,5 @@
 const std = @import("std");
+const Object = @import("../engine/object.zig").Object;
 
 pub fn TileMap(comptime Value: type) type {
     return struct {
@@ -13,7 +14,7 @@ pub fn TileMap(comptime Value: type) type {
                 };
             }
 
-            pub fn deinit(self: Column) void {
+            pub fn deinit(self: *Column) void {
                 self.values.deinit();
             }
 
@@ -27,35 +28,45 @@ pub fn TileMap(comptime Value: type) type {
         };
 
         allocator: std.mem.Allocator,
-        columns: std.ArrayList(Column),
+        columns: std.AutoHashMap(i64, Column),
 
         pub fn init(allocator: std.mem.Allocator) Self {
             return Self{
                 .allocator = allocator,
-                .columns = std.ArrayList(Column).init(allocator),
+                .columns = std.AutoHashMap(i64, Column).init(allocator),
             };
         }
 
-        pub fn deinit(self: Self) void {
-            for (self.columns.items) |item| {
-                item.deinit();
+        pub fn deinit(self: *Self) void {
+            var columns = self.columns.valueIterator();
+            while (columns.next()) |c| {
+                c.deinit();
             }
             self.columns.deinit();
         }
 
-        pub fn column(self: Self, i: i64) *Column {
-            return &self.columns.items[@intCast(usize, i)];
+        pub fn column(self: Self, x: i64) *Column {
+            return self.columns.getPtr(x).?;
         }
 
-        pub fn ensureColumns(self: *Self, n: usize) !void {
-            while (self.columns.items.len < n) {
-                try self.columns.append(Column.init(self.allocator));
+        pub fn ensureColumn(self: *Self, x: i64) !*Column {
+            if (self.columns.getPtr(x)) |c| {
+                return c;
             }
+            try self.columns.put(x, Column.init(self.allocator));
+            return self.columns.getPtr(x).?;
         }
 
-        pub fn set(self: *Self, c: i64, r: i64, value: Value) !void {
-            try self.ensureColumns(@intCast(usize, c) + 1);
-            try self.column(c).set(r, value);
+        pub fn get(self: Self, x: i64, y: i64) ?Value {
+            if (self.columns.get(x)) |c| {
+                return c.get(y);
+            }
+            return null;
+        }
+
+        pub fn set(self: *Self, x: i64, y: i64, value: Value) !void {
+            const c = try self.ensureColumn(x);
+            try c.set(y, value);
         }
     };
 }

src/game_scene.zig

@@ -10,13 +10,13 @@ pub const GameScene = struct {
     game: game.Game = undefined,
 
     pub fn enter(self: *GameScene, ctx: *Context) void {
-        const level = game.Level.load(ctx.allocator, paths.AssetsDir ++ "/levels/level1.txt") catch unreachable;
-        self.game = game.Game.init(level, &ctx.renderer);
+        const level = game.Level.init(ctx.allocator, paths.AssetsDir ++ "/levels/level1.txt") catch unreachable;
+        self.game = game.Game.init(ctx.allocator, level, &ctx.renderer);
     }
 
     pub fn exit(self: *GameScene, ctx: *Context) void {
+        self.game.deinit();
         _ = ctx;
-        _ = self;
     }
 
     pub fn handle(self: *GameScene, ctx: *Context, event: *allegro.Event) !void {
@@ -68,20 +68,22 @@ pub const GameScene = struct {
 
         var x = tileBounds.min.x;
         while (x < tileBounds.max.x) : (x += 1) {
-            self.game.drawSpriteFrame("tiles_dirt_32", 0, x, 19);
-            self.game.drawSpriteFrame("tiles_dirt_32", 3, x, 20);
+            const randomDirtOffset = self.game.randomTileOffset(x, 99, 3);
+            self.game.drawSpriteFrame("tiles_dirt_32", 0 + randomDirtOffset, x, 19);
+            self.game.drawSpriteFrame("tiles_dirt_32", 3 + randomDirtOffset, x, 20);
 
             if (x < 0) continue;
 
-            const tiles = self.game.level.tiles.column(x);
-            const collectables = self.game.level.collectables.column(x);
+            const tiles = self.game.level.tiles.ensureColumn(x) catch continue;
+            const collectables = self.game.level.collectables.ensureColumn(x) catch continue;
             var y = tileBounds.min.y;
             while (y < tileBounds.max.y) : (y += 1) {
                 if (tiles.get(y)) |tile| {
                     switch (tile) {
                         game.Level.Tile.Grass => {
-                            self.game.drawSpriteFrame("tiles_grass_32", 1, x, y - 1);
-                            self.game.drawSpriteFrame("tiles_grass_32", 5, x, y);
+                            const randomOffset = self.game.randomTileOffset(x, y, 2);
+                            self.game.drawSpriteFrame("tiles_grass_32", 1 + randomOffset, x, y - 1);
+                            self.game.drawSpriteFrame("tiles_grass_32", 5 + randomOffset, x, y);
                         },
                         // else => {},
                     }