From 880cf8ab4e94e9b0551d724c7e3a39a870d70741 Mon Sep 17 00:00:00 2001
From: Rokas Puzonas <rokas.puz@gmail.com>
Date: Fri, 30 Jan 2026 03:48:02 +0200
Subject: [PATCH] implement collisions

---
 libs/tiled/src/layer.zig      |  84 ++++---
 libs/tiled/src/property.zig   |   9 +
 libs/tiled/src/tilemap.zig    |  20 ++
 src/assets.zig                |   2 +-
 src/assets/map.tmx            | 193 ++++++++++++---
 src/engine/frame.zig          |  39 +--
 src/engine/input.zig          |  97 ++++----
 src/engine/math.zig           |  14 +-
 src/engine/root.zig           |  23 +-
 src/game.zig                  | 444 +++++++++++++++++++++++++++++++---
 src/raycast_tile_iterator.zig |  97 ++++++++
 11 files changed, 841 insertions(+), 181 deletions(-)
 create mode 100644 src/raycast_tile_iterator.zig

diff --git a/libs/tiled/src/layer.zig b/libs/tiled/src/layer.zig
index 970550e..184380a 100644
--- a/libs/tiled/src/layer.zig
+++ b/libs/tiled/src/layer.zig
@@ -8,6 +8,46 @@ const Position = @import("./position.zig");
 
 const Layer = @This();
 
+pub const Bounds = struct {
+    left: i32,
+    right: i32,
+    top: i32,
+    bottom: i32,
+
+    pub const zero = Bounds{
+        .left = 0,
+        .right = 0,
+        .top = 0,
+        .bottom = 0,
+    };
+
+    pub fn initFromRect(x: i32, y: i32, width: i32, height: i32) Bounds {
+        return Bounds{
+            .left = x,
+            .right = x + width,
+            .top = y,
+            .bottom = y + height,
+        };
+    }
+
+    pub fn getWidth(self: Bounds) u32 {
+        return @intCast(self.right - self.left + 1);
+    }
+
+    pub fn getHeight(self: Bounds) u32 {
+        return @intCast(self.bottom - self.top + 1);
+    }
+
+    pub fn combine(lhs: Bounds, rhs: Bounds) Bounds {
+        return Bounds{
+            .left   = @min(lhs.left, rhs.left),
+            .right  = @max(lhs.right, rhs.right),
+            .top    = @min(lhs.top, rhs.top),
+            .bottom = @max(lhs.bottom, rhs.bottom)
+        };
+    }
+};
+
 pub const TileVariant = struct {
     pub const Chunk = struct {
         x: i32,
@@ -15,6 +55,10 @@ pub const TileVariant = struct {
         width: u32,
         height: u32,
         data: []u32,
+
+        pub fn getBounds(self: Chunk) Bounds {
+            return Bounds.initFromRect(self.x, self.y, @intCast(self.width), @intCast(self.height));
+        }
     };
 
     pub const Data = union(enum) {
@@ -143,48 +187,18 @@ pub const TileVariant = struct {
         return result;
     }
 
-    const Bounds = struct {
-        left: i32,
-        right: i32,
-        top: i32,
-        bottom: i32,
-
-        pub fn width(self: Bounds) u32 {
-            return @intCast(self.right - self.left);
-        }
-
-        pub fn height(self: Bounds) u32 {
-            return @intCast(self.bottom - self.top);
-        }
-    };
-
     pub fn getBounds(self: TileVariant) Bounds {
         if (self.data == .fixed) {
-            return Bounds{
-                .left = 0,
-                .right = @intCast(self.width),
-                .top = 0,
-                .bottom = @intCast(self.height),
-            };
+            return Bounds.initFromRect(0, 0, @intCast(self.width), @intCast(self.height));
+
         } else if (self.data == .chunks) {
             const chunks = self.data.chunks;
 
-            var result = Bounds{
-                .left = 0,
-                .right = 0,
-                .top = 0,
-                .bottom = 0
-            };
+            var result: Bounds = .zero;
             if (chunks.len > 0) {
-                result.left   = chunks[0].x;
-                result.right  = chunks[0].x + @as(i32, @intCast(chunks[0].width));
-                result.top    = chunks[0].y;
-                result.bottom = chunks[0].y + @as(i32, @intCast(chunks[0].height));
+                result = chunks[0].getBounds();
                 for (chunks[1..]) |chunk| {
-                    result.left   = @min(result.left, chunk.x);
-                    result.right  = @max(result.right, chunk.x + @as(i32, @intCast(chunk.width)));
-                    result.top    = @min(result.top, chunk.y);
-                    result.bottom = @max(result.bottom, chunk.y + @as(i32, @intCast(chunk.height)));
+                    result = result.combine(chunk.getBounds());
                 }
             }
 
diff --git a/libs/tiled/src/property.zig b/libs/tiled/src/property.zig
index 1fa29df..19af15b 100644
--- a/libs/tiled/src/property.zig
+++ b/libs/tiled/src/property.zig
@@ -74,6 +74,15 @@ pub const List = struct {
         }
         return null;
     }
+
+    pub fn getBool(self: List, name: []const u8) ?bool {
+        if (self.get(name)) |value| {
+            if (value == .bool) {
+                return value.bool;
+            }
+        }
+        return null;
+    }
 };
 
 pub fn init(name: []const u8, value: Value) Property {
diff --git a/libs/tiled/src/tilemap.zig b/libs/tiled/src/tilemap.zig
index 14d6bc4..3bf4e47 100644
--- a/libs/tiled/src/tilemap.zig
+++ b/libs/tiled/src/tilemap.zig
@@ -241,6 +241,26 @@ pub fn getTileByPosition(self: *const Tilemap, layer: *const Layer, tilesets: Ti
     };
 }
 
+pub fn getTileBounds(self: *const Tilemap) Layer.Bounds {
+    var result: ?Layer.Bounds = null;
+
+    for (self.layers) |layer| {
+        if (layer.variant != .tile) {
+            continue;
+        }
+
+        const layer_bounds = layer.variant.tile.getBounds();
+        if (result == null) {
+            result = layer_bounds;
+        } else {
+            result = layer_bounds.combine(result.?);
+        }
+    }
+
+
+    return result orelse .zero;
+}
+
 pub fn deinit(self: *const Tilemap) void {
     self.arena.deinit();
 }
diff --git a/src/assets.zig b/src/assets.zig
index e53a2e8..119f1f0 100644
--- a/src/assets.zig
+++ b/src/assets.zig
@@ -84,7 +84,7 @@ pub fn init(gpa: std.mem.Allocator) !Assets {
     );
 
     var tilesets: tiled.Tileset.List = .empty;
-    try tilesets.add(gpa, "tileset.tsx", tileset);
+    try tilesets.add(gpa, "tilemap.tsx", tileset);
 
     const players_image = try STBImage.load(@embedFile("assets/kenney_desert-shooter-pack_1.0/PNG/Players/tilemap_packed.png"));
     defer players_image.deinit();
diff --git a/src/assets/map.tmx b/src/assets/map.tmx
index e03bc97..302035f 100644
--- a/src/assets/map.tmx
+++ b/src/assets/map.tmx
@@ -1,8 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<map version="1.10" tiledversion="1.11.2" orientation="orthogonal" renderorder="right-down" width="30" height="20" tilewidth="16" tileheight="16" infinite="1" nextlayerid="3" nextobjectid="2">
- <tileset firstgid="1" source="tileset.tsx"/>
- <tileset firstgid="235" source="tilemap.tsx"/>
- <layer id="1" name="Tile Layer 1" width="30" height="20">
+<map version="1.10" tiledversion="1.11.2" orientation="orthogonal" renderorder="right-down" width="30" height="20" tilewidth="16" tileheight="16" infinite="1" nextlayerid="5" nextobjectid="2">
+ <tileset firstgid="1" source="tilemap.tsx"/>
+ <layer id="1" name="ground" width="30" height="20">
   <data encoding="csv">
    <chunk x="-32" y="-32" width="16" height="16">
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
@@ -18,9 +17,9 @@
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 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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-0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,325,
-0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,343,
-0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,343
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,91,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,109,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,109
 </chunk>
    <chunk x="-16" y="-32" width="16" height="16">
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@@ -35,15 +34,15 @@
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+0,0,0,0,0,0,0,0,65,65,0,0,0,0,0,0,
+92,92,92,92,92,92,92,93,65,65,0,0,0,0,0,0,
+110,20,110,110,110,110,110,112,110,65,0,0,0,0,0,0,
+110,110,110,110,20,110,110,110,110,65,65,0,0,0,0,0
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    <chunk x="-32" y="-16" width="16" height="16">
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@@ -59,20 +58,20 @@
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    <chunk x="-16" y="-16" width="16" height="16">
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@@ -82,15 +81,137 @@
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+</chunk>
+  </data>
+ </layer>
+ <layer id="3" name="walls" width="30" height="20">
+  <properties>
+   <property name="solid" type="bool" value="true"/>
+  </properties>
+  <data encoding="csv">
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+  </data>
+ </layer>
+ <layer id="4" name="walls 2" width="30" height="20">
+  <properties>
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+0,0,0,0,0,0,0,0,0,0,0,0,0,73,74,74,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+</chunk>
+   <chunk x="0" y="-16" width="16" height="16">
+56,56,174,75,0,0,0,0,0,0,0,0,0,0,0,0,
+174,174,174,75,0,0,0,0,0,0,0,0,0,0,0,0,
+174,174,56,75,0,0,0,0,0,0,0,0,0,0,0,0,
+174,56,56,75,0,0,0,0,0,0,0,0,0,0,0,0,
+74,74,74,75,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
-0,0,0,299,299,299,0,0,0,0,0,0,0,0,0,0,
-299,299,299,299,299,299,0,0,0,0,0,0,0,0,0,0,
-0,0,299,299,299,299,299,0,0,0,0,0,0,0,0,0,
-299,299,299,299,299,299,299,0,0,0,0,0,0,0,0,0,
-299,299,299,299,299,299,0,0,0,0,0,0,0,0,0,0,
-299,299,299,299,299,0,0,0,0,0,0,0,0,0,0,0,
-299,299,299,0,0,0,0,0,0,0,0,0,0,0,0,0,
-299,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 </chunk>
diff --git a/src/engine/frame.zig b/src/engine/frame.zig
index 59a83bd..4b4f2bf 100644
--- a/src/engine/frame.zig
+++ b/src/engine/frame.zig
@@ -4,7 +4,7 @@ const log = std.log.scoped(.engine);
 
 const InputSystem = @import("./input.zig");
 const KeyCode = InputSystem.KeyCode;
-const Mouse = InputSystem.Mouse;
+const MouseButton = InputSystem.MouseButton;
 
 const AudioSystem = @import("./audio/root.zig");
 const AudioData = AudioSystem.Data;
@@ -27,19 +27,14 @@ pub const Nanoseconds = u64;
 const Frame = @This();
 
 pub const Input = struct {
-    down_keys: std.EnumSet(KeyCode),
-    pressed_keys: std.EnumSet(KeyCode),
-    released_keys: std.EnumSet(KeyCode),
-    pressed_keys_at: std.EnumMap(KeyCode, Nanoseconds),
-
-    mouse: Mouse,
+    keyboard: InputSystem.ButtonStateSet(KeyCode),
+    mouse_button: InputSystem.ButtonStateSet(MouseButton),
+    mouse_position: ?Vec2,
 
     pub const empty = Input{
-        .down_keys = .initEmpty(),
-        .pressed_keys = .initEmpty(),
-        .released_keys = .initEmpty(),
-        .pressed_keys_at = .init(.{}),
-        .mouse = .empty
+        .keyboard = .empty,
+        .mouse_button = .empty,
+        .mouse_position = null,
     };
 };
 
@@ -139,7 +134,8 @@ pub fn time(self: Frame) f64 {
 }
 
 pub fn isKeyDown(self: Frame, key_code: KeyCode) bool {
-    return self.input.down_keys.contains(key_code);
+    const keyboard = &self.input.keyboard;
+    return keyboard.down.contains(key_code);
 }
 
 pub fn getKeyDownDuration(self: Frame, key_code: KeyCode) ?f32 {
@@ -147,18 +143,21 @@ pub fn getKeyDownDuration(self: Frame, key_code: KeyCode) ?f32 {
         return null;
     }
 
-    const pressed_at_ns = self.input.pressed_keys_at.get(key_code).?;
+    const keyboard = &self.input.keyboard;
+    const pressed_at_ns = keyboard.pressed_at.get(key_code).?;
     const duration_ns = self.time_ns - pressed_at_ns;
 
     return @as(f32, @floatFromInt(duration_ns)) / std.time.ns_per_s;
 }
 
 pub fn isKeyPressed(self: Frame, key_code: KeyCode) bool {
-    return self.input.pressed_keys.contains(key_code);
+    const keyboard = &self.input.keyboard;
+    return keyboard.pressed.contains(key_code);
 }
 
 pub fn isKeyReleased(self: Frame, key_code: KeyCode) bool {
-    return self.input.released_keys.contains(key_code);
+    const keyboard = &self.input.keyboard;
+    return keyboard.released.contains(key_code);
 }
 
 pub fn getKeyState(self: Frame, key_code: KeyCode) KeyState {
@@ -170,6 +169,14 @@ pub fn getKeyState(self: Frame, key_code: KeyCode) KeyState {
     };
 }
 
+pub fn isMousePressed(self: Frame, button: MouseButton) bool {
+    return self.input.mouse_button.pressed.contains(button);
+}
+
+pub fn isMouseDown(self: Frame, button: MouseButton) bool {
+    return self.input.mouse_button.down.contains(button);
+}
+
 fn pushAudioCommand(self: *Frame, command: AudioCommand) void {
     const arena = self.arena.allocator();
 
diff --git a/src/engine/input.zig b/src/engine/input.zig
index 700c556..ee7ed33 100644
--- a/src/engine/input.zig
+++ b/src/engine/input.zig
@@ -19,38 +19,59 @@ pub const KeyCode = @Type(.{
     }
 });
 
-pub const Mouse = struct {
-    pub const Button = enum {
-        left,
-        right,
-        middle,
+pub const MouseButton = enum(i3) {
+    left = @intFromEnum(sokol.app.Mousebutton.LEFT),
+    right = @intFromEnum(sokol.app.Mousebutton.RIGHT),
+    middle = @intFromEnum(sokol.app.Mousebutton.MIDDLE),
+    _
+};
 
-        pub fn fromSokol(mouse_button: sokol.app.Mousebutton) ?Button {
-            return switch(mouse_button) {
-                .LEFT => Button.left,
-                .RIGHT => Button.right,
-                .MIDDLE => Button.middle,
-                else => null
-            };
+pub fn ButtonStateSet(E: type) type {
+    return struct {
+        const Self = @This();
+
+        down: std.EnumSet(E),
+        pressed: std.EnumSet(E),
+        released: std.EnumSet(E),
+        pressed_at: std.EnumMap(E, Nanoseconds),
+
+        pub const empty = Self{
+            .down = .initEmpty(),
+            .pressed = .initEmpty(),
+            .released = .initEmpty(),
+            .pressed_at = .init(.{}),
+        };
+
+        fn press(self: *Self, button: E, now: Nanoseconds) void {
+            self.pressed_at.put(button, now);
+            self.pressed.insert(button);
+            self.down.insert(button);
+        }
+
+        fn release(self: *Self, button: E) void {
+            self.down.remove(button);
+            self.released.insert(button);
+            self.pressed_at.remove(button);
+        }
+
+        fn releaseAll(self: *Self) void {
+            var iter = self.down.iterator();
+            while (iter.next()) |key_code| {
+                self.released.insert(key_code);
+            }
+            self.down = .initEmpty();
+            self.pressed_at = .init(.{});
         }
     };
-
-    position: ?Vec2,
-    buttons: std.EnumSet(Button),
-
-    pub const empty = Mouse{
-        .position = null,
-        .buttons = .initEmpty()
-    };
-};
+}
 
 pub const Event = union(enum) {
     mouse_pressed: struct {
-        button: Mouse.Button,
+        button: MouseButton,
         position: Vec2,
     },
     mouse_released: struct {
-        button: Mouse.Button,
+        button: MouseButton,
         position: Vec2,
     },
     mouse_move: Vec2,
@@ -72,39 +93,31 @@ pub fn processEvent(frame: *Frame, event: Event) void {
     switch (event) {
         .key_pressed => |opts| {
             if (!opts.repeat) {
-                input.pressed_keys_at.put(opts.code, frame.time_ns);
-                input.pressed_keys.insert(opts.code);
-                input.down_keys.insert(opts.code);
+                input.keyboard.press(opts.code, frame.time_ns);
             }
         },
         .key_released => |key_code| {
-            input.down_keys.remove(key_code);
-            input.released_keys.insert(key_code);
-            input.pressed_keys_at.remove(key_code);
+            input.keyboard.release(key_code);
         },
         .mouse_leave => {
-            var iter = input.down_keys.iterator();
-            while (iter.next()) |key_code| {
-                input.released_keys.insert(key_code);
-            }
-            input.down_keys = .initEmpty();
-            input.pressed_keys_at = .init(.{});
+            input.keyboard.releaseAll();
 
-            input.mouse = .empty;
+            input.mouse_position = null;
+            input.mouse_button = .empty;
         },
         .mouse_enter => |pos| {
-            input.mouse.position = pos;
+            input.mouse_position = pos;
         },
         .mouse_move => |pos| {
-            input.mouse.position = pos;
+            input.mouse_position = pos;
         },
         .mouse_pressed => |opts| {
-            input.mouse.position = opts.position;
-            input.mouse.buttons.insert(opts.button);
+            input.mouse_position = opts.position;
+            input.mouse_button.press(opts.button, frame.time_ns);
         },
         .mouse_released => |opts| {
-            input.mouse.position = opts.position;
-            input.mouse.buttons.remove(opts.button);
+            input.mouse_position = opts.position;
+            input.mouse_button.release(opts.button);
         },
         else => {}
     }
diff --git a/src/engine/math.zig b/src/engine/math.zig
index 301b334..95d0178 100644
--- a/src/engine/math.zig
+++ b/src/engine/math.zig
@@ -124,14 +124,22 @@ pub const Vec2 = extern struct {
         );
     }
 
+    pub fn lengthSqr(self: Vec2) f32 {
+        return self.x*self.x + self.y*self.y;
+    }
+
     pub fn length(self: Vec2) f32 {
-        return @sqrt(self.x*self.x + self.y*self.y);
+        return @sqrt(self.lengthSqr());
     }
 
     pub fn distance(self: Vec2, other: Vec2) f32 {
         return self.sub(other).length();
     }
 
+    pub fn distanceSqr(self: Vec2, other: Vec2) f32 {
+        return self.sub(other).lengthSqr();
+    }
+
     pub fn limitLength(self: Vec2, max_length: f32) Vec2 {
         const self_length = self.length();
         if (self_length > max_length) {
@@ -395,6 +403,10 @@ pub const Rect = struct {
         return self.pos.y + self.size.y;
     }
 
+    pub fn center(self: Rect) Vec2 {
+        return self.pos.add(self.size.multiplyScalar(0.5));
+    }
+
     pub fn multiply(self: Rect, xy: Vec2) Rect {
         return Rect{
             .pos = self.pos.multiply(xy),
diff --git a/src/engine/root.zig b/src/engine/root.zig
index 162edf9..36b9e3e 100644
--- a/src/engine/root.zig
+++ b/src/engine/root.zig
@@ -165,11 +165,11 @@ fn sokolFrame(self: *Engine) !void {
 
     var revert_mouse_position: ?Vec2 = null;
     if (self.canvas_size) |canvas_size| {
-        if (self.frame.input.mouse.position) |mouse| {
+        if (self.frame.input.mouse_position) |mouse| {
             const transform = ScreenScalar.init(screen_size, canvas_size);
 
             revert_mouse_position = mouse;
-            self.frame.input.mouse.position = mouse.sub(transform.translation).divideScalar(transform.scale);
+            self.frame.input.mouse_position = mouse.sub(transform.translation).divideScalar(transform.scale);
         }
     }
 
@@ -195,8 +195,10 @@ fn sokolFrame(self: *Engine) !void {
 
         try self.game.tick(&self.frame);
 
-        frame.input.pressed_keys = .initEmpty();
-        frame.input.released_keys = .initEmpty();
+        frame.input.keyboard.pressed = .initEmpty();
+        frame.input.keyboard.released = .initEmpty();
+        frame.input.mouse_button.pressed = .initEmpty();
+        frame.input.mouse_button.released = .initEmpty();
     }
 
     if (self.canvas_size) |canvas_size| {
@@ -234,7 +236,7 @@ fn sokolFrame(self: *Engine) !void {
     }
 
     if (revert_mouse_position) |pos| {
-        self.frame.input.mouse.position = pos;
+        self.frame.input.mouse_position = pos;
     }
 }
 
@@ -262,7 +264,6 @@ fn sokolEvent(self: *Engine, e_ptr: [*c]const sapp.Event) !bool {
     defer zone.deinit();
 
     const e = e_ptr.*;
-    const MouseButton = Input.Mouse.Button;
 
     if (imgui.handleEvent(e)) {
         if (self.mouse_inside) {
@@ -274,13 +275,11 @@ fn sokolEvent(self: *Engine, e_ptr: [*c]const sapp.Event) !bool {
         return true;
     }
 
-    blk: switch (e.type) {
+    switch (e.type) {
         .MOUSE_DOWN => {
-            const mouse_button = MouseButton.fromSokol(e.mouse_button) orelse break :blk;
-
             Input.processEvent(&self.frame, .{
                 .mouse_pressed = .{
-                    .button = mouse_button,
+                    .button = @enumFromInt(@intFromEnum(e.mouse_button)),
                     .position = Vec2.init(e.mouse_x, e.mouse_y)
                 }
             });
@@ -288,11 +287,9 @@ fn sokolEvent(self: *Engine, e_ptr: [*c]const sapp.Event) !bool {
             return true;
         },
         .MOUSE_UP => {
-            const mouse_button = MouseButton.fromSokol(e.mouse_button) orelse break :blk;
-
             Input.processEvent(&self.frame, .{
                 .mouse_released = .{
-                    .button = mouse_button,
+                    .button = @enumFromInt(@intFromEnum(e.mouse_button)),
                     .position = Vec2.init(e.mouse_x, e.mouse_y)
                 }
             });
diff --git a/src/game.zig b/src/game.zig
index d55d6b4..12e0628 100644
--- a/src/game.zig
+++ b/src/game.zig
@@ -2,6 +2,7 @@ const std = @import("std");
 const Allocator = std.mem.Allocator;
 const assert = std.debug.assert;
 const clamp = std.math.clamp;
+const log = std.log.scoped(.game);
 
 const Assets = @import("./assets.zig");
 const Tilemap = Assets.Tilemap;
@@ -17,6 +18,9 @@ const rgba = Engine.Math.rgba;
 const Range = Engine.Math.Range;
 const TextureId = Engine.Graphics.TextureId;
 const AudioId = Engine.Audio.Data.Id;
+const Sprite = Engine.Graphics.Sprite;
+
+const RaycastTileIterator = @import("./raycast_tile_iterator.zig");
 
 const Game = @This();
 
@@ -94,6 +98,69 @@ const AudioBundle = struct {
      }
 };
 
+const Bullet = struct {
+    position: Vec2,
+    velocity: Vec2
+};
+
+const Tile = struct {
+    sprites_buffer: [4]Sprite,
+    sprites_len: usize,
+
+    solid: bool,
+
+    const empty = Tile{
+        .sprites_buffer = undefined,
+        .sprites_len = 0,
+        .solid = false
+    };
+
+    fn sprites(self: *Tile) []Sprite {
+        return self.sprites_buffer[0..self.sprites_len];
+    }
+
+    fn appendSprite(self: *Tile, sprite: Sprite) void {
+        var list: std.ArrayList(Sprite) = .{
+            .items = self.sprites(),
+            .capacity = self.sprites_buffer.len
+        };
+
+        if (list.items.len == list.capacity) {
+            _ = list.orderedRemove(0);
+            log.warn("Too many sprites on a single tile", .{});
+        }
+        list.appendAssumeCapacity(sprite);
+
+        self.sprites_len = list.items.len;
+    }
+};
+
+const TileGrid = struct {
+    origin: Vec2,
+    width: usize,
+    height: usize,
+    tile_size: Vec2,
+    tiles: []Tile,
+
+    pub fn get(self: TileGrid, x: usize, y: usize) *Tile {
+        assert(0 <= x and x < self.width);
+        assert(0 <= y and y < self.height);
+        return &self.tiles[y * self.width + x];
+    }
+
+    pub fn isInBounds(self: TileGrid, x: i32, y: i32) bool {
+        return (0 <= x and x < @as(i32, @intCast(self.width))) and (0 <= y and y < @as(i32, @intCast(self.height)));
+    }
+
+    pub fn toTileSpace(self: TileGrid, pos: Vec2) Vec2 {
+        return pos.sub(self.origin).divide(self.tile_size);
+    }
+
+    pub fn fromTileSpace(self: TileGrid, pos: Vec2) Vec2 {
+        return pos.multiply(self.tile_size).add(self.origin);
+    }
+};
+
 arena: std.heap.ArenaAllocator,
 gpa: Allocator,
 rng: RNGState,
@@ -105,6 +172,9 @@ last_faced_left: bool = false,
 player_walk_sound: AudioBundle = .empty,
 hand_offset: Vec2 = .zero,
 
+bullets: std.ArrayList(Bullet) = .empty,
+tilegrid: TileGrid,
+
 player_anim: Animation,
 
 pub fn init(gpa: Allocator, seed: u64, assets: *Assets) !Game {
@@ -125,18 +195,76 @@ pub fn init(gpa: Allocator, seed: u64, assets: *Assets) !Game {
         }),
     };
 
+    const tilemap = assets.terrain_tilemap;
+    const map_bounds = assets.map.getTileBounds(); 
+
+    const map_width = map_bounds.getWidth();
+    const map_height = map_bounds.getHeight();
+    const tilegrid = TileGrid{
+        .origin = Vec2.initFromInt(i32, map_bounds.left, map_bounds.top).multiply(tilemap.tile_size),
+        .width = map_width,
+        .height = map_height,
+        .tile_size = tilemap.tile_size,
+        .tiles = try arena.allocator().alloc(Tile, map_width * map_height),
+    };
+
+    @memset(tilegrid.tiles, .empty);
+
+    {
+        const texture_info = Engine.Graphics.getTextureInfo(tilemap.texture);
+        const tilemap_size = Vec2.initFromInt(u32, texture_info.width, texture_info.height);
+
+        for (assets.map.layers) |layer| {
+            if (layer.variant != .tile) {
+                continue;
+            }
+
+            const is_layer_solid = layer.properties.getBool("solid") orelse false;
+
+            const tile_layer = layer.variant.tile;
+            const layer_bounds = tile_layer.getBounds();
+            for (0..layer_bounds.getHeight()) |oy| {
+                const y = layer_bounds.top + @as(i32, @intCast(oy));
+
+                for (0..layer_bounds.getWidth()) |ox| {
+                    const x = layer_bounds.left + @as(i32, @intCast(ox));
+                    const tile_gid = tile_layer.get(x, y) orelse continue;
+                    if (tile_gid == 0) continue;
+                    const tile = assets.map.getTile(assets.tilesets, tile_gid) orelse continue;
+
+                    const tile_id_f32: f32 = @floatFromInt(tile.id);
+                    const width_in_tiles = tilemap_size.x / tilemap.tile_size.x;
+                    const tile_x = @rem(tile_id_f32, width_in_tiles);
+                    const tile_y  =@divFloor(tile_id_f32, width_in_tiles);
+
+                    const tilegrid_tile = tilegrid.get(
+                        @intCast(x - map_bounds.left),
+                        @intCast(y - map_bounds.top)
+                    );
+                    tilegrid_tile.solid |= is_layer_solid;
+                    tilegrid_tile.appendSprite(.{
+                        .texture = tilemap.texture,
+                        .uv = tilemap.getTileUV(tile_x, tile_y)
+                    });
+                }
+            }
+        }
+    }
+
     return Game{
         .arena = arena,
         .gpa = gpa,
         .assets = assets,
         .player = findSpawnpoint(assets) orelse .init(0, 0),
         .player_anim = player_anim,
-        .rng = RNGState.init(seed)
+        .rng = RNGState.init(seed),
+        .tilegrid = tilegrid
     };
 }
 
 pub fn deinit(self: *Game) void {
     self.arena.deinit();
+    self.bullets.deinit(self.gpa);
 }
 
 fn findSpawnpoint(assets: *Assets) ?Vec2 {
@@ -187,42 +315,181 @@ fn drawTile(frame: *Engine.Frame, opts: DrawTileOptions) void {
 }
 
 fn drawTilemap(self: *Game, frame: *Engine.Frame) void {
-    const tilemap = self.assets.terrain_tilemap;
-    const texture_info = Engine.Graphics.getTextureInfo(tilemap.texture);
-    const tilemap_size = Vec2.initFromInt(u32,texture_info.width, texture_info.height);
+    for (0..self.tilegrid.height) |y| {
+        for (0..self.tilegrid.width) |x| {
+            const tile = self.tilegrid.get(x, y);
+            if (tile.sprites_len == 0) continue;
 
-    const map = self.assets.map;
+            const tile_pos = Vec2.initFromInt(usize, x, y).multiply(self.tilegrid.tile_size);
+            const tile_rect = Rect{
+                .pos = self.tilegrid.origin.add(tile_pos),
+                .size = self.tilegrid.tile_size
+            };
 
-    for (map.layers) |layer| {
-        if (layer.variant != .tile) {
-            continue;
-        }
-
-        const tile_layer = layer.variant.tile;
-        const layer_bounds = tile_layer.getBounds();
-        for (0..layer_bounds.height()) |oy| {
-            const y = layer_bounds.top + @as(i32, @intCast(oy));
-
-            for (0..layer_bounds.width()) |ox| {
-                const x = layer_bounds.left + @as(i32, @intCast(ox));
-                const tile_gid = tile_layer.get(x, y) orelse continue;
-                const tile = map.getTile(self.assets.tilesets, tile_gid) orelse continue;
-
-                const tile_id_f32: f32 = @floatFromInt(tile.id);
-                const width_in_tiles = tilemap_size.x / tilemap.tile_size.x;
-                const tile_x = @rem(tile_id_f32, width_in_tiles);
-                const tile_y = @divFloor(tile_id_f32, width_in_tiles);
-
-                drawTile(frame, .{
-                    .pos = Vec2.initFromInt(i32, x, y).multiply(tilemap.tile_size),
-                    .tilemap = tilemap,
-                    .tile = .init(tile_x, tile_y)
+            const color = rgb(255, 255, 255);
+            for (tile.sprites()) |sprite| {
+                frame.drawRectangle(.{
+                    .rect = tile_rect,
+                    .color = color,
+                    .sprite = sprite
                 });
             }
         }
     }
 }
 
+const CollisionResult = struct {
+    time: f32,
+    normal: Vec2,
+};
+
+fn sweptAABB(b1: Rect, v1: Vec2, b2: Rect) ?CollisionResult {
+    var entry_x: f32 = undefined;
+    var exit_x: f32 = undefined;
+    if (v1.x > 0) {
+        entry_x = b2.left() - b1.right();
+        exit_x  = b2.right() - b1.left();
+    } else {
+        entry_x = b2.right() - b1.left();
+        exit_x  = b2.left() - b1.right();
+    }
+
+    var entry_y: f32 = undefined;
+    var exit_y: f32 = undefined;
+    if (v1.y > 0) {
+        entry_y = b2.top() - b1.bottom();
+        exit_y  = b2.bottom() - b1.top();
+    } else {
+        entry_y = b2.bottom() - b1.top();
+        exit_y  = b2.top() - b1.bottom();
+    }
+
+    const inf = std.math.inf(f32);
+
+    var entry_x_time: f32 = undefined;
+    var exit_x_time: f32 = undefined;
+    if (v1.x == 0) {
+        entry_x_time = -inf;
+        exit_x_time = inf;
+    } else {
+        entry_x_time = entry_x / v1.x;
+        exit_x_time = exit_x / v1.x;
+    }
+
+    var entry_y_time: f32 = undefined;
+    var exit_y_time: f32 = undefined;
+    if (v1.y == 0) {
+        entry_y_time = -inf;
+        exit_y_time = inf;
+    } else {
+        entry_y_time = entry_y / v1.y;
+        exit_y_time = exit_y / v1.y;
+    }
+
+    const entry_time = @max(entry_x_time, entry_y_time);
+    const exit_time = @min(exit_x_time, exit_y_time);
+
+    if (entry_time > exit_time or
+        (entry_x_time < 0 and entry_y_time < 0) or
+        entry_x_time > 1.0 or
+        entry_y_time > 1.0
+    ) {
+        return null;
+    }
+
+    var result = CollisionResult{
+        .time = entry_time,
+        .normal = .zero
+    };
+
+    if (entry_x_time > entry_y_time) {
+        result.normal.x = if ((exit_x - entry_x) < 0.0) 1 else -1;
+    } else {
+        result.normal.y = if ((exit_y - entry_y) < 0.0) 1 else -1;
+    }
+
+    return result;
+}
+
+fn getStepBounds(rect: Rect, step: Vec2) Rect {
+    var result = rect;
+
+    if (step.x >= 0) {
+        result.size.x += step.x;
+    } else {
+        result.pos.x += step.x;
+        result.size.x -= step.x;
+    }
+
+    if (step.y >= 0) {
+        result.size.y += step.y;
+    } else {
+        result.pos.y += step.y;
+        result.size.y -= step.y;
+    }
+
+    return result;
+}
+
+fn collisionResponseSlide(step: *Vec2, collision: CollisionResult) void {
+    var new_step = step.multiplyScalar(collision.time);
+
+    const remaining_time = 1 - collision.time;
+    const dotprod = (step.x * collision.normal.y + step.y * collision.normal.x) * remaining_time;
+    new_step.x += dotprod * collision.normal.y;
+    new_step.y += dotprod * collision.normal.x;
+
+    step.* = new_step;
+}
+
+fn listNearestSolids(self: *Game, gpa: Allocator, bounds: Rect) ![]Rect {
+    var result: std.ArrayList(Rect) = .empty;
+    errdefer result.deinit(gpa);
+
+    var distances: std.ArrayList(f32) = .empty;
+    defer distances.deinit(gpa);
+
+    const top_left = self.tilegrid.toTileSpace(Vec2.init(bounds.left(), bounds.top()));
+    const bottom_right = self.tilegrid.toTileSpace(Vec2.init(bounds.right(), bounds.bottom()));
+
+    var y = @floor(top_left.y);
+    while (y < bottom_right.y) : (y += 1) {
+        var x = @floor(top_left.x);
+        while (x < bottom_right.x) : (x += 1) {
+            const x_i32: i32 = @intFromFloat(x);
+            const y_i32: i32 = @intFromFloat(y);
+            if (!self.tilegrid.isInBounds(x_i32, y_i32)) continue;
+
+            const tile = self.tilegrid.get(@intCast(x_i32), @intCast(y_i32));
+            if (tile.solid) {
+                const tile_collider = Rect{
+                    .pos = self.tilegrid.fromTileSpace(Vec2.init(x, y)),
+                    .size = self.tilegrid.tile_size
+                };
+                try result.append(gpa, tile_collider);
+                try distances.append(gpa, Vec2.distanceSqr(tile_collider.center(), bounds.center()));
+            }
+        }
+    }
+
+    const Context = struct {
+        bounds_center: Vec2,
+
+        fn lessThanFn(ctx: @This(), lhs: Rect, rhs: Rect) bool {
+            const lhs_distance = Vec2.distanceSqr(lhs.center(), ctx.bounds_center);
+            const rhs_distance = Vec2.distanceSqr(rhs.center(), ctx.bounds_center);
+            return lhs_distance < rhs_distance;
+        }
+    };
+
+    const ctx = Context{
+        .bounds_center = bounds.center()
+    };
+    std.mem.sort(Rect, result.items, ctx, Context.lessThanFn);
+
+    return try result.toOwnedSlice(gpa);
+}
+
 pub fn tick(self: *Game, frame: *Engine.Frame) !void {
     const dt = frame.deltaTime();
 
@@ -242,6 +509,8 @@ pub fn tick(self: *Game, frame: *Engine.Frame) !void {
     frame.pushTransform(camera_offset, .init(1, 1));
     defer frame.popTransform();
 
+    self.drawTilemap(frame);
+
     var dir = Vec2.init(0, 0);
     if (frame.isKeyDown(.W)) {
         dir.y -= 1;
@@ -269,11 +538,59 @@ pub fn tick(self: *Game, frame: *Engine.Frame) !void {
         self.player_anim_state.frame_index = 0;
     }
 
-    self.player = self.player.add(dir.multiplyScalar(50 * dt));
+    const velocity = dir.multiplyScalar(50);
+    var step = velocity.multiplyScalar(dt);
 
-    const regular_font = self.assets.font_id.get(.regular);
+    const player_collider_size = Vec2.init(20, 20);
+    const player_collider = Rect{
+        .pos = self.player.sub(player_collider_size.divideScalar(2)),
+        .size = player_collider_size,
+    };
 
-    self.drawTilemap(frame);
+    {
+        // const solids = try self.listNearestSolids(frame.arena.allocator(), getStepBounds(player_collider, step));
+        // for (solids) |solid| {
+        //     if (sweptAABB(player_collider, step, solid)) |collision| {
+        //         collisionResponseSlide(&step, collision);
+        //     }
+        // }
+
+        inline for (.{
+            // Vec2.init(0, 0),
+            // Vec2.init(1, 0),
+            Vec2.init(0, 1),
+            // Vec2.init(1, 1),
+        }) |corner_offset| {
+            const corner = player_collider.pos.add(player_collider.size.multiply(corner_offset));
+            var iter = RaycastTileIterator.init(
+                self.tilegrid.toTileSpace(corner),
+                self.tilegrid.toTileSpace(corner.add(step)),
+            );
+            while (iter.next()) |collision| {
+                if (!self.tilegrid.isInBounds(collision.tile_x, collision.tile_y)) break;
+                const tile = self.tilegrid.get(@intCast(collision.tile_x), @intCast(collision.tile_y));
+                if (tile.solid) {
+                    const time = collision.distance / step.divide(self.tilegrid.tile_size).length();
+                    collisionResponseSlide(&step, .{
+                        .normal = .initFromInt(i32, collision.normal_x, collision.normal_y),
+                        .time = time
+                    });
+
+                    const pos = Vec2.initFromInt(i32, collision.tile_x, collision.tile_y).multiply(self.tilegrid.tile_size).add(self.tilegrid.origin);
+                    frame.drawRectangle(.{
+                        .rect = Rect{
+                            .pos = pos,
+                            .size = self.tilegrid.tile_size,
+                        },
+                        .color = rgba(200, 20, 20, 0.5)
+                    });
+                    break;
+                }
+            }
+        }
+    }
+
+    self.player = self.player.add(step);
 
     if (dir.x < 0) {
         self.last_faced_left = true;
@@ -297,8 +614,14 @@ pub fn tick(self: *Game, frame: *Engine.Frame) !void {
         }
     });
 
+    frame.drawRectangle(.{
+        .rect = player_collider,
+        .color = rgba(20, 255, 255, 0.5)
+    });
+
+
     const max_hand_length = 32;
-    if (frame.input.mouse.position) |mouse_screen| {
+    if (frame.input.mouse_position) |mouse_screen| {
         const mouse = mouse_screen.sub(camera_offset);
         const player_to_mouse = mouse.sub(self.player);
         self.hand_offset = mouse.sub(self.player).limitLength(max_hand_length);
@@ -311,6 +634,38 @@ pub fn tick(self: *Game, frame: *Engine.Frame) !void {
             .tile = .init(4, 2)
         });
         frame.hide_cursor = true;
+
+        if (false) {
+        var iter = RaycastTileIterator.init(
+            self.tilegrid.toTileSpace(self.player),
+            self.tilegrid.toTileSpace(mouse),
+        );
+        while (iter.next()) |item| {
+            if (!self.tilegrid.isInBounds(item.tile_x, item.tile_y)) break;
+
+            const tile = self.tilegrid.get(@intCast(item.tile_x), @intCast(item.tile_y));
+            const pos = Vec2.initFromInt(i32, item.tile_x, item.tile_y).multiply(self.tilegrid.tile_size).add(self.tilegrid.origin);
+
+            frame.drawRectangle(.{
+                .rect = Rect{
+                    .pos = pos,
+                    .size = self.tilegrid.tile_size,
+                },
+                .color = rgba(200, 20, 20, 0.5)
+            });
+            frame.drawRectangle(.{
+                .rect = Rect{
+                    .pos = pos.add(self.tilegrid.tile_size.multiplyScalar(0.25)).add(self.tilegrid.tile_size.multiplyScalar(0.25).multiply(.initFromInt(i32, item.normal_x, item.normal_y))),
+                    .size = self.tilegrid.tile_size.divideScalar(2),
+                },
+                .color = rgba(20, 200, 20, 0.5)
+            });
+
+            if (tile.solid) {
+                break;
+            }
+        }
+        }
     }
 
     const hand = self.player.add(self.hand_offset);
@@ -329,10 +684,25 @@ pub fn tick(self: *Game, frame: *Engine.Frame) !void {
         .rotation = self.hand_offset.getAngle()
     });
 
-    frame.drawText(self.player, "Player", .{
-        .font = regular_font,
-        .size = 16
-    });
+    if (frame.isMousePressed(.left)) {
+        try self.bullets.append(self.gpa, .{
+            .position = hand,
+            .velocity = self.hand_offset.normalized().multiplyScalar(100)
+        });
+    }
+
+    for (self.bullets.items) |*bullet| {
+        bullet.position = bullet.position.add(bullet.velocity.multiplyScalar(dt));
+
+        const bullet_size = Vec2.init(16, 16);
+        frame.drawRectangle(.{
+            .rect = .{
+                .pos = bullet.position.sub(bullet_size.multiplyScalar(0.5)),
+                .size = bullet_size
+            },
+            .color = rgb(200, 10, 10)
+        });
+    }
 }
 
 pub fn debug(self: *Game) !void {
diff --git a/src/raycast_tile_iterator.zig b/src/raycast_tile_iterator.zig
new file mode 100644
index 0000000..f3257f9
--- /dev/null
+++ b/src/raycast_tile_iterator.zig
@@ -0,0 +1,97 @@
+const Engine = @import("./engine/root.zig");
+const Vec2 = Engine.Vec2;
+
+// DDA Algorithm: https://lodev.org/cgtutor/raycasting.html
+const RaycastTileIterator = @This();
+
+max_distance: f32,
+ray_length_1d: Vec2,
+check_x: i32,
+check_y: i32,
+step_x: i32,
+step_y: i32,
+unit_step_size: Vec2,
+
+const Item = struct {
+    tile_x: i32,
+    tile_y: i32,
+    normal_x: i32,
+    normal_y: i32,
+    distance: f32,
+};
+
+pub fn init(origin: Vec2, target: Vec2) RaycastTileIterator {
+    const target_origin = target.sub(origin);
+    const max_distance = target_origin.length();
+    const dir = target_origin.normalized();
+
+    var unit_step_size_x: f32 = 0;
+    if (dir.x != 0) {
+        unit_step_size_x = dir.y / dir.x;
+    }
+
+    var unit_step_size_y: f32= 0;
+    if (dir.y != 0) {
+        unit_step_size_y = dir.x / dir.y;
+    }
+
+    const unit_step_size = Vec2{
+        .x = Vec2.init(1, unit_step_size_x).length(),
+        .y = Vec2.init(unit_step_size_y, 1).length()
+    };
+
+    const step_x: i32 = if (dir.x < 0) -1 else 1;
+    const step_y: i32 = if (dir.y < 0) -1 else 1;
+
+    const step_x_f32: f32 = @floatFromInt(step_x);
+    const step_y_f32: f32 = @floatFromInt(step_y);
+
+    const ray_length_1d = (Vec2{
+        .x = ((step_x_f32 + 1)/2 - step_x_f32 * @mod(origin.x, 1)),
+        .y = ((step_y_f32 + 1)/2 - step_y_f32 * @mod(origin.y, 1))
+    }).multiply(unit_step_size);
+
+    const check_x: i32 = @intFromFloat(origin.x);
+    const check_y: i32 = @intFromFloat(origin.y);
+
+    return RaycastTileIterator{
+        .max_distance = max_distance,
+        .ray_length_1d = ray_length_1d,
+        .check_x = check_x,
+        .check_y = check_y,
+        .step_x = step_x,
+        .step_y = step_y,
+        .unit_step_size = unit_step_size
+    };
+}
+
+pub fn next(self: *RaycastTileIterator) ?Item {
+    if (self.ray_length_1d.x > self.max_distance and self.ray_length_1d.y > self.max_distance) {
+        return null;
+    }
+
+    var normal_x: i32 = 0;
+    var normal_y: i32 = 0;
+    var distance: f32 = undefined;
+    if (self.ray_length_1d.x < self.ray_length_1d.y) {
+        distance = self.ray_length_1d.x;
+
+        normal_x = -self.step_x;
+        self.check_x += self.step_x;
+        self.ray_length_1d.x += self.unit_step_size.x;
+    } else {
+        distance = self.ray_length_1d.y;
+
+        normal_y = -self.step_y;
+        self.check_y += self.step_y;
+        self.ray_length_1d.y += self.unit_step_size.y;
+    }
+
+    return .{
+        .distance = distance,
+        .tile_x = self.check_x,
+        .tile_y = self.check_y,
+        .normal_x = normal_x,
+        .normal_y = normal_y
+    };
+}