add health

src/game.zig

@@ -56,7 +56,10 @@ const Kinetic = struct {
 const Player = struct {
     kinetic: Kinetic = .{},
     money: u32 = 0,
+    health: u32 = 0,
+    max_health: u32 = 0,
     last_shot_at: ?Nanoseconds = null,
+    invincible_until: ?Nanoseconds = null,
 
     pub fn getRect(self: Player) Rect {
         return getCenteredRect(self.kinetic.pos, 16);
@@ -102,6 +105,7 @@ const Pickup = struct {
     kind: Kind,
 };
 
+const invincibility_duration_s = 0.5;
 const pickup_spawn_duration_s = Range.init(1, 5);
 const wave_infos = [_]Wave.Info{
     .{
@@ -145,7 +149,9 @@ pub fn init(gpa: Allocator, seed: u64, assets: *Assets) !Game {
         .player = .{
             .kinetic = .{
                 .pos = .init(50, 50),
-            }
+            },
+            .health = 3,
+            .max_health = 3
         },
         .rng = rng
     };
@@ -379,6 +385,22 @@ pub fn tick(self: *Game, frame: *Engine.Frame) !void {
         enemy.kinetic.update(dt, .{});
 
         const enemy_rect = getCenteredRect(enemy.kinetic.pos, enemy.size);
+
+        if (enemy_rect.hasOverlap(self.player.getRect())) {
+            var is_invincible = false;
+            if (self.player.invincible_until) |invincible_until| {
+                is_invincible = frame.time_ns < invincible_until;
+            }
+
+            if (self.player.health > 0 and !is_invincible) {
+                self.player.health -= 1;
+
+                var invincible_until = frame.time_ns;
+                invincible_until += @as(Nanoseconds, @intFromFloat(invincibility_duration_s * std.time.ns_per_s));
+                self.player.invincible_until = invincible_until;
+            }
+        }
+
         frame.drawRectangle(.{
             .rect = enemy_rect,
             .color = rgb(20, 200, 20)
@@ -394,7 +416,11 @@ pub fn tick(self: *Game, frame: *Engine.Frame) !void {
             const pickup_rect = Rect.initCentered(pickup.pos.x, pickup.pos.y, 10, 10);
 
             if (pickup_rect.hasOverlap(self.player.getRect())) {
-                self.player.money += 1;
+                switch (pickup.kind) {
+                    .money => {
+                        self.player.money += 1;
+                    }
+                }
                 destroy = true;
             }
 
@@ -442,6 +468,7 @@ pub fn tick(self: *Game, frame: *Engine.Frame) !void {
     });
 
     frame.drawTextFormat(.init(10, 30), text_opts, "{d}", .{ self.player.money });
+    frame.drawTextFormat(.init(10, 50), text_opts, "{d}/{d}", .{ self.player.health, self.player.max_health });
 }
 
 pub fn debug(self: *Game) !void {
@@ -461,6 +488,7 @@ pub fn debug(self: *Game) !void {
     const time_left_til_pickup = self.next_pickup_spawn_at - self.wave_timer;
 
     imgui.textFmt("Waves: {}\n", .{self.waves.items.len});
+    imgui.textFmt("Bullets: {}\n", .{self.bullets.items.len});
     imgui.textFmt("Enemies: {}\n", .{self.enemies.items.len});
     imgui.textFmt("Time until next pickup: {d:.2}s\n", .{@as(f32, @floatFromInt(time_left_til_pickup)) / std.time.ns_per_s});
 }