make spinning easier

src/main-scene.zig

@@ -16,7 +16,7 @@ const Player = struct {
     position: rl.Vector2,
     velocity: rl.Vector2 = rl.Vector2.zero(),
     acceleration: rl.Vector2 = rl.Vector2.zero(),
-    handDirection: rl.Vector2 = rl.Vector2{ .x = 1, .y = 0 }
+    handDirection: rl.Vector2 = rl.Vector2{ .x = 1, .y = 0 },
 };
 
 const Rope = struct {
@@ -100,7 +100,9 @@ const Rope = struct {
             const offset = offsets.get(i);
             vel.* = vel.add(acc.scale(dt));
             vel.* = vel.scale(1 - self.friction);
-            pos.* = pos.add(vel.scale(dt*10000));
+
+            const amplifier = @as(f32, @floatFromInt(i-1))/@as(f32, @floatFromInt(node_count-2));
+            pos.* = pos.add(vel.scale(dt*10000 + amplifier*5));
             pos.* = pos.add(offset.scale(0.01));
         }
     }
@@ -116,10 +118,12 @@ enemies: std.ArrayList(Enemy),
 player: Player,
 rope: Rope,
 
+camera: rl.Camera2D,
+
 const Self = @This();
 
 pub fn init(allocator: Allocator) Self {
-    var playerPosition = rl.Vector2{ .x = 400, .y = 400 };
+    var playerPosition = rl.Vector2{ .x = 0, .y = 0 };
     var ropeSize: f32 = 200;
     var handPosition = playerPosition.add(rl.Vector2{ .x = handDistance, .y = 0});
 
@@ -128,7 +132,8 @@ pub fn init(allocator: Allocator) Self {
         .prng = std.rand.DefaultPrng.init(@bitCast(std.time.timestamp())),
         .enemies = std.ArrayList(Enemy).init(allocator),
         .player = .{ .position = playerPosition },
-        .rope = Rope.init(handPosition, handPosition.add(.{ .x = ropeSize, .y = 0.002 }), 10)
+        .rope = Rope.init(handPosition, handPosition.add(.{ .x = ropeSize, .y = 0.002 }), 10),
+        .camera = .{ .target = playerPosition }
     };
 }
 
@@ -144,6 +149,14 @@ pub fn deinit(self: Self) void {
 pub fn tick(self: *Self) !void {
     rl.ClearBackground(rl.BLACK);
 
+    const screenWidth: f32 = @floatFromInt(rl.GetScreenWidth());
+    const screenHeight: f32 = @floatFromInt(rl.GetScreenHeight());
+    const mouseDelta = rl.GetMouseDelta();
+
+    self.camera.offset.x = screenWidth/2;
+    self.camera.offset.y = screenHeight/2;
+    self.camera.target = self.player.position;
+
     const dt = rl.GetFrameTime();
     var rng = self.prng.random();
     var player = &self.player;
@@ -156,7 +169,7 @@ pub fn tick(self: *Self) !void {
         self.enemyTimer = 0.5 + rng.float(f32) * 2;
         self.spawnedEnemiesCount += 1;
         try enemies.append(Enemy{
-            .position = rl.Vector2.randomOnUnitCircle(rng).scale(100)
+            .position = rl.Vector2.randomOnUnitCircle(rng).scale(400)
         });
     }
 
@@ -175,16 +188,16 @@ pub fn tick(self: *Self) !void {
         moveDx += 1;
     }
 
-    var handDx: f32 = 0;
+    var handDx: f32 = mouseDelta.x;
-    var handDy: f32 = 0;
+    var handDy: f32 = mouseDelta.y;
 
     var gamepad: i32 = 0;
     if (rl.IsGamepadAvailable(gamepad)) {
-        moveDx += rl.GetGamepadAxisMovement(gamepad, rl.GamepadAxis.GAMEPAD_AXIS_LEFT_X);
+        moveDx += rl.GetGamepadAxisMovement(gamepad, .GAMEPAD_AXIS_LEFT_X);
-        moveDy += rl.GetGamepadAxisMovement(gamepad, rl.GamepadAxis.GAMEPAD_AXIS_LEFT_Y);
+        moveDy += rl.GetGamepadAxisMovement(gamepad, .GAMEPAD_AXIS_LEFT_Y);
 
-        handDx = rl.GetGamepadAxisMovement(gamepad, rl.GamepadAxis.GAMEPAD_AXIS_RIGHT_X);
+        handDx += rl.GetGamepadAxisMovement(gamepad, .GAMEPAD_AXIS_RIGHT_X);
-        handDy = rl.GetGamepadAxisMovement(gamepad, rl.GamepadAxis.GAMEPAD_AXIS_RIGHT_Y);
+        handDy += rl.GetGamepadAxisMovement(gamepad, .GAMEPAD_AXIS_RIGHT_Y);
     }
 
     var moveDir = rl.Vector2{ .x = moveDx, .y = moveDy };
@@ -221,86 +234,18 @@ pub fn tick(self: *Self) !void {
 
         const directionToPlayer = toPlayer.normalize();
         enemy.position = enemy.position.add(directionToPlayer.scale(enemySpeed * dt));
-        rl.DrawCircle(
-            @intFromFloat(enemy.position.x),
-            @intFromFloat(enemy.position.y),
-            enemySize,
-            rl.RED
-        );
     }
 
     const handPosition = player.position.add(player.handDirection.scale(handDistance));
 
-    const enemyCountText = try std.fmt.allocPrintZ(allocator, "{d}", .{self.spawnedEnemiesCount});
+    const rope_root_node: rl.Vector2 = rope.nodePositions.get(0);
-    defer allocator.free(enemyCountText);
+    rope.nodePositions.set(0, rope_root_node.lerp(handPosition, 0.25));
-    rl.DrawText(enemyCountText, 10, 10, 24, rl.RED);
+    // rope.nodePositions.set(0, handPosition);
-
-    const killCountText = try std.fmt.allocPrintZ(allocator, "{d}", .{self.killCount});
-    defer allocator.free(killCountText);
-    rl.DrawText(killCountText, 10, 30, 24, rl.GREEN);
-
-    rl.DrawCircle(
-        @intFromFloat(player.position.x),
-        @intFromFloat(player.position.y),
-        playerSize,
-        rl.RAYWHITE
-    );
-    rl.DrawCircle(
-        @intFromFloat(handPosition.x),
-        @intFromFloat(handPosition.y),
-        5,
-        rl.RAYWHITE
-    );
-    rl.DrawLine(
-        @intFromFloat(player.position.x),
-        @intFromFloat(player.position.y),
-        @intFromFloat(player.position.x + player.velocity.x),
-        @intFromFloat(player.position.y + player.velocity.y),
-        rl.GREEN
-    );
-
-    rl.DrawCircle(
-        @intFromFloat(player.position.x + moveDir.x * maxSpeed),
-        @intFromFloat(player.position.y + moveDir.y * maxSpeed),
-        5,
-        rl.GREEN
-    );
-
-    rope.nodePositions.set(0, handPosition);
 
     rope.update(dt);
 
-    const rope_color = rl.PURPLE;
-    for (0..(rope.nodePositions.len-1)) |i| {
-        var node1: rl.Vector2 = rope.nodePositions.get(i);
-        var node2: rl.Vector2 = rope.nodePositions.get(i+1);
-        rl.DrawLine(
-            @intFromFloat(node1.x),
-            @intFromFloat(node1.y),
-            @intFromFloat(node2.x),
-            @intFromFloat(node2.y),
-            rope_color
-        );
-    }
-
-    for (rope.nodePositions.slice()) |node| {
-        rl.DrawCircle(
-            @intFromFloat(node.x),
-            @intFromFloat(node.y),
-            5,
-            rope_color
-        );
-    }
-
     const deathBallPosition = rope.nodePositions.get(rope.nodePositions.len-1);
 
-    rl.DrawCircle(
-        @intFromFloat(deathBallPosition.x),
-        @intFromFloat(deathBallPosition.y),
-        deathBallSize,
-        rl.RED
-    );
-
     {
         var i: usize = 0;
         while (i < enemies.items.len) {
@@ -314,4 +259,85 @@ pub fn tick(self: *Self) !void {
             i += 1;
         }
     }
+
+    { // UI
+        const enemyCountText = try std.fmt.allocPrintZ(allocator, "{d}", .{self.spawnedEnemiesCount});
+        defer allocator.free(enemyCountText);
+        rl.DrawText(enemyCountText, 10, 10, 24, rl.RED);
+
+        const killCountText = try std.fmt.allocPrintZ(allocator, "{d}", .{self.killCount});
+        defer allocator.free(killCountText);
+        rl.DrawText(killCountText, 10, 30, 24, rl.GREEN);
+    }
+
+    rl.BeginMode2D(self.camera);
+    {
+        rl.DrawCircle(0, 0, 5, rl.GOLD);
+
+        rl.DrawCircle(
+            @intFromFloat(player.position.x),
+            @intFromFloat(player.position.y),
+            playerSize,
+            rl.RAYWHITE
+        );
+        rl.DrawCircle(
+            @intFromFloat(handPosition.x),
+            @intFromFloat(handPosition.y),
+            5,
+            rl.RAYWHITE
+        );
+        rl.DrawLine(
+            @intFromFloat(player.position.x),
+            @intFromFloat(player.position.y),
+            @intFromFloat(player.position.x + player.velocity.x),
+            @intFromFloat(player.position.y + player.velocity.y),
+            rl.GREEN
+        );
+
+        rl.DrawCircle(
+            @intFromFloat(player.position.x + moveDir.x * maxSpeed),
+            @intFromFloat(player.position.y + moveDir.y * maxSpeed),
+            5,
+            rl.GREEN
+        );
+
+        for (enemies.items) |*enemy| {
+            rl.DrawCircle(
+                @intFromFloat(enemy.position.x),
+                @intFromFloat(enemy.position.y),
+                enemySize,
+                rl.RED
+            );
+        }
+
+        const rope_color = rl.PURPLE;
+        for (0..(rope.nodePositions.len-1)) |i| {
+            var node1: rl.Vector2 = rope.nodePositions.get(i);
+            var node2: rl.Vector2 = rope.nodePositions.get(i+1);
+            rl.DrawLine(
+                @intFromFloat(node1.x),
+                @intFromFloat(node1.y),
+                @intFromFloat(node2.x),
+                @intFromFloat(node2.y),
+                rope_color
+            );
+        }
+
+        for (rope.nodePositions.slice()) |node| {
+            rl.DrawCircle(
+                @intFromFloat(node.x),
+                @intFromFloat(node.y),
+                5,
+                rope_color
+            );
+        }
+
+        rl.DrawCircle(
+            @intFromFloat(deathBallPosition.x),
+            @intFromFloat(deathBallPosition.y),
+            deathBallSize,
+            rl.RED
+        );
+    }
+    rl.EndMode2D();
 }

src/main.zig

@@ -9,7 +9,8 @@ pub fn main() !void {
     defer _ = gpa.deinit();
 
     rl.SetTargetFPS(60);
-    rl.InitWindow(800, 800, "Step kill");
+    rl.InitWindow(1200, 1200, "Step kill");
+    rl.DisableCursor();
     defer rl.CloseWindow();
 
     var scene = MainScene.init(allocator);