/******************************************************************************************* * * raylib [shapes] example - bullet hell * * Example complexity rating: [★☆☆☆] 1/4 * * Example originally created with raylib 5.6, last time updated with raylib 5.6 * * Example contributed by Zero (@zerohorsepower) and reviewed by Ramon Santamaria (@raysan5) * * Example licensed under an unmodified zlib/libpng license, which is an OSI-certified, * BSD-like license that allows static linking with closed source software * * Copyright (c) 2025 Zero (@zerohorsepower) * ********************************************************************************************/ using System; using System.Numerics; using static Raylib_cs.Raylib; namespace Examples.Shapes; public partial class BulletHell : IExample { private const int screenWidth = 800; private const int screenHeight = 450; private const int MAX_BULLETS = 500000; // Max bullets to be processed public string Name => "Shapes / Bullet Hell"; public string Title => "raylib [shapes] example - bullet hell"; //---------------------------------------------------------------------------------- // Types and Structures Definition //---------------------------------------------------------------------------------- private struct Bullet { public Vector2 position; // Bullet position on screen public Vector2 acceleration; // Amount of pixels to be incremented to position every frame public bool disabled; // Skip processing and draw case out of screen public Color color; // Bullet color } // Bullets definition private Bullet[] bullets; private int bulletCount; private int bulletDisabledCount; // Used to calculate how many bullets are on screen private int bulletRadius; private float bulletSpeed; private int bulletRows; private Color[] bulletColor; // Spawner variables private float baseDirection; private int angleIncrement; // After spawn all bullet rows, increment this value on the baseDirection for next the frame private float spawnCooldown; private float spawnCooldownTimer; // Magic circle private float magicCircleRotation; // Used on performance drawing private RenderTexture2D bulletTexture; private bool drawInPerformanceMode; // Switch between DrawCircle() and DrawTexture() public void Init() { // Bullets definition bullets = new Bullet[MAX_BULLETS]; // Bullets array bulletCount = 0; bulletDisabledCount = 0; bulletRadius = 10; bulletSpeed = 3.0f; bulletRows = 6; bulletColor = new[] { Color.Red, Color.Blue }; // Spawner variables baseDirection = 0; angleIncrement = 5; spawnCooldown = 2; spawnCooldownTimer = spawnCooldown; // Magic circle magicCircleRotation = 0; // Used on performance drawing bulletTexture = LoadRenderTexture(24, 24); // Draw circle to bullet texture, then draw bullet using DrawTexture() // NOTE: This is done to improve the performance, since DrawCircle() is very slow BeginTextureMode(bulletTexture); DrawCircle(12, 12, (float)bulletRadius, Color.White); DrawCircleLines(12, 12, (float)bulletRadius, Color.Black); EndTextureMode(); drawInPerformanceMode = true; } public void Update() { // Update //---------------------------------------------------------------------------------- // Reset the bullet index // New bullets will replace the old ones that are already disabled due to out-of-screen if (bulletCount >= MAX_BULLETS) { bulletCount = 0; bulletDisabledCount = 0; } spawnCooldownTimer--; if (spawnCooldownTimer < 0) { spawnCooldownTimer = spawnCooldown; // Spawn bullets float degreesPerRow = 360.0f/bulletRows; for (int row = 0; row < bulletRows; row++) { if (bulletCount < MAX_BULLETS) { bullets[bulletCount].position = new Vector2((float)screenWidth/2, (float)screenHeight/2); bullets[bulletCount].disabled = false; bullets[bulletCount].color = bulletColor[row%2]; float bulletDirection = baseDirection + (degreesPerRow*row); // Bullet speed*bullet direction, this will determine how much pixels will be incremented/decremented // from the bullet position every frame. Since the bullets doesn't change its direction and speed, // only need to calculate it at the spawning time // 0 degrees = right, 90 degrees = down, 180 degrees = left and 270 degrees = up, basically clockwise // Case you want it to be anti-clockwise, add "* -1" at the y acceleration bullets[bulletCount].acceleration = new Vector2( bulletSpeed*MathF.Cos(bulletDirection*DEG2RAD), bulletSpeed*MathF.Sin(bulletDirection*DEG2RAD) ); bulletCount++; } } baseDirection += angleIncrement; } // Update bullets position based on its acceleration for (int i = 0; i < bulletCount; i++) { // Only update bullet if inside the screen if (!bullets[i].disabled) { bullets[i].position.X += bullets[i].acceleration.X; bullets[i].position.Y += bullets[i].acceleration.Y; // Disable bullet if out of screen if ((bullets[i].position.X < -bulletRadius*2) || (bullets[i].position.X > screenWidth + bulletRadius*2) || (bullets[i].position.Y < -bulletRadius*2) || (bullets[i].position.Y > screenHeight + bulletRadius*2)) { bullets[i].disabled = true; bulletDisabledCount++; } } } // Input logic if ((IsKeyPressed(KeyboardKey.Right) || IsKeyPressed(KeyboardKey.D)) && (bulletRows < 359)) bulletRows++; if ((IsKeyPressed(KeyboardKey.Left) || IsKeyPressed(KeyboardKey.A)) && (bulletRows > 1)) bulletRows--; if (IsKeyPressed(KeyboardKey.Up) || IsKeyPressed(KeyboardKey.W)) bulletSpeed += 0.25f; if ((IsKeyPressed(KeyboardKey.Down) || IsKeyPressed(KeyboardKey.S)) && (bulletSpeed > 0.50f)) bulletSpeed -= 0.25f; if (IsKeyPressed(KeyboardKey.Z) && (spawnCooldown > 1)) spawnCooldown--; if (IsKeyPressed(KeyboardKey.X)) spawnCooldown++; if (IsKeyPressed(KeyboardKey.Enter)) drawInPerformanceMode = !drawInPerformanceMode; if (IsKeyDown(KeyboardKey.Space)) { angleIncrement += 1; angleIncrement %= 360; } if (IsKeyPressed(KeyboardKey.C)) { bulletCount = 0; bulletDisabledCount = 0; } //---------------------------------------------------------------------------------- // Draw //---------------------------------------------------------------------------------- BeginDrawing(); ClearBackground(Color.RayWhite); // Draw magic circle magicCircleRotation++; DrawRectanglePro(new Rectangle((float)screenWidth/2, (float)screenHeight/2, 120, 120), new Vector2(60.0f, 60.0f), magicCircleRotation, Color.Purple); DrawRectanglePro(new Rectangle((float)screenWidth/2, (float)screenHeight/2, 120, 120), new Vector2(60.0f, 60.0f), magicCircleRotation + 45, Color.Purple); DrawCircleLines(screenWidth/2, screenHeight/2, 70, Color.Black); DrawCircleLines(screenWidth/2, screenHeight/2, 50, Color.Black); DrawCircleLines(screenWidth/2, screenHeight/2, 30, Color.Black); // Draw bullets if (drawInPerformanceMode) { // Draw bullets using pre-rendered texture containing circle for (int i = 0; i < bulletCount; i++) { // Do not draw disabled bullets (out of screen) if (!bullets[i].disabled) { DrawTexture(bulletTexture.Texture, (int)(bullets[i].position.X - bulletTexture.Texture.Width*0.5f), (int)(bullets[i].position.Y - bulletTexture.Texture.Height*0.5f), bullets[i].color); } } } else { // Draw bullets using DrawCircle(), less performant for (int i = 0; i < bulletCount; i++) { // Do not draw disabled bullets (out of screen) if (!bullets[i].disabled) { DrawCircleV(bullets[i].position, (float)bulletRadius, bullets[i].color); DrawCircleLinesV(bullets[i].position, (float)bulletRadius, Color.Black); } } } // Draw UI DrawRectangle(10, 10, 280, 150, new Color(0, 0, 0, 200)); DrawText("Controls:", 20, 20, 10, Color.LightGray); DrawText("- Right/Left or A/D: Change rows number", 40, 40, 10, Color.LightGray); DrawText("- Up/Down or W/S: Change bullet speed", 40, 60, 10, Color.LightGray); DrawText("- Z or X: Change spawn cooldown", 40, 80, 10, Color.LightGray); DrawText("- Space (Hold): Change the angle increment", 40, 100, 10, Color.LightGray); DrawText("- Enter: Switch draw method (Performance)", 40, 120, 10, Color.LightGray); DrawText("- C: Clear bullets", 40, 140, 10, Color.LightGray); DrawRectangle(610, 10, 170, 30, new Color(0, 0, 0, 200)); if (drawInPerformanceMode) DrawText("Draw method: DrawTexture(*)", 620, 20, 10, Color.Green); else DrawText("Draw method: DrawCircle(*)", 620, 20, 10, Color.Red); DrawRectangle(135, 410, 530, 30, new Color(0, 0, 0, 200)); DrawText($"[ FPS: {GetFPS()}, Bullets: {bulletCount - bulletDisabledCount}, Rows: {bulletRows}, Bullet speed: {bulletSpeed:F2}, Angle increment per frame: {angleIncrement}, Cooldown: {spawnCooldown:F0} ]", 155, 420, 10, Color.Green); EndDrawing(); //---------------------------------------------------------------------------------- } public void Unload() { UnloadRenderTexture(bulletTexture); // Unload bullet texture } public static int Main() { // Initialization //-------------------------------------------------------------------------------------- InitWindow(screenWidth, screenHeight, "raylib [shapes] example - bullet hell"); SetTargetFPS(60); //-------------------------------------------------------------------------------------- var game = new BulletHell(); game.Init(); // Main game loop while (!WindowShouldClose()) // Detect window close button or ESC key { game.Update(); } game.Unload(); // De-Initialization //-------------------------------------------------------------------------------------- CloseWindow(); // Close window and OpenGL context //-------------------------------------------------------------------------------------- return 0; } }