Add Top Down Lights & Bullet Hell Examples

examples/shapes/bullet_hell/main.go

@@ -0,0 +1,213 @@
+package main
+
+import (
+	"fmt"
+	"math"
+
+	rl "github.com/gen2brain/raylib-go/raylib"
+)
+
+const maxBullets = 500000 // Max bullets to be processed
+
+type Bullet struct {
+	Position     rl.Vector2
+	Acceleration rl.Vector2
+	Disabled     bool
+	Color        rl.Color
+}
+
+func main() {
+	// Initialization
+	const screenWidth = 800
+	const screenHeight = 450
+
+	rl.InitWindow(screenWidth, screenHeight, "raylib [shapes] example - bullet hell")
+	defer rl.CloseWindow()
+
+	// Bullets definition
+	bullets := make([]Bullet, maxBullets)
+	bulletCount := 0
+	bulletDisabledCount := 0
+	bulletRadius := float32(10)
+	bulletSpeed := float32(3.0)
+	bulletRows := 6
+	bulletColor := [2]rl.Color{rl.Red, rl.Blue}
+
+	// Spawner variables
+	baseDirection := float32(0)
+	angleIncrement := 5
+	spawnCooldown := float32(2)
+	spawnCooldownTimer := spawnCooldown
+
+	// Magic circle
+	magicCircleRotation := float32(0)
+
+	// Used on performance drawing
+	bulletTexture := rl.LoadRenderTexture(24, 24)
+	defer rl.UnloadRenderTexture(bulletTexture)
+
+	// Pre-render circle to texture for performance mode
+	rl.BeginTextureMode(bulletTexture)
+	rl.DrawCircle(12, 12, bulletRadius, rl.White)
+	rl.DrawCircleLines(12, 12, bulletRadius, rl.Black)
+	rl.EndTextureMode()
+
+	drawInPerformanceMode := true
+
+	rl.SetTargetFPS(60)
+
+	// Main game loop
+	for !rl.WindowShouldClose() {
+		// Update
+		// Reset the bullet index when capacity is reached
+		if bulletCount >= maxBullets {
+			bulletCount = 0
+			bulletDisabledCount = 0
+		}
+
+		spawnCooldownTimer--
+		if spawnCooldownTimer < 0 {
+			spawnCooldownTimer = spawnCooldown
+
+			// Spawn bullets
+			degreesPerRow := float32(360.0) / float32(bulletRows)
+			for row := 0; row < bulletRows; row++ {
+				if bulletCount < maxBullets {
+					bullets[bulletCount].Position = rl.NewVector2(float32(screenWidth)/2.0, float32(screenHeight)/2.0)
+					bullets[bulletCount].Disabled = false
+					bullets[bulletCount].Color = bulletColor[row%2]
+
+					bulletDirection := baseDirection + (degreesPerRow * float32(row))
+
+					rad := float64(bulletDirection * rl.Deg2rad)
+					bullets[bulletCount].Acceleration = rl.NewVector2(
+						bulletSpeed*float32(math.Cos(rad)),
+						bulletSpeed*float32(math.Sin(rad)),
+					)
+
+					bulletCount++
+				}
+			}
+
+			baseDirection += float32(angleIncrement)
+		}
+
+		// Update bullets position based on acceleration
+		for i := 0; i < bulletCount; i++ {
+			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 > float32(screenWidth)+bulletRadius*2 ||
+					bullets[i].Position.Y < -bulletRadius*2 ||
+					bullets[i].Position.Y > float32(screenHeight)+bulletRadius*2 {
+					bullets[i].Disabled = true
+					bulletDisabledCount++
+				}
+			}
+		}
+
+		// Input logic
+		if (rl.IsKeyPressed(rl.KeyRight) || rl.IsKeyPressed(rl.KeyD)) && bulletRows < 359 {
+			bulletRows++
+		}
+		if (rl.IsKeyPressed(rl.KeyLeft) || rl.IsKeyPressed(rl.KeyA)) && bulletRows > 1 {
+			bulletRows--
+		}
+		if rl.IsKeyPressed(rl.KeyUp) || rl.IsKeyPressed(rl.KeyW) {
+			bulletSpeed += 0.25
+		}
+		if (rl.IsKeyPressed(rl.KeyDown) || rl.IsKeyPressed(rl.KeyS)) && bulletSpeed > 0.50 {
+			bulletSpeed -= 0.25
+		}
+		if rl.IsKeyPressed(rl.KeyZ) && spawnCooldown > 1 {
+			spawnCooldown--
+		}
+		if rl.IsKeyPressed(rl.KeyX) {
+			spawnCooldown++
+		}
+		if rl.IsKeyPressed(rl.KeyEnter) {
+			drawInPerformanceMode = !drawInPerformanceMode
+		}
+
+		if rl.IsKeyDown(rl.KeySpace) {
+			angleIncrement = (angleIncrement + 1) % 360
+		}
+
+		if rl.IsKeyPressed(rl.KeyC) {
+			bulletCount = 0
+			bulletDisabledCount = 0
+		}
+
+		// Draw
+		rl.BeginDrawing()
+
+		rl.ClearBackground(rl.RayWhite)
+
+		// Draw magic circle
+		magicCircleRotation++
+		centerRec := rl.NewRectangle(float32(screenWidth)/2.0, float32(screenHeight)/2.0, 120, 120)
+		centerOrigin := rl.NewVector2(60.0, 60.0)
+
+		rl.DrawRectanglePro(centerRec, centerOrigin, magicCircleRotation, rl.Purple)
+		rl.DrawRectanglePro(centerRec, centerOrigin, magicCircleRotation+45, rl.Purple)
+		rl.DrawCircleLines(int32(screenWidth/2), int32(screenHeight/2), 70, rl.Black)
+		rl.DrawCircleLines(int32(screenWidth/2), int32(screenHeight/2), 50, rl.Black)
+		rl.DrawCircleLines(int32(screenWidth/2), int32(screenHeight/2), 30, rl.Black)
+
+		// Draw bullets
+		if drawInPerformanceMode {
+			texWidth := float32(bulletTexture.Texture.Width)
+			texHeight := float32(bulletTexture.Texture.Height)
+
+			for i := 0; i < bulletCount; i++ {
+				if !bullets[i].Disabled {
+					rl.DrawTexture(
+						bulletTexture.Texture,
+						int32(bullets[i].Position.X-texWidth*0.5),
+						int32(bullets[i].Position.Y-texHeight*0.5),
+						bullets[i].Color,
+					)
+				}
+			}
+		} else {
+			for i := 0; i < bulletCount; i++ {
+				if !bullets[i].Disabled {
+					rl.DrawCircleV(bullets[i].Position, bulletRadius, bullets[i].Color)
+					// Use DrawCircleLines instead of DrawCircleLinesV to avoid purego FFI bug
+					rl.DrawCircleLines(int32(bullets[i].Position.X), int32(bullets[i].Position.Y), bulletRadius, rl.Black)
+				}
+			}
+		}
+
+		// Draw UI
+		bgOverlay := rl.NewColor(0, 0, 0, 200)
+
+		rl.DrawRectangle(10, 10, 280, 150, bgOverlay)
+		rl.DrawText("Controls:", 20, 20, 10, rl.LightGray)
+		rl.DrawText("- Right/Left or A/D: Change rows number", 40, 40, 10, rl.LightGray)
+		rl.DrawText("- Up/Down or W/S: Change bullet speed", 40, 60, 10, rl.LightGray)
+		rl.DrawText("- Z or X: Change spawn cooldown", 40, 80, 10, rl.LightGray)
+		rl.DrawText("- Space (Hold): Change the angle increment", 40, 100, 10, rl.LightGray)
+		rl.DrawText("- Enter: Switch draw method (Performance)", 40, 120, 10, rl.LightGray)
+		rl.DrawText("- C: Clear bullets", 40, 140, 10, rl.LightGray)
+
+		rl.DrawRectangle(610, 10, 170, 30, bgOverlay)
+		if drawInPerformanceMode {
+			rl.DrawText("Draw method: DrawTexture(*)", 620, 20, 10, rl.Green)
+		} else {
+			rl.DrawText("Draw method: DrawCircle(*)", 620, 20, 10, rl.Red)
+		}
+
+		rl.DrawRectangle(135, 410, 530, 30, bgOverlay)
+		rl.DrawText(
+			fmt.Sprintf("[ FPS: %d, Bullets: %d, Rows: %d, Bullet speed: %.2f, Angle increment per frame: %d, Cooldown: %.0f ]",
+				rl.GetFPS(), bulletCount-bulletDisabledCount, bulletRows, bulletSpeed, angleIncrement, spawnCooldown),
+			155, 420, 10, rl.Green,
+		)
+
+		rl.EndDrawing()
+	}
+}