Creating a radar sweep animation using Pygame in Python

Pygame is a cross-platform set of Python modules designed for writing video games. It includes computer graphics and sound libraries designed to be used with the Python programming language. A radar sweep animation creates a rotating line that sweeps across a circular display, commonly used in games and simulations to represent detection systems.

Components of a Radar Sweep Animation

A basic radar sweep animation consists of the following components ?

• Radar Circle ? The circular boundary representing the radar's detection range
• Radar Sweep ? A rotating line that sweeps around the center at 360 degrees
• Radar Targets ? Objects or points that appear when detected by the sweep

Setting Up the Environment

First, we need to import the required libraries and initialize Pygame ?

import pygame
import math
import random

# Initialize Pygame
pygame.init()

# Constants
WIDTH = 800
HEIGHT = 600
FPS = 60

# Colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
GREEN = (0, 255, 0)
RED = (255, 0, 0)
BLUE = (0, 0, 255)

Creating the Game Window

Set up the display window and clock for frame rate control ?

screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Radar Sweep Animation")
clock = pygame.time.Clock()

Defining Radar Properties

Configure the radar circle, sweep line, and target properties ?

# Radar circle properties
radar_center_x = WIDTH // 2
radar_center_y = HEIGHT // 2
radar_radius = 200

# Radar sweep properties
sweep_angle = 0
sweep_length = radar_radius

# Generate random targets
num_targets = 8
targets = []
for i in range(num_targets):
    # Generate targets within the radar circle
    angle = random.uniform(0, 2 * math.pi)
    distance = random.uniform(50, radar_radius - 20)
    x = radar_center_x + distance * math.cos(angle)
    y = radar_center_y + distance * math.sin(angle)
    targets.append((int(x), int(y)))

Drawing Functions

Create functions to draw the radar components ?

def draw_radar_circle():
    """Draw the radar circle boundary"""
    pygame.draw.circle(screen, GREEN, (radar_center_x, radar_center_y), radar_radius, 2)

def draw_radar_sweep():
    """Draw the rotating sweep line"""
    end_x = radar_center_x + sweep_length * math.cos(math.radians(sweep_angle))
    end_y = radar_center_y + sweep_length * math.sin(math.radians(sweep_angle))
    pygame.draw.line(screen, GREEN, (radar_center_x, radar_center_y), (end_x, end_y), 3)

def draw_targets():
    """Draw targets and check if they're detected by sweep"""
    sweep_end_x = radar_center_x + sweep_length * math.cos(math.radians(sweep_angle))
    sweep_end_y = radar_center_y + sweep_length * math.sin(math.radians(sweep_angle))
    
    for target in targets:
        # Calculate if target is near the sweep line
        target_angle = math.degrees(math.atan2(target[1] - radar_center_y, target[0] - radar_center_x))
        if target_angle < 0:
            target_angle += 360
        
        # Check if target is within sweep detection range
        angle_diff = abs(target_angle - sweep_angle)
        if angle_diff > 180:
            angle_diff = 360 - angle_diff
            
        if angle_diff < 10:  # Detection range
            pygame.draw.circle(screen, RED, target, 8)  # Detected target
        else:
            pygame.draw.circle(screen, BLUE, target, 5)  # Undetected target

def update_sweep():
    """Update the sweep angle for animation"""
    global sweep_angle
    sweep_angle = (sweep_angle + 2) % 360

Complete Radar Animation Program

import pygame
import math
import random

# Initialize Pygame
pygame.init()

# Constants
WIDTH = 800
HEIGHT = 600
FPS = 60

# Colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
GREEN = (0, 255, 0)
RED = (255, 0, 0)
BLUE = (0, 0, 255)

# Set up display
screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Radar Sweep Animation")
clock = pygame.time.Clock()

# Radar properties
radar_center_x = WIDTH // 2
radar_center_y = HEIGHT // 2
radar_radius = 200
sweep_angle = 0
sweep_length = radar_radius

# Generate random targets
num_targets = 8
targets = []
for i in range(num_targets):
    angle = random.uniform(0, 2 * math.pi)
    distance = random.uniform(50, radar_radius - 20)
    x = radar_center_x + distance * math.cos(angle)
    y = radar_center_y + distance * math.sin(angle)
    targets.append((int(x), int(y)))

def draw_radar_circle():
    pygame.draw.circle(screen, GREEN, (radar_center_x, radar_center_y), radar_radius, 2)

def draw_radar_sweep():
    end_x = radar_center_x + sweep_length * math.cos(math.radians(sweep_angle))
    end_y = radar_center_y + sweep_length * math.sin(math.radians(sweep_angle))
    pygame.draw.line(screen, GREEN, (radar_center_x, radar_center_y), (end_x, end_y), 3)

def draw_targets():
    for target in targets:
        target_angle = math.degrees(math.atan2(target[1] - radar_center_y, target[0] - radar_center_x))
        if target_angle < 0:
            target_angle += 360
        
        angle_diff = abs(target_angle - sweep_angle)
        if angle_diff > 180:
            angle_diff = 360 - angle_diff
            
        if angle_diff < 10:
            pygame.draw.circle(screen, RED, target, 8)
        else:
            pygame.draw.circle(screen, BLUE, target, 5)

def update_sweep():
    global sweep_angle
    sweep_angle = (sweep_angle + 2) % 360

# Main game loop
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
    
    # Clear screen
    screen.fill(BLACK)
    
    # Update and draw
    update_sweep()
    draw_radar_circle()
    draw_radar_sweep()
    draw_targets()
    
    # Update display
    pygame.display.flip()
    clock.tick(FPS)

pygame.quit()

Key Features

Conclusion

This radar sweep animation demonstrates fundamental game development concepts using Pygame. The animation combines mathematical calculations for rotation, collision detection logic, and real-time rendering to create an interactive radar display effect.