Required version: Sponge >=1.0.4

Basic Window

The simplest example that creates a window:

use sdl2;

sdl2.init();
sdl2.create_window("Hello Sponge", 800, 600);

while sdl2.is_window_open() {
    sdl2.clear_screen();
    sdl2.render_present();
}

Drawing Shapes

Draw various shapes with different colors:

use sdl2;

sdl2.init();
sdl2.create_window("Shapes Demo", 800, 600);

while sdl2.is_window_open() {
    sdl2.clear_screen();
    
    # Red filled circle
    sdl2.set_draw_color(255, 0, 0);
    sdl2.fill_circle(200, 200, 50);
    
    # Green circle outline
    sdl2.set_draw_color(0, 255, 0);
    sdl2.draw_circle(400, 200, 50);
    
    # Blue rectangle
    sdl2.set_draw_color(0, 0, 255);
    sdl2.draw_rect(200, 350, 100, 100);
    
    # Yellow filled rectangle
    sdl2.set_draw_color(255, 255, 0);
    sdl2.fill_rect(400, 350, 100, 100);
    
    # White lines
    sdl2.set_draw_color(255, 255, 255);
    sdl2.draw_line(0, 0, 800, 600);
    sdl2.draw_line(800, 0, 0, 600);
    
    sdl2.render_present();
}

Animation

Create an animated scene:

use sdl2;

sdl2.init();
sdl2.create_window("Animation Demo", 800, 600);

let frame = 0;
let center_x = 400;
let center_y = 300;

while sdl2.is_window_open() {
    sdl2.clear_screen();
    
    # Draw pulsing circle
    sdl2.set_draw_color(255, 0, 0);
    let radius = 30 + (frame % 30);
    sdl2.fill_circle(center_x, center_y, radius);
    
    # Draw rotating lines
    sdl2.set_draw_color(0, 255, 0);
    let line_offset = (frame * 2) % 400;
    sdl2.draw_line(center_x - line_offset, center_y, center_x + line_offset, center_y);
    
    sdl2.render_present();
    frame = frame + 1;
}

Interactive Grid

Draw an interactive grid pattern:

use sdl2;

sdl2.init();
sdl2.create_window("Grid Demo", 800, 600);

let cell_size = 40;

while sdl2.is_window_open() {
    sdl2.clear_screen();
    
    # Draw grid
    sdl2.set_draw_color(100, 100, 100);
    
    let x = 0;
    while x < 800 {
        sdl2.draw_line(x, 0, x, 600);
        x = x + cell_size;
    }
    
    let y = 0;
    while y < 600 {
        sdl2.draw_line(0, y, 800, y);
        y = y + cell_size;
    }
    
    # Draw center point
    sdl2.set_draw_color(255, 0, 0);
    sdl2.fill_circle(400, 300, 5);
    
    sdl2.render_present();
}

Window Info

Get and display window information:

use sdl2;

sdl2.init();
sdl2.create_window("Window Info", 1024, 768);

let width = sdl2.get_window_width();
let height = sdl2.get_window_height();

print("Window created with dimensions: ");
print(width);
print("x");
print(height);

sdl2.set_draw_color(255, 255, 255);
sdl2.draw_line(0, 0, width, height);
sdl2.draw_line(width, 0, 0, height);

while sdl2.is_window_open() {
    sdl2.clear_screen();
    
    sdl2.set_draw_color(255, 255, 255);
    sdl2.draw_line(0, 0, width, height);
    sdl2.draw_line(width, 0, 0, height);
    
    sdl2.render_present();
}

Common Patterns

Game Loop

The standard game loop structure:

use sdl2;

def main() {
    sdl2.init();
    sdl2.create_window("Game", 800, 600);
    
    while sdl2.is_window_open() {
        # Clear
        sdl2.clear_screen();
        
        # Update game state
        # ... your code here ...
        
        # Draw
        # ... drawing code here ...
        
        # Present
        sdl2.render_present();
    }
}

Color Constants

Define reusable colors:

def set_red() {
    sdl2.set_draw_color(255, 0, 0);
}

def set_green() {
    sdl2.set_draw_color(0, 255, 0);
}

def set_blue() {
    sdl2.set_draw_color(0, 0, 255);
}

def set_white() {
    sdl2.set_draw_color(255, 255, 255);
}

def set_black() {
    sdl2.set_draw_color(0, 0, 0);
}

Drawing Functions

Create reusable drawing functions:

def draw_grid(width, height, spacing) {
    let x = 0;
    while x < width {
        sdl2.draw_line(x, 0, x, height);
        x = x + spacing;
    }
    
    let y = 0;
    while y < height {
        sdl2.draw_line(0, y, width, y);
        y = y + spacing;
    }
}

def draw_cross(cx, cy, size) {
    sdl2.draw_line(cx - size, cy, cx + size, cy);
    sdl2.draw_line(cx, cy - size, cx, cy + size);
}

Delta Time Example

Required version: Sponge >=1.0.6

Create frame-rate independent movement:

use sdl2;

def main() {
    sdl2.init();
    sdl2.create_window("Delta Time Demo", 800, 600);
    sdl2.set_max_fps(60);
    
    let x = 0;
    let speed = 200;  # pixels per second
    
    while sdl2.is_window_open() {
        let dt = sdl2.delta_time();
        x = x + speed * dt;
        
        sdl2.clear_screen();
        sdl2.set_draw_color(255, 0, 0);
        sdl2.fill_rect(x, 100, 50, 50);
        sdl2.render_present();
    }
}

Movement Example