module main

import gg

struct App {
mut:
    gg       &gg.Context = unsafe { nil }
    rotation f32         = f32(0)
    edge     int         = 3
}

fn main() {
    println('rotation: left arrow key, right arrow key')
    println('center polygon edge: up arrow key, down arrow key')

    mut app := &App{}

    app.gg = gg.new_context(
        window_title: 'Simple Polygons'
        width:        500
        height:       500
        bg_color:     gg.black
        event_fn:     event
        frame_fn:     render
        user_data:    app
    )

    app.gg.run()
}

fn render(app &App) {
    app.gg.begin()

    color := gg.Color{
        r: 175
        g: 0
        b: 0
        a: 200
    }
    mut edge := 3
    for i := 0; i <= 5; i++ {
        for j := 0; j <= 5; j++ {
            if i == 0 || j == 0 || i == 5 || j == 5 {
                app.gg.draw_polygon_filled(50 + 80 * i, 50 + 80 * j, 30, edge, app.rotation,
                    color)
                edge++
            }
        }
    }

    app.gg.draw_polygon_filled(250, 250, 150, app.edge, app.rotation, color)

    app.gg.end()
}

fn event(e &gg.Event, mut app App) {
    match e.typ {
        .key_down {
            match e.key_code {
                .up {
                    app.edge++
                }
                .down {
                    if app.edge > 3 {
                        app.edge--
                    }
                }
                .right {
                    app.rotation++
                }
                .left {
                    app.rotation--
                }
                .escape {
                    app.gg.quit()
                }
                else {}
            }
        }
        else {}
    }
}