module main

import os
import gg
import math

@[heap]
pub struct Window {
pub mut:
    ctx   &gg.Context = unsafe { 0 }
    image gg.Image
}

pub fn (mut window Window) init() {
    logo_path := os.join_path(@VEXEROOT, 'examples/assets/logo.png')
    window.image = window.ctx.create_image(logo_path) or { panic(err) }
}

pub fn (mut window Window) draw(_ voidptr) {
    window.ctx.begin()

    myconfig := gg.DrawImageConfig{
        img:      &window.image
        img_id:   window.image.id
        img_rect: gg.Rect{
            x:      400 - window.image.width / 2
            y:      300 - window.image.height / 2
            width:  window.image.width
            height: window.image.height
        }
        rotation: f32(window.ctx.frame)
        // effect: .alpha <-- this can be omitted completely as it is alpha by default.
    }
    window.ctx.draw_image_with_config(gg.DrawImageConfig{ ...myconfig, flip_x: true })

    // Red
    window.ctx.draw_image_with_config(gg.DrawImageConfig{
        ...myconfig
        img_rect: gg.Rect{
            ...myconfig.img_rect
            x: myconfig.img_rect.x + f32(math.sin(f32(window.ctx.frame) / 10.0) * 60)
            y: myconfig.img_rect.y + f32(math.cos(f32(window.ctx.frame) / 10.0) * 60)
        }
        color:    gg.Color{255, 0, 0, 255}
        effect:   .add
    })

    // Green
    window.ctx.draw_image_with_config(gg.DrawImageConfig{
        ...myconfig
        img_rect: gg.Rect{
            ...myconfig.img_rect
            x: myconfig.img_rect.x + f32(math.sin(f32(window.ctx.frame) / 10.0) * 80)
            y: myconfig.img_rect.y + f32(math.cos(f32(window.ctx.frame) / 10.0) * 80)
        }
        color:    gg.Color{0, 255, 0, 255}
        effect:   .add
    })

    // Blue
    window.ctx.draw_image_with_config(gg.DrawImageConfig{
        ...myconfig
        img_rect: gg.Rect{
            ...myconfig.img_rect
            x: myconfig.img_rect.x + f32(math.sin(f32(window.ctx.frame) / 10.0) * 100)
            y: myconfig.img_rect.y + f32(math.cos(f32(window.ctx.frame) / 10.0) * 100)
        }
        color:    gg.Color{0, 0, 255, 255}
        effect:   .add
    })

    // More examples
    window.ctx.draw_image_with_config(gg.DrawImageConfig{
        ...myconfig
        img_rect: gg.Rect{
            ...myconfig.img_rect
            x: 50
            y: 0
        }
        color:    gg.Color{255, 0, 0, 255}
        effect:   .add
    })

    window.ctx.draw_image_with_config(gg.DrawImageConfig{
        ...myconfig
        img_rect: gg.Rect{
            ...myconfig.img_rect
            x: 50
            y: 50
        }
        color:    gg.Color{0, 255, 0, 255}
        effect:   .add
    })

    window.ctx.draw_image_with_config(gg.DrawImageConfig{
        ...myconfig
        img_rect: gg.Rect{
            ...myconfig.img_rect
            x: 50
            y: 100
        }
        color:    gg.Color{0, 0, 255, 255}
        effect:   .add
    })

    window.ctx.end()
}

fn main() {
    mut window := &Window{}

    window.ctx = gg.new_context(
        window_title: 'Additive colors & image rotation'
        width:        800
        height:       600
        user_data:    window
        bg_color:     gg.gray
        // FNs
        init_fn:  window.init
        frame_fn: window.draw
    )

    window.ctx.run()
}