// Package
package main

// Libraries
import (
	"math/rand"

	"github.com/go-gl/gl/v2.1/gl"
)

// Structures
type Square struct {
	x, y     float32
	vx, vy   float32
	r, g, b  float32
	cTrigger bool
}

// Interfaces
func (c *Square) Init() {
	c.x = 0
	c.y = 0
	c.vx = 0.005
	c.vy = 0.005

	c.r = rand.Float32()
	c.g = rand.Float32()
	c.b = rand.Float32()
}
func (c *Square) Update(onCollide func(s *Square)) {
	// Movement
	c.x += c.vx
	c.y += c.vy

	// STAY INSIDE BOUNDS!
	if c.x > 1 {
		c.x = 0.9
		c.vx *= -1
	} else if c.x < -1 {
		c.x = -0.9
		c.vx *= -1
	} else if c.y > 1 {
		c.y = 0.9
		c.vy *= -1
	} else if c.y < -1 {
		c.y = -0.9
		c.vy *= -1
	}

	// Can we trigger a collision?
	if c.cTrigger {
		// Collision Detection
		if c.x+0.05 > 1 || c.x-0.05 < -1 {
			c.vx *= -1

			go onCollide(c)
		}
		if c.y+0.1 > 1 || c.y-0.1 < -1 {
			c.vy *= -1

			go onCollide(c)
		}
	} else {
		if (c.x < 0.9 && c.x > -0.9) && (c.y < 0.9 && c.y > -0.9) {
			c.cTrigger = true
		}
	}
}
func (c *Square) Draw() {
	gl.LoadIdentity()

	gl.Translatef(c.x, c.y, 0)
	gl.Color3f(c.r, c.g, c.b)

	gl.Translatef(-0.05, -0.05, 0)

	gl.Begin(gl.QUADS)

	gl.Vertex2f(0, 0)
	gl.Vertex2f(0.1, 0)
	gl.Vertex2f(0.1, 0.1)
	gl.Vertex2f(0, 0.1)

	gl.End()
}