survive/gameelement/canvas.go

package gameelement

import (
	"fmt"
	"image"
	"image/color"
	"math"
	"math/rand/v2"
	"mover/assets"
	"mover/elements"
	"mover/fonts"
	"mover/gamedata"

	"github.com/hajimehoshi/ebiten/v2"
	"github.com/hajimehoshi/ebiten/v2/text"
	"github.com/hajimehoshi/ebiten/v2/vector"
)

type Canvas struct {
	Sprite            *ebiten.Image
	collisionMask     *ebiten.Image
	projectileMask    *ebiten.Image
	laserMask         *ebiten.Image
	heroCollisionMask *ebiten.Image
	heroCollisionCpy  *ebiten.Image

	eventmap map[gamedata.GameEvent]func()

	initialized   bool
	goblinspawned bool
	goblindead    bool
	lastInputs    gamedata.GameInputs
	runtime       float64
	counter       int
	score         int
	splashes      []*elements.Splash
	hero          *elements.Hero
	charge        *elements.Explosion
	goblin        *elements.FlyGoblin
	enemies       []elements.Enemies
	projectiles   []*elements.Projectile
	laser         *elements.Laser
	gameover      bool

	lasercoords []gamedata.Coordinates
}

func NewCanvas(a gamedata.Area) *Canvas {
	c := &Canvas{
		Sprite:            ebiten.NewImage(a.Width, a.Height),
		projectileMask:    ebiten.NewImage(a.Width, a.Height),
		collisionMask:     ebiten.NewImage(a.Width, a.Height),
		laserMask:         ebiten.NewImage(a.Width, a.Height),
		heroCollisionMask: ebiten.NewImage(48, 48),
		heroCollisionCpy:  ebiten.NewImage(48, 48),
		hero:              elements.NewHero(),
		charge:            elements.NewExplosion(),
		laser:             elements.NewLaser(gamedata.Coordinates{X: 320, Y: 240}, 0),
		initialized:       false,
		gameover:          false,
		goblinspawned:     false,
		goblindead:        false,
		score:             0,
		runtime:           0.,
		counter:           0,
	}
	c.laserMask.Clear()
	c.eventmap = make(map[gamedata.GameEvent]func())
	c.lasercoords = make([]gamedata.Coordinates, 4)
	return c
}

func (c *Canvas) SetInputs(gi gamedata.GameInputs) {
	c.lastInputs = gi
}

func (c *Canvas) Update() error {
	if !c.initialized {
		c.Initialize()
	} else {
		c.UpdateHero()
		c.UpdateProjectiles()
		c.UpdateLaser()
		c.UpdateCharge()
		c.UpdateEnemies()
		c.SpawnEnemies()
		c.CleanupTargets()
		c.UpdateSplashes()
		c.CleanSplashes()
		c.counter++
	}

	return nil
}

func (c *Canvas) Draw(drawimg *ebiten.Image) {
	c.Sprite.Clear()
	c.projectileMask.Clear()
	//c.laserMask.Clear()

	//vector.DrawFilledCircle(c.Sprite, float32(c.hero.Pos.X), float32(c.hero.Pos.Y), 100, color.White, true)

	//render heor
	c.hero.Draw()
	op := &ebiten.DrawImageOptions{}
	op.GeoM.Translate(c.hero.Pos.X-48/2, c.hero.Pos.Y-48/2)
	c.Sprite.DrawImage(c.hero.Sprite, op)

	//render weapon
	if !c.gameover {
		op.GeoM.Reset()
		op.GeoM.Translate(0, -16)
		op.GeoM.Rotate(c.lastInputs.ShotAngle)
		op.GeoM.Translate(c.hero.Pos.X, c.hero.Pos.Y)
		c.Sprite.DrawImage(assets.ImageBank[assets.Weapon], op)
	}

	//draw enemy shadows
	for _, es := range c.enemies {
		if es.GetEnemyState() < gamedata.EnemyStateExploding {

			dx := float64(assets.ImageBank[assets.FlyEyeShadow].Bounds().Dx()) / 2
			dy := float64(assets.ImageBank[assets.FlyEyeShadow].Bounds().Dy()) / 2
			sx := float64(es.GetSprite().Bounds().Dx()) / 48
			sy := float64(es.GetSprite().Bounds().Dy()) / 48

			op := &ebiten.DrawImageOptions{}
			op.GeoM.Translate(-dx, -dy)
			op.GeoM.Scale(sx, sy)
			op.GeoM.Translate(es.GetPosition().X, es.GetPosition().Y+float64(es.GetSprite().Bounds().Dx())/2)
			c.Sprite.DrawImage(assets.ImageBank[assets.FlyEyeShadow], op)
		}
	}

	//draw enemies
	for _, e := range c.enemies {
		e.Draw()

		xshift := float64(e.GetSprite().Bounds().Dx() / 2)
		yshift := float64(e.GetSprite().Bounds().Dy() / 2)

		op := &ebiten.DrawImageOptions{}
		op.GeoM.Translate(-xshift, -yshift)
		op.GeoM.Rotate(e.GetAngle())
		op.GeoM.Translate(e.GetPosition().X, e.GetPosition().Y)

		c.Sprite.DrawImage(e.GetSprite(), op)

		//do we need a health bar for this enemy?
		if e.Health() > 0 {

			hbWidth := float64(e.MaxHealth())*2 + 4
			p1 := float64(e.GetSprite().Bounds().Dx())
			p0 := e.GetPosition().X - p1/2
			x0 := p0 - (hbWidth-p1)/2
			y0 := e.GetPosition().Y - 2/3.*float64(e.GetSprite().Bounds().Dy())
			vector.DrawFilledRect(c.Sprite, float32(x0), float32(y0), float32(e.MaxHealth())*2+4, 12, color.Black, true)
			vector.DrawFilledRect(c.Sprite, float32(x0+2), float32(y0+2), float32(e.Health())*2, 8, color.RGBA{R: 0xff, G: 0x00, B: 0x00, A: 0xff}, true)
		}
	}

	//draw projectiles
	for _, p := range c.projectiles {
		vector.DrawFilledCircle(c.projectileMask, float32(p.Pos.X), float32(p.Pos.Y), 3, color.White, true)
	}
	c.Sprite.DrawImage(c.projectileMask, nil)

	//draw laser(s)
	if c.laser.IsFiring() {
		c.laser.Draw()
		c.Sprite.DrawImage(c.laserMask, nil)
	}
	//c.Sprite.DrawImage(c.laser.Sprite, op)

	vector.StrokeCircle(c.Sprite, float32(c.charge.Origin.X), float32(c.charge.Origin.Y), float32(c.charge.Radius), 3, color.White, true)

	//TEMPORARY let's see how far off the beam we are
	vector.StrokeLine(c.Sprite, float32(c.lasercoords[2].X), float32(c.lasercoords[2].Y), float32(c.lasercoords[3].X), float32(c.lasercoords[3].Y), 2, color.White, true)

	//let's render our laser 'splashes'
	for _, sp := range c.splashes {
		sp.Draw()
		op := &ebiten.DrawImageOptions{}
		op.GeoM.Translate(sp.GetPosition().X-128/2, sp.GetPosition().Y-128/2)
		c.Sprite.DrawImage(sp.Sprite, op)
	}

	if !c.gameover {
		c.runtime = float64(c.counter) / 60.
	}
	s := fmt.Sprintf("%02.3f", c.runtime)
	if !c.gameover {
		text.Draw(c.Sprite, "TIME: "+s, fonts.SurviveFont.Arcade, 640/2-250, 25, color.White)
		text.Draw(c.Sprite, fmt.Sprintf("SCORE: %d", c.score*10), fonts.SurviveFont.Arcade, 640/2+100, 25, color.White)
	} else {
		if (c.counter/30)%2 == 0 {
			text.Draw(c.Sprite, "TIME: "+s, fonts.SurviveFont.Arcade, 640/2-250, 25, color.White)
			text.Draw(c.Sprite, fmt.Sprintf("SCORE: %d", c.score*10), fonts.SurviveFont.Arcade, 640/2+100, 25, color.White)
		}

		text.Draw(c.Sprite, "PRESS START TO TRY AGAIN", fonts.SurviveFont.Arcade, 640/2-150, 480/2, color.White)
	}

	op.GeoM.Reset()
	drawimg.DrawImage(c.Sprite, op)
}

func (c *Canvas) Initialize() {

	c.InitializeHero()
	c.CleanSplashes()
	c.enemies = c.enemies[:0]
	c.gameover = false
	c.initialized = true
	c.score = 0
	c.counter = 0
	c.runtime = 0.
	c.goblinspawned = false
	c.goblindead = false

	//temporary
	c.hero.Action = elements.HeroActionDefault
}

func (c *Canvas) UpdateHero() {
	c.hero.Update()
	if !c.gameover {
		c.UpdateHeroPosition()
		c.ComputeHeroCollisions()
		c.AddProjectiles()
	}
}

func (c *Canvas) UpdateHeroPosition() {
	if c.lastInputs.XAxis >= 0.15 || c.lastInputs.XAxis <= -0.15 {
		c.hero.Left = c.lastInputs.XAxis < 0
		c.hero.Pos.X += c.lastInputs.XAxis * 5
	}

	if c.lastInputs.YAxis >= 0.15 || c.lastInputs.YAxis <= -0.15 {
		c.hero.Pos.Y += c.lastInputs.YAxis * 5
	}
}

func (c *Canvas) ComputeHeroCollisions() {
	for _, e := range c.enemies {
		//compute collision with hero
		if c.hero.Pos.X >= e.GetPosition().X-float64(e.GetSprite().Bounds().Dx())/2 && c.hero.Pos.X <= e.GetPosition().X+float64(e.GetSprite().Bounds().Dx())/2 &&
			c.hero.Pos.Y >= e.GetPosition().Y-float64(e.GetSprite().Bounds().Dy())/2 && c.hero.Pos.Y <= e.GetPosition().Y+float64(e.GetSprite().Bounds().Dy())/2 &&
			e.GetEnemyState() < gamedata.EnemyStateDying {

			// 			target.Action < elements.MoverActionDying && g.hero.Action < elements.HeroActionDying {

			c.heroCollisionMask.Clear()
			c.heroCollisionMask.DrawImage(c.hero.Sprite, nil)

			op := &ebiten.DrawImageOptions{}
			op.GeoM.Reset()
			op.Blend = ebiten.BlendSourceIn
			op.GeoM.Translate((c.hero.Pos.X-e.GetPosition().X)-float64(e.GetSprite().Bounds().Dx())/2, (c.hero.Pos.Y-e.GetPosition().Y)-float64(e.GetSprite().Bounds().Dy())/2)
			c.heroCollisionMask.DrawImage(e.GetSprite(), op)

			if c.HasCollided(c.heroCollisionMask, 48*48*4) {
				c.hero.SetHit()
				c.gameover = true

				if c.eventmap[gamedata.GameEventPlayerDeath] != nil {
					c.eventmap[gamedata.GameEventPlayerDeath]()
				}
			}
		}
	}
}

func (c *Canvas) AddProjectiles() {

	//add new projectiles
	/*
		if c.lastInputs.Shot && c.counter%14 == 0 {

			loc := gamedata.Coordinates{
				X: c.hero.Pos.X,
				Y: c.hero.Pos.Y,
			}
			angle := c.lastInputs.ShotAngle
			velocity := 5.

			c.projectiles = append(c.projectiles, elements.NewProjectile(loc, angle, velocity))

			if c.hero.Upgrade {
				c.projectiles = append(c.projectiles, elements.NewProjectile(loc, angle+math.Pi, velocity))
			}

			if c.eventmap[gamedata.GameEventNewShot] != nil {
				c.eventmap[gamedata.GameEventNewShot]()
			}

		}
	*/
	if c.lastInputs.Shot {
		c.laser.SetPosition(c.hero.Pos)
		c.laser.SetAngle(c.lastInputs.ShotAngle)
	}

}

func (c *Canvas) InitializeHero() {
	//recenter the hero
	pos := gamedata.Coordinates{
		X: float64(c.Sprite.Bounds().Dx() / 2),
		Y: float64(c.Sprite.Bounds().Dy() / 2),
	}
	c.hero.SetOrigin(pos)
}

func (c *Canvas) UpdateProjectiles() {
	i := 0
	for _, p := range c.projectiles {
		p.Update()

		projectilevalid := true

		if p.Pos.X < -640/2 || p.Pos.X > 1.5*640 || p.Pos.Y < -480/2 || p.Pos.Y > 1.5*480 {
			projectilevalid = false
		}

		for _, e := range c.enemies {
			if p.Pos.X >= e.GetPosition().X-float64(e.GetSprite().Bounds().Dx())/2 && p.Pos.X <= e.GetPosition().X+float64(e.GetSprite().Bounds().Dx())/2 &&
				p.Pos.Y >= e.GetPosition().Y-float64(e.GetSprite().Bounds().Dy())/2 && p.Pos.Y <= e.GetPosition().Y+float64(e.GetSprite().Bounds().Dy())/2 &&
				e.IsToggled() && e.GetEnemyState() < gamedata.EnemyStateDying {
				c.collisionMask.Clear()
				c.collisionMask.DrawImage(c.projectileMask, nil)

				op := &ebiten.DrawImageOptions{}
				op.GeoM.Reset()
				op.Blend = ebiten.BlendSourceIn
				op.GeoM.Translate(e.GetPosition().X-float64(e.GetSprite().Bounds().Dx())/2, e.GetPosition().Y-float64(e.GetSprite().Bounds().Dy())/2)
				c.collisionMask.DrawImage(e.GetSprite(), op)

				if c.HasCollided(c.collisionMask, 640*480*4) {
					projectilevalid = false
					e.SetHit()

					if c.eventmap[gamedata.GameEventTargetHit] != nil {
						c.eventmap[gamedata.GameEventTargetHit]()
					}
				}
			}
		}

		if projectilevalid {
			c.projectiles[i] = p
			i++
		}
	}

	for j := i; j < len(c.projectiles); j++ {
		c.projectiles[j] = nil
	}
	c.projectiles = c.projectiles[:i]

}

func (c *Canvas) UpdateLaser() {

	c.laser.SetFiring(c.lastInputs.Shot)
	if c.lastInputs.Shot {
		c.laserMask.Clear()
		lpos := c.laser.GetPosition()
		op := &ebiten.DrawImageOptions{}
		op.GeoM.Reset()
		//op.GeoM.Translate(-float64(c.laser.Sprite.Bounds().Dx())/2, -float64(c.laser.Sprite.Bounds().Dy())/2)
		op.GeoM.Translate(0, -float64(c.laser.Sprite.Bounds().Dy())/2)
		op.GeoM.Rotate(c.laser.GetAngle())
		op.GeoM.Translate(lpos.X, lpos.Y)
		c.laserMask.DrawImage(c.laser.Sprite, op)

		//c.LaserAttempt1()
		//c.LaserAttempt2()
		//c.LaserAttempt3()
		c.LaserAttempt4()
	}
}

func (c *Canvas) UpdateCharge() {

	if c.lastInputs.Charge && !c.charge.Active && !c.gameover {
		c.charge.SetOrigin(c.hero.Pos)
		c.charge.Reset()
		c.charge.ToggleActivate()

		if c.eventmap[gamedata.GameEventCharge] != nil {
			c.eventmap[gamedata.GameEventCharge]()
		}
	}

	c.charge.Update()
	if c.charge.Active {
		if c.charge.Radius > math.Sqrt(640*640+480*480) {
			c.charge.ToggleActivate()
			c.charge.Reset()
			c.ResetTargetTouches()
		}

		for _, e := range c.enemies {
			dx := e.GetPosition().X - c.hero.Pos.X
			dy := e.GetPosition().Y - c.hero.Pos.Y
			r := math.Sqrt(dx*dx + dy*dy)

			if r >= c.charge.Radius-5 && r <= c.charge.Radius+5 &&
				!e.IsTouched() && e.GetEnemyState() <= gamedata.EnemyStateHit {
				e.SetToggle()
				e.SetTouched()
			}
		}
	}
}

func (c *Canvas) ResetTargetTouches() {
	for _, e := range c.enemies {
		e.ClearTouched()
	}
}

func (c *Canvas) UpdateEnemies() {
	//update existing enemies
	for _, e := range c.enemies {
		if !c.gameover {
			e.SetTarget(c.hero.Pos)

			if e.GetEnemyState() == gamedata.EnemyStateExploding && !e.ExplosionInitiated() {
				if c.eventmap[gamedata.GameEventExplosion] != nil {
					c.eventmap[gamedata.GameEventExplosion]()
				}
				e.SetExplosionInitiated()
			}
		} else {
			e.SetTarget(e.GetPosition())
		}

		e.Update()
	}

}

func (c *Canvas) SpawnEnemies() {
	if !c.gameover {

		if !c.goblinspawned || c.goblindead {
			c.SpawnFlyEyes()
		}

		if !c.goblinspawned && c.counter > 2400 && !c.goblindead {
			c.SpawnGoblin()
		}

	}
}

func (c *Canvas) SpawnFlyEyes() {
	//spawn new enemies
	f := 40000 / (c.counter + 1)

	if c.counter%f == 0 {
		newenemy := elements.NewFlyEye()

		x0 := rand.Float64() * 640
		y0 := rand.Float64() * 480
		quadrant := rand.IntN(3)

		switch quadrant {
		case 0:
			newenemy.SetPosition(gamedata.Coordinates{X: x0, Y: -48})
		case 1:
			newenemy.SetPosition(gamedata.Coordinates{X: x0, Y: 480 + 48})
		case 2:
			newenemy.SetPosition(gamedata.Coordinates{X: -48, Y: y0})
		case 3:
			newenemy.SetPosition(gamedata.Coordinates{X: 640 + x0, Y: y0})
		}

		newenemy.SetTarget(c.hero.Pos)

		c.enemies = append(c.enemies, newenemy)
	}
}

func (c *Canvas) SpawnGoblin() {
	newfg := elements.NewFlyGoblin()
	newfg.SetDeathEvent(c.GoblinDeathEvent)
	newfg.SetFireballCallback(c.GoblinFireballEvent)

	x0 := rand.Float64() * 640
	y0 := rand.Float64() * 480
	quadrant := rand.IntN(3)

	switch quadrant {
	case 0:
		newfg.SetPosition(gamedata.Coordinates{X: x0, Y: -96})
	case 1:
		newfg.SetPosition(gamedata.Coordinates{X: x0, Y: 480 + 48})
	case 2:
		newfg.SetPosition(gamedata.Coordinates{X: -96, Y: y0})
	case 3:
		newfg.SetPosition(gamedata.Coordinates{X: 640 + x0, Y: y0})
	}

	c.goblin = newfg
	c.enemies = append(c.enemies, newfg)
	c.goblinspawned = true
}

func (c *Canvas) HasCollided(mask *ebiten.Image, size int) bool {
	var result bool = false
	var pixels []byte = make([]byte, size)
	mask.ReadPixels(pixels)
	for i := 0; i < len(pixels); i = i + 4 {
		if pixels[i+3] != 0 {
			result = true
			break
		}
	}
	return result
}

func (c *Canvas) RegisterEvents(e gamedata.GameEvent, f func()) {
	c.eventmap[e] = f
}

func (c *Canvas) CleanupTargets() {
	// remove dead targets by iterating over all targets
	i := 0
	for _, e := range c.enemies {
		//moving valid targets to the front of the slice
		if e.GetEnemyState() < elements.MoverActionDead &&
			!(e.GetPosition().X < -640*2 || e.GetPosition().X > 640*2 ||
				e.GetPosition().Y > 480*2 || e.GetPosition().Y < -480*2) {
			c.enemies[i] = e
			i++
		}
	}

	//then culling the last elements of the slice, and conveniently we can update
	//our base score with the number of elements removed (bonuses calculated elsewhere)
	if len(c.enemies)-i > 0 {
		c.score += len(c.enemies) - i
	}

	for j := i; j < len(c.enemies); j++ {
		c.enemies[j] = nil
	}
	c.enemies = c.enemies[:i]
}

func (c *Canvas) GoblinDeathEvent() {
	c.goblindead = true
	c.goblinspawned = false
	c.score += 10
}

func (c *Canvas) GoblinFireballEvent() {

	if !c.gameover {
		velocity := 8.
		dx := c.hero.Pos.X - c.goblin.GetPosition().X
		dy := c.hero.Pos.Y - c.goblin.GetPosition().Y
		angle := math.Atan2(dy, dx)

		//add some randomness to the angle
		arand := rand.Float64() * math.Pi / 3

		newfb := elements.NewFireBall(angle+arand, velocity)
		newfb.SetPosition(c.goblin.GetPosition())
		c.enemies = append(c.enemies, newfb)

		if c.eventmap[gamedata.GameEventFireball] != nil {
			c.eventmap[gamedata.GameEventFireball]()
		}

	}
}

func IsPixelColliding(img1, img2 *ebiten.Image, offset1, offset2 image.Point) bool {
	// Get the pixel data from both images
	bounds1 := img1.Bounds()
	bounds2 := img2.Bounds()

	// Create slices to hold the pixel data
	pixels1 := make([]byte, 4*bounds1.Dx()*bounds1.Dy()) // RGBA (4 bytes per pixel)
	pixels2 := make([]byte, 4*bounds2.Dx()*bounds2.Dy())

	// Read pixel data from the images
	img1.ReadPixels(pixels1)
	img2.ReadPixels(pixels2)

	// Determine the overlapping rectangle
	rect1 := bounds1.Add(offset1)
	rect2 := bounds2.Add(offset2)
	intersection := rect1.Intersect(rect2)

	if intersection.Empty() {
		return false // No overlap
	}

	// Check pixel data in the overlapping region
	for y := intersection.Min.Y; y < intersection.Max.Y; y++ {
		for x := intersection.Min.X; x < intersection.Max.X; x++ {
			// Calculate the indices in the pixel slices
			idx1 := ((y-offset1.Y)*bounds1.Dx() + (x - offset1.X)) * 4
			idx2 := ((y-offset2.Y)*bounds2.Dx() + (x - offset2.X)) * 4

			// Extract alpha values (transparency)
			alpha1 := pixels1[idx1+3]
			alpha2 := pixels2[idx2+3]

			// If both pixels are non-transparent, there's a collision
			if alpha1 > 0 && alpha2 > 0 {
				return true
			}
		}
	}

	return false // No collision detected
}

// RotatePoint rotates a point (x, y) around an origin (ox, oy) by a given angle (in radians).
func RotatePoint(x, y, ox, oy, angle float64) (float64, float64) {
	sin, cos := math.Sin(angle), math.Cos(angle)
	dx, dy := x-ox, y-oy
	return ox + dx*cos - dy*sin, oy + dx*sin + dy*cos
}

// IsPixelCollidingWithRotation checks for pixel-perfect collision between two rotated images.
func IsPixelCollidingWithRotation(img1, img2 *ebiten.Image, center1, center2 image.Point, angle1, angle2 float64) bool {
	// Get pixel data
	bounds1 := img1.Bounds()
	bounds2 := img2.Bounds()

	pixels1 := make([]byte, 4*bounds1.Dx()*bounds1.Dy())
	pixels2 := make([]byte, 4*bounds2.Dx()*bounds2.Dy())

	img1.ReadPixels(pixels1)
	img2.ReadPixels(pixels2)

	// Loop through all pixels in the bounding boxes of the first image
	for y1 := bounds1.Min.Y; y1 < bounds1.Max.Y; y1++ {
		for x1 := bounds1.Min.X; x1 < bounds1.Max.X; x1++ {
			// Get alpha for the pixel in img1
			idx1 := (y1*bounds1.Dx() + x1) * 4
			alpha1 := pixels1[idx1+3]
			if alpha1 == 0 {
				continue // Skip transparent pixels
			}

			// Rotate this pixel to its global position
			globalX, globalY := RotatePoint(float64(x1), float64(y1), float64(bounds1.Dx()/2), float64(bounds1.Dy()/2), angle1)
			globalX += float64(center1.X)
			globalY += float64(center1.Y)

			// Transform global position to img2's local space
			localX, localY := RotatePoint(globalX-float64(center2.X), globalY-float64(center2.Y), 0, 0, -angle2)

			// Check if the transformed position is within img2's bounds
			lx, ly := int(localX)+bounds2.Dx()/2, int(localY)+bounds2.Dy()/2
			if lx < 0 || ly < 0 || lx >= bounds2.Dx() || ly >= bounds2.Dy() {
				continue
			}

			// Get alpha for the pixel in img2
			idx2 := (ly*bounds2.Dx() + lx) * 4
			alpha2 := pixels2[idx2+3]
			if alpha2 > 0 {
				return true // Collision detected
			}
		}
	}

	return false // No collision
}

func (c *Canvas) LaserAttempt1() {
	//for _, e := range c.enemies {
	/*
		rgba1 := c.laserMask.SubImage(c.laserMask.Bounds()).(*image.RGBA)
		rgba2 := e.GetSprite().SubImage(e.GetSprite().Bounds()).(*image.RGBA)
	*/

	// Check collision
	/*
		if IsPixelCollidingWithRotation(c.laser.Sprite,
			e.GetSprite(),
			image.Pt(int(c.laser.GetPosition().X), int(c.laser.GetPosition().Y)),
			image.Pt(int(e.GetPosition().X), int(e.GetPosition().Y)),
			c.laser.GetAngle(),
			0,
		) {
			println("Pixel-perfect collision detected!")
		}
	*/
	/*
		c.collisionMask.Clear()
		c.collisionMask.DrawImage(c.laserMask, nil)

		op := &ebiten.DrawImageOptions{}
		op.GeoM.Reset()
		op.Blend = ebiten.BlendDestinationIn
		op.GeoM.Translate(e.GetPosition().X-float64(e.GetSprite().Bounds().Dx())/2, e.GetPosition().Y-float64(e.GetSprite().Bounds().Dy())/2)
		c.collisionMask.DrawImage(e.GetSprite(), op)
	*/

	/*
		if c.HasCollided(c.collisionMask, 640*480*4) {

				if c.eventmap[gamedata.GameEventTargetHit] != nil {
					c.eventmap[gamedata.GameEventTargetHit]()
				}

			fmt.Println("enemy sliced")
		}
	*/
	//}
}

// try to find if the enemy is along the laser line first, then apply pixel collision
func (c *Canvas) LaserAttempt2() {
	for _, e := range c.enemies {

		a := c.lastInputs.ShotAngle

		x0 := c.hero.Pos.X
		y0 := c.hero.Pos.Y

		thresh := 25.
		x := e.GetPosition().X
		y := math.Tan(a)*(x-x0) + y0
		var laserd bool = false
		if !math.IsNaN(math.Tan(a)) {
			if math.Abs(e.GetPosition().Y-y) <= thresh {
				laserd = true
			} else {
				if math.Abs(e.GetPosition().X-x0) <= thresh {
					laserd = true
				}
			}
		}
		if laserd {
			//check for pixel collision

			if IsPixelColliding(c.laserMask, e.GetSprite(),
				image.Pt(0, 0),
				image.Pt(int(e.GetPosition().X), int(e.GetPosition().Y))) {
				e.SetHit()

				if c.eventmap[gamedata.GameEventTargetHit] != nil {
					c.eventmap[gamedata.GameEventTargetHit]()
				}
				fmt.Println("laser'd")
			}
		}
	}
}

// straight up just pixel collision check, expensive though
func (c *Canvas) LaserAttempt3() {
	for _, e := range c.enemies {

		if IsPixelColliding(c.laserMask, e.GetSprite(),
			image.Pt(0, 0),
			image.Pt(int(e.GetPosition().X), int(e.GetPosition().Y))) {
			e.SetHit()

			if c.eventmap[gamedata.GameEventTargetHit] != nil {
				c.eventmap[gamedata.GameEventTargetHit]()
			}
			fmt.Println("laser'd")
		}
	}
}

// straight up just pixel collision check, expensive though
func (c *Canvas) LaserAttempt4() {
	for _, e := range c.enemies {

		c.lasercoords[2] = e.GetPosition()

		x0 := c.hero.Pos.X
		y0 := c.hero.Pos.Y

		x1 := e.GetPosition().X
		y1 := e.GetPosition().Y

		a := c.lastInputs.ShotAngle

		var d float64 = 100

		/*
			if !math.IsNaN(math.Tan(a)) {

				m0 := math.Tan(a)
				if m0 == 0 {
					d = math.Abs(y1 - y0)
					fmt.Printf("horizontal beam\n")
					c.lasercoords[3] = gamedata.Coordinates{X: x1, Y: y0}
				} else {
					m1 := -1 / m0

					if (m0 - m1) != 0 {
						xi := (y1 + x0*m0 - y0 - m1*x1) / (m0 - m1)
						yi := xi*m0 - x0*m0 + y0

						c.lasercoords[3] = gamedata.Coordinates{X: xi, Y: yi}

						d = math.Sqrt(math.Pow(x1-xi, 2) + math.Pow(y1-yi, 2))
						fmt.Printf("%f \n", d)
					} else {
					}
				}
				fmt.Printf("%f \n", a)
			} else {
				c.lasercoords[3] = gamedata.Coordinates{X: x1, Y: y1}
				d = math.Abs(x1 - x0)
				fmt.Printf("vertical beam\n")
			}
		*/

		if math.Abs(math.Mod(a, math.Pi)) == math.Pi/2 { // Check for vertical beam
			d = math.Abs(x1 - x0)
			c.lasercoords[3] = gamedata.Coordinates{X: x0, Y: y1} // Align on x-axis
			fmt.Printf("vertical beam\n")
		} else if math.Tan(a) == 0 { // Check for horizontal beam
			d = math.Abs(y1 - y0)
			c.lasercoords[3] = gamedata.Coordinates{X: x1, Y: y0} // Align on y-axis
			fmt.Printf("horizontal beam\n")
		} else { // General case
			m0 := math.Tan(a)
			m1 := -1 / m0
			xi := (y1 + x0*m0 - y0 - m1*x1) / (m0 - m1)
			yi := xi*m0 - x0*m0 + y0
			c.lasercoords[3] = gamedata.Coordinates{X: xi, Y: yi}
			d = math.Sqrt(math.Pow(x1-xi, 2) + math.Pow(y1-yi, 2))
			fmt.Printf("%f \n", d)
		}
		fmt.Printf("%f \n", a)

		if d <= 50 && e.GetEnemyState() <= gamedata.EnemyStateHit {

			if IsPixelColliding(c.laserMask, e.GetSprite(),
				image.Pt(0, 0),
				image.Pt(int(e.GetPosition().X), int(e.GetPosition().Y))) {
				e.SetHit()

				newsplash := elements.NewSplash()
				//newsplash.SetPosition(c.lasercoords[3])
				newsplash.SetPosition(e.GetPosition())
				c.splashes = append(c.splashes, newsplash)

				if c.eventmap[gamedata.GameEventTargetHit] != nil {
					c.eventmap[gamedata.GameEventTargetHit]()
				}
				fmt.Println("laser'd")
			}
		}
	}
}

func (c *Canvas) UpdateSplashes() {
	for _, sp := range c.splashes {
		sp.Update()
	}
}

func (c *Canvas) CleanSplashes() {
	i := 0
	for _, sp := range c.splashes {
		if sp.GetAlpha() > 0 {
			c.splashes[i] = sp
			i++
		}
	}

	for j := i; j < len(c.splashes); j++ {
		c.splashes[j] = nil
	}

	c.splashes = c.splashes[:i]
}