Added weapon drops and collection. New laser item asset.

gameelement/canvas.go

@@ -35,6 +35,7 @@ type Canvas struct {
 	counter       int
 	score         int
 	splashes      []*elements.Splash
+	wpdrops       []*elements.WeaponDrop
 	hero          *elements.Hero
 	charge        *elements.Explosion
 	goblin        *elements.FlyGoblin
@@ -82,6 +83,7 @@ func (c *Canvas) Update() error {
 		c.Initialize()
 	} else {
 		c.UpdateHero()
+		c.UpdateWeaponDrops()
 		c.UpdateWeapons()
 		c.UpdateProjectiles()
 		c.UpdateCharge()
@@ -90,6 +92,7 @@ func (c *Canvas) Update() error {
 		c.CleanupTargets()
 		c.UpdateSplashes()
 		c.CleanSplashes()
+		c.CleanupDrops()
 		c.counter++
 	}
 
@@ -135,6 +138,14 @@ func (c *Canvas) Draw(drawimg *ebiten.Image) {
 		}
 	}
 
+	//draw weapon drops
+	for _, drop := range c.wpdrops {
+		drop.Draw()
+		op := &ebiten.DrawImageOptions{}
+		op.GeoM.Translate(drop.GetPosition().X-float64(drop.Sprite.Bounds().Dx())/2, drop.GetPosition().Y-float64(drop.Sprite.Bounds().Dy())/2)
+		c.Sprite.DrawImage(drop.Sprite, op)
+	}
+
 	//draw enemies
 	for _, e := range c.enemies {
 		e.Draw()
@@ -212,6 +223,7 @@ func (c *Canvas) Initialize() {
 
 	c.InitializeHero()
 	c.CleanSplashes()
+	c.ResetWeaponDrops()
 	c.enemies = c.enemies[:0]
 	c.gameover = false
 	c.initialized = true
@@ -536,6 +548,16 @@ func (c *Canvas) CleanupTargets() {
 	// remove dead targets by iterating over all targets
 	i := 0
 	for _, e := range c.enemies {
+
+		//compute odds for dropping an item on dead enemies
+		if e.GetEnemyState() == elements.MoverActionDead {
+			if rand.Float64() > 0.98 {
+				drop := elements.NewWeaponDrop(gamedata.WeaponTypeLaser)
+				drop.SetPosition(e.GetPosition())
+				c.wpdrops = append(c.wpdrops, drop)
+			}
+		}
+
 		//moving valid targets to the front of the slice
 		if e.GetEnemyState() < elements.MoverActionDead &&
 			!(e.GetPosition().X < -640*2 || e.GetPosition().X > 640*2 ||
@@ -847,7 +869,7 @@ func (c *Canvas) LaserAttempt4() {
 		}
 		//fmt.Printf("%f \n", a)
 
-		if d <= 50 && e.GetEnemyState() <= gamedata.EnemyStateHit {
+		if d <= float64(e.GetSprite().Bounds().Dx()) && e.GetEnemyState() <= gamedata.EnemyStateHit {
 
 			if IsPixelColliding(c.laserMask, e.GetSprite(),
 				image.Pt(0, 0),
@@ -890,6 +912,22 @@ func (c *Canvas) CleanSplashes() {
 	c.splashes = c.splashes[:i]
 }
 
+func (c *Canvas) CleanupDrops() {
+	i := 0
+	for _, drop := range c.wpdrops {
+		if !drop.IsCollected() {
+			c.wpdrops[i] = drop
+			i++
+		}
+	}
+
+	for j := i; j < len(c.wpdrops); j++ {
+		c.wpdrops[j] = nil
+	}
+
+	c.wpdrops = c.wpdrops[:i]
+}
+
 func (c *Canvas) UpdateWeapons() {
 	if !c.gameover {
 		//check for weapon inputs
@@ -909,3 +947,41 @@ func (c *Canvas) UpdateWeapons() {
 	}
 
 }
+
+func (c *Canvas) UpdateWeaponDrops() {
+	//do we have any drops? let's calculate the chances
+	//
+
+	for _, drop := range c.wpdrops {
+		drop.Update()
+
+		//has the hero collided with any? add to holster
+		//boundary box collision check
+		if c.hero.Pos.X >= drop.GetPosition().X-float64(drop.Sprite.Bounds().Dx())/2 &&
+			c.hero.Pos.X <= drop.GetPosition().X+float64(drop.Sprite.Bounds().Dx())/2 &&
+			c.hero.Pos.Y >= drop.GetPosition().Y-float64(drop.Sprite.Bounds().Dy())/2 &&
+			c.hero.Pos.Y <= drop.GetPosition().Y+float64(drop.Sprite.Bounds().Dy())/2 {
+			//fmt.Println("hero trying to pick up weapon maybe")
+
+			if IsPixelColliding(
+				c.hero.Sprite,
+				drop.Sprite,
+				image.Pt(int(c.hero.Pos.X), int(c.hero.Pos.Y)),
+				image.Pt(int(drop.GetPosition().X), int(drop.GetPosition().Y)),
+			) {
+				fmt.Println("weapon acquired")
+				drop.SetCollected(true)
+				c.holster.AddWeapon(weapons.NewLaser())
+			}
+
+		}
+	}
+
+}
+
+func (c *Canvas) ResetWeaponDrops() {
+	for i := range c.wpdrops {
+		c.wpdrops[i] = nil
+	}
+	c.wpdrops = c.wpdrops[:0]
+}