implementar hitbox dos inimigos

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"math"
 
 	rl "github.com/gen2brain/raylib-go/raylib"
 )
@@ -34,6 +35,7 @@ type player struct {
     pos rl.Vector2
     moveSpeed float32
     bulletMoveSpeed float32
+    hitBoxRadius float32
 }
 
 type enemy struct {
@@ -41,6 +43,7 @@ type enemy struct {
     health int
     movePattern func(*enemy)rl.Vector2
     shootPattern func()
+    hitBoxRadius float32
 }
 
 func (g game) insideArena(v rl.Vector2) bool {
@@ -48,12 +51,16 @@ func (g game) insideArena(v rl.Vector2) bool {
     v.Y <= float32(g.screenHeight) && v.X <= float32(g.screenWidth)
 }
 
+func (g *game) removeBullet(index int) {
+    g.bullets[index] = g.bullets[len(g.bullets)-1]
+    g.bullets = g.bullets[:len(g.bullets)-1]
+}
+
 func (b *bullet) update(g *game, index int) {
     b.pos = rl.Vector2Add(b.pos, b.speed)
 
     if !g.insideArena(b.pos) {
-        g.bullets[index] = g.bullets[len(g.bullets)-1]
+        g.removeBullet(index)
-        g.bullets = g.bullets[:len(g.bullets)-1]
         return
     }
 
@@ -65,6 +72,7 @@ func (e *enemy) shoot(g *game) {
         return
     }
 
+
     g.bullets = append(g.bullets, &bullet{
         speed: rl.Vector2{X: 0, Y: 10},
         size: 4,
@@ -87,13 +95,73 @@ func horizonalPattern(g *game) (func(*enemy)rl.Vector2) {
     }
 }
 
+func circlePattern(g *game, center rl.Vector2) (func(*enemy)rl.Vector2) {
 
-func (e *enemy) update(g *game) {
+    t := float64(0.5)
+
+    return func(e *enemy) rl.Vector2 {
+        // x' = (x - x₀) * cos(θ) - (y - y₀) * sin(θ) + x₀
+        // y' = (x - x₀) * sin(θ) + (y - y₀) * cos(θ) + y₀
+
+        // x' = x * cos(θ) - y * sin(θ)
+        // y' = x * sin(θ) + y * cos(θ)
+
+        // result := center
+        //
+        // result.X = result.X + (e.pos.X - result.X) * float32(math.Cos(t)) - 
+        // (e.pos.Y - result.Y) * float32(math.Sin(t))
+        //
+        // result.Y =  result.Y + (e.pos.Y - result.Y) * float32(math.Sin(t)) + 
+        // (e.pos.Y - result.Y) * float32(math.Cos(t))
+
+        result := center
+        result.X = result.X * float32(math.Cos(t)) - result.Y * float32(math.Sin(t))
+        result.Y = result.X * float32(math.Sin(t)) - result.Y * float32(math.Cos(t))
+
+        t += .08
+        return result
+    }
+}
+
+func (e *enemy) checkHit(g *game) (bool, *bullet, int) {
+    for index, bullet := range g.bullets {
+
+        playerBullet := !bullet.enemy
+        if !playerBullet {
+            continue
+        }
+        distance := rl.Vector2Distance(e.pos, bullet.pos) - bullet.size
+        // fmt.Println(distance)
+
+        if distance < e.hitBoxRadius {
+            return true, bullet, index
+        }
+    }
+    return false, nil, 0
+}
+
+func (g *game) killEnemy(index int) {
+    g.enemies[index] = g.enemies[len(g.enemies)-1]
+    g.enemies = g.enemies[:len(g.enemies)-1]
+}
+
+
+func (e *enemy) update(g *game, index int) {
 
     if e.movePattern != nil {
         e.pos = e.movePattern(e)
     }
 
+    if hit, bullet, idx := e.checkHit(g); hit {
+        e.health -= bullet.dmg
+        g.removeBullet(idx)
+    }
+
+    if e.health <= 0 {
+        g.killEnemy(index)
+        return
+    }
+
     e.shoot(g)
 
     rl.DrawCircleV(e.pos, 5, rl.Blue)
@@ -134,7 +202,7 @@ func (p *player) checkHit(g *game) {
         distance := rl.Vector2Distance(p.pos, bullet.pos) - bullet.size
         // fmt.Println(distance)
 
-        if distance < 0 {
+        if distance < p.hitBoxRadius {
             fmt.Println("hit!")
         }
     }
@@ -149,7 +217,7 @@ func (p *player) update(g *game) {
     p.checkHit(g)
 
     // hitbox
-    rl.DrawCircleV(p.pos, 5, rl.Red)
+    rl.DrawCircleV(p.pos, p.hitBoxRadius, rl.Red)
 
     // mira
     mouse := rl.GetMousePosition()
@@ -157,7 +225,7 @@ func (p *player) update(g *game) {
     inverted = rl.Vector2Negate(inverted)
     inverted = rl.Vector2Normalize(inverted)
     inverted = rl.Vector2Scale(inverted, 2000)
-    rl.DrawLineV(p.pos, rl.Vector2Add(mouse, inverted), rl.Red)
+    rl.DrawLineV(p.pos, rl.Vector2Add(mouse, inverted), rl.NewColor(255, 0, 0, 100))
 
 }
 
@@ -169,29 +237,40 @@ func main() {
         pos: rl.Vector2{X: 100, Y: 100},
         moveSpeed: 4,
         bulletMoveSpeed: 8,
+        hitBoxRadius: 5,
     }
 
     rl.SetTraceLog(rl.LogWarning | rl.LogDebug)
 	rl.InitWindow(state.screenWidth, state.screenHeight, "danmaku")
 	rl.SetTargetFPS(60)
 
-    state.enemies = append(state.enemies, &enemy{
+    state.enemies = []*enemy{
-        pos: rl.Vector2{X: 200, Y: 200},
+        {
-        health: 10,
+            pos: rl.Vector2{X: 200, Y: 200},
-        movePattern: horizonalPattern(state),
+            health: 1,
-    })
+            hitBoxRadius: 5,
-    state.enemies = append(state.enemies, &enemy{
+            movePattern: horizonalPattern(state),
-        pos: rl.Vector2{X: 169, Y: 222},
+        },
-        health: 10,
+        {
-        movePattern: horizonalPattern(state),
+            pos: rl.Vector2{X: 169, Y: 222},
-    })
+            health: 1,
-    state.enemies = append(state.enemies, &enemy{
+            hitBoxRadius:5,
-        pos: rl.Vector2{X: 219, Y: 195},
+            movePattern: horizonalPattern(state),
-        health: 10,
+        },
-        movePattern: horizonalPattern(state),
+        {
-    })
+            pos: rl.Vector2{X: 400, Y: 400},
+            health: 1,
+            hitBoxRadius:5,
+            // movePattern: circlePattern(state, rl.Vector2{X: 200, Y: 200}),
+        },
+        {
+            pos: rl.Vector2{X: 200, Y: 200},
+            health: 1,
+            hitBoxRadius:5,
+            // movePattern: circlePattern(state, rl.Vector2{X: 200, Y: 200}),
+        }}
 
-	for ; !rl.WindowShouldClose(); state.time += 1 {
+    for ; !rl.WindowShouldClose(); state.time += 1 {
 		rl.BeginDrawing()
 		rl.ClearBackground(rl.Black)
 
@@ -202,7 +281,7 @@ func main() {
         player.update(state)
 
         for i := range state.enemies {
-            state.enemies[i].update(state)
+            state.enemies[i].update(state, i)
         }
 
         for i := 0; i < len(state.bullets); i++ {