quadtree

main.go

@@ -17,12 +17,70 @@ import (
 )
 
 
+type quadnode struct {
+    topleft, bottomright rl.Vector2
+    magnet *magnet
+    parent *quadnode
+    nodes []*quadnode
+}
+
+func newQuadTree() *quadnode {
+    return &quadnode{
+        topleft: rl.NewVector2(0, 0),
+        bottomright: rl.NewVector2(windowWidth, windowHeight),
+        nodes: nil,
+    }
+}
+
+func (q *quadnode) subdivide() {
+    halfX := q.bottomright.X/2 
+    halfY := q.bottomright.X/2 
+
+    q.nodes = []*quadnode{
+        {
+            topleft: q.topleft,
+            bottomright: rl.Vector2{X: halfX, Y: halfY},
+            parent: q,
+        },
+        {
+            topleft: rl.Vector2{X: halfX, Y: q.topleft.Y},
+            bottomright: rl.Vector2{X: q.bottomright.X, Y: halfY},
+            parent: q,
+        },
+        {
+            topleft: rl.Vector2{X: q.topleft.X, Y: halfY},
+            bottomright: rl.Vector2{X: halfX, Y: q.bottomright.Y},
+            parent: q,
+        },
+        {
+            topleft: rl.Vector2{X: halfX, Y: halfY},
+            bottomright: q.bottomright,
+            parent: q,
+        },
+    }
+}
+
+func (q *quadnode) drawBoundaries() {
+    if q.nodes == nil {
+        return
+    }
+    for _, node := range q.nodes {
+        node.drawBoundaries()
+        size := rl.Vector2Subtract(node.bottomright, node.topleft)
+        rl.DrawRectangleLines(
+            int32(node.topleft.X), int32(node.topleft.Y), 
+            int32(size.X), int32(size.Y),
+            rl.Green,
+        )
+    }
+}
+
 type magnet struct {
     pos rl.Vector2
     speed rl.Vector2
     color rl.Color
-    // force float32
-    // radius float32
+    mass float32
+    radius float32
 }
 
 // type ball struct {
@@ -34,15 +92,40 @@ type magnet struct {
 // }
 
 // parâmetros
-const initalMagnetCount = 100
+const initalMagnetCount = 10
 const windowWidth = 700
 const windowHeight = 700
 const magnetRadius = 5 
 const gravConst float32 = 10
 
-// func insideArea(pos rl.Vector2) (bool, bool) {
-//     return pos.X > 0 && pos.X < windowWidth, pos.Y > 0 && pos.Y < windowHeight
-// }
+func tick(magnets []*magnet) {
+
+    for _, a := range magnets {
+        for _, b := range magnets {
+            if a == b { continue }
+            // não creio que isso esteja certo porem isso quaqueja que nem um pato
+            direction := rl.Vector2Normalize(rl.Vector2Subtract(a.pos, b.pos))
+            distance := rl.Vector2Distance(a.pos, b.pos)
+            distanceSquared := math.Pow(float64(distance), 2)
+            force := gravConst / float32(distanceSquared)
+            acceleration := rl.Vector2Scale(direction, force)
+
+            if distance < magnetRadius*2 {
+                continue
+            } 
+            // f = m * a 
+            forceA := rl.Vector2Scale(acceleration, a.mass)
+            forceB := rl.Vector2Scale(acceleration, b.mass)
+            a.speed = rl.Vector2Add(a.speed, rl.Vector2Negate(forceB))
+            b.speed = rl.Vector2Add(b.speed, forceA)
+
+        }
+    }
+
+    for _, magnet := range magnets {
+        magnet.pos = rl.Vector2Add(magnet.pos, magnet.speed)
+    }
+}
 
 func (m *magnet) update(magnets []*magnet) {
     magnetsPull := rl.Vector2{}
@@ -52,9 +135,9 @@ func (m *magnet) update(magnets []*magnet) {
 
         direction := rl.Vector2Normalize(rl.Vector2Subtract(m.pos, magnet.pos))
         distance := rl.Vector2Distance(magnet.pos, m.pos)
-        if (distance < magnetRadius*2) {
-            // direction = rl.Vector2Negate(direction)
-            continue
+        if (distance < magnetRadius*2 + 10) {
+            direction = rl.Vector2Negate(direction)
+            // continue
         }
         distanceSquared := math.Pow(float64(distance), 2)
         force := gravConst / float32(distanceSquared)
@@ -74,28 +157,30 @@ func (m *magnet) update(magnets []*magnet) {
     m.pos = newPos
 }
 
-func randomMagnet() *magnet {
+func newMagnet(x, y, mass float32) *magnet {
     newMagnet := magnet{
-        pos: rl.Vector2{
-            X: float32(rand.Intn(windowWidth - 100) + 50),
-            Y: float32(rand.Intn(windowHeight - 100) + 50),
-        },
+        pos: rl.Vector2{X: x, Y: y},
         color: rl.NewColor(
             uint8(rand.Int()),
             uint8(rand.Int()),
             uint8(rand.Int()),
             255,
         ),
+        mass: mass,
+        radius: mass,
     }
     return &newMagnet
 }
 
-func createMagnets(n int) []*magnet {
+func randomMagnets(n int) []*magnet {
     var magnets []*magnet
 
     for i := 0; i < n; i++ {
-        magnets = append(magnets, randomMagnet())
+        x := float32(rand.Intn(windowWidth - 100) + 50)
+        y := float32(rand.Intn(windowHeight - 100) + 50)
+        magnets = append(magnets, newMagnet(x, y, 1))
     }
+
     return magnets
 }
 
@@ -107,29 +192,48 @@ func main() {
 	defer rl.CloseWindow()
 	rl.SetTargetFPS(60)
 
-    magnets := createMagnets(initalMagnetCount)
+    magnets := randomMagnets(initalMagnetCount)
+
+    quadtree := newQuadTree()
+    quadtree.subdivide()
+
+    pause := true
 
 	for !rl.WindowShouldClose() {
+
 		rl.BeginDrawing()
 		rl.ClearBackground(rl.Black)
         rl.DrawFPS(0, 0)
-
-// func rl.DrawText(text string, posX int32, posY int32, fontSize int32, col color.RGBA)
         rl.DrawText(strconv.Itoa(len(magnets)), 0, 20, 20, rl.White)
+        if pause {
+            rl.DrawText("pausado (E)", 0, 40, 20, rl.White)
+        }
 
         {
             if rl.IsKeyPressed(rl.KeyR) {
-                magnets = createMagnets(len(magnets))
+                magnets = randomMagnets(initalMagnetCount)
             }
             if rl.IsKeyPressed(rl.KeyW) {
-                magnets = append(magnets, createMagnets(100)...)
+                magnets = append(magnets, randomMagnets(100)...)
+            }
+            if rl.IsKeyPressed(rl.KeyE) {
+                pause = !pause
+            }
+            if rl.IsKeyPressed(rl.KeySpace) {
+                mouse := rl.GetMousePosition()
+                magnets = append(magnets, newMagnet(mouse.X, mouse.Y, 50))
             }
         }
 
+        if !pause {
+            tick(magnets)
+        }
+
+        quadtree.drawBoundaries()
+
         for _, magnet := range magnets {
-            magnet.update(magnets)
-            rl.DrawCircleV(magnet.pos, magnetRadius+1, rl.White)
-            rl.DrawCircleV(magnet.pos, magnetRadius, magnet.color)
+            rl.DrawCircleV(magnet.pos, magnet.radius+1, rl.White)
+            rl.DrawCircleV(magnet.pos, magnet.radius, magnet.color)
         }
 
         rl.EndDrawing()