distancia ao quadrado

main.go

@@ -8,7 +8,7 @@ import (
 	// "fmt"
 	"fmt"
 	"math"
-	"math/rand"
+	// "math/rand"
 
 	rl "github.com/gen2brain/raylib-go/raylib"
 )
@@ -32,20 +32,19 @@ type ball struct {
 // parâmetros
 const windowWidth = 700
 const windowHeight = 700
-const magnetRadius = 8 
-const magnetForce = 10
-const magnetsDistance float32 = 80
-const gridDivision = 10
+const gridDivision = 8
 const verticalGrids = windowHeight/gridDivision
 const horizontalGrids = windowWidth/gridDivision
-const ballMass float32 = 1 // sensivel
-const gravConst float32 = 1 // sensivel
+const magnetsDistance float32 = 80
+const magnetRadius = 10 
+const gravConst float32 = 200
 const magnetsAngle = 0
 const luminance = false
 const hideBalls = false
 const hideMagnets = false
-var startingBallSpeed = rl.Vector2{X: -0.5, Y: 0.5} // joga a bola em alguma diração 
+var startingBallSpeed = rl.Vector2{X: 0, Y: 0} // joga a bola em alguma diração 
 // antes que ela comece a ser atraida pelos ímãs
+var cameraOffset = rl.Vector2{X: 0, Y: 0}
 
 
 func (ball *ball) update(magnets []magnet) (bool, rl.Color) {
@@ -56,7 +55,8 @@ func (ball *ball) update(magnets []magnet) (bool, rl.Color) {
             rl.Vector2Subtract(ball.pos, magnet.pos),
         )
         distance := rl.Vector2Distance(magnet.pos, ball.pos)
-        force := gravConst * (ballMass * magnet.force) / distance
+        distanceSquared := float32(math.Pow(float64(distance), 2))
+        force := gravConst / distanceSquared
 
         acceleration := rl.Vector2Scale(direction, -force)
 
@@ -77,10 +77,15 @@ func (ball *ball) update(magnets []magnet) (bool, rl.Color) {
 
 }
 
+// var colors = []rl.Color{
+//     rl.Red, rl.Green, rl.Blue, rl.Yellow, rl.NewColor(0, 255, 255, 255), 
+//     rl.Magenta, rl.White,
+// }
+
 func main() {
 	rl.InitWindow(
         windowWidth, windowHeight, 
-        "raylib [core] example - basic window",
+        "magnets",
     )
 	defer rl.CloseWindow()
 	// rl.SetTargetFPS(60)
@@ -89,23 +94,28 @@ func main() {
         {
             color: rl.Red,
             radius: magnetRadius,
-            force: magnetForce,
+            // force: magnetForce,
         },
         {
             color: rl.Green,
             radius: magnetRadius,
-            force: magnetForce,
+            // force: magnetForce,
         },
         {
             color: rl.Blue,
             radius: magnetRadius,
-            force: magnetForce,
+            // force: magnetForce,
+        },
+        {
+            color: rl.Yellow,
+            radius: magnetRadius,
+            // force: magnetForce,
         },
     }
 
-    // pocisionar imas no meio da tela
-    xCenter := float32(windowWidth / 2)
-    yCenter := float32(windowHeight / 2)
+    // posiciona imas em volta de um circulo
+    xCenter := float32(windowWidth / 2) + cameraOffset.X
+    yCenter := float32(windowHeight / 2) + cameraOffset.Y
     for i := range magnets {
         angle := 2.0 * math.Pi * float64(i) / float64(len(magnets)) + magnetsAngle
 
@@ -145,10 +155,10 @@ func main() {
             })
         }
     }
-    rand.Shuffle(len(fallingBallOrder), func(i, j int) {
-        fallingBallOrder[i], fallingBallOrder[j] = 
-        fallingBallOrder[j], fallingBallOrder[i]
-    })
+    // rand.Shuffle(len(fallingBallOrder), func(i, j int) {
+    //     fallingBallOrder[i], fallingBallOrder[j] = 
+    //     fallingBallOrder[j], fallingBallOrder[i]
+    // })
 
     for _, randomGrid := range fallingBallOrder {
         x := randomGrid.X * gridSize.X + gridSize.X/2