From 35b316123c6d768cfb064c1abfdbc41bb54b9e68 Mon Sep 17 00:00:00 2001
From: Martin Kagamino Lehoux <martin@lehoux.net>
Date: Sun, 3 Sep 2023 19:05:41 +0200
Subject: feat: Move along grid

---
 main.go   | 19 ++++++++++++-------
 move.go   | 42 ++++++++++++++++++++++++++++++++++++------
 person.go |  4 ++--
 3 files changed, 50 insertions(+), 15 deletions(-)

diff --git a/main.go b/main.go
index 718e261..dd36ea1 100644
--- a/main.go
+++ b/main.go
@@ -40,14 +40,19 @@ func (g *Game) Update() error {
 		g.Selection.IsActive = true
 	}
 	if inpututil.IsMouseButtonJustReleased(ebiten.MouseButtonRight) {
-		tileClick := Point{x - soil.Position.X, y - soil.Position.Y}
+		destination := Point{
+			(x-soil.Position.X)/100*100 + 50,
+			(y-soil.Position.Y)/100*100 + 50,
+		}
 		for _, p := range g.Persons {
-			futureBounds := Rectangle{
-				tileClick.Sub(p.size.Div(2)),
-				tileClick.Add(p.size.Div(2)),
-			}
-			if p.IsSelected && futureBounds.In(soil.Bounds()) {
-				p.MoveTo(tileClick)
+			if p.IsSelected {
+				futureBounds := Rectangle{
+					destination.Sub(p.size.Div(2)),
+					destination.Add(p.size.Div(2)),
+				}
+				if futureBounds.In(soil.Bounds()) {
+					p.MoveTo(destination)
+				}
 			}
 		}
 	}
diff --git a/move.go b/move.go
index f2cee2b..97d4809 100644
--- a/move.go
+++ b/move.go
@@ -1,19 +1,49 @@
 package main
 
+import (
+	"math"
+)
+
 type Move struct {
 	IsActive    bool
+	Origin      Point
 	Destination Point
+	Nodes       []Point
+}
+
+func NewMove(origin Point, destination Point) Move {
+	nodes := []Point{}
+	current := Point{
+		origin.X/100*100 + 50,
+		origin.Y/100*100 + 50,
+	}
+	for current != destination {
+		next := current
+		if math.Abs(float64(destination.X-current.X)) > math.Abs(float64(destination.Y-current.Y)) {
+			next.X = current.X + int(math.Copysign(100, float64(destination.X-current.X)))
+		} else {
+			next.Y = current.Y + int(math.Copysign(100, float64(destination.Y-current.Y)))
+		}
+		nodes = append(nodes, next)
+		current = next
+	}
+	return Move{IsActive: true, Origin: origin, Destination: destination, Nodes: nodes}
 }
 
 func (m *Move) Update(position Point, speed int) Point {
 	if !m.IsActive {
 		return position
 	}
-	remainingMove := m.Destination.Sub(position)
-	delta := remainingMove.Mul(speed).Div(int(Length(remainingMove)))
-	next := position.Add(delta)
-	if Distance(next, m.Destination) < float64(speed) {
-		m.IsActive = false
+	next := m.Nodes[0]
+	if Distance(position, next) < float64(speed) {
+		if next == m.Destination {
+			m.IsActive = false
+		} else {
+			m.Nodes = m.Nodes[1:]
+		}
+		return next
 	}
-	return next
+	remainingMove := next.Sub(position)
+	delta := remainingMove.Mul(speed).Div(int(Length(remainingMove)))
+	return position.Add(delta)
 }
diff --git a/person.go b/person.go
index 9ca5743..66e30cd 100644
--- a/person.go
+++ b/person.go
@@ -41,9 +41,9 @@ func (p Person) CollisionBounds() Rectangle {
 }
 
 func (p *Person) MoveTo(destination Point) {
-	p.move = Move{IsActive: true, Destination: destination}
+	p.move = NewMove(p.Position, destination)
 }
 
 func (p *Person) Update() {
-	p.Position = p.move.Update(p.Position, 30)
+	p.Position = p.move.Update(p.Position, 10)
 }
-- 
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