From 727e8244c687663d1212a0f8a8019af48ca4bcea Mon Sep 17 00:00:00 2001
From: danhale-git <36298392+danhale-git@users.noreply.github.com>
Date: Sat, 18 Jul 2020 23:07:13 +0100
Subject: [PATCH] Implemented Position in Path and PathTile (#605)

* Unnecessary constructor assignments removed.

* Position implemented in d2common.Path

* Position implemented in mapEntity.Step.

* Position implemented in d2common.PathTile.
---
 d2common/d2fileformats/d2ds1/ds1.go         |  6 ++--
 d2common/d2math/d2vector/position.go        |  8 +++++
 d2common/path.go                            |  7 +++--
 d2common/path_tile.go                       | 33 +++++++++------------
 d2core/d2map/d2mapengine/walk_mesh.go       |  7 +++--
 d2core/d2map/d2mapentity/map_entity.go      | 16 ++++------
 d2core/d2map/d2mapentity/map_entity_test.go |  2 +-
 d2core/d2map/d2mapentity/missile.go         |  4 ++-
 d2core/d2map/d2mapentity/npc.go             |  3 +-
 d2core/d2map/d2mapstamp/stamp.go            |  7 +++--
 10 files changed, 51 insertions(+), 42 deletions(-)

diff --git a/d2common/d2fileformats/d2ds1/ds1.go b/d2common/d2fileformats/d2ds1/ds1.go
index 2a0c74c7..a37d979a 100644
--- a/d2common/d2fileformats/d2ds1/ds1.go
+++ b/d2common/d2fileformats/d2ds1/ds1.go
@@ -4,6 +4,7 @@ import (
 	"github.com/OpenDiablo2/OpenDiablo2/d2common"
 	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2data"
 	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2enum"
+	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2math/d2vector"
 )
 
 const maxActNumber = 5
@@ -223,8 +224,9 @@ func (ds1 *DS1) loadNpcPaths(br *d2common.StreamReader, objIdx, numPaths int) {
 
 	for pathIdx := 0; pathIdx < numPaths; pathIdx++ {
 		newPath := d2common.Path{}
-		newPath.X = int(br.GetInt32())
-		newPath.Y = int(br.GetInt32())
+		newPath.Position = d2vector.NewPosition(
+			float64(br.GetInt32()),
+			float64(br.GetInt32()))
 
 		if ds1.Version >= 15 { //nolint:gomnd // Version number
 			newPath.Action = int(br.GetInt32())
diff --git a/d2common/d2math/d2vector/position.go b/d2common/d2math/d2vector/position.go
index d22a24e7..437d9c5e 100644
--- a/d2common/d2math/d2vector/position.go
+++ b/d2common/d2math/d2vector/position.go
@@ -28,6 +28,14 @@ func NewPosition(x, y float64) Position {
 	return p
 }
 
+// NewPosition returns a Position struct with the given tile coordinates where 1 = 1 tile, with a fractional offset.
+func NewPositionTile(x, y float64) Position {
+	p := Position{NewVector(x*subTilesPerTile, y*subTilesPerTile)}
+	p.checkValues()
+
+	return p
+}
+
 // Set sets this position to the given sub tile coordinates where 1 = 1 sub tile, with a fractional offset.
 func (p *Position) Set(x, y float64) {
 	p.x, p.y = x, y
diff --git a/d2common/path.go b/d2common/path.go
index 0b53ca66..b490bd7b 100644
--- a/d2common/path.go
+++ b/d2common/path.go
@@ -1,8 +1,9 @@
 package d2common
 
+import "github.com/OpenDiablo2/OpenDiablo2/d2common/d2math/d2vector"
+
 // Path represents a path
 type Path struct {
-	X      int
-	Y      int
-	Action int
+	Position d2vector.Position
+	Action   int
 }
diff --git a/d2common/path_tile.go b/d2common/path_tile.go
index 14a89b6f..709c74d9 100644
--- a/d2common/path_tile.go
+++ b/d2common/path_tile.go
@@ -1,12 +1,18 @@
 package d2common
 
-import "github.com/OpenDiablo2/OpenDiablo2/d2common/d2astar"
+import (
+	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2astar"
+	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2math/d2vector"
+)
 
 // PathTile represents a node in path finding
 type PathTile struct {
-	Walkable                                                    bool
-	Up, Down, Left, Right, UpLeft, UpRight, DownLeft, DownRight *PathTile
-	X, Y                                                        float64
+	Walkable            bool
+	Up, Down            *PathTile
+	Left, Right         *PathTile
+	UpLeft, UpRight     *PathTile
+	DownLeft, DownRight *PathTile
+	Position            d2vector.Position
 }
 
 // PathNeighbors returns the direct neighboring nodes of this node which can be pathed to
@@ -54,20 +60,9 @@ func (t *PathTile) PathNeighborCost(to d2astar.Pather) float64 {
 
 // PathEstimatedCost is a heuristic method for estimating movement costs between non-adjacent nodes
 func (t *PathTile) PathEstimatedCost(to d2astar.Pather) float64 {
-	toT := to.(*PathTile)
-	absX := toT.X - t.X
+	delta := to.(*PathTile).Position.Clone()
+	delta.Subtract(&t.Position.Vector)
+	delta.Abs()
 
-	if absX < 0 {
-		absX = -absX
-	}
-
-	absY := toT.Y - t.Y
-
-	if absY < 0 {
-		absY = -absY
-	}
-
-	r := absX + absY
-
-	return r
+	return delta.X() + delta.Y()
 }
diff --git a/d2core/d2map/d2mapengine/walk_mesh.go b/d2core/d2map/d2mapengine/walk_mesh.go
index 61fcd7ba..93425b9c 100644
--- a/d2core/d2map/d2mapengine/walk_mesh.go
+++ b/d2core/d2map/d2mapengine/walk_mesh.go
@@ -3,6 +3,8 @@ package d2mapengine
 import (
 	"math"
 
+	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2math/d2vector"
+
 	"github.com/OpenDiablo2/OpenDiablo2/d2common"
 	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2astar"
 	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2enum"
@@ -51,8 +53,9 @@ func (m *MapEngine) RegenerateWalkPaths() {
 			index := subTileX + (subTileY * m.size.Width * 5)
 			m.walkMesh[index] = d2common.PathTile{
 				Walkable: !isBlocked,
-				X:        float64(subTileX) / 5.0,
-				Y:        float64(subTileY) / 5.0,
+				Position: d2vector.NewPosition(
+					float64(subTileX),
+					float64(subTileY)),
 			}
 
 			ySkew := m.size.Width * 5
diff --git a/d2core/d2map/d2mapentity/map_entity.go b/d2core/d2map/d2mapentity/map_entity.go
index a34b0b82..fd42ca66 100644
--- a/d2core/d2map/d2mapentity/map_entity.go
+++ b/d2core/d2map/d2mapentity/map_entity.go
@@ -23,14 +23,11 @@ type mapEntity struct {
 
 // newMapEntity creates an instance of mapEntity
 func newMapEntity(x, y int) mapEntity {
-	locX, locY := float64(x), float64(y)
+	pos := d2vector.NewPosition(float64(x), float64(y))
 
 	return mapEntity{
-		Position:  d2vector.NewPosition(locX, locY),
-		Target:    d2vector.NewPosition(locX, locY),
-		Speed:     6,
-		drawLayer: 0,
-		path:      []d2astar.Pather{},
+		Position: pos,
+		Target:   pos,
 	}
 }
 
@@ -143,8 +140,7 @@ func (m *mapEntity) nextPath() {
 	if m.hasPath() {
 		// Set next path node
 		m.setTarget(
-			m.path[0].(*d2common.PathTile).X*5,
-			m.path[0].(*d2common.PathTile).Y*5,
+			m.path[0].(*d2common.PathTile).Position,
 			m.done,
 		)
 
@@ -165,9 +161,9 @@ func (m *mapEntity) hasPath() bool {
 }
 
 // setTarget sets target coordinates and changes animation based on proximity and direction.
-func (m *mapEntity) setTarget(tx, ty float64, done func()) {
+func (m *mapEntity) setTarget(p d2vector.Position, done func()) {
 	// Set the target
-	m.Target.Set(tx, ty)
+	m.Target.Copy(&p.Vector)
 	m.done = done
 
 	// Update the direction
diff --git a/d2core/d2map/d2mapentity/map_entity_test.go b/d2core/d2map/d2mapentity/map_entity_test.go
index 229deba6..6839d467 100644
--- a/d2core/d2map/d2mapentity/map_entity_test.go
+++ b/d2core/d2map/d2mapentity/map_entity_test.go
@@ -51,7 +51,7 @@ func path(length int, origin d2vector.Position) []d2astar.Pather {
 }
 
 func pathTile(x, y float64) *d2common.PathTile {
-	return &d2common.PathTile{X: x, Y: y}
+	return &d2common.PathTile{Position: d2vector.NewPositionTile(x, y)}
 }
 
 func TestMapEntity_Step(t *testing.T) {
diff --git a/d2core/d2map/d2mapentity/missile.go b/d2core/d2map/d2mapentity/missile.go
index 992e2504..056df43f 100644
--- a/d2core/d2map/d2mapentity/missile.go
+++ b/d2core/d2map/d2mapentity/missile.go
@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"math"
 
+	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2math/d2vector"
+
 	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2data/d2datadict"
 	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2enum"
 	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2resource"
@@ -54,7 +56,7 @@ func (m *Missile) SetRadians(angle float64, done func()) {
 	x := m.Position.X() + (r * math.Cos(angle))
 	y := m.Position.Y() + (r * math.Sin(angle))
 
-	m.setTarget(x, y, done)
+	m.setTarget(d2vector.NewPosition(x, y), done)
 }
 
 // Advance is called once per frame and processes a
diff --git a/d2core/d2map/d2mapentity/npc.go b/d2core/d2map/d2mapentity/npc.go
index 62ad2bef..fa778a16 100644
--- a/d2core/d2map/d2mapentity/npc.go
+++ b/d2core/d2map/d2mapentity/npc.go
@@ -137,8 +137,7 @@ func (v *NPC) Advance(tickTime float64) {
 		v.isDone = false
 		path := v.NextPath()
 		v.setTarget(
-			float64(path.X),
-			float64(path.Y),
+			path.Position,
 			v.next,
 		)
 
diff --git a/d2core/d2map/d2mapstamp/stamp.go b/d2core/d2map/d2mapstamp/stamp.go
index b91b4fe4..f9875fb6 100644
--- a/d2core/d2map/d2mapstamp/stamp.go
+++ b/d2core/d2map/d2mapstamp/stamp.go
@@ -4,6 +4,8 @@ import (
 	"math"
 	"math/rand"
 
+	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2math/d2vector"
+
 	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2map/d2mapentity"
 	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2object"
 
@@ -171,8 +173,9 @@ func convertPaths(tileOffsetX, tileOffsetY int, paths []d2common.Path) []d2commo
 	result := make([]d2common.Path, len(paths))
 	for i := 0; i < len(paths); i++ {
 		result[i].Action = paths[i].Action
-		result[i].X = paths[i].X + (tileOffsetX * 5)
-		result[i].Y = paths[i].Y + (tileOffsetY * 5)
+		result[i].Position = d2vector.NewPosition(
+			paths[i].Position.X()+float64(tileOffsetX*5),
+			paths[i].Position.Y()+float64(tileOffsetY*5))
 	}
 
 	return result