Setup NPCs to follow paths (#243)

Change location to contain canonical location, add field to get rounded location for tile rendering.
If NPC has path, loop through path.

d2core/d2scene/game.go

@@ -77,7 +77,8 @@ func (v *Game) Load() []func() {
 			v.mapEngine = d2mapengine.CreateMapEngine(v.gameState, v.soundManager, v.fileProvider)
 			// TODO: This needs to be different depending on the act of the player
 			v.mapEngine.GenerateMap(d2enum.RegionAct1Town, 1, 0)
-			region := v.mapEngine.GetRegion(0)
+			v.mapEngine.SetRegion(0)
+			region := v.mapEngine.Region()
 			rx, ry := d2helper.IsoToScreen(region.Region.StartX, region.Region.StartY, 0, 0)
 			v.mapEngine.CenterCameraOn(rx, ry)
 			v.mapEngine.Hero = d2core.CreateHero(
@@ -108,13 +109,34 @@ func (v *Game) Update(tickTime float64) {
 		v.mapEngine.Hero.AnimatedEntity.Step(tickTime)
 	}
 
+	for _, npc := range v.mapEngine.Region().Region.NPCs {
+
+		if npc.HasPaths &&
+			npc.AnimatedEntity.LocationX == npc.AnimatedEntity.TargetX &&
+			npc.AnimatedEntity.LocationY == npc.AnimatedEntity.TargetY {
+			// If at the target, set target to the next path.
+			// TODO: pause at target, figure out how to use Path.Action
+			path := npc.NextPath()
+			npc.AnimatedEntity.SetTarget(
+				float64(path.X),
+				float64(path.Y),
+			)
+		}
+
+		if npc.AnimatedEntity.LocationX != npc.AnimatedEntity.TargetX ||
+			npc.AnimatedEntity.LocationY != npc.AnimatedEntity.TargetY {
+			npc.AnimatedEntity.Step(tickTime)
+		}
+
+	}
+
 	if ebiten.IsMouseButtonPressed(ebiten.MouseButtonLeft) {
 		mx, my := ebiten.CursorPosition()
 		px, py := d2helper.ScreenToIso(float64(mx)-v.mapEngine.OffsetX, float64(my)-v.mapEngine.OffsetY)
 
-		v.mapEngine.Hero.AnimatedEntity.SetTarget(px, py)
+		v.mapEngine.Hero.AnimatedEntity.SetTarget(px*5, py*5)
 	}
 
-	rx, ry := d2helper.IsoToScreen(v.mapEngine.Hero.AnimatedEntity.LocationX, v.mapEngine.Hero.AnimatedEntity.LocationY, 0, 0)
-	v.mapEngine.CenterCameraOn(float64(rx), float64(ry))
+	rx, ry := d2helper.IsoToScreen(v.mapEngine.Hero.AnimatedEntity.LocationX/5, v.mapEngine.Hero.AnimatedEntity.LocationY/5, 0, 0)
+	v.mapEngine.CenterCameraOn(rx, ry)
 }

d2core/npc.go

@@ -11,19 +11,36 @@ import (
 
 type NPC struct {
 	AnimatedEntity d2render.AnimatedEntity
+	HasPaths       bool
 	Paths          []d2common.Path
+	path           int
 }
 
 func CreateNPC(x, y int32, object *d2datadict.ObjectLookupRecord, fileProvider d2interface.FileProvider, direction int) *NPC {
 	result := &NPC{
 		AnimatedEntity: d2render.CreateAnimatedEntity(x, y, object, fileProvider, d2enum.Units),
+		HasPaths:       false,
 	}
 	result.AnimatedEntity.SetMode(object.Mode, object.Class, direction)
 	return result
 }
 
+func (v *NPC) Path() d2common.Path {
+	return v.Paths[v.path]
+}
+
+func (v *NPC) NextPath() d2common.Path {
+	v.path++
+	if v.path == len(v.Paths) {
+		v.path = 0
+	}
+
+	return v.Paths[v.path]
+}
+
 func (v *NPC) SetPaths(paths []d2common.Path) {
 	v.Paths = paths
+	v.HasPaths = len(paths) > 0
 }
 
 func (v *NPC) Render(target *ebiten.Image, offsetX, offsetY int) {

d2render/animated_entity.go

@@ -33,12 +33,11 @@ type LayerCacheEntry struct {
 
 // AnimatedEntity represents an entity on the map that can be animated
 type AnimatedEntity struct {
-	fileProvider d2interface.FileProvider
-	// LocationX represents the tile X position of the entity
-	LocationX float64
-	// LocationY represents the tile Y position of the entity
-	subcellX, subcellY float64 // Subcell coordinates within the current tile
+	fileProvider       d2interface.FileProvider
+	LocationX          float64
 	LocationY          float64
+	TileX, TileY       int     // Coordinates of the tile the unit is within
+	subcellX, subcellY float64 // Subcell coordinates within the current tile
 	dccLayers          map[string]d2dcc.DCC
 	Cof                *d2cof.COF
 	palette            d2enum.PaletteType
@@ -72,13 +71,15 @@ func CreateAnimatedEntity(x, y int32, object *d2datadict.ObjectLookupRecord, fil
 		//frameLocations: []d2common.Rectangle{},
 	}
 	result.dccLayers = make(map[string]d2dcc.DCC)
-	result.LocationX = float64(x) / 5
-	result.LocationY = float64(y) / 5
+	result.LocationX = float64(x)
+	result.LocationY = float64(y)
 	result.TargetX = result.LocationX
 	result.TargetY = result.LocationY
 
-	result.subcellX = 1 + math.Mod(float64(x), 5)
-	result.subcellY = 1 + math.Mod(float64(y), 5)
+	result.TileX = int(result.LocationX / 5)
+	result.TileY = int(result.LocationY / 5)
+	result.subcellX = 1 + math.Mod(result.LocationX, 5)
+	result.subcellY = 1 + math.Mod(result.LocationY, 5)
 
 	return result
 }
@@ -309,7 +310,7 @@ func (v AnimatedEntity) GetDirection() int {
 }
 
 func (v *AnimatedEntity) getStepLength(tickTime float64) (float64, float64) {
-	speed := 2.5
+	speed := 6.0
 	length := tickTime * speed
 
 	angle := 359 - d2helper.GetAngleBetween(
@@ -318,7 +319,7 @@ func (v *AnimatedEntity) getStepLength(tickTime float64) (float64, float64) {
 		v.TargetX,
 		v.TargetY,
 	)
-	radians := (math.Pi / 180.0) * float64(angle)
+	radians := (math.Pi / 180.0) * angle
 	oneStepX := length * math.Cos(radians)
 	oneStepY := length * math.Sin(radians)
 	return oneStepX, oneStepY
@@ -339,9 +340,15 @@ func (v *AnimatedEntity) Step(tickTime float64) {
 	if v.LocationY != v.TargetY {
 		v.LocationY += stepY
 	}
+
+	v.subcellX = 1 + math.Mod(v.LocationX, 5)
+	v.subcellY = 1 + math.Mod(v.LocationY, 5)
+	v.TileX = int(v.LocationX / 5)
+	v.TileY = int(v.LocationY / 5)
+
 	if v.LocationX == v.TargetX && v.LocationY == v.TargetY {
-		if v.animationMode != d2enum.AnimationModePlayerTownNeutral.String() {
-			v.SetMode(d2enum.AnimationModePlayerTownNeutral.String(), v.weaponClass, v.direction)
+		if v.animationMode != d2enum.AnimationModeObjectNeutral.String() {
+			v.SetMode(d2enum.AnimationModeObjectNeutral.String(), v.weaponClass, v.direction)
 		}
 	}
 }
@@ -354,13 +361,28 @@ func (v *AnimatedEntity) SetTarget(tx, ty float64) {
 		tx,
 		ty,
 	)
-	newAnimationMode := d2enum.AnimationModePlayerTownNeutral.String()
+	// TODO: Check if is in town and if is player.
+	newAnimationMode := d2enum.AnimationModeMonsterWalk.String()
 	if tx != v.LocationX || ty != v.LocationY {
 		v.TargetX, v.TargetY = tx, ty
-		newAnimationMode = d2enum.AnimationModePlayerTownWalk.String()
+		newAnimationMode = d2enum.AnimationModeMonsterWalk.String()
 	}
-	newDirection := int((float64(angle) / 360.0) * 16.0)
+
+	newDirection := angleToDirection(angle, v.Cof.NumberOfDirections)
 	if newDirection != v.GetDirection() || newAnimationMode != v.animationMode {
 		v.SetMode(newAnimationMode, v.weaponClass, newDirection)
 	}
 }
+
+func angleToDirection(angle float64, numberOfDirections int) int {
+	degreesPerDirection := 360.0 / float64(numberOfDirections)
+	offset := 45.0 - (degreesPerDirection / 2)
+	newDirection := int((angle - offset) / degreesPerDirection)
+	if newDirection >= numberOfDirections {
+		newDirection = newDirection - numberOfDirections
+	} else if newDirection < 0 {
+		newDirection = numberOfDirections + newDirection
+	}
+
+	return newDirection
+}

d2render/animated_entity_test.go

@@ -0,0 +1,54 @@
+package d2render
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestAngleToDirection_16Directions(t *testing.T) {
+
+	numberOfDirections := 16
+
+	angle := 45.0
+	for i := 0; i < numberOfDirections; i++ {
+		assert.Equal(t, i, angleToDirection(angle, numberOfDirections))
+		angle += 22.5
+	}
+
+	angle = 50.0
+	for i := 0; i < numberOfDirections; i++ {
+		assert.Equal(t, i, angleToDirection(angle, numberOfDirections))
+		angle += 22.5
+	}
+
+	angle = 40.0
+	for i := 0; i < numberOfDirections; i++ {
+		assert.Equal(t, i, angleToDirection(angle, numberOfDirections))
+		angle += 22.5
+	}
+
+}
+
+func TestAngleToDirection_8Directions(t *testing.T) {
+
+	numberOfDirections := 8
+
+	angle := 45.0
+	for i := 0; i < numberOfDirections; i++ {
+		assert.Equal(t, i, angleToDirection(angle, numberOfDirections))
+		angle += 45
+	}
+
+	angle = 50.0
+	for i := 0; i < numberOfDirections; i++ {
+		assert.Equal(t, i, angleToDirection(angle, numberOfDirections))
+		angle += 45
+	}
+
+	angle = 40.0
+	for i := 0; i < numberOfDirections; i++ {
+		assert.Equal(t, i, angleToDirection(angle, numberOfDirections))
+		angle += 45
+	}
+
+}

d2render/d2mapengine/engine.go

@@ -3,7 +3,6 @@ package d2mapengine
 import (
 	"fmt"
 	"image/color"
-	"math"
 	"strings"
 
 	"github.com/OpenDiablo2/D2Shared/d2common/d2enum"
@@ -35,6 +34,7 @@ type Engine struct {
 	soundManager *d2audio.Manager
 	gameState    *d2core.GameState
 	fileProvider d2interface.FileProvider
+	region       int
 	regions      []EngineRegion
 	OffsetX      float64
 	OffsetY      float64
@@ -52,6 +52,14 @@ func CreateMapEngine(gameState *d2core.GameState, soundManager *d2audio.Manager,
 	return result
 }
 
+func (v *Engine) Region() *EngineRegion {
+	return &v.regions[v.region]
+}
+
+func (v *Engine) SetRegion(region int)  {
+	v.region = region
+}
+
 func (v *Engine) GetRegion(regionIndex int) *EngineRegion {
 	return &v.regions[regionIndex]
 }
@@ -244,17 +252,17 @@ func (v *Engine) RenderPass2(region *Region, offX, offY, x, y int, target *ebite
 	}
 
 	for _, obj := range region.AnimationEntities {
-		if int(math.Floor(obj.LocationX)) == x && int(math.Floor(obj.LocationY)) == y {
+		if obj.TileX == x && obj.TileY == y {
 			obj.Render(target, offX+int(v.OffsetX), offY+int(v.OffsetY))
 		}
 	}
 	for _, npc := range region.NPCs {
-		if int(math.Floor(npc.AnimatedEntity.LocationX)) == x && int(math.Floor(npc.AnimatedEntity.LocationY)) == y {
+		if npc.AnimatedEntity.TileX == x && npc.AnimatedEntity.TileY == y {
 			npc.Render(target, offX+int(v.OffsetX), offY+int(v.OffsetY))
 		}
 	}
-	if v.Hero != nil && int(v.Hero.AnimatedEntity.LocationX) == x && int(v.Hero.AnimatedEntity.LocationY) == y {
-		v.Hero.Render(target, 400, 300)
+	if v.Hero != nil && v.Hero.AnimatedEntity.TileX == x && v.Hero.AnimatedEntity.TileY == y {
+		v.Hero.Render(target, offX+int(v.OffsetX), offY+int(v.OffsetY))
 	}
 }