entity debug rendering (#609)

* entity debug rendering, with command

needed to add getter method to MapEntity interface, so that's the reasoning for changing objects/npcs/player/etc

this currently brings allocs/s up to 10 (you can check by running `fps` command, se we need to look into d2debugutils and how it handles drawing text

* reverting velocity copy, broke the map entity tests. debug display wont show velocity currently.

* adding velocity debug

d2common/d2interface/map_entity.go

@@ -1,10 +1,13 @@
 package d2interface
 
+import "github.com/OpenDiablo2/OpenDiablo2/d2common/d2math/d2vector"
+
 // MapEntity is something that can be positioned on and rendered on the game map
 type MapEntity interface {
 	Render(target Surface)
 	Advance(tickTime float64)
-	GetPosition() (float64, float64)
+	GetPosition() d2vector.Position
+	GetVelocity() d2vector.Vector
 	GetLayer() int
 	GetPositionF() (float64, float64)
 	Name() string

d2core/d2map/d2mapentity/map_entity.go

@@ -26,6 +26,7 @@ func newMapEntity(x, y int) mapEntity {
 	return mapEntity{
 		Position: pos,
 		Target:   pos,
+		velocity: d2vector.NewVector(0, 0),
 	}
 }
 
@@ -65,22 +66,23 @@ func (m *mapEntity) Step(tickTime float64) {
 			m.done = nil
 		}
 
+		m.velocity.SetLength(0)
+
 		return
 	}
 
-	// Set velocity (speed and direction)
 	m.setVelocity(tickTime * m.Speed)
 
-	// This loop handles the situation where the velocity exceeds the distance to the current target. Each repitition applies
-	// the remaining velocity in the direction of the next path target.
+	v := m.velocity.Clone() // Create a new vector
+
 	for {
-		applyVelocity(&m.Position.Vector, &m.velocity, &m.Target.Vector)
+		applyVelocity(&m.Position.Vector, &v, &m.Target.Vector) // Pass the new vector to the function which alters it
 
 		if m.atTarget() {
 			m.nextPath()
 		}
 
-		if m.velocity.IsZero() {
+		if v.IsZero() { // Check if the new vector is zero (keeping this as m.velocity.IsZero() would break the test (infinite loop)
 			break
 		}
 	}

d2core/d2map/d2mapentity/missile.go

@@ -19,6 +19,14 @@ type Missile struct {
 	record *d2datadict.MissileRecord
 }
 
+func (m *Missile) GetPosition() d2vector.Position {
+	return m.AnimatedEntity.Position
+}
+
+func (m *Missile) GetVelocity() d2vector.Vector {
+	return m.AnimatedEntity.velocity
+}
+
 // CreateMissile creates a new Missile and initializes it's animation.
 func CreateMissile(x, y int, record *d2datadict.MissileRecord) (*Missile, error) {
 	animation, err := d2asset.LoadAnimation(

d2core/d2map/d2mapentity/npc.go

@@ -1,6 +1,7 @@
 package d2mapentity
 
 import (
+	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2math/d2vector"
 	"math/rand"
 
 	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2interface"
@@ -206,3 +207,13 @@ func (v *NPC) Selectable() bool {
 func (v *NPC) Name() string {
 	return v.name
 }
+
+// GetPosition returns the NPC's position
+func (v *NPC) GetPosition() d2vector.Position {
+	return v.mapEntity.Position
+}
+
+// GetVelocity returns the NPC's velocity vector
+func (v *NPC) GetVelocity() d2vector.Vector {
+	return v.mapEntity.velocity
+}

d2core/d2map/d2mapentity/player.go

@@ -1,10 +1,10 @@
 package d2mapentity
 
 import (
-	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2interface"
-
 	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2data/d2datadict"
 	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2enum"
+	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2interface"
+	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2math/d2vector"
 	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2resource"
 	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2asset"
 	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2hero"
@@ -223,3 +223,13 @@ func (v *Player) Selectable() bool {
 	// Players are selectable when in town
 	return v.IsInTown()
 }
+
+// GetPosition returns the entity's position
+func (p *Player) GetPosition() d2vector.Position {
+	return p.mapEntity.Position
+}
+
+// GetVelocity returns the entity's velocity vector
+func (p *Player) GetVelocity() d2vector.Vector {
+	return p.mapEntity.velocity
+}

d2core/d2map/d2maprenderer/renderer.go

@@ -17,14 +17,16 @@ import (
 
 // MapRenderer manages the game viewport and Camera. It requests tile and entity data from MapEngine and renders it.
 type MapRenderer struct {
-	renderer      d2interface.Renderer   // Used for drawing operations
-	mapEngine     *d2mapengine.MapEngine // The map engine that is being rendered
-	palette       d2interface.Palette    // The palette used for this map
-	viewport      *Viewport              // Used for rendering offsets
-	Camera        Camera                 // Used to determine where on the map we are rendering
-	debugVisLevel int                    // Debug visibility index (0=none, 1=tiles, 2=sub-tiles)
-	lastFrameTime float64                // The last time the map was rendered
-	currentFrame  int                    // Current render frame (for animations)
+	renderer         d2interface.Renderer   // Used for drawing operations
+	mapEngine        *d2mapengine.MapEngine // The map engine that is being rendered
+	palette          d2interface.Palette    // The palette used for this map
+	viewport         *Viewport              // Used for rendering offsets
+	Camera           Camera                 // Used to determine where on the map we are rendering
+	mapDebugVisLevel int                    // Map debug visibility index (0=none, 1=tiles,
+	// 2=sub-tiles)
+	entityDebugVisLevel int     // Entity Debug visibility index (0=none, 1=vectors)
+	lastFrameTime       float64 // The last time the map was rendered
+	currentFrame        int     // Current render frame (for animations)
 }
 
 // CreateMapRenderer creates a new MapRenderer, sets the required fields and returns a pointer to it.
@@ -36,12 +38,16 @@ func CreateMapRenderer(renderer d2interface.Renderer, mapEngine *d2mapengine.Map
 	}
 
 	result.Camera = Camera{}
-	startPosition := d2vector.NewPosition(0,0)
+	startPosition := d2vector.NewPosition(0, 0)
 	result.Camera.position = &startPosition
 	result.viewport.SetCamera(&result.Camera)
 
 	term.BindAction("mapdebugvis", "set map debug visualization level", func(level int) {
-		result.debugVisLevel = level
+		result.mapDebugVisLevel = level
+	})
+
+	term.BindAction("entitydebugvis", "set entity debug visualization level", func(level int) {
+		result.entityDebugVisLevel = level
 	})
 
 	if mapEngine.LevelType().ID != 0 {
@@ -87,12 +93,16 @@ func (mr *MapRenderer) Render(target d2interface.Surface) {
 	mr.renderPass1(target, startX, startY, endX, endY)
 	mr.renderPass2(target, startX, startY, endX, endY)
 
-	if mr.debugVisLevel > 0 {
-		mr.renderDebug(mr.debugVisLevel, target, startX, startY, endX, endY)
+	if mr.mapDebugVisLevel > 0 {
+		mr.renderMapDebug(mr.mapDebugVisLevel, target, startX, startY, endX, endY)
 	}
 
 	mr.renderPass3(target, startX, startY, endX, endY)
 	mr.renderPass4(target, startX, startY, endX, endY)
+
+	if mr.entityDebugVisLevel > 0 {
+		mr.renderEntityDebug(target)
+	}
 }
 
 // MoveCameraTo sets the position of the Camera to the given x and y coordinates.
@@ -146,7 +156,9 @@ func (mr *MapRenderer) renderPass2(target d2interface.Surface, startX, startY, e
 
 			// TODO: Do not loop over every entity every frame
 			for _, mapEntity := range *mr.mapEngine.Entities() {
-				entityX, entityY := mapEntity.GetPosition()
+				pos := mapEntity.GetPosition()
+				vec := pos.World()
+				entityX, entityY := vec.X(), vec.Y()
 
 				if mapEntity.GetLayer() != 1 {
 					continue
@@ -176,7 +188,9 @@ func (mr *MapRenderer) renderPass3(target d2interface.Surface, startX, startY, e
 
 			// TODO: Do not loop over every entity every frame
 			for _, mapEntity := range *mr.mapEngine.Entities() {
-				entityX, entityY := mapEntity.GetPosition()
+				pos := mapEntity.GetPosition()
+				vec := pos.World()
+				entityX, entityY := vec.X(), vec.Y()
 
 				if mapEntity.GetLayer() == 1 {
 					continue
@@ -299,16 +313,46 @@ func (mr *MapRenderer) renderShadow(tile d2ds1.FloorShadowRecord, target d2inter
 	target.Render(img)
 }
 
-func (mr *MapRenderer) renderDebug(debugVisLevel int, target d2interface.Surface, startX, startY, endX, endY int) {
+func (mr *MapRenderer) renderMapDebug(mapDebugVisLevel int, target d2interface.Surface, startX, startY, endX, endY int) {
 	for tileY := startY; tileY < endY; tileY++ {
 		for tileX := startX; tileX < endX; tileX++ {
 			mr.viewport.PushTranslationWorld(float64(tileX), float64(tileY))
-			mr.renderTileDebug(tileX, tileY, debugVisLevel, target)
+			mr.renderTileDebug(tileX, tileY, mapDebugVisLevel, target)
 			mr.viewport.PopTranslation()
 		}
 	}
 }
 
+func (mr *MapRenderer) renderEntityDebug(target d2interface.Surface) {
+	entities := *mr.mapEngine.Entities()
+	for idx := range entities {
+		e := entities[idx]
+		pos := e.GetPosition()
+		world := pos
+		x, y := world.X()/5, world.Y()/5
+		velocity := e.GetVelocity()
+		velocity = velocity.Clone()
+		// velocity.Scale(60) // arbitrary scale value, just to make it easy to see
+		vx, vy := mr.viewport.WorldToOrtho(velocity.X(), velocity.Y())
+		screenX, screenY := mr.viewport.WorldToScreen(x, y)
+
+		offX, offY := 40, -40
+
+		mr.viewport.PushTranslationWorld(x, y)
+		target.PushTranslation(screenX, screenY)
+		target.DrawLine(offX, offY, color.RGBA{255, 255, 255, 128})
+		target.PushTranslation(offX+10, offY-20)
+		target.PushTranslation(-10, -10)
+		target.DrawRect(200, 50, color.RGBA{0, 0, 0, 64})
+		target.Pop()
+		target.DrawTextf("World (%.2f, %.2f)\nVelocity (%.2f, %.2f)", x, y, vx, vy)
+		target.Pop()
+		target.DrawLine(int(vx), int(vy), color.RGBA{64, 255, 0, 255})
+		target.Pop()
+		mr.viewport.PopTranslation()
+	}
+}
+
 // WorldToScreen returns the screen (pixel) position for the given isometric world position as two ints.
 func (mr *MapRenderer) WorldToScreen(x, y float64) (int, int) {
 	return mr.viewport.WorldToScreen(x, y)

d2core/d2object/object.go

@@ -122,12 +122,6 @@ func (ob *Object) GetLayer() int {
 	return ob.drawLayer
 }
 
-// GetPosition of the object
-func (ob *Object) GetPosition() (x, y float64) {
-	w := ob.Position.Tile()
-	return w.X(), w.Y()
-}
-
 // GetPositionF of the object but differently
 func (ob *Object) GetPositionF() (x, y float64) {
 	w := ob.Position.World()
@@ -138,3 +132,13 @@ func (ob *Object) GetPositionF() (x, y float64) {
 func (ob *Object) Name() string {
 	return ob.name
 }
+
+// GetPosition returns the object's position
+func (ob *Object) GetPosition() d2vector.Position {
+	return ob.Position
+}
+
+// GetVelocity returns the object's velocity vector
+func (ob *Object) GetVelocity() d2vector.Vector {
+	return d2vector.NewVector(0, 0)
+}