Updated test cases for frontend-backend-collision-reconciliation.

battle_srv/models/room.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"github.com/golang/protobuf/proto"
 	"github.com/gorilla/websocket"
-	"github.com/kvartborg/vector"
 	"github.com/solarlune/resolv"
 	"go.uber.org/zap"
 	"math/rand"
@@ -1159,27 +1158,13 @@ func (pR *Room) applyInputFrameDownsyncDynamics(fromRenderFrameId int32, toRende
 				if collision := playerCollider.Check(oldDx, oldDy, "Barrier"); collision != nil {
 					playerShape := playerCollider.Shape.(*resolv.ConvexPolygon)
 					barrierShape := collision.Objects[0].Shape.(*resolv.ConvexPolygon)
-					origX, origY := playerShape.Position() 
+					if overlapped, pushbackX, pushbackY := CalcPushbacks(oldDx, oldDy, playerShape, barrierShape); overlapped {
-					playerShape.SetPosition(origX+oldDx, origY+oldDy) 
+						Logger.Info(fmt.Sprintf("Collided & overlapped: player.X=%v, player.Y=%v, oldDx=%v, oldDy=%v, playerShape=%v, toCheckBarrier=%v, pushbackX=%v, pushbackY=%v", playerCollider.X, playerCollider.Y, oldDx, oldDy, ConvexPolygonStr(playerShape), ConvexPolygonStr(barrierShape), pushbackX, pushbackY))
-					if colliding := IsPolygonPairColliding(playerShape, barrierShape, nil); colliding {
+						dx -= pushbackX
-						Logger.Info(fmt.Sprintf("Collided: playerShape=%v, oldDx=%v, oldDy=%v", playerShape, oldDx, oldDy))
+						dy -= pushbackY
-						overlapResult := &SatResult{
+					} else {
-							Overlap: 0,
+						Logger.Info(fmt.Sprintf("Collider BUT not overlapped: player.X=%v, player.Y=%v, oldDx=%v, oldDy=%v, playerShape=%v, toCheckBarrier=%v", playerCollider.X, playerCollider.Y, oldDx, oldDy, ConvexPolygonStr(playerShape), ConvexPolygonStr(barrierShape)))
-							OverlapX: 0, 
-							OverlapY: 0, 
-							AContainedInB: true,
-							BContainedInA: true,
-							Axis: vector.Vector{0, 0},
 					}
-						e := vector.Vector{oldDx, oldDy}.Unit()
-						if separatableAlongMovement := IsPolygonPairSeparatedByDir(playerShape, barrierShape, e, overlapResult); !separatableAlongMovement {
-							pushbackX, pushbackY := overlapResult.Overlap*overlapResult.OverlapX, overlapResult.Overlap*overlapResult.OverlapY  
-							Logger.Info(fmt.Sprintf("Collided: playerShape=%v, oldDx=%v, oldDy=%v, toCheckBarrier=%v, pushbackX=%v, pushbackY=%v", playerShape, oldDx, oldDy, barrierShape, pushbackX, pushbackY))
-							dx, dy = oldDx-pushbackX, oldDy-pushbackY 
-						} 
-					}   
-
-					playerShape.SetPosition(origX, origY)
 				}
 				playerCollider.X += dx
 				playerCollider.Y += dy

collider_visualizer/worldColliderDisplay.go

@@ -4,7 +4,6 @@ import (
 	. "dnmshared"
 	"fmt"
 	"github.com/hajimehoshi/ebiten/v2"
-	"github.com/kvartborg/vector"
 	"github.com/solarlune/resolv"
 	"go.uber.org/zap"
 	"image/color"
@@ -56,43 +55,22 @@ func NewWorldColliderDisplay(game *Game, stageDiscreteW, stageDiscreteH, stageTi
 	moveToCollide := true
 	if moveToCollide {
 		toTestPlayerCollider := playerColliders[0]
-        oldDx, oldDy := 135.0, 135.0
+		oldDx, oldDy := -2.98, -50.0
 		dx, dy := oldDx, oldDy
 		if collision := toTestPlayerCollider.Check(oldDx, oldDy, "Barrier"); collision != nil {
 			playerShape := toTestPlayerCollider.Shape.(*resolv.ConvexPolygon)
 			barrierShape := collision.Objects[0].Shape.(*resolv.ConvexPolygon)
-            origX, origY := playerShape.Position() 
+			if overlapped, pushbackX, pushbackY := CalcPushbacks(oldDx, oldDy, playerShape, barrierShape); overlapped {
-            playerShape.SetPosition(origX+oldDx, origY+oldDy)
+				Logger.Info(fmt.Sprintf("Collided & overlapped: player.X=%v, player.Y=%v, oldDx=%v, oldDy=%v, playerShape=%v, toCheckBarrier=%v, pushbackX=%v, pushbackY=%v", toTestPlayerCollider.X, toTestPlayerCollider.Y, oldDx, oldDy, ConvexPolygonStr(playerShape), ConvexPolygonStr(barrierShape), pushbackX, pushbackY))
-            if colliding := IsPolygonPairColliding(playerShape, barrierShape, nil); colliding {
+				dx -= pushbackX
-                Logger.Info(fmt.Sprintf("Collided: playerShape=%v, oldDx=%v, oldDy=%v", playerShape, oldDx, oldDy))
+				dy -= pushbackY
-                overlapResult := &SatResult{
-                    Overlap: 0,
-                    OverlapX: 0, 
-                    OverlapY: 0, 
-                    AContainedInB: true,
-                    BContainedInA: true,
-                    Axis: vector.Vector{0, 0},
-                }
-                e := vector.Vector{oldDx, oldDy}.Unit()
-                if separatableAlongMovement := IsPolygonPairSeparatedByDir(playerShape, barrierShape, e, overlapResult); !separatableAlongMovement {
-                    pushbackX, pushbackY := overlapResult.Overlap*overlapResult.OverlapX, overlapResult.Overlap*overlapResult.OverlapY  
-                    Logger.Info(fmt.Sprintf("Collided: playerShape=%v, oldDx=%v, oldDy=%v, toCheckBarrier=%v, pushbackX=%v, pushbackY=%v", playerShape, oldDx, oldDy, barrierShape, pushbackX, pushbackY))
-                    dx, dy = oldDx-pushbackX, oldDy-pushbackY 
 			} else {
-                    Logger.Info(fmt.Sprintf("Not Collided: playerShape=%v, oldDx=%v, oldDy=%v, toCheckBarrier=%v, e=%v", playerShape, oldDx, oldDy, barrierShape, e))
+				Logger.Info(fmt.Sprintf("Collider BUT not overlapped: player.X=%v, player.Y=%v, oldDx=%v, oldDy=%v, playerShape=%v, toCheckBarrier=%v", toTestPlayerCollider.X, toTestPlayerCollider.Y, oldDx, oldDy, ConvexPolygonStr(playerShape), ConvexPolygonStr(barrierShape)))
 			}
-            } else {
-                Logger.Info(fmt.Sprintf("Not collided: playerShape=%v, oldDx=%v, oldDy=%v, toCheckBarrier=%v", playerShape, oldDx, oldDy, barrierShape))
 		}
 
-            playerShape.SetPosition(origX, origY)
-
 		toTestPlayerCollider.X += dx
 		toTestPlayerCollider.Y += dy
-        } else {
-            Logger.Info(fmt.Sprintf("Collision Test: shape=%v, oldDx=%v, oldDy=%v, not colliding with any Barrier", toTestPlayerCollider.Shape, oldDx, oldDy))
-        }
-
 		toTestPlayerCollider.Update()
 	}
 

dnmshared/resolv_helper.go

@@ -1,11 +1,22 @@
 package dnmshared
 
 import (
+	"fmt"
 	"github.com/kvartborg/vector"
 	"github.com/solarlune/resolv"
 	"math"
+	"strings"
 )
 
+func ConvexPolygonStr(body *resolv.ConvexPolygon) string {
+	var s []string = make([]string, len(body.Points))
+	for i, p := range body.Points {
+		s[i] = fmt.Sprintf("[%v, %v]", p[0]+body.X, p[1]+body.Y)
+	}
+
+	return fmt.Sprintf("[%s]", strings.Join(s, ", "))
+}
+
 func GenerateRectCollider(origX, origY, w, h, spaceOffsetX, spaceOffsetY float64, tag string) *resolv.Object {
 	collider := resolv.NewObject(origX-w*0.5+spaceOffsetX, origY-h*0.5+spaceOffsetY, w, h, tag)
 	shape := resolv.NewRectangle(0, 0, w, h)
@@ -43,6 +54,28 @@ func GenerateConvexPolygonCollider(unalignedSrc *Polygon2D, spaceOffsetX, spaceO
 	return collider
 }
 
+func CalcPushbacks(oldDx, oldDy float64, playerShape, barrierShape *resolv.ConvexPolygon) (bool, float64, float64) {
+	origX, origY := playerShape.Position()
+	defer func() {
+		playerShape.SetPosition(origX, origY)
+	}()
+	playerShape.SetPosition(origX+oldDx, origY+oldDy)
+	overlapResult := &SatResult{
+		Overlap:       0,
+		OverlapX:      0,
+		OverlapY:      0,
+		AContainedInB: true,
+		BContainedInA: true,
+		Axis:          vector.Vector{0, 0},
+	}
+	if overlapped := IsPolygonPairOverlapped(playerShape, barrierShape, overlapResult); overlapped {
+		pushbackX, pushbackY := overlapResult.Overlap*overlapResult.OverlapX, overlapResult.Overlap*overlapResult.OverlapY
+		return true, pushbackX, pushbackY
+	} else {
+		return false, 0, 0
+	}
+}
+
 type SatResult struct {
 	Overlap       float64
 	OverlapX      float64
@@ -52,7 +85,7 @@ type SatResult struct {
 	Axis          vector.Vector
 }
 
-func IsPolygonPairColliding(a, b *resolv.ConvexPolygon, result *SatResult) bool {
+func IsPolygonPairOverlapped(a, b *resolv.ConvexPolygon, result *SatResult) bool {
 	aCnt, bCnt := len(a.Points), len(b.Points)
 	// Single point case
 	if 1 == aCnt && 1 == bCnt {
@@ -64,7 +97,7 @@ func IsPolygonPairColliding(a, b *resolv.ConvexPolygon, result *SatResult) bool
 
 	if 1 < aCnt {
 		for _, axis := range a.SATAxes() {
-			if IsPolygonPairSeparatedByDir(a, b, axis.Unit(), result) {
+			if isPolygonPairSeparatedByDir(a, b, axis.Unit(), result) {
 				return false
 			}
 		}
@@ -72,7 +105,7 @@ func IsPolygonPairColliding(a, b *resolv.ConvexPolygon, result *SatResult) bool
 
 	if 1 < bCnt {
 		for _, axis := range b.SATAxes() {
-			if IsPolygonPairSeparatedByDir(a, b, axis.Unit(), result) {
+			if isPolygonPairSeparatedByDir(a, b, axis.Unit(), result) {
 				return false
 			}
 		}
@@ -81,10 +114,26 @@ func IsPolygonPairColliding(a, b *resolv.ConvexPolygon, result *SatResult) bool
 	return true
 }
 
-func IsPolygonPairSeparatedByDir(a, b *resolv.ConvexPolygon, e vector.Vector, result *SatResult) bool {
+func isPolygonPairSeparatedByDir(a, b *resolv.ConvexPolygon, e vector.Vector, result *SatResult) bool {
+	/*
+		[WARNING] This function is deliberately made private, it shouldn't be used alone (i.e. not along the norms of a polygon), otherwise the pushbacks calculated would be meaningless.
+
+		Consider the following example
+		a: {
+			anchor: [1337.19 1696.74]
+			points: [[0 0] [24 0] [24 24] [0 24]]
+		},
+		b: {
+			anchor: [1277.72 1570.56]
+			points: [[642.57 319.16] [0 319.16] [5.73 0] [643.75 0.90]]
+		}
+
+		e = (-2.98, 1.49).Unit()
+	*/
+
 	var aStart, aEnd, bStart, bEnd float64 = math.MaxFloat64, -math.MaxFloat64, math.MaxFloat64, -math.MaxFloat64
 	for _, p := range a.Points {
-		dot := p.X()*e.X() + p.Y()*e.Y()
+		dot := (p.X()+a.X)*e.X() + (p.Y()+a.Y)*e.Y()
 
 		if aStart > dot {
 			aStart = dot
@@ -96,7 +145,7 @@ func IsPolygonPairSeparatedByDir(a, b *resolv.ConvexPolygon, e vector.Vector, re
 	}
 
 	for _, p := range b.Points {
-		dot := p.X()*e.X() + p.Y()*e.Y()
+		dot := (p.X()+b.X)*e.X() + (p.Y()+b.Y)*e.Y()
 
 		if bStart > dot {
 			bStart = dot

frontend/assets/scripts/collision_test_nodejs.js

@@ -0,0 +1,39 @@
+const collisions = require('./modules/Collisions');
+
+const collisionSys = new collisions.Collisions();
+
+/*
+Backend result reference
+
+2022-10-22T12:11:25.156+0800	INFO	collider_visualizer/worldColliderDisplay.go:77	Collided: player.X=1257.665, player.Y=1415.335, oldDx=-2.98, oldDy=-50, playerShape=&{[[0 0] [64 0] [64 64] [0 64]] 1254.685 1365.335 true}, toCheckBarrier=&{[[628.626 54.254500000000064] [0 56.03250000000003] [0.42449999999999477 1.1229999999999905] [625.9715000000001 0]] 1289.039 1318.0805 true}, pushbackX=-0.15848054013127655, pushbackY=-56.03205175509715, result=&{56.03227587710039 -0.0028283794946841584 -0.9999960001267175 false false [0.9988052279193613 -0.04886836073527201]}
+*/
+function polygonStr(body) {
+  let coords = [];
+  let cnt = body._coords.length;
+  for (let ix = 0, iy = 1; ix < cnt; ix += 2, iy += 2) {
+    coords.push([body._coords[ix], body._coords[iy]]);
+  }
+  return JSON.stringify(coords);
+}
+
+const playerCollider = collisionSys.createPolygon(1257.665, 1415.335, [[0, 0], [64, 0], [64, 64], [0, 64]]);
+const barrierCollider = collisionSys.createPolygon(1289.039, 1318.0805, [[628.626, 54.254500000000064], [0, 56.03250000000003], [0.42449999999999477, 1.1229999999999905], [625.9715000000001, 0]]);
+
+const oldDx = -2.98;
+const oldDy = -50.0;
+
+playerCollider.x += oldDx;
+playerCollider.y += oldDy;
+
+collisionSys.update();
+const result = collisionSys.createResult();
+
+const potentials = playerCollider.potentials();
+
+let overlapCheckId = 0;
+for (const barrier of potentials) {
+  if (!playerCollider.collides(barrier, result)) continue;
+  const pushbackX = result.overlap * result.overlap_x;
+  const pushbackY = result.overlap * result.overlap_y;
+  console.log("For overlapCheckId=" + overlapCheckId + ", the overlap: a=", polygonStr(result.a), ", b=", polygonStr(result.b), ", pushbackX=", pushbackX, ", pushbackY=", pushbackY);
+}

frontend/assets/scripts/collision_test_nodejs.js.meta

@@ -0,0 +1,9 @@
+{
+  "ver": "1.0.5",
+  "uuid": "fce86138-76fc-44d5-8eac-2731b3b0cefd",
+  "isPlugin": false,
+  "loadPluginInWeb": true,
+  "loadPluginInNative": true,
+  "loadPluginInEditor": false,
+  "subMetas": {}
+}