reorganized the project

roads.go

@@ -1277,54 +1277,6 @@ func enforcePerpendicularWallCrossing(points []PathPoint, start, wallStart, wall
 	return out
 }
 
-func estimateWallTangent(mid image.Point, wallMask *PixelMask) (float64, float64, bool) {
-	if wallMask == nil {
-		return 0, 0, false
-	}
-	const r = 4
-	var pts [][2]float64
-	for dy := -r; dy <= r; dy++ {
-		y := mid.Y + dy
-		if y < 0 || y >= wallMask.Height {
-			continue
-		}
-		for dx := -r; dx <= r; dx++ {
-			x := mid.X + dx
-			if x < 0 || x >= wallMask.Width {
-				continue
-			}
-			if wallMask.GetXY(x, y) {
-				pts = append(pts, [2]float64{float64(x), float64(y)})
-			}
-		}
-	}
-	if len(pts) < 3 {
-		return 0, 0, false
-	}
-
-	var mx, my float64
-	for _, p := range pts {
-		mx += p[0]
-		my += p[1]
-	}
-	mx /= float64(len(pts))
-	my /= float64(len(pts))
-
-	var sxx, syy, sxy float64
-	for _, p := range pts {
-		dx := p[0] - mx
-		dy := p[1] - my
-		sxx += dx * dx
-		syy += dy * dy
-		sxy += dx * dy
-	}
-	if sxx+syy < 0.001 {
-		return 0, 0, false
-	}
-	theta := 0.5 * math.Atan2(2*sxy, sxx-syy)
-	return math.Cos(theta), math.Sin(theta), true
-}
-
 func crossingAngleToTangentDegrees(rx, ry, tx, ty float64) float64 {
 	rn := math.Hypot(rx, ry)
 	tn := math.Hypot(tx, ty)
@@ -1958,21 +1910,3 @@ func ensureGateRoadConnections(gateRoads []*Road, allRoads []*Road, wallLayout *
 	}
 	return append(allRoads, connectors...)
 }
-
-func clamp(v, lo, hi float64) float64 {
-	if v < lo {
-		return lo
-	}
-	if v > hi {
-		return hi
-	}
-	return v
-}
-
-// abs returns the absolute value of an integer.
-func abs(x int) int {
-	if x < 0 {
-		return -x
-	}
-	return x
-}