changed how building distribution works

buildings.go

@@ -170,18 +170,28 @@ func GenerateBuildings(
 
 	// Main loop for placing buildings
 	buildingsPlaced := 0
-	searchTries := 100                                // Number of attempts to find a spot for a building around an anchor
-	maxPlacementAttempts := settings.NumBuildings * 5 // To prevent infinite loops
+	maxPlacementAttempts := settings.NumBuildings * 3 // To prevent infinite loops
 	minBuildingSizePx, maxBuildingSizePx := getBuildingSizeRangePixels(settings, width, height)
+	avgBuildingSizePx := (minBuildingSizePx + maxBuildingSizePx) * 0.5
 	anchorUsage := make(map[image.Point]int, len(anchorPoints))
 	normalAnchorCap := 0
 	exitAnchorCap := 0
+	distributionFactor := clamp01(settings.BuildingDistribution / 100.0)
+	roadPlacementBias := 1.0 - distributionFactor
+	roadAnchorMinOffset := clamp(avgBuildingSizePx*0.55, 2, 16)
+	roadAnchorMaxOffset := roadAnchorMinOffset + math.Pow(distributionFactor, 1.05)*clamp(avgBuildingSizePx*13.0, 16, 180)
+	roadSearchTries := 42
+	randomSearchTries := 18
 	if len(normalRoadAnchors) > 0 {
 		normalAnchorCap = max(2, int(math.Ceil((float64(settings.NumBuildings)/float64(len(normalRoadAnchors)))*1.15)))
 	}
 	if len(exitRoadAnchors) > 0 {
 		exitAnchorCap = max(1, int(math.Ceil((float64(settings.NumBuildings)/float64(len(exitRoadAnchors)))*0.20)))
 	}
+	if settings.NumBuildings <= 80 {
+		normalAnchorCap = max(normalAnchorCap, 6)
+		exitAnchorCap = max(exitAnchorCap, 2)
+	}
 
 	pickAnchorWithCapacity := func(candidates []image.Point, capLimit int) (image.Point, bool) {
 		if len(candidates) == 0 {
@@ -209,13 +219,28 @@ func GenerateBuildings(
 		return image.Point{}, false
 	}
 
+	pickLeastUsedAnchor := func(candidates []image.Point) (image.Point, bool) {
+		if len(candidates) == 0 {
+			return image.Point{}, false
+		}
+		best := candidates[randSrc.Intn(len(candidates))]
+		bestCount := anchorUsage[best]
+		for _, candidate := range candidates {
+			if count := anchorUsage[candidate]; count < bestCount {
+				best = candidate
+				bestCount = count
+			}
+		}
+		return best, true
+	}
+
 	for buildingsPlaced < settings.NumBuildings && maxPlacementAttempts > 0 {
 		maxPlacementAttempts--
 
 		// Select an anchor point for the new building
 		var anchor image.Point
 		usedRoadAnchor := false
-		if randSrc.Float64() > settings.BuildingDistribution/100.0 {
+		if len(anchorPoints) > 0 && randSrc.Float64() < roadPlacementBias {
 			// Buildings should only rarely use exit-road anchors.
 			useExitAnchor := len(exitRoadAnchors) > 0 && randSrc.Float64() < 0.02
 			if useExitAnchor {
@@ -235,31 +260,72 @@ func GenerateBuildings(
 				}
 			}
 			if !usedRoadAnchor {
-				p, ok := sampleRandomLandPoint(width, height, waterMask, roadMask, randSrc)
-				if !ok {
-					continue
+				if a, ok := pickLeastUsedAnchor(normalRoadAnchors); ok {
+					anchor = a
+					usedRoadAnchor = true
+				} else if a, ok := pickLeastUsedAnchor(anchorPoints); ok {
+					anchor = a
+					usedRoadAnchor = true
+				} else {
+					p, ok := sampleRandomLandPoint(width, height, waterMask, roadMask, randSrc)
+					if !ok {
+						continue
+					}
+					anchor = p
 				}
-				anchor = p
 			}
-		} else {
+		}
+		if !usedRoadAnchor {
 			p, ok := sampleRandomLandPoint(width, height, waterMask, roadMask, randSrc)
 			if !ok {
-				continue // No land to place buildings on
+				if a, ok := pickLeastUsedAnchor(normalRoadAnchors); ok {
+					anchor = a
+					usedRoadAnchor = true
+				} else if a, ok := pickLeastUsedAnchor(anchorPoints); ok {
+					anchor = a
+					usedRoadAnchor = true
+				} else {
+					continue // No land to place buildings on
+				}
+			} else {
+				anchor = p
 			}
-			anchor = p
+		}
+
+		searchTries := randomSearchTries
+		if usedRoadAnchor {
+			searchTries = roadSearchTries
 		}
 
 		// Search for a valid building location around the anchor
 		for i := 0; i < searchTries; i++ {
-			searchRadius := float64(i) * 2.0 // Search in expanding circles
+			// Sample building shape/size first so road-adjacent placement can leave enough setback.
+			size := minBuildingSizePx + randSrc.Float64()*(maxBuildingSizePx-minBuildingSizePx)
+			shape := settings.BuildingShape
+			if shape == "mixed" {
+				shape = chooseShape(randSrc, settings.BuildingShapeRatios)
+			}
+
 			angle := randSrc.Float64() * 2 * math.Pi
-			dist := searchRadius * randSrc.Float64()
+			dist := 0.0
+			if usedRoadAnchor {
+				minSetback := max(roadAnchorMinOffset, size*0.85+2.0)
+				progress := float64(i) / float64(max(searchTries-1, 1))
+				searchRadius := minSetback + progress*(roadAnchorMaxOffset-minSetback)
+				if searchRadius < minSetback {
+					searchRadius = minSetback
+				}
+				dist = minSetback + randSrc.Float64()*(searchRadius-minSetback)
+			} else {
+				searchRadius := clamp(float64(i+1)*avgBuildingSizePx*0.45, avgBuildingSizePx, avgBuildingSizePx*5.5)
+				dist = randSrc.Float64() * searchRadius
+			}
 			center := image.Point{
 				X: anchor.X + int(dist*math.Cos(angle)),
 				Y: anchor.Y + int(dist*math.Sin(angle)),
 			}
-			// For fully random distribution, pick any point on the map
-			if settings.BuildingDistribution == 100 {
+			// Non-road placement is fully random over the map.
+			if !usedRoadAnchor {
 				center = image.Point{
 					X: randSrc.Intn(width),
 					Y: randSrc.Intn(height),
@@ -271,13 +337,6 @@ func GenerateBuildings(
 				continue
 			}
 
-			// Attempt to create a building at the selected center
-			size := minBuildingSizePx + randSrc.Float64()*(maxBuildingSizePx-minBuildingSizePx)
-			shape := settings.BuildingShape
-			if shape == "mixed" {
-				shape = chooseShape(randSrc, settings.BuildingShapeRatios)
-			}
-
 			var pixels []image.Point
 			var ok bool