From 5c7188be817736c73bb690a977832d8c16a2cb4b Mon Sep 17 00:00:00 2001
From: Ashley Newson <ashleynewson@smartsim.org.uk>
Date: Thu, 29 May 2025 21:06:48 +0100
Subject: [PATCH] Avoid denoising unbiased resources in map generator

Resource placement is usually biased by mpspawns or resources spawns
(mines or blossom trees), which feed into a mutilplier for the
resource noise. Previously, all cells outside of the circle of
influence of a bias source got a multiplier of zero, essentially
giving them no noise pattern. This could lead to ugly horizontal
streaks of resources for which the layout was determined only by the
internals of PriorityArray.

This change fixes this by ensuring the noise multiplier has a
baseline value of 1.
---
 .../Traits/World/ExperimentalMapGenerator.cs  | 36 ++++++++++---------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/OpenRA.Mods.Common/Traits/World/ExperimentalMapGenerator.cs b/OpenRA.Mods.Common/Traits/World/ExperimentalMapGenerator.cs
index 325f6d7c83..d586337feb 100644
--- a/OpenRA.Mods.Common/Traits/World/ExperimentalMapGenerator.cs
+++ b/OpenRA.Mods.Common/Traits/World/ExperimentalMapGenerator.cs
@@ -1584,6 +1584,7 @@ namespace OpenRA.Mods.Common.Traits
 							if (!strengths1024ths.TryGetValue(resource, out var strength1024ths))
 							{
 								strength1024ths = new CellLayer<int>(map);
+								strength1024ths.Clear(1);
 								strengths1024ths.Add(resource, strength1024ths);
 							}
 
@@ -1599,6 +1600,7 @@ namespace OpenRA.Mods.Common.Traits
 					}
 
 					var maxStrength1024ths = new CellLayer<int>(map);
+					maxStrength1024ths.Clear(1);
 					var bestResource = new CellLayer<ResourceTypeInfo>(map);
 					bestResource.Clear(param.DefaultResource);
 					foreach (var resourceStrength in strengths1024ths)
@@ -1614,68 +1616,68 @@ namespace OpenRA.Mods.Common.Traits
 					}
 
 					// Closer to +inf means "more preferable" for plan.
-					var plan1024ths = new CellLayer<int>(map);
+					var plan = new CellLayer<int>(map);
 					foreach (var mpos in map.AllCells.MapCoords)
-						plan1024ths[mpos] = pattern1024ths[mpos] * maxStrength1024ths[mpos] / 1024;
+						plan[mpos] = pattern1024ths[mpos] * maxStrength1024ths[mpos];
 
 					var wSpawnBuildSizeSq = (long)param.SpawnBuildSize * param.SpawnBuildSize * 1024 * 1024;
 					foreach (var actorPlan in actorPlans)
 						if (actorPlan.Reference.Type == "mpspawn")
 							CellLayerUtils.OverCircle(
-								cellLayer: plan1024ths,
+								cellLayer: plan,
 								wCenter: actorPlan.WPosLocation,
 								wRadius: param.SpawnRegionSize * 2 * 1024,
 								outside: false,
 								action: (mpos, _, _, rSq) =>
-									plan1024ths[mpos] += (int)(plan1024ths[mpos] * param.SpawnResourceBias * wSpawnBuildSizeSq / Math.Max(rSq, 1024 * 1024) / FractionMax));
+									plan[mpos] += (int)(plan[mpos] * param.SpawnResourceBias * wSpawnBuildSizeSq / Math.Max(rSq, 1024 * 1024) / FractionMax));
 
 					foreach (var mpos in map.AllCells.MapCoords)
 						if (!playableArea[mpos] || !param.AllowedTerrainResourceCombos.Contains((bestResource[mpos], map.GetTerrainIndex(mpos))))
-							plan1024ths[mpos] = -int.MaxValue;
+							plan[mpos] = -int.MaxValue;
 
 					foreach (var actorPlan in actorPlans)
 						if (actorPlan.Reference.Type == "mpspawn")
 							CellLayerUtils.OverCircle(
-								cellLayer: plan1024ths,
+								cellLayer: plan,
 								wCenter: actorPlan.WPosLocation,
 								wRadius: param.SpawnBuildSize * 1024,
 								outside: false,
-								action: (mpos, _, _, _) => plan1024ths[mpos] = -int.MaxValue);
+								action: (mpos, _, _, _) => plan[mpos] = -int.MaxValue);
 
 					foreach (var actorPlan in actorPlans)
 						foreach (var (cpos, _) in actorPlan.Footprint())
-							if (plan1024ths.Contains(cpos))
-								plan1024ths[cpos] = -int.MaxValue;
+							if (plan.Contains(cpos))
+								plan[cpos] = -int.MaxValue;
 
 					// Improve symmetry.
 					{
 						var newPlan = new CellLayer<int>(map);
 						Symmetry.RotateAndMirrorOverCPos(
-							plan1024ths,
+							plan,
 							param.Rotations,
 							param.Mirror,
 							(sources, destination)
 								=> newPlan[destination] =
-									sources.Min(source => plan1024ths.TryGetValue(source, out var value) ? value : -int.MaxValue));
-						plan1024ths = newPlan;
+									sources.Min(source => plan.TryGetValue(source, out var value) ? value : -int.MaxValue));
+						plan = newPlan;
 					}
 
 					var remaining = param.ResourcesPerPlayer * entityMultiplier / EntityBonusMax;
 
 					// Closer to -inf means "more preferable" for priorities.
 					var priorities = new PriorityArray<int>(
-						plan1024ths.Size.Width * plan1024ths.Size.Height,
+						plan.Size.Width * plan.Size.Height,
 						int.MaxValue);
 					{
 						var i = 0;
-						foreach (var v in plan1024ths)
+						foreach (var v in plan)
 							priorities[i++] = -v;
 					}
 
-					int PriorityIndex(MPos mpos) => mpos.V * plan1024ths.Size.Width + mpos.U;
+					int PriorityIndex(MPos mpos) => mpos.V * plan.Size.Width + mpos.U;
 					MPos PriorityMPos(int index)
 					{
-						var v = Math.DivRem(index, plan1024ths.Size.Width, out var u);
+						var v = Math.DivRem(index, plan.Size.Width, out var u);
 						return new MPos(u, v);
 					}
 
@@ -1748,7 +1750,7 @@ namespace OpenRA.Mods.Common.Traits
 
 						var chosenMPos = PriorityMPos(n);
 						var chosenCPos = chosenMPos.ToCPos(gridType);
-						foreach (var cpos in Symmetry.RotateAndMirrorCPos(chosenCPos, plan1024ths, param.Rotations, param.Mirror))
+						foreach (var cpos in Symmetry.RotateAndMirrorCPos(chosenCPos, plan, param.Rotations, param.Mirror))
 							if (map.Resources.Contains(cpos))
 								remaining -= AddResource(cpos);
 					}