From afa6d8c552354f39abb6dae8ffd780e6e30b27af Mon Sep 17 00:00:00 2001
From: Marius DAVID <git@mariusdavid.fr>
Date: Sat, 30 Aug 2025 13:14:09 +0200
Subject: [PATCH] CS: Make the terrain editing error preview match with the new
 correction algorithm.

---
 apps/opencs/view/render/terrainstorage.cpp | 32 ++++++++--------------
 apps/opencs/view/render/terrainstorage.hpp |  3 --
 2 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/apps/opencs/view/render/terrainstorage.cpp b/apps/opencs/view/render/terrainstorage.cpp
index 4bb9e15dcb..e9f3c1fedc 100644
--- a/apps/opencs/view/render/terrainstorage.cpp
+++ b/apps/opencs/view/render/terrainstorage.cpp
@@ -107,14 +107,14 @@ namespace CSVRender
 
     int TerrainStorage::getUpHeight(int col, int row, std::span<const float> heightData) const
     {
-        return heightData[(col - 1) * ESM::Land::LAND_SIZE + row]
-            + mAlteredHeight[static_cast<unsigned int>((col - 1) * ESM::Land::LAND_SIZE + row)];
+        return heightData[(col + 1) * ESM::Land::LAND_SIZE + row]
+            + mAlteredHeight[static_cast<unsigned int>((col + 1) * ESM::Land::LAND_SIZE + row)];
     }
 
     int TerrainStorage::getDownHeight(int col, int row, std::span<const float> heightData) const
     {
-        return heightData[(col + 1) * ESM::Land::LAND_SIZE + row]
-            + mAlteredHeight[static_cast<unsigned int>((col + 1) * ESM::Land::LAND_SIZE + row)];
+        return heightData[(col - 1) * ESM::Land::LAND_SIZE + row]
+            + mAlteredHeight[static_cast<unsigned int>((col - 1) * ESM::Land::LAND_SIZE + row)];
     }
 
     int TerrainStorage::getHeightDifferenceToLeft(int col, int row, std::span<const float> heightData) const
@@ -137,29 +137,19 @@ namespace CSVRender
         return abs(getThisHeight(col, row, heightData) - getDownHeight(col, row, heightData));
     }
 
-    bool TerrainStorage::leftOrUpIsOverTheLimit(
-        int col, int row, int heightWarningLimit, std::span<const float> heightData) const
-    {
-        return getHeightDifferenceToLeft(col, row, heightData) >= heightWarningLimit
-            || getHeightDifferenceToUp(col, row, heightData) >= heightWarningLimit;
-    }
-
-    bool TerrainStorage::rightOrDownIsOverTheLimit(
-        int col, int row, int heightWarningLimit, std::span<const float> heightData) const
-    {
-        return getHeightDifferenceToRight(col, row, heightData) >= heightWarningLimit
-            || getHeightDifferenceToDown(col, row, heightData) >= heightWarningLimit;
-    }
-
     void TerrainStorage::adjustColor(int col, int row, const ESM::LandData* heightData, osg::Vec4ub& color) const
     {
         if (!heightData)
             return;
         // Highlight broken height changes
         int heightWarningLimit = 1024;
-        if (((col > 0 && row > 0) && leftOrUpIsOverTheLimit(col, row, heightWarningLimit, heightData->getHeights()))
-            || ((col < ESM::Land::LAND_SIZE - 1 && row < ESM::Land::LAND_SIZE - 1)
-                && rightOrDownIsOverTheLimit(col, row, heightWarningLimit, heightData->getHeights())))
+        if ((row > 0 && (getHeightDifferenceToRight(col, row, heightData->getHeights()) >= heightWarningLimit))
+            || (row > 0 && row < ESM::Land::LAND_SIZE
+                && (getHeightDifferenceToLeft(col, row, heightData->getHeights()) >= heightWarningLimit))
+            || (row == 0 && col > 0
+                && (getHeightDifferenceToDown(col, row, heightData->getHeights()) >= heightWarningLimit))
+            || (row == 0 && col < ESM::Land::LAND_SIZE
+                && (getHeightDifferenceToUp(col, row, heightData->getHeights()) >= heightWarningLimit)))
         {
             color.r() = 255;
             color.g() = 0;
diff --git a/apps/opencs/view/render/terrainstorage.hpp b/apps/opencs/view/render/terrainstorage.hpp
index 7906c75cf6..3477306e3e 100644
--- a/apps/opencs/view/render/terrainstorage.hpp
+++ b/apps/opencs/view/render/terrainstorage.hpp
@@ -52,9 +52,6 @@ namespace CSVRender
         int getHeightDifferenceToRight(int col, int row, std::span<const float> heightData) const;
         int getHeightDifferenceToUp(int col, int row, std::span<const float> heightData) const;
         int getHeightDifferenceToDown(int col, int row, std::span<const float> heightData) const;
-        bool leftOrUpIsOverTheLimit(int col, int row, int heightWarningLimit, std::span<const float> heightData) const;
-        bool rightOrDownIsOverTheLimit(
-            int col, int row, int heightWarningLimit, std::span<const float> heightData) const;
 
         void adjustColor(int col, int row, const ESM::LandData* heightData, osg::Vec4ub& color) const override;
         float getAlteredHeight(int col, int row) const override;