Raise and Dig Terrain

Hellou, i have a litlle problem. I have method for Raise terrain. It works good if i have terrain width 1000 and terrain length 1000, if i make terrain for example 5000x5000 brush is same but hill is 5 x bigger or if i make terrain 200x200 brush is same but hill is 5 x smaller.. I add here two methods where i make hills or dig but i dont use terraindata.size or something like that, so i dont understand. Thanks for all help

 private float ApplyBrush(float height, float brushStrength, int x, int y)
     {
         if (this.mode == TerrainEditMode.Height)
                         return height + (brush.shiftDown == false ? brushStrength : +brushStrength);
                 else if (this.mode == TerrainEditMode.Kopanie) {
             return height - (brush.shiftDown == false ? brushStrength : - brushStrength);    
             }
         else if (this.mode == TerrainEditMode.Flatten)
         {
 
 
             if (this.normalizedTargetHeight > height)
             {
 
                 height += brushStrength;
                 height = Mathf.Min(height, this.normalizedTargetHeight);
                 
                 return height;
             }
             else
             {
 
                // height = Mathf.Lerp(height, this.normalizedTargetHeight, Time.deltaTime);
                 height -= brushStrength;
                 height = Mathf.Max(height, this.normalizedTargetHeight);
                 
                 return height;
             }
         }
         else if (this.mode == TerrainEditMode.Smooth) {
             float smoothed = Mathf.Lerp(height, this.Smooth(x, y), brushStrength);
             return smoothed;
         }
         else
             return height;
     }
 
     /// <summary>
     /// Paints the height.  returns if edited or not
     /// </summary>
     /// <returns><c>true</c>, if height was painted, <c>false</c> otherwise.</returns>
     /// <param name="xCenter">X center.</param>
     /// <param name="yCenter">Y center.</param>
     public bool PaintHeight(float xCenter, float yCenter)
     {
         int xSize = (int)xCenter;
         int ySize = (int)yCenter;
 
         int halfSize = brush.Size / 2;
         int remainder = brush.Size % 2;
 
         bool changedHeight = false;
 
         int xBase = Mathf.Clamp(xSize - halfSize , 0, this.terrainData.heightmapWidth);
         int yBase = Mathf.Clamp(ySize - halfSize , 0, this.terrainData.heightmapHeight);
         int xEnd = Mathf.Clamp(xSize + halfSize + remainder, 0, this.terrainData.heightmapWidth);
         int yEnd = Mathf.Clamp(ySize + halfSize + remainder, 0, this.terrainData.heightmapHeight);
         int width = xEnd - xBase;
         int height = yEnd - yBase;
 
         if (width == 0 || height == 0)
         {
             
             return (xBase == (0 | terrainData.heightmapWidth - 1) || yBase == (0 | terrainData.heightmapWidth - 1) || xEnd == (0 | terrainData.heightmapWidth - 1) || yEnd == (0 | terrainData.heightmapWidth - 1));
         }
 
         float[,] heights = terrainData.GetHeights(xBase, yBase, width, height);
 
         for (int yIndex = 0; yIndex < height; ++yIndex)
         {
             for (int xIndex = 0; xIndex < width; ++xIndex)
             {
                 float strengthInt = this.brush.GetStrengthInt(xBase + xIndex - (xSize - halfSize), yBase + yIndex - (ySize - halfSize));
 
                 float strength = strengthInt * brush.strength * .5f;
 
                 if(mode != TerrainEditMode.Smooth)
                     strength *= Time.deltaTime;
 
                 float newHeight = this.ApplyBrush(heights[yIndex, xIndex], strength, xIndex + xBase, yIndex + yBase);
 
                 if(changedHeight == false && heights[yIndex, xIndex] != newHeight)
                     changedHeight = true;
 
                 heights[yIndex, xIndex] = newHeight;     //why unity why?
             }
         }
 
         this.terrainData.SetHeights(xBase, yBase, heights);
 
         if (mode == TerrainEditMode.Flatten && changedHeight == false)      //fixes seam problems
         {
             changedHeight = (xBase == (0 | terrainData.heightmapWidth - 1) || yBase == (0 | terrainData.heightmapWidth - 1) || xEnd == (0 | terrainData.heightmapWidth - 1) || yEnd == (0 | terrainData.heightmapWidth - 1));
 
             Debug.Log(xBase + " " + yBase + " " + xEnd + " " + yEnd);
         }
 
         return changedHeight;
     }
  public void EditHeights(Terrain terrain, Vector3 mousePos)
     {
         TerrainUndoManager.AddActionToUndo(terrain, terrain.terrainData.GetHeights(0, 0, terrain.terrainData.heightmapWidth, terrain.terrainData.heightmapHeight));
 
         int xRes = (terrain.terrainData.heightmapWidth);
         int zRes = (terrain.terrainData.heightmapHeight);
 
         float x =(((mousePos.x - terrain.transform.position.x) / terrain.terrainData.size.x) * xRes);
         float z =(((mousePos.z - terrain.transform.position.z) / terrain.terrainData.size.z) * zRes);
 
         terrainData = terrain.terrainData;
         PaintHeight((int)x, (int)z);
 }