Add ITerrainSceneNode::setFixedBorderLOD to handle connecting terrain nodes without gaps. Thanks @diho for the bugreport, testcase and a patch proposal.

Forum: http://irrlicht.sourceforge.net/forum/viewtopic.php?f=9&t=51220


git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@5610 dfc29bdd-3216-0410-991c-e03cc46cb475

changes.txt

@@ -1,7 +1,8 @@
 --------------------------
 Changes in 1.9 (not yet released)
-- PLY loader now works with files which use "st" instead of "uv" for texture coordinates (like generated from Blender or Assimp). Thanks @JLouisB for patch (http://irrlicht.sourceforge.net/forum/viewtopic.php?f=9&t=52261)
-- STL writer does now also write binary files when EMWF_WRITE_BINARY flag is used. Based on patch from JLouisB. (Forum: http://irrlicht.sourceforge.net/forum/viewtopic.php?f=9&t=52261)
+- Add ITerrainSceneNode::setFixedBorderLOD to handle connecting terrain nodes without gaps. Thanks @diho for the bugreport, testcase and a patch proposal (http://irrlicht.sourceforge.net/forum/viewtopic.php?f=9&t=51220).
+- PLY loader now works with files which use "st" instead of "uv" for texture coordinates (like generated from Blender or Assimp). Thanks @JLouisB for patch (http://irrlicht.sourceforge.net/forum/viewtopic.php?f=9&t=52261).
+- STL writer does now also write binary files when EMWF_WRITE_BINARY flag is used. Based on patch from JLouisB (http://irrlicht.sourceforge.net/forum/viewtopic.php?f=9&t=52261).
  (EMWF_WRITE_COMPRESSED also still works for downward compatibility)
 - Improved PLY exporter. Thanks for Patch from JLouisB. (Forum: http://irrlicht.sourceforge.net/forum/viewtopic.php?f=9&t=52261):
   - Support for UV and vertex colors.

include/ITerrainSceneNode.h

@@ -100,7 +100,9 @@ namespace scene
 		virtual s32 getCurrentLODOfPatches(core::array<s32>& LODs) const =0;
 
 		//! Manually sets the LOD of a patch
-		/** \param patchX Patch x coordinate.
+		/** NOTE: Any values set here are overwritten again in the automatic
+		recalculations when the camera changes.
+		\param patchX Patch x coordinate.
 		\param patchZ Patch z coordinate.
 		\param LOD The level of detail to set the patch to. */
 		virtual void setLODOfPatch(s32 patchX, s32 patchZ, s32 LOD=0) =0;
@@ -172,6 +174,12 @@ namespace scene
 			video::SColor vertexColor=video::SColor(255,255,255,255),
 			s32 smoothFactor=0) =0;
 
+		//! Force node to use a fixed LOD level at the borders of the terrain.
+		/** This can be useful when several TerrainSceneNodes are connected.
+		\param borderLOD When >= 0 all patches at the 4 borders will use the 
+		given LOD. When < 0 borders are just regular patches (that's default).	*/
+		virtual void setFixedBorderLOD(irr::s32 borderLOD=0) = 0;
+
 	};
 
 } // end namespace scene

source/Irrlicht/CTerrainSceneNode.cpp

@@ -38,6 +38,7 @@ namespace scene
 	TerrainData(patchSize, maxLOD, position, rotation, scale), RenderBuffer(0),
 	VerticesToRender(0), IndicesToRender(0), DynamicSelectorUpdate(false),
 	OverrideDistanceThreshold(false), UseDefaultRotationPivot(true), ForceRecalculation(true),
+	FixedBorderLOD(-1),
 	CameraMovementDelta(10.0f), CameraRotationDelta(1.0f),CameraFOVDelta(0.1f),
 	TCoordScale1(1.0f), TCoordScale2(1.0f), SmoothFactor(0), FileSystem(fs)
 	{
@@ -640,7 +641,18 @@ namespace scene
 			{
 				const f32 distance = cameraPosition.getDistanceFromSQ(TerrainData.Patches[j].Center);
 
+				if ( FixedBorderLOD >= 0 )
+				{
+					TerrainData.Patches[j].CurrentLOD = FixedBorderLOD;
+					if (j < TerrainData.PatchCount 
+						|| j >= (count - TerrainData.PatchCount) 
+						|| (j % TerrainData.PatchCount) == 0 
+						|| (j % TerrainData.PatchCount) == TerrainData.PatchCount-1)
+						continue;
+				}
+
 				TerrainData.Patches[j].CurrentLOD = 0;
+
 				for (s32 i = TerrainData.MaxLOD - 1; i>0; --i)
 				{
 					if (distance >= TerrainData.LODDistanceThreshold[i])

source/Irrlicht/CTerrainSceneNode.h

@@ -202,6 +202,12 @@ namespace scene
 		//! Scales the two textures
 		virtual void scaleTexture(f32 scale = 1.0f, f32 scale2 = 0.0f) _IRR_OVERRIDE_;
 
+		//! Force node to use a fixed LOD level at the borders of the terrain.
+		virtual void setFixedBorderLOD(irr::s32 borderLOD)  _IRR_OVERRIDE_
+		{
+			FixedBorderLOD = borderLOD;
+		}
+
 		//! Returns type of the scene node
 		virtual ESCENE_NODE_TYPE getType() const _IRR_OVERRIDE_ {return ESNT_TERRAIN;}
 
@@ -303,6 +309,7 @@ namespace scene
 		bool OverrideDistanceThreshold;
 		bool UseDefaultRotationPivot;
 		bool ForceRecalculation;
+		s32 FixedBorderLOD;
 
 		core::vector3df	OldCameraPosition;
 		core::vector3df	OldCameraRotation;