Add option to allow nodes to ignore the scale/rotation parts of their parents transformation.

ISceneNode::setUpdateAbsolutePosBehavior can now control what ISceneNode::updateAbsolutePosition really does.
Having only the position and not the rotation/scale of a child node affected by the parent transformation was previously impossible inside the scene-graph. So people always had to break the scene-graph and code it themselves.
Old behaviour is default. 
Extra check for new variable has a small cost, thought new behaviour can actually be faster when it's used.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@6432 dfc29bdd-3216-0410-991c-e03cc46cb475

changes.txt

@@ -1,6 +1,7 @@
 --------------------------
 Changes in 1.9 (not yet released)
 
+- Add ISceneNode::UpdateAbsolutePosBehavior variable to allow nodes to ignore the scale/rotation parts of their parents transformation.
 - Add IGUISpinBox functions getValueFor and getOldValue
 - Bugfix: IGUIElement::getNextElement now passing includeInvisible and includeDisabled flags recursively instead of disabling those for children.
   This fixes problems that elements sometimes didn't get a tab order because some parent was invisible and so tab'ing for them failed completely.

include/ESceneNodeUpdateAbs.h

@@ -0,0 +1,34 @@
+// This file is part of the "Irrlicht Engine".
+// For conditions of distribution and use, see copyright notice in irrlicht.h
+
+#ifndef IRR_E_SCENE_NODE_UPDATE_ABS_H_INCLUDED
+#define IRR_E_SCENE_NODE_UPDATE_ABS_H_INCLUDED
+
+namespace irr
+{
+namespace scene
+{
+	//! Options how ISceneNode::updateAbsolutePosition calculates the AbsoluteTransformation
+	enum ESCENE_NODE_UPDATE_ABS
+	{
+		//! Node and parent transformation matrices are multiplied (default)
+		ESNUA_TRANSFORM_MATRIX,
+
+		//! Only transform the position of the node transformation matrix 
+		//! by the parent transformation matrix.
+		//! Parent will not affect the rotation/scale of the node transformation.
+		ESNUA_TRANSFORM_POSITION
+	};
+
+	//! Names for culling type
+	const c8* const SceneNodeUpdateAbsNames[] =
+	{
+		"matrix",
+		"pos",
+		0
+	};
+
+} // end namespace scene
+} // end namespace irr
+
+#endif

include/ISceneNode.h

@@ -7,6 +7,7 @@
 
 #include "IAttributeExchangingObject.h"
 #include "ESceneNodeTypes.h"
+#include "ESceneNodeUpdateAbs.h"
 #include "ECullingTypes.h"
 #include "EDebugSceneTypes.h"
 #include "ISceneNodeAnimator.h"
@@ -29,6 +30,7 @@ namespace scene
 	//! Typedef for list of scene node animators
 	typedef core::list<ISceneNodeAnimator*> ISceneNodeAnimatorList;
 
+
 	//! Scene node interface.
 	/** A scene node is a node in the hierarchical scene graph. Every scene
 	node may have children, which are also scene nodes. Children move
@@ -48,7 +50,8 @@ namespace scene
 				const core::vector3df& scale = core::vector3df(1.0f, 1.0f, 1.0f))
 			: RelativeTranslation(position), RelativeRotation(rotation), RelativeScale(scale),
 				Parent(0), SceneManager(mgr), TriangleSelector(0), ID(id),
-				AutomaticCullingState(EAC_BOX), DebugDataVisible(EDS_OFF),
+				AutomaticCullingState(EAC_BOX), UpdateAbsolutePosBehavior(ESNUA_TRANSFORM_MATRIX),
+				DebugDataVisible(EDS_OFF),
 				IsVisible(true), IsDebugObject(false)
 		{
 			if (parent)
@@ -558,6 +561,18 @@ namespace scene
 			return AutomaticCullingState;
 		}
 
+		//! Set how updateAbsolutePosition calculates the absolute transformation matrix
+		void setUpdateAbsolutePosBehavior(ESCENE_NODE_UPDATE_ABS behavior)
+		{
+			UpdateAbsolutePosBehavior = behavior;
+		}
+
+		//! Get how updateAbsolutePosition calculates the absolute transformation matrix
+		ESCENE_NODE_UPDATE_ABS getUpdateAbsolutePosBehavior() const
+		{
+			return UpdateAbsolutePosBehavior;
+		}
+
 
 		//! Sets if debug data like bounding boxes should be drawn.
 		/** A bitwise OR of the types from @ref irr::scene::E_DEBUG_SCENE_TYPE.
@@ -659,16 +674,25 @@ namespace scene
 		}
 
 
-		//! Updates the absolute position based on the relative and the parents position
-		/** Note: This does not recursively update the parents absolute positions, so if you have a deeper
+		//! Updates the absolute tranformation or position based on the relative and the parents transformation
+		/** It's exact behavior can be controlled by setUpdateAbsolutePosBehavior.
+		Note: This does not recursively update the parents absolute positions, so if you have a deeper
 			hierarchy you might want to update the parents first.*/
 		virtual void updateAbsolutePosition()
 		{
 			if (Parent)
+			{
+				if ( UpdateAbsolutePosBehavior == ESNUA_TRANSFORM_MATRIX )
 				{
 					AbsoluteTransformation =
 						Parent->getAbsoluteTransformation() * getRelativeTransformation();
 				}
+				else if ( UpdateAbsolutePosBehavior == ESNUA_TRANSFORM_POSITION )
+				{
+					AbsoluteTransformation = getRelativeTransformation();
+					Parent->getAbsoluteTransformation().transformVect(reinterpret_cast<irr::core::vector3df&>(AbsoluteTransformation[12]));
+				}
+			}
 			else
 				AbsoluteTransformation = getRelativeTransformation();
 		}
@@ -709,6 +733,7 @@ namespace scene
 			out->addVector3d("Scale", getScale() );
 
 			out->addBool("Visible", IsVisible );
+			out->addEnum("AbsPosUpdate", (s32)UpdateAbsolutePosBehavior, SceneNodeUpdateAbsNames);
 			out->addInt("AutomaticCulling", AutomaticCullingState);
 			out->addInt("DebugDataVisible", DebugDataVisible );
 			out->addBool("IsDebugObject", IsDebugObject );
@@ -734,8 +759,12 @@ namespace scene
 			setScale(in->getAttributeAsVector3d("Scale", RelativeScale));
 
 			IsVisible = in->getAttributeAsBool("Visible", IsVisible);
+
+			UpdateAbsolutePosBehavior = (ESCENE_NODE_UPDATE_ABS)in->getAttributeAsEnumeration("AbsPosUpdate", SceneNodeUpdateAbsNames, (s32)UpdateAbsolutePosBehavior);
+
 			if (in->existsAttribute("AutomaticCulling"))
 			{
+				// compatibility for older version, new one uses int's
 				const s32 tmpState = in->getAttributeAsEnumeration("AutomaticCulling",
 						scene::AutomaticCullingNames);
 				if (tmpState != -1)
@@ -779,6 +808,7 @@ namespace scene
 			RelativeScale = toCopyFrom->RelativeScale;
 			ID = toCopyFrom->ID;
 			setTriangleSelector(toCopyFrom->TriangleSelector);
+			UpdateAbsolutePosBehavior = toCopyFrom->UpdateAbsolutePosBehavior;
 			AutomaticCullingState = toCopyFrom->AutomaticCullingState;
 			DebugDataVisible = toCopyFrom->DebugDataVisible;
 			IsVisible = toCopyFrom->IsVisible;
@@ -853,6 +883,9 @@ namespace scene
 		//! ID of the node.
 		s32 ID;
 
+		//! How updateAbsolutePosition calculates AbsoluteTransformation
+		ESCENE_NODE_UPDATE_ABS UpdateAbsolutePosBehavior;
+
 		//! Automatic culling state
 		u32 AutomaticCullingState;
 

source/Irrlicht/Irrlicht10.0.vcxproj

@@ -846,6 +846,7 @@
     <ClInclude Include="..\..\include\EMaterialTypes.h" />
     <ClInclude Include="..\..\include\EMeshBufferTypes.h" />
     <ClInclude Include="..\..\include\EReadFileType.h" />
+    <ClInclude Include="..\..\include\ESceneNodeUpdateAbs.h" />
     <ClInclude Include="..\..\include\EShaderTypes.h" />
     <ClInclude Include="..\..\include\fast_atof.h" />
     <ClInclude Include="..\..\include\IAnimatedMeshMD3.h" />

source/Irrlicht/Irrlicht10.0.vcxproj.filters

@@ -1441,6 +1441,9 @@
     <ClInclude Include="..\..\include\EMeshBufferTypes.h">
       <Filter>include\scene</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\include\ESceneNodeUpdateAbs.h">
+      <Filter>include\scene</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include="..\..\changes.txt">

tests/tests-last-passed-at.txt

@@ -1,4 +1,4 @@
 Tests finished. 72 tests of 72 passed.
 Compiled as DEBUG
-Test suite pass at GMT Sat Sep 24 13:51:42 2022
+Test suite pass at GMT Thu Sep 29 16:32:30 2022