simplified global - local transformation methods

fixed position bug when posing bones
initial IK method

skeleton.cpp

@@ -12,13 +12,56 @@ namespace vb01{
 	}
 
 	void Skeleton::update(){
-		/*
-		for(Bone *b : bones)
-			b->update();
-			*/
+		for(Bone *b : bones){
+			//b->update();
+			if(b->getIkTarget())
+				solveIk(b);
+		}
 		controller->update();
 	}
 
+	void Skeleton::solveIk(Bone *ikBone){
+		const int chainLength = ikBone->getIkChainLength();
+		Bone *ikTarget = ikBone->getIkTarget();
+		Bone *boneChain[chainLength];
+		Bone *ikBoneAncestor = ikBone;
+		Vector3 boneIkPos[chainLength], targetPos = ikTarget->getModelSpacePos();
+		float sumLengths = 0;
+
+		for(int i = 0; i < chainLength; i++){
+			sumLengths += ikBoneAncestor->getLength();
+			boneChain[i] = ikBoneAncestor;
+			ikBoneAncestor = (Bone*)ikBoneAncestor->getParent();
+			boneIkPos[i] = boneChain[i]->getModelSpacePos();
+		}
+
+		Vector3 startPos = boneChain[chainLength - 1]->getModelSpacePos();
+		if(startPos.getDistanceFrom(targetPos) < sumLengths){
+			int numIterations = 500;
+	
+			for(int i = 0 ; i < numIterations; i++){
+				bool backward = i % 2;
+				for(int j = 0; j < chainLength; j++){
+					int boneId = (backward ? j : chainLength - 1 - j);
+					Vector3 ikPos = (j == 0 ? (backward ? targetPos : startPos) : boneIkPos[boneId]);
+					Vector3 fromBoneToIkPos = ikPos - boneChain[boneId]->getModelSpacePos();
+					boneIkPos[boneId] = ikPos - fromBoneToIkPos * boneChain[boneId]->getLength();
+				}
+			}
+		}
+		/*
+		else{
+			Vector3 fromStartToTarget = targetPos - startPos;
+			for(int i = 0; i < chainLength; i++){
+			}
+		}
+		*/
+
+		Bone *rootBone = getRootBone();
+		for(int i = 0; i < chainLength; i++)
+			(boneChain[i])->lookAt(boneIkPos[i], rootBone->getParent());
+	}
+
 	void Skeleton::addBone(Bone *bone, Bone *parent){
 		if(parent)
 			parent->attachChild(bone);