Cloned Texture not displayed with Linked List

Dissipate · 2013-01-29T00:25:57

I have a clone function that succesfully clones the vertex and index buffers of a square with a texture. It displays it correctly. The linked list uses nodes with pData of type VOID that is statically cast to a CSprTex. The CSprTexdisplays and updates correctly but the texture is not displayed and I dont know why. class CNode { public: CNode(void); ~CNode(void); UINT m_uNodeType; // Leaf or non leaf-(head or end) VOID* pData; // Can be cast to any class type eg CSprite* CNode* pNext; // Pointer to the next object CNode* pPrev; // Pointer to the previous object private: };// CNode CLinked list's Add Node function: void CLinkedList::AddNode(VOID* pData) { g_FileDebug->Write("Add a Node\n"); CNode* pNewNode = new CNode; // Create the Node pNewNode->pData = pData; // Assign the Sprite data pNewNode->m_uNodeType = CNODE_NODE; ...// insert behind Node End m_iNumberOfNodes++; // Keep track of how many nodes there are g_FileDebug->WriteEx("Number of nodes = ", m_iNumberOfNodes); }// AddNode And this is how I draw it. with a loop that accesses the nodes. CNode* pCurrentNode = m_LLFaces.m_HeadNode.pNext; // Point to first in list while (pCurrentNode != &m_LLFaces.m_EndNode) { CSprTex* pSprCurrent = static_cast<CSprTex*>(pCurrentNode->pData); // Void to CSprite if (pSprCurrent != NULL) { pSprCurrent->Orbit(index, 0.0f, index); pSprCurrent->Rotate(m_fRotateXClone, m_fRotateY, m_fRotateZ); pSprCurrent->SetTransformTransByRotXYZ(); pSprCurrent->SelectBuffers(); pSprCurrent->Draw(); } pCurrentNode = pCurrentNode->pNext; // Go to next in the list }// end while*> This is the cloning function: int CSpriteManager::Clone(CSprTex* pSource, CSprTex* pDest) { // vertex and index buffers pDest->SetVertexBuffer(pSource->GetVertexBuffer()); pDest->SetIndexBuffer(pSource->GetIndexBuffer()); //pDest->m_pVertexBuffer = pSource->m_pVertexBuffer; //pDest->m_pIndexBuffer = pSource->m_pIndexBuffer; // number of verticies and indicies and primitive count pDest->m_iNumOfVertices = pSource->m_iNumOfVertices; pDest->m_iNumOfIndicies = pSource->m_iNumOfIndicies; pDest->m_iPrimCount = pSource->m_iPrimCount; // rotational and translational matricies pDest->m_matRotateX = pSource->m_matRotateX; pDest->m_matRotateY = pSource->m_matRotateY; pDest->m_matRotateZ = pSource->m_matRotateZ; pDest->m_matTranslate = pSource->m_matTranslate; return (1); }// Clone (overloaded) So why doesn't the texture display? The square does display though and I can move (any number of them) independantly of the master. Cloning an object outside of the Linked list structure displays the texture fine. What am I missing?

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Started by Dissipate January 21, 2013 11:48 PM

29 comments, last by Dissipate 11 years, 2 months ago

Dissipate

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January 29, 2013 12:25 AM

Posted 24 January 2013 - 05:49 PM

DeleteAllNodes definitely contains a bug, it fails to clear the "head" and "tail" pointers. CNode calls "delete" on a VOID pointer, which is undefined. You should use templates to maintain type safety. The destructor does not deallocate memory.
The lack of copy constructors and assignment operators on the two classes is also problematic. You need to obey the rule of three, or "disable" copying and assignment by declaring the copy constructor and assignment operator as private, and not implementing them.
I don't see any other major bugs, but due to the unencapsulated implementation every single client access needs to be perfectly correct or it could corrupt the loop.
There are a few minor issues too:
(m_uNodeType != CNODE_HEAD) || (m_uNodeType != CNODE_END) is a tautology. Consider, if X is any number, then (X != 1) || (x != 2) is true.
You don't need to check a pointer is NULL before calling delete - delete does the right thing with null pointers and you are duplicating those checks.
You don't need to have two value nodes in the linked list. Most implementations just have a pair of pointers to nodes. Using such "sentinel" nodes isn't necessarily a bad thing, it is a valid implementation strategy, but you should not force client code to reason about this.
You don't need the "node type" concept. Just have the head and tail contain NULL data pointers.
Don't depend on Windows.h: just use void * rather than VOID * if it was necessary
Use an enum rather than #defines for something like "node type", if it was necessary
Main.h is almost always a poor idea.
In general, strive for as few dependencies as possible, particularly for something generic like a linked list. Avoid coupling this implementation to the rest of your project

I have made all the changes you suggested, making a Circular, templated, doubley linked list and applying the rule of three. Implementing this into my project and utilising it does not solve the problem (I'll research dynamic arrays later!). Please can you help me understand whats happening as I can't continue otherwise. Maybe someone can post a short excerpt/code-list on how to clone and draw a textured quad. My D3DXSprite clones fine.
(hoping...!)

Cloned Texture not displayed with Linked List

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