Index and Vertex Buffer Issue

/* Code to create the buffers and etc; Buffers can only hold 3 Quads of data before being "full" */

//Map flag at start
mappingFlag = D3D11_MAP_WRITE_NO_OVERWRITE;

void SystemBatcher::endBatch()
{
	//Lock the buffers for mapping
	batchContext->Map(vertexBuffer, 0, mappingFlag, 0, &mapVertexResource);
	batchContext->Map(indexBuffer, 0, mappingFlag, 0, &mapIndexResource);

	//For all the quads that need to be drawn place them in the buffer
	for(std::vector<Quad>::iterator i = drawData.begin(); i != drawData.end(); i++)
	{
		//If the buffer is full
		if(vertexBufferSize - drawDataAmount == 0)
		{
			//State the buffer is full
			std::cout<<"Vertex Buffer is full"<<std::endl;

			//Unlock the buffer
			batchContext->Unmap(indexBuffer, 0);
			batchContext->Unmap(vertexBuffer, 0);

			//Draw the quad data
			//indexDrawCount: number of indices to draw
			//indexOffset: The start location to use in the index buffer
			//drawnVertexCount: The start location to use in the Vertex Buffer
			batchContext->IASetPrimitiveTopology(D3D10_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
			batchContext->DrawIndexed(indexDrawCount, indexOffset, drawnVertexCount);

			//Change the flag to discard since we are fill; Reset the buffer positions
			//Reset the other counts
			mappingFlag = D3D11_MAP_WRITE_DISCARD;
			vertexBufferPosition = 0;
			indexBufferPosition = 0;
			indexDrawCount = 0;
			drawDataAmount = 0;

			//Reset the start location
			drawnVertexCount = 0;
			indexOffset = 0;

			//Re lock the buffers with the DISCARD Flag; Change th flag back to NO OVERWRITE
			batchContext->Map(vertexBuffer, 0, mappingFlag, 0, &mapVertexResource);
			batchContext->Map(indexBuffer, 0, mappingFlag, 0, &mapIndexResource);
			mappingFlag = D3D11_MAP_WRITE_NO_OVERWRITE;
		}

		//Copy the vertex buffer data in from the Quad
		memcpy((Vertex*)mapVertexResource.pData + vertexBufferPosition, (*i).vertices, sizeof((*i).vertices));

		//Calculate the index positions based on the vertex buffer
		((SHORT*)mapIndexResource.pData)[indexBufferPosition] = vertexBufferPosition;
		((SHORT*)mapIndexResource.pData)[indexBufferPosition + 1] = vertexBufferPosition + 1;
		((SHORT*)mapIndexResource.pData)[indexBufferPosition + 2] = vertexBufferPosition + 2;
		((SHORT*)mapIndexResource.pData)[indexBufferPosition + 3] = vertexBufferPosition + 3;
		((SHORT*)mapIndexResource.pData)[indexBufferPosition + 4] = vertexBufferPosition;
		((SHORT*)mapIndexResource.pData)[indexBufferPosition + 5] = vertexBufferPosition + 2;

		//Add on to the buffer positions
		vertexBufferPosition += 4;
		indexBufferPosition += 6;

		//Add onto the drawDataAmount we have (Used when calculating if the buffer is full);
		//Add onto the index count used when drawning
		drawDataAmount += 4 * vertexSize;
		indexDrawCount += 6;
	}

	//Unlock the buffers
	batchContext->Unmap(indexBuffer, 0);
	batchContext->Unmap(vertexBuffer, 0);

	//Draw the quad data
	//indexDrawCount: number of indices to draw
	//indexOffset: The start location to use in the index buffer
	//drawnVertexCount: The start location to use in the Vertex Buffer
	batchContext->IASetPrimitiveTopology(D3D10_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
	batchContext->DrawIndexed(indexDrawCount, indexOffset, drawnVertexCount);

	//Add onto the offsets used in the DrawIndexed calls
	drawnVertexCount += vertexBufferPosition;
	indexOffset += indexDrawCount;
	indexDrawCount = 0;

	//Clear out all of the drawData that was in the drawData vector
	drawData.clear();
}