Added a method to VertexIndex to determine the size in bytes of an element in the index array

src/modules/graphics/opengl/VertexBuffer.cpp

@@ -253,6 +253,7 @@ VertexBuffer *VertexIndex::element_array = NULL;
 
 VertexIndex::VertexIndex(size_t size)
 	: size(size)
+	, elementSize(0)
 {
 	// The upper limit is the maximum of GLuint divided by six (the number
 	// of indices per size) and divided by the size of GLuint. This guarantees
@@ -287,6 +288,11 @@ GLenum VertexIndex::getType(size_t s) const
 	// if buffer-size > max(GLushort) then GL_UNSIGNED_INT else GL_UNSIGNED_SHORT
 }
 
+size_t VertexIndex::getElementSize()
+{
+	return elementSize;
+}
+
 VertexBuffer *VertexIndex::getVertexBuffer() const
 {
 	return element_array;
@@ -342,9 +348,12 @@ void VertexIndex::resize(size_t size)
 	}
 
 	VertexBuffer *new_element_array;
+	
 	// Depending on the size, a switch to int and more memory is needed.
 	GLenum target_type = getType(size);
-	size_t array_size = (target_type == GL_UNSIGNED_SHORT ? sizeof(GLushort) : sizeof(GLuint)) * 6 * size;
+	size_t elem_size = (target_type == GL_UNSIGNED_SHORT) ? sizeof(GLushort) : sizeof(GLuint);
+
+	size_t array_size = elem_size * 6 * size;
 
 	// Create may throw out-of-memory exceptions.
 	// VertexIndex will propagate the exception and keep the old VertexBuffer.
@@ -362,6 +371,7 @@ void VertexIndex::resize(size_t size)
 	delete element_array;
 	element_array = new_element_array;
 	maxSize = size;
+	elementSize = elem_size;
 
 	switch (target_type)
 	{

src/modules/graphics/opengl/VertexBuffer.h

@@ -331,10 +331,6 @@ private:
 	// Set if the buffer was modified while operating on gpu memory
 	// and needs to be synchronized.
 	bool is_dirty;
-
-	// Usage hint for map()/unmap() pair. Same as `access' parameter in
-	// glBufferData or 0 if not mapped.
-	GLenum mapped_access;
 };
 
 /**
@@ -409,6 +405,15 @@ public:
 		return getType(maxSize);
 	}
 
+	/**
+	 * Returns the size in bytes of an element in the element array.
+	 * Can be used with getPointer to calculate an offset into the array based
+	 * on a number of elements.
+	 *
+	 * @return The size of an element in bytes.
+	 **/
+	size_t getElementSize();
+
 	/**
 	 * Returns the pointer to the VertexBuffer.
 	 * The pointer will change if a new size request or removal causes
@@ -463,6 +468,9 @@ private:
 	// The size of the array requested by this instance.
 	size_t size;
 
+	// The size in bytes of an element in the element array.
+	size_t elementSize;
+
 	// The current VertexBuffer size. 0 means no VertexBuffer.
 	static size_t maxSize;
 	// The list of sizes. Needs to be kept sorted in ascending order.