+ * Compute the index of the last array element that can be safely accessed
+ * in a vertex array. We can really only do this when the array lives in
+ * a VBO.
+ * The array->_MaxElement field will be updated.
+ * Later in glDrawArrays/Elements/etc we can do some bounds checking.
+ */
+static void
+compute_max_element(struct gl_client_array *array)
+{
+ assert(array->Enabled);
+ if (array->BufferObj->Name) {
+ GLsizeiptrARB offset = (GLsizeiptrARB) array->Ptr;
+ GLsizeiptrARB obj_size = (GLsizeiptrARB) array->BufferObj->Size;
+
+ if (offset < obj_size) {
+ array->_MaxElement = (obj_size - offset +
+ array->StrideB -
+ array->_ElementSize) / array->StrideB;
+ } else {
+ array->_MaxElement = 0;
+ }
+ /* Compute the max element we can access in the VBO without going
+ * out of bounds.
+ */
+ array->_MaxElement = ((GLsizeiptrARB) array->BufferObj->Size
+ - (GLsizeiptrARB) array->Ptr + array->StrideB
+ - array->_ElementSize) / array->StrideB;
+ }
+ else {
+ /* user-space array, no idea how big it is */
+ array->_MaxElement = 2 * 1000 * 1000 * 1000; /* just a big number */
+ }
+}
+
+
+/**
+ * Helper for update_arrays().
+ * \return min(current min, array->_MaxElement).
+ */
+static GLuint
+update_min(GLuint min, struct gl_client_array *array)
+{
+ compute_max_element(array);
+ return MIN2(min, array->_MaxElement);
+}
+
+
+/**
+ * Update ctx->Array._MaxElement (the max legal index into all enabled arrays).
+ * Need to do this upon new array state or new buffer object state.