DrawMolecule

Files:	DrawMolecule.h, DrawMolecule.C
Derived from:	\bf BaseMolecule, \bf Displayable
Global instance (if any):	none
Used in optional component:	Part of main VMD code

Description

DrawMolecule is derived from BaseMolecule, and is the next level in the Molecule class hierarchy. It embodies the level of control and functionality responsible for creating a graphical image of the molecule. It is derived from Displayable (actually, from Displayable3D), and so will be part of the Scene that will be drawn by a DisplayDevice.

Each DrawMolecule keeps a list of DrawMolItem objects; each DrawMolItem is also a Displayable, and is responsible for a single representation of the molecule. Each representation contains a display list used to draw a single view of the molecule. To define a single representation, each DrawMolItem contains one instance each of the following objects:

• AtomColor - defines how to color each atom in the representation.
• AtomRep - defines what shape to draw the components of the representation.
• AtomSel - determines which atoms out of all the ones in the molecule are to be drawn in that representation.

When a new DrawMolecule is created (i.e. when a new Molecule is created), it is added as a child Displayable to a global MoleculeList object. Thus, you can rotate just the MoleculeList, and this will rotate all the molecules at the same time. When a molecule is first displayed, it is scaled and translated to fit within a -1 ... 1 size box centered around the origin. In order to have all the molecules be the proper size in relation to each other, and to preserve the spatial position of the molecules, only one molecule is used to determine the scaling and translation positions, and the others then use those same scaling and translation values.

Each DrawMolItem added to this object are added as child Displayable objects of DrawMolecule, and so scaling and rotating the molecule will do so to all the DrawMolItem objects at the same time.

Constructors

• DrawMolecule::DrawMolecule(Scene *)
  Specifies the Scene to which to add this object. Should only be used if no MoleculeList is being used.

• DrawMolecule::DrawMolecule(Displayable *)
  Specified a parent Displayable to which to add this object as a child. This is the main form used in VMD, as all Molecule objects are added to a global MoleculeList.

Internal data structures

• int active - is this molecule an active one? This is used by MoleculeList.

• int needRedraw - a flag indicating whether this item needs to reconstruct its display list during the prepare routine. After the display list is remade, this flag is cleared.

• ResizeArray<DrawMolItem *> repList - the list of representations.

Nonvirtual member functions

• int atom_displayed(int) - returns TRUE if any of the representations are currently displaying the given atom.

• int components(void) - returns the number of representations in the molecule.

• DrawMolItem *component(int) - return a pointer to the Nth representation.

• int del_rep(int) - delete the Nth representation, and return the success.

Virtual member functions

• virtual void set_name(char *) - used to change or set the name of the molecule. Called during the create phase of molecule construction.

• virtual void create_cmdlist(void) - regenerates the display list, which contains the list of primitive drawing commands necessary to draw the object.

• virtual int create(void) - the version of create for DrawMolecule ... this is called by derived classes after they have read in and initialized the molecule. The DrawMolecule version of create will then call the BaseMolecule's create routine, and finally then construct the initial version of the display list.

• virtual void prepare(DisplayDevice *) - provided since this is a Displayable object. This determines if the display list needs to be reconstructed, and if so it does the reconstruction.

• virtual int add_rep(AtomColor *, AtomRep *, AtomSel *) - requests for a new representation to be made, using the given objects to describe what the representation should be. Returns success.

• virtual int change_rep(int, AtomColor *, AtomRep *, AtomSel *) - changes the Nth representation to use the new settings specified in the given objects.

Method of use

The user should never create a DrawMolecule directly; it should instead be used as a base class for Molecule.