Methods on GraphicDevice

 

The most important methods on GraphicDevice are described at the beginning of section 9.2.

   

(GRAPHICDEVICE *) GRAPE(dev1, "copy")(dev2, name)

GRAPHICDEVICE *dev1, *dev2
char *name

This method copies the usual data (matrices etc.) of the graphic device dev1 to dev2 if this is an instance. If dev2 is a subclass (e.g. GraphicGt) of GraphicDevice a new instance of this class will be created with the pointer dev2. The named instance's return value is dev2.

               

(int *) GRAPE(dev, "grid-patch")()

(int *) GRAPE(dev, "global-grid-patch")()

(int *) GRAPE(dev, "set-grid-patch")(mode)

(int *) GRAPE(dev, "set-glbl-gr-ptch")(mode)

GRAPHICDEVICE *dev
int mode

Any graphic device has two different modes. If patches are display able they will be displayed shaded with normals at the vertices or displayed flat without normal information. Otherwise only wire frames are displayed.

The current mode is hold in the device instance variable grid_patch. The values are G_GRID for wire frames and G_PATCH for patch models. The variable grid_patch may be read. To change the mode use the method "grid-patch" which return value is the new mode. An unconditional setting of the mode is done by "set-grid-patch" and not by assignment at all.

If the global value global_grid_patch is set to G_GRID, "set-grid-patch" will not switch to another mode then G_GRID. This is because of the implementation of the GraphicDevice subclasses which have no hardware 3D support: they will work very much faster if no patches are drawn.

   

GRAPE(dev, "get-pick-pos")(pickx, picky, pickkey)

GRAPHICDEVICE *dev
double *pickx, *picky
int *pickkey

The coordinates of the current mouse position in the actual graphic device will be stored in *pickx and *picky in the range of -1.0 and 1.0. *pickkey holds the actual mouse or keyboard event. Unfortunately the values are coded in decimal. The codes are:

If the mouse does not point into the graphic window pickkey is set to zero, but pickx, picky have any values.

   

(LAYER *)GRAPE(dev, "create-config")()

GRAPHICDEVICE *dev

Create a Layer for editing device specific values.

If this method is supplied by a subclass of GraphicDevice, one can fine tune its settings.

   

GRAPE(dev, "show-lights")()

GRAPHICDEVICE *dev

Display balls and arrows for the lightsources. This method is used by the light menu option.

   

GRAPE(dev, "supported")(display)

GRAPHICDEVICE *dev
char *display

Returns non NULL if the display described by display supports this subclass of GraphicDevice. This does not work well with the class GraphicGt, which is the reason why users of this class have to supply environment strings for this purpose.