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SYNOPSIS

#include <agar/core.h>
#include <freesg/sg.h>

DESCRIPTION

The SG object is a general-purpose scene-graph, or a collection of nodes (i.e., SG_Node(3) objects) organized in a tree structure. The SG_Node object is used to describe both "group" nodes and "leaf" nodes.

Scene-graphs are usually rendered using the SG_View(3) widget (or a subclass of it).

INHERITANCE HIERARCHY

AG_Object(3)-> SG.

INITIALIZATION

SG * SG_New (void *parent, const char *name, Uint flags)

void SG_Clear (SG *sg)

The SG_New() function allocates, initializes, and attaches a SG object. Acceptable flags options include:

SG_OVERLAY_WIREFRAME	Overlay wireframe onto geometric objects when rendering scene.
SG_OVERLAY_VERTICES	Overlay vertices onto geometric objects when rendering scene.
SG_OVERLAY_VNORMALS	Overlay vertex normals when rendering scene.
SG_OVERLAY_FNORMALS	Overlay facet normals when rendering scene.
SG_SKIP_UNKNOWN_NODES	When loading the contents of a scene, ignore unknown/unimplemented elements (otherwise, encountering an unknown node will make the load operation fail).
SG_NO_DEFAULT_NODES	Don't create the default nodes (e.g., Camera0, Light0).

The SG_Clear() routine reinitializes sg to an empty scene. If default nodes (e.g., Camera0) are used, they are preserved but their state is reinitialized.

NODE QUERIES

SG_Node * SG_SearchNodes (SG_Node *parent, const char *name)

void * SG_FindNode (SG *sg, const char *name)

int SG_Intersect (SG_Node *node, M_Geom3 g, M_GeomSet3 *S)

The SG_SearchNodes() function scans all descendants of parent for a node of the specified name. The SG_FindNode() function searches the entire scene graph sg for a node of the specified name. On success, SG_SearchNodes() and SG_FindNode() return a pointer to the matching node.

The SG_Intersect() function performs an intersection test between the given node and an arbitrary geometrical object g (see M_Geom3(3)). The function returns 1 if the objects intersect, 0 if they don't intersect, or -1 if the test is not implemented. If the S argument is non-NULL, the intersections are computed and returned as one or more geometrical objects, into S. The structure pointed to by S should have been previously initialized with M_GEOM_SET_EMPTY(3).

EXAMPLES

See demos/sgview in the FreeSG source distribution.

HISTORY

The SG object first appeared in FreeSG 1.0.