NAME

SG_Image — Agar-SG polygonal 2D image object

SYNOPSIS

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

DESCRIPTION

The SG_Image node maps an input image onto a polygonal mesh. If transparency information is available, SG_Image generates a complex polygon contour for the image.

INHERITANCE HIERARCHY

AG_Object(3) -> SG_Node(3) -> SG_Image.

INITIALIZATION

SG_Image *
SG_ImageNew(SG_Node *parent, const char *name);

SG_Image *
SG_ImageFromSurface(SG_Node *parent, const char *name, AG_Surface *s);

SG_Image *
SG_ImageFromSurfaceNODUP(SG_Node *parent, const char *name, AG_Surface *s);

SG_Image *
SG_ImageFromAnim(SG_Node *parent, const char *name, const AG_Anim *anim);

SG_Image *
SG_ImageFromAnimNODUP(SG_Node *parent, const char *name, AG_Anim *anim);

void
SG_ImageSetSurface(SG_Image *bb, const AG_Surface *s, M_Real scale);

void
SG_ImageSetSurfaceNODUP(SG_Image *bb, AG_Surface *s);

int
SG_ImageSetAnim(SG_Image *bb, AG_Anim *anim);

int
SG_ImageSetAnimNODUP(SG_Image *bb, AG_Anim *anim);

void
SG_ImageAnimPlay(SG_Image *bb);

void
SG_ImageAnimStop(SG_Image *bb);

void
SG_ImageSetShape(SG_Image *bb, enum sg_image_shape shape);

void
SG_ImageSetShapeAuto(SG_Image *bb);

void
SG_ImageSetProj(SG_Image *bb, int enable);

void
SG_ImageSetTolContour(SG_Image *bb, float tol);

void
SG_ImageSetSize(SG_Image *bb, M_Real w, M_Real h);

void
SG_ImageSetColor(SG_Image *bb, const AG_Color *c);

The SG_ImageNew() function creates a new image node at the origin of the parent node. The SG_ImageFromSurface() and SG_ImageFromAnim() variants set an initial surface or animation.

The SG_ImageSetSurface() function loads the specified surface. Image pixels are related to SG(3) node coordinates by the scaling factor scale.

The SG_ImageSetAnim() function loads the specified animation (see AG_Anim(3)). Playback can be initiated or stopped with SG_ImageAnimPlay() and SG_ImageAnimStop().

SG_ImageSetShape() selects the contour shape for the image object. Possible values for shape include:

SG_IMAGE_RECT

Render as solid rectangle.

SG_IMAGE_POLYGON

Render as a complex polygon calculated from the contours of the image. The contour of the polygon is reduced to a manageable set of vertices using Douglas-Peucker polygon simplification.

The SG_ImageSetShapeAuto() function scans the image and selects SG_IMAGE_POLYGON if a usable shape exists over a transparent background, otherwise the SG_IMAGE_RECT shape is selected.

SG_ImageSetProj() configures the image projection mode. If an argument of 1 is given, the image object will be rendered as to always face the camera. Otherwise, the object is rendered as a textured plane in its original orientation (the default).

SG_ImageSetTolContour() sets the tolerance for Douglas-Peucker simplification (default is 10.0).

SG_ImageSetSize() sets the relative size of the image (default is 1.0 x 1.0).

SG_ImageSetColor() sets the background color (RGBA) of the image object (default is transparent black).

FLAGS

The following public SG_Image flags are defined:

SG_IMAGE_BILLBOARD

Enable billboard projection (image will be rendered as facing the camera).

SG_IMAGE_WIREFRAME

Overlay the wireframe structure ontop of the image surface. This can be useful when adjusting the contour tolerance.

STRUCTURE DATA

For the SG_Image object:

Uint flags

Option flags (see “FLAGS” section).

M_Color color

Background color.

AG_Surface *su

Current source surface (read-only; use

M_Real w

Width (default is 1.0).

M_Real h

Height (default is 1.0).

float tolContour

Tolerance for polygon simplification (default is 10.0).

SEE ALSO

AG_Surface(3), M_Color(3), M_Real(3), M_Vector(3), SG(3), SG_Intro(3), SG_Node(3), SG_Plane(3)

HISTORY

The SG_Image node class first appeared in Agar 1.6.0.