mvView(3dm)mvView(3dm)NAME
mvSetViewOffset, mvGetViewOffset, mvQueryViewOffset, mvSetViewSize,
mvGetViewSize, mvQueryViewSize, mvSetViewOffsetAndSize,
mvGetViewKeepAspect - Change the location and size of the region for
movie display inside a GL window
SYNOPSIS
#include <dmedia/moviefile.h>
#include <dmedia/movieplay.h>
void mvSetViewOffset(MVid movieid, int offsetx, int offsety,
DMboolean glcoordsystem);
void mvGetViewOffset(MVid movieid, int *offsetxreturn,
int *offsetyreturn, DMboolean glcoordsystem);
void mvQueryViewOffset(MVid movieid, int offsetx, int offsety,
int *offsetxreturn, int *offsetyreturn,
DMboolean glcoordsystem);
void mvSetViewSize(MVid movieid, int newwidth, int newheight,
DMboolean keepAspect);
void mvGetViewSize(MVid movieid, int *widthreturn, int *heightreturn);
void mvQueryViewSize(MVid movieid, int width, int height,
DMboolean unused, int *widthreturn,
int *heightreturn);
void mvSetViewOffsetAndSize(MVid movieid, int offsetx, int offsety,
int newwidth, int newheight,
DMboolean glcoordsystem);
DMboolean mvGetViewKeepAspect(MVid movieid);
DESCRIPTIONmSetViewOffset(3dm) sets the offset for the view for rendering movie
frames in an OpenGL window, relative to the origin of the window.
You use the glcoordsystem parameter to determine the screen coordinate
system for the y offset. If glcoordsystem is DM_TRUE, Movie Playback
Library assumes the OpenGL screen coordinate system with (0, 0) in lower
left. If it is DM_FALSE, Movie Library assumes the X coordinate system
with (0, 0) in upper left.
mvQueryViewOffset(3dm) returns the actual offset for the movie view for a
given set of parameters to mvSetViewOffset(3dm). Because the size of the
movie frame may not match the size of the view you specify (see
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mvView(3dm)mvView(3dm)mvSetViewSize(3dm) below), the actual origin of the movie frame may be
different than what you specify. The Movie Library automatically centers
the movie frame inside the view.
mvGetViewOffset(3dm) will return the current origin of the movie frame,
unless it is different from the value you specified with
mvSetViewOffset(3dm). In that case, it returns the last offset you
specified. Thus, any portion of your application code can inspect both
the requested origin (via mvGetViewOffset(3dm)) and the actual origin
(via mvQueryViewOffset(3dm)).
The default offset is (0, 0) in the OpenGL coordinate system.
mvSetViewSize(3dm) sets the size of the Movie Library view for rendering
movie frames in a window. The Movie Library will zoom the movie
rectangle as large as possible to fit within the specified size. (The
IRIS GL version only supports zooming by integer multiples, whereas
OpenGL supports arbitrary pixel zooming.) The Movie Playback Library will
preserve the aspect ratio of the movie frame and center the movie
rectangle within the viewport.
Because various members of the Silicon Graphics product family have
differing hardware image manipulation capabilities, the same values
provided to mvSetViewSize(3dm) may produce different results when your
code runs on various machines. The actual movie view size may not be
identical to the size you specify. To determine what the actual movie
frame size will be for a desired width and height, use
mvQueryViewSize(3dm).
The Movie Library centers the movie frames in the view you specify. It
also fills the areas within the view which are not part of the movie
frame with background color. To specify the background color, use
mvSetViewBackground(3dm).
If the movie will appear by itself in the window, and not along with
other graphics, you may want to ensure that your code chooses the proper
window size by calling mvQueryViewSize(3dm). You may use the results to
constrain the dimensions of the window to match those of the movie.
Alternatively, you can simply choose a background color for the unused
portions of the display with mvSetViewBackground(3dm).
If the movie will appear in a OpenGL/X window along with other graphic
elements (i.e. a movie embedded in a larger display), you may wish to set
your view size carefully by first calling mvQueryViewSize(3dm) and using
the results as inputs to mvSetViewSize(3dm). This will ensure that the
Movie Library draws on the display only over regions the movie frame
actually appears.
mvGetViewSize(3dm) returns the size of the movie frame, unless it differs
from the value you specified with mvSetViewSize(3dm). In that case, it
returns the last size you specified. Thus, any portion of your
application code can inspect both the requested size (via
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mvView(3dm)mvView(3dm)mvGetViewSize(3dm)) and the actual frame size (via mvQueryViewSize(3dm)).
mvGetViewKeepAspect(3dm) returns the flag set with mvGetViewSize(3dm).
The default view size is the width and height of the movie bounding rect.
mvQueryViewSize(3dm) returns the actual size the movie will actually
choose for the size of the playback view, given a set of view dimensions.
mvSetViewOffsetAndSize(3dm) sets the view offset and size atomically. You
can use this call in place of a pair of calls to mvSetViewOffset(3dm) and
You may call these functions for a specified movie instance regardless of
whether or not the movie is playing. mvSetViewSize(3dm) to avoid an
unnecessary redraw.
You may only call these functions for a specified movie while it is bound
to a window (see mvBindOpenGLWindow(3dm)).
NOTES
The current implementation on all platforms guarentees that the actual
view size requested by mvSetViewSize(3dm) will be maintained.
Previous versions of mvSetViewSize(3dm) ignored the keepAspect flag and
always assumed it was DM_TRUE. This behavior can be enabled by setting
MV_IGNORE_KEEPASPECT in the environment.
SEE ALSOmvBindOpenGLWindow(3dm), mvIntro(3dm), mvSetViewBackground(3dm),
mvGetViewBackground(3dm), mvMovieRect(3dm).
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