Environments are objects that define
specific OpenGL
settings such
as the projection matrix and are also given a chance to draw in the
framebuffer before anything else for purposes of creating a specific
feel to the environment. Like most of the public classes provided
by Vision the Environment class is meant to be subclassed and have its
messages overridden. Its main main messages are outlined below:
-
(void) BoundsChange
This message is sent
if the
bounds of the viewport change. The
Environment object might want to modify its aspect ratio or alter other
data accordingly.
-
(void) Clear
This message is sent
every frame before any drawing occurs and by
default simply clears the current framebuffer.
-
(void) Projection
This message is also
sent
every
frame before drawing occurs but after
the - (void) Clear message and lets the Environment object have the
opportunity
set up the projection matrix.
-
(void) Camera
This message is also
sent
every
frame after the Projection message and
allows for any initial translations, rotations, scalings etc that are
to be performed on the modelview matrix.
-
(void) InverseCamera
This message does the
same
thing
as Camera except in the inverse.
-
(void) Draw
Called every frame
after
Camera
to give the Environment object first
dibs on drawing that frame so as to set an initial feel or environment
(things like drawing a skybox or background picture).
Environments are objects that define specific OpenGL settings such as the projection matrix and are also given a chance to draw in the framebuffer before anything else for purposes of creating a specific feel to the environment. Like most of the public classes provided by Vision the Environment class is meant to be subclassed and have its messages overridden. Its main main messages are outlined below: