NAME

image_sharestorage - Setup two VIDs to use the same texture store.

SYNOPSIS

bool
image_sharestorage( vid:src, vid:dst )

DESCRIPTION

A vid contains a number of metadata states such as position and orientation, along with the idea of a 'storage' which is the textual, image or external source tied to the vid. As a means of preventing multiple views of the same storage, this function can be used to share the storage of vid as the storage of dst.

NOTES

1: Texture coordinates are initially copied over but are otherwise managed separately in each object.
2: WORLDID is a valid src argument, ( WORLDID as dst is undefined) but any surface that shares storage with WORLDID should not be part of a visible rendertarget.
3: Video image post processing (scale, flips and filtermode) are bound to the texture store and not to any- single object.
4: non-textured objects (null, color, instances and persistant) cannot bu used as src.
5: Sharing into a dst that is also used as the storage for a rendertarget will invalidate the state of the rendertarget and an explicit
rendertarget_forceupdate will be called.
6: There is no ordering imposed in rendertarget updates, which means that a store that is used as the destination for a rendertarget will need to have all dependent rendertargets manually updated in the preframe stage or the result of using vid that shares backing store with a rendertarget will be undefined.
7: persistent objects and instances cannot be used as dst.

EXAMPLE

function image_sharestorage0()
      a = load_image("test.png");
      b = null_surface(64, 64);
      move_image(b, 100, 100);
      show_image({a, b});
      image_sharestorage(a, b);
end

MISUSE

function image_sharestorage0()
      image_sharestorage(b, a);
end

MISUSE

function image_sharestorage1()
      persist_image(a);
      image_sharestorage(a, b);
end