The Set Projection function indicates to the WHIP! data reading application
what portion of the logical coordinate space is viewed.
Syntax
Opcode
format
Opcode
Operand
Format
Comments
Extended
ASCII
(Projection
[<ws>]<TProj>)
Selects
a view projection
Proj A description of how the selected view is projected
into the containing window.
Details
The Set Projection opcode specifies how the WHIP! data reading application
handles the case when the aspect ratio of the selected View does not equal
the aspect ratio of the window into which the view is projected. Legal
values for Proj include the following:
normal—The selected view is symmetrically scaled so that it completely
fits within the containing window without distortion. In the case that
the window’s aspect ratio is larger than the view’s aspect ratio, the view
is scaled such that, horizontally, it fits tightly within the containing
window. However, the view is scaled vertically such that a larger region
of the logical coordinate space is viewed than was requested. When the
window’s aspect ratio is less than the view’s aspect ratio, the view fits
tightly in the vertical direction, and an excess of logical space is viewed
horizontally (from what was requested).
stretch—The selected view is asymmetrically scaled so that it exactly
fills the containing window in both dimensions, and thus is distorted when
the aspect ratios differ (circles become ellipses).
chop—Similar to normal, however, the areas of excess logical
space are not rendered. This results in leaving a gap on two sides of the
containing window where no geometry is rendered.
Notes
WHIP! data reading applications may receive projection information from the
execution of URLs. In this case... (TBD—WORK-IN-PROGRESS).
Default
By default the projection attribute is set to "normal", which is the
equivalent of executing the following opcode: