HP SVA V2.0 Parallel Compositing Reference Guide

pcFrameBegin(3)
NAME
pcFrameBegin -- Begins a new frame.
Synopsis
PCerr pcFrameBegin(
PCcontext ctx,
PCid* frameId,
PCuint numFramelets,
PCuint* xOffset,
PCuint* yOffset,
PCuint* width,
PCuint* height,
PCuint* order
);
Parameters
ctx
The context for this frame.
frameId
A unique ID generated by the Library for this frame. This ID is used on
subsequent calls to the Library to identify the call as being for this frame.
numFramelets
The number of framelets that are generated by this host for this frame.
xOffset
An array giving the horizontal offsets of each framelet within the frame.
yOffset
An array giving the vertical offsets of each framelet within the frame.
width
An array giving the width of each framelet within the frame.
height
An array giving the height of each framelet within the frame.
order
An array giving the order of each framelet within the frame.
Returns
On successful completion, this function returns a frame ID number in the frameId parameter.
It also returns PC_NO_ERROR on successful completion.
Description
Use this function to begin compositing for a frame. It corresponds to the Begin the frame Step in
Table 1-2 (page 15) of the Parallel Compositing Reference Guide. It must be called by all host members
of the context specified by the ctx parameter.
Each host may provide 0 or more pixel contributions to the frame. Each of these contributions
is called a framelet and has the following properties:
The x offset of the origin of the framelet within the frame.
xOffset
The y offset of the origin of the framelet within the frame.
yOffset
The width of the framelet in pixels.
width
The height of the framelet in pixels.
height
Implicitly given by the PC_PIXEL_FORMAT context
property.
pixel format
This property specifies the order with respect to other
framelets. This is useful because some types of
compositing (notably alpha blending) have an ordering
among the framelets being composited.
order
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