Overview
- This extension allows an application to deterine what portion of the
+ This extension allows an application to determine what portion of the
swap period has elapsed since the last swap operation completed. The
"usage" value is a floating point value on the range [0,max] which is
calculated as follows:
is taken from the completion of one swap to the issuance of the next.
This representation may not be as useful as measuring between
completions, as a significant amount of time may pass between the
- issuance of a swap and the swap actually occuring.
+ issuance of a swap and the swap actually occurring.
There is also a mechanism to determine whether a frame swap was
missed.
Additions to the GLX 1.3 Specification
The frame usage is measured as the percentage of the swap period elapsed
- between two buffer-swap operations being commited. In unextened GLX the
+ between two buffer-swap operations being committed. In unextended GLX the
swap period is the vertical refresh time. If SGI_swap_control or
MESA_swap_control are supported, the swap period is the vertical refresh
time multiplied by the swap interval (or one if the swap interval is set
If OML_sync_control is supported, the swap period is the vertical
refresh time multiplied by the divisor parameter to
glXSwapBuffersMscOML. The frame usage in this case is less than 1.0 if
- the swap is commited before target_msc, and is greater than or equal to
+ the swap is committed before target_msc, and is greater than or equal to
1.0 otherwise. The actual usage value is based on the divisor and is
never less than 0.0.
The current missed frame count and total number of swaps since
the last call to glXBeginFrameTrackingMESA can be obtained by
- callling the following function:
+ calling the following function:
int glXQueryFrameTrackingMESA(Display *dpy,
GLXDrawable drawable,
float *lastMissedUsage)
The location pointed to by <swapCount> will be updated with the
- number of swaps that have been commited. This value may not match the
+ number of swaps that have been committed. This value may not match the
number of swaps that have been requested since swaps may be
queued by the implementation. This function can be called at any
time and does not synchronize to vertical blank.
application can call glXQueryFrameTrackingMESA for a final swap and
missed frame count.
- If these functions are succesful, zero is returned. If the context
+ If these functions are successful, zero is returned. If the context
associated with dpy and drawable is not a direct context,
GLX_BAD_CONTEXT is returned.