XXX - Not complete yet!!!
Name
SGIX_complex_polar
Name Strings
GL_SGIX_complex_polar
Version
$Date: 1996/06/12 03:45:06 $ $Revision: 1.2 $
Number
??
Dependencies
SGIX_complex is required
Overview
This extension generates the magnitude and phase of a complex input
source. Computing the spectrum (magnitude) and the phase of a
fourier transform (a typical complex input source) is useful
for signal and image processing applications.
Issues
- this extension is somewhat of hack to work around the problem
of generating only 1 component from an input that has 2 components:
real and imaginary. This extension is really computing 2 operations
that, for generality, should be defined as atomic operations.
New Procedures and Functions
None
New Tokens
Accepted by the parameter of Enable, Disable, and IsEnabled, by the
parameter of GetBooleanv, GetIntegerv, GetFloatv, and GetDoublev:
COMPLEX_POLAR_EXT 0x????
Additions to Chapter 2 of the 1.0 Specification (OpenGL Operation)
None
Additions to Chapter 3 of the 1.0 Specification (Rasterization)
****On RedTail we'll be implementing this through texture LUTs. However,
the more natural fit would be to do it as a post blending operation.
Thus, I'm unclear as to what chapter this description will fall in:
The specification of generating the magnitude and phase of a fourier
signal is added to the GL Specification in section X.X.X. The resulting
fragment will be:
C_real' = SQRT((Cs_real * Cs_real) + (Cd_imaginary * Cd_imaginary))
C_imaginary' = arctan(Cs_real / Cs_imaginary)
where Cs_real and Cs_imaginary are the source fragment real and imaginary
subcomponents and C_real' and C_imaginary' are the result fragment
subcomponents.
In all cases the above equation is evaluated separately for each
color component.
Additions to Chapter 4 of the 1.0 Specification (Per-Fragment Operations
and the Frame Buffer)
None
Additions to Chapter 5 of the GL Specification (Special Functions)
None
Additions to Chapter 6 of the GL Specification (State and State Requests)
None
Additions to the GLX Specification
None
GLX Protocol
None
Errors
None
New State
Get Value Get Command Type Initial Value Attribute
--------- ----------- ---- ------------- ---------
COMPLEX_POLAR_EXT IsEnabled B False color-buffer
New Implementation Dependent State
None