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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 <cap> parameter of Enable, Disable, and IsEnabled, by the
<pname> 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