% Psychtoolbox:PsychGLImageProcessing  -- OpenGL image processing functions.
%
% This subfolder contains subroutines, tests and demos on how to use
% the PTB built-in image processing pipeline.
%
% The built in pipeline provides the infrastructure to define image processing
% or stimulus image postprocessing operations on stimuli drawn by PTB's Screen
% 2D drawing commands or MOGL 3D OpenGL drawing commands.
%
% The pipeline provides the data flow and API to define type and parameterization
% of the image processing operations. Operations are usually implemented via
% OpenGL GLSL shader plugins, vertex & fragment shader programs written in the
% high level OpenGL Shading langugage GLSL and executed directly inside the
% graphics processing unit GPU. While this is the most efficient way, operations
% may also be defined in standard OpenGL code, Matlab M-Functions or C callable
% functions.
%
% Typical applications, realized via plugins are:
%
% * Stereo display algorithms.
% * High dynamic range display output drivers.
% * Standard operations like 2D convolution, noise, linear superposition.
% * Geometric undistortion of displays.
% * Per pixel output corrections like gamma, color, gain, display PDF.
%
% This part of PTB is under heavy construction. This intro will get extended
% soon with more useful infos...
%
%
% Files:
%
% Add2DConvolutionToGLOperator  - Create and add a shader for 2D image convolution to a GLOperator.
% Add2DSeparableConvolutionToGLOperator  - Create and add a shader for 2D separable image convolution to a GLOperator.
% AddImageUndistortionToGLOperator - Add geometric image correction to a GLOperator.
% AddToGLOperator               - Add a shader with options to a GLOperator.
% BitsPlusPlus                  - Setup function for imaging pipelines built-in Bits++ support.
% CountSlotsInGLOperator        - Count number of processing slots in a given GLOperator.
% CreateDisplayWarp             - Internal helper function for setup of geometric display undistortion.
% CreateGLOperator              - Create a new GLOperator as container for imaging operations.
% CreateProceduralColorGrating  - Create a procedural texture for fast drawing of either sinusoidal or square gratings varying between two colors.
% CreateProceduralGabor         - Create a procedural texture for fast drawing of Gabor patches.
% CreateProceduralNoise         - Create a procedural texture for fast drawing of random noise patches.
% CreateProceduralSineGrating   - Create a procedural texture for fast drawing of sine grating patches.
% CreateProceduralSmoothedApertureSineGrating - Create a procedural texture for fast drawing of smoothed aperture sine grating patches.
% CreateProceduralSmoothedDisc  - Create a procedural texture for fast drawing of smoothed edge discs.
% CreateProceduralSquareWaveGrating - Create a procedural texture for fast drawing of squarewave grating patches.
% CreatePseudoGrayLUT           - Create a lookup table for pseudogray conversion - Internal helper function.
% CreateResolutionPyramid       - Build a mip-map image resolution pyramid for given texture.
% CreateSinglePassImageProcessingShader - Create a single pass image processing shader for simple but common operations.
% DisplayUndistortionBezier     - Interactive geometric display calibration for simple needs.
% DisplayUndistortionBVL        - Interactive geometric display calibration. Recommended!
% DisplayUndistortionCSV        - Import ASCII data file with geometric display calibration for NVidia "Warp API".
% DisplayUndistortionHalfCylinder - Interactive geometric display calibration for half-cylinder or spherical projections.
% DisplayUndistortionLabRiggerMouseStim - Create display undistortion based on method from LabRigger for mouse visual stims.
% DisplayUndistortionSphere     - Interactive geometric display calibration for spherical projections.
% ImagingStereoDemo             - Counterpart to StereoDemo, but using imaging pipeline
%                                 for increased fidelity, flexibility, ease of use.
% MakeTextureDrawShader         - Create GLSL shader for use with Screen('DrawTexture') and Screen('MakeTexture')
%                                 to apply on-the-fly texture filtering operations during texture draw.
%
% PsychHDR                      - Support and control stimulus display to HDR "High dynamic range" displays.
%
% PsychImaging                  - Generic setup routine for the imaging pipeline. Allows to setup
%                                 and initialize the pipeline for many common tasks.
%
% PsychVideoSwitcher            - Setup routine for the Xiangru Li et al. "VideoSwitcher" video attenuator device.
%
% PsychVulkan                   - Interface with the Vulkan graphics and compute api for special purpose tasks.
%
% SetAnaglyphStereoParameters       - Function for runtime tuning of Anaglyph stereo parameters,
%                                     see ImagingStereoDemo for example of use.
% SetStereoBlueLineSyncParameters   - Change settings for drawing of stereo sync lines in frame-sequential stereo mode.
% SetStereoSideBySideParameters     - Change parameters for side-by-side stereo display modes (4 and 5).
% SetCompressedStereoSideBySideParameters - Change parameters for compressed side-by-side stereo display modes.
%
% VignetCalibration                 - Vignetted luminance calibration procedure for undistortion of distorted display luminance.
%
%
% Constants for use as 'flipFlags' with the imaging pipeline function
% Screen('HookFunction', windowPtr, 'SetOneshotFlipFlags' ..., flipFlags):
%
% kPsychDontAutoResetOneshotFlags   - Prevent "one-shot" flip flags from being automatically cleared after execution of the next Screen('Flip') operation.
% kPsychSkipSwapForFlipOnce         - Skip OpenGL double-buffer swap during execution of next Screen('Flip').
% kPsychSkipTimestampingForFlipOnce - Skip timestamping of OpenGL double-buffer swap stimulus onset after execution of next Screen('Flip').
% kPsychSkipVsyncForFlipOnce        - Do not synchronize next OpenGL buffer swap to vertical retrace during execution of next Screen('Flip').
% kPsychSkipWaitForFlipOnce         - Do not schedule OpenGL buffer swap for specific target time, leave it to some external method.
%
%
% Constants for imagingmode flag of Screen('OpenWindow', ...., imagingmode);
% One can 'or' them together, e.g., imagingmode = mor(kPsychNeed16BPCFixed, kPsychNeedFastBackingStore);
%
% kPsychNeed16BPCFixed          - Request 16 bit per color component, fixed point framebuffer.
% kPsychNeed16BPCFloat          - Request 16 bit per color component, floating point framebuffer.
% kPsychNeed32BPCFloat          - Request 32 bit per color component, floating point framebuffer.
% kPsychNeedDualPass            - Indicate that some of the used image processing plugins will need
%                                 at two render passes for processing.
% kPsychNeedFastBackingStore    - Enable minimal imaging pipeline. This flag is implied when using any
%                                 of the other flags.
% kPsychNeedFastOffscreenWindows - Only enable support for fast Offscreen windows, nothing else.
% kPsychNeedHalfWidthWindow     - Tell imaging pipe to create internal buffers half the real window width. Internal flag, not useful for end-user code.
% kPsychNeedHalfHeightWindow    - Tell imaging pipe to create internal buffers half the real window height. Internal flag, not useful for end-user code.
% kPsychNeedImageProcessing     - Request explicit support for image processing.
% kPsychNeedMultiPass           - Indicate that some of the used plugins will need more than two passes.
% kPsychNeedOutputConversion    - Indicate that display output is going to some special output device that
%                                 needs special output formatting, e.g., Bits++ or Brightside HDR.
% kPsychNeedTwiceWidthWindow    - Tell imaging pipe to create internal buffers twice the real window width. Internal flag, not useful for end-user code.
% kPsychNeedTripleWidthWindow   - Tell imaging pipe to create internal buffers triple the real window width. Internal flag, not useful for end-user code.
%
%
% Constants for specialflags of Screen('OpenWindow', ..., specialflags);
% One can 'or' them together:
%
% kPsychSkipSecondaryVsyncForFlip - Disable vsync for bufferswaps on secondary/slave windows.