OpenGLImageRenderer Class Reference

Base class for OpenGL image renderer. More...

#include <cvb/ui/opengl_image_renderer.hpp>

Inherits QOpenGLFunctions.

Public Member Functions
void	UpdateMaping (const QRectF &sourceRect, Size2D< int > textureSize) noexcept
	Updates the vertex and texture coordinates before rendering. More...
void	Render (const QRectF &viewportRect) noexcept
	Actually renders the image. More...
OpenGLBufferFormat	BufferFormat () const noexcept
	Returns the current buffer format. More...
virtual void *	BeginBufferAccess (int &linePad) noexcept=0
	Maps the pixel buffer to upload data. More...
virtual void	EndBufferAccess () noexcept=0
	End the pixel buffer mapping. More...
virtual void	UpdateBufferFormat (const OpenGLBufferFormat &bufferFormat) noexcept=0
	Updates the buffer format associated with the current rendering. More...
virtual bool	MonoUploadSupported () const noexcept=0
	Check if a mono image can be uploaded without duplicating the date in the color channels. More...

Detailed Description

Base class for OpenGL image renderer.

You dot need to use this class to render the image with CvbQtImageView. However this class is meant for convenient usage with a custom OpenGL context, in order to render the image to something different than CvbQtImageView. Please be aware that for all member function a QOpenGLContext must be current.

Note

The use of this class is an advanced topic and requires significant knowledge about Qt and OpenGL!

Member Function Documentation

BeginBufferAccess()

virtual void * BeginBufferAccess ( int &  linePad )

pure virtualnoexcept

Maps the pixel buffer to upload data.

Parameters

[out]

linePad

Line padding used by the current buffer format, for convenience.

Returns

Pointer to the buffer.

Exceptions

Does	not throw any exception.

BufferFormat()

OpenGLBufferFormat BufferFormat ( ) const

inlinenoexcept

Returns the current buffer format.

Returns

The buffer format associated with the current rendering.

Exceptions

Does	not throw any exception.

EndBufferAccess()

virtual void EndBufferAccess ( )

pure virtualnoexcept

End the pixel buffer mapping.

Exceptions

Does	not throw any exception.

MonoUploadSupported()

virtual bool MonoUploadSupported ( ) const

pure virtualnoexcept

Check if a mono image can be uploaded without duplicating the date in the color channels.

Returns

True if supported false otherwise.

Exceptions

Does	not throw any exception.

Render()

void Render ( const QRectF &  viewportRect )

inlinenoexcept

Actually renders the image.

Parameters

[in]

viewportRect

Visible rectangle of the image.

Exceptions

Does	not throw any exception.

This method does not reset the OpenGL state, and does not clear anything. Make sure you are in a suitable state for rendering a texture.

UpdateBufferFormat()

virtual void UpdateBufferFormat ( const OpenGLBufferFormat &  bufferFormat )

pure virtualnoexcept

Updates the buffer format associated with the current rendering.

Parameters

[in]

bufferFormat

The new buffer format.

Exceptions

Does	not throw any exception.

UpdateMaping()

void UpdateMaping ( const QRectF &  sourceRect, Size2D< int >  textureSize  )

inlinenoexcept

Updates the vertex and texture coordinates before rendering.

Parameters

[in]	sourceRect	Rectangle holding the vertex coordinates for the visible part of the texture.
[in]	textureSize	Pixel size of the texture to adjust the texture coordinates for e.g. sub pixel scrolling. This is only relevant if vertex coordinates have a fractional part.

Exceptions

Does	not throw any exception.