--- name: "SbViewportRegion" section: "3" platform: "linux" package: "coin" version: "1:4.0.10-1" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/SbViewportRegion" --- # SbViewportRegion(3) The SbViewportRegion class is a viewport within a full window. ## NAME SbViewportRegion - The **SbViewportRegion** class is a viewport within a full window. ## SYNOPSIS \#include \ ### Public Member Functions **SbViewportRegion** (void)\ **SbViewportRegion** (short width, short height)\ **SbViewportRegion** (**SbVec2s** winSize)\ **SbViewportRegion** (const **SbViewportRegion** &vpReg)\ void **setWindowSize** (short width, short height)\ void **setWindowSize** (**SbVec2s** winSize)\ void **setViewport** (float left, float bottom, float width, float height)\ void **setViewport** (**SbVec2f** origin, **SbVec2f** size)\ void **setViewportPixels** (short left, short bottom, short width, short height)\ void **setViewportPixels** (**SbVec2s** origin, **SbVec2s** size)\ const **SbVec2s** & **getWindowSize** (void) const\ const **SbVec2f** & **getViewportOrigin** (void) const\ const **SbVec2s** & **getViewportOriginPixels** (void) const\ const **SbVec2f** & **getViewportSize** (void) const\ const **SbVec2s** & **getViewportSizePixels** (void) const\ float **getViewportAspectRatio** (void) const\ void **scaleWidth** (float ratio)\ void **scaleHeight** (float ratio)\ void **setPixelsPerInch** (float ppi)\ float **getPixelsPerInch** (void) const\ float **getPixelsPerPoint** (void) const\ void **print** (FILE \*file) const\ ## Detailed Description The **SbViewportRegion** class is a viewport within a full window. The **SbViewportRegion** class contains information to represent a subview within a window. It stores information about the origin and size of the subview, as well as the size of the underlying "full" window. Available methods include inquiries and manipulation in both normalized coordinates and pixel coordinates. Below is a small example showing how the viewport of a viewer class can be modified, within a "proper" Coin and window system context. Hit 'D' or 'U' to move the viewport region 40 pixels down or up, respectively. Click 'Esc' and zoom with left + middle mouse buttons, to see how the region is defined, where no 3D geometry will be visible outside it. Click 'Esc' again to use 'U' and 'D'. ``` // Copyright (C) by Kongsberg Oil & Gas Technologies. All rights reserved. #include #include #include #include #include #include // ************************************************************ static void keypresscbfunc(void * userdata, SoEventCallback * keyboardcb) { SoQtExaminerViewer * viewer = (SoQtExaminerViewer *)userdata; const SoEvent * event = keyboardcb->getEvent(); int shift = 0; if (SO_KEY_PRESS_EVENT(event, U)) { shift = 40; keyboardcb->setHandled(); } else if (SO_KEY_PRESS_EVENT(event, D)) { shift = -40; keyboardcb->setHandled(); } if (keyboardcb->isHandled()) { SbViewportRegion vpr = viewer->getViewportRegion(); SbVec2s size = vpr.getViewportSizePixels(); SbVec2s origin = vpr.getViewportOriginPixels(); origin[1] -= shift; vpr.setViewportPixels(origin, size); viewer->setViewportRegion(vpr); } } // ************************************************************ int main(int argc, char ** argv) { QWidget * window = SoQt::init(argv[0]); SoSeparator * root = new SoSeparator; root->ref(); root->addChild(new SoCone); SoQtExaminerViewer * viewer = new SoQtExaminerViewer(window); SoEventCallback * eventcb = new SoEventCallback; eventcb->addEventCallback(SoKeyboardEvent::getClassTypeId(), keypresscbfunc, viewer); root->insertChild(eventcb, 0); viewer->setViewing(FALSE); viewer->setDecoration(FALSE); viewer->setSceneGraph(root); viewer->show(); SoQt::show(window); SoQt::mainLoop(); delete viewer; root->unref(); return 0; } ``` **See also** **SbViewVolume** ## Constructor & Destructor Documentation ### SbViewportRegion::SbViewportRegion (void ) The default **SbViewportRegion** constructor initializes the viewport to fully cover a \[100, 100\] size window with 72 pixels per inch resolution. ### SbViewportRegion::SbViewportRegion (short width, short height) Construct and initialize an **SbViewportRegion** instance with the given pixel value window dimensions. The viewport within this window will be set to cover the window completely. ### SbViewportRegion::SbViewportRegion (SbVec2s winsizearg) Construct and initialize an **SbViewportRegion** instance with the given pixel value window dimensions. The viewport within this window will be set to cover the window completely. ### SbViewportRegion::SbViewportRegion (const SbViewportRegion & vpReg) Copy constructor. ## Member Function Documentation ### void SbViewportRegion::setWindowSize (short width, short height) Set the window size in pixels. The viewport rectangle dimensions will stay intact. **See also** **getWindowSize()** ### void SbViewportRegion::setWindowSize (SbVec2s winsizearg) This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. ### void SbViewportRegion::setViewport (float left, float bottom, float width, float height) Set up the origin and size of the viewport region in normalized coordinates. **See also** **getViewportOrigin()**, **getViewportSize()**, **setViewportPixels()**. ### void SbViewportRegion::setViewport (SbVec2f origin, SbVec2f size) This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. ### void SbViewportRegion::setViewportPixels (short left, short bottom, short width, short height) Set up the origin and size of the viewport region in pixel coordinates. **See also** **getViewportOriginPixels()**, **getViewportSizePixels()**, **setViewport()** ### void SbViewportRegion::setViewportPixels (SbVec2s origin, SbVec2s size) This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. ### const SbVec2s & SbViewportRegion::getWindowSize (void ) const Returns window dimensions (which are in absolute (i.e. pixel) coordinates). **See also** **setWindowSize()**. ### const SbVec2f & SbViewportRegion::getViewportOrigin (void ) const Return normalized viewport origin coordinates. **See also** **setViewport()**, **getViewportOriginPixels()**. ### const SbVec2s & SbViewportRegion::getViewportOriginPixels (void ) const Return viewport origin coordinates in pixel values. **See also** **setViewportPixels()**, **getViewportOrigin()**. ### const SbVec2f & SbViewportRegion::getViewportSize (void ) const Returns the normalized viewport size. **See also** **setViewport()**, **getViewportSizePixels()**. ### const SbVec2s & SbViewportRegion::getViewportSizePixels (void ) const Returns viewport size in pixel coordinates. **See also** **setViewportPixels()**, **getViewportSize()**. ### float SbViewportRegion::getViewportAspectRatio (void ) const Returns the aspect ratio of the viewport region. The aspect ratio is calculated as pixelwidth divided on pixelheight. ### void SbViewportRegion::scaleWidth (float ratio) Scale the width of the viewport region. The scale factor should not make the viewport larger than the window. If this happens, the viewport will be clamped. The scaling will be done around the viewport region center point, but if this causes the viewport origin to be moved below (0,0), the origin coordinates will be clamped. **See also** **scaleHeight()**. ### void SbViewportRegion::scaleHeight (float ratio) Scale the height of the viewport region. The scale factor should not make the viewport larger than the window. If this happens, the viewport will be clamped. The scaling will be done around the viewport region center point, but if this causes the viewport origin to be moved below (0,0), the origin coordinates will be clamped. **See also** **scaleWidth()**. ### void SbViewportRegion::setPixelsPerInch (float ppi) Set pixels per inch. Default value is 72. **See also** **getPixelsPerInch()**. ### float SbViewportRegion::getPixelsPerInch (void ) const Get pixels per inch. **See also** **setPixelsPerInch()**. ### float SbViewportRegion::getPixelsPerPoint (void ) const Get pixels per point. A *point* is defined as something you can put 72 of per inch... **See also** **setPixelsPerInch()**, **getPixelsPerInch()**. ### void SbViewportRegion::print (FILE \* fp) const Dump the state of this object to the *fp* file stream. Only works in debug version of library, method does nothing in an optimized build. ## Author Generated automatically by Doxygen for Coin from the source code.