Open Inventor显示区域SbViewportRegion-优快云博客

本文介绍了一个使用C++实现的键盘事件处理代理函数，通过将按键操作映射到视图区域的平移，展示了如何在Inventor框架中响应用户输入并调整视图位置。

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#include <Inventor/Win/SoWin.h> #include <Inventor/Win/viewers/SoWinExaminerViewer.h> #include <Inventor/nodes/SoEventCallback.h> #include <Inventor/nodes/SoSeparator.h> #include <Inventor/nodes/SoCone.h> #include <Inventor/events/SoKeyboardEvent.h> // ************************************************************ static void keypresscbfunc(void * userdata, SoEventCallback * keyboardcb) { SoWinExaminerViewer * viewer = (SoWinExaminerViewer *)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) { HWND window = SoWin::init(argv[0]); SoSeparator * root = new SoSeparator; root->ref(); root->addChild(new SoCone); SoWinExaminerViewer * viewer = new SoWinExaminerViewer(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(); SoWin::show(window); SoWin::mainLoop(); delete viewer; root->unref(); return 0; }