Open Inventor练习-SoRayPickAction和SoMouseButtonEvent点选操作

SoRayPickAction是三维物体射线选择操作，SoPickedPoin用来存放选择的坐标，SoMouseButtonEvent用来鼠标操作信息处理。例子中获得鼠标点击物体的类型和坐标位置信息，在Console控制台窗口中输出。代码如下。

#define COIN_DLL  
#define SOWIN_DLL  
// 加载COIN库文件  
#ifdef _DEBUG  
#pragma comment(lib, "SoWin1d.lib")  
#pragma comment(lib, "Coin3d.lib")  
#else  
#pragma comment(lib, "SoWin1.lib")  
#pragma comment(lib, "Coin3.lib")  
#endif  
// 添加COIN头文件-Window操作显示库和节点库  
#include <Inventor/Win/viewers/SoWinExaminerViewer.h>
#include <Inventor/Win/SoWin.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoSphere.h>
#include <Inventor/nodes/SoMaterial.h>
#include <Inventor/nodes/SoEventCallback.h>
#include <Inventor/actions/SoRayPickAction.h>
#include <Inventor/events/SoMouseButtonEvent.h>
#include <Inventor/SoPickedPoint.h>

SoWinExaminerViewer *viewer = NULL;
SoSeparator *root = NULL;

void button_event_cb(void *userdata, SoEventCallback *node)
{
	const SoMouseButtonEvent *event = (SoMouseButtonEvent *)node->getEvent();
	SbVec2s pos = event->getPosition(viewer->getViewportRegion());
	if (event->getButton()==SoMouseButtonEvent::BUTTON1 &&
		event->getState()==SoButtonEvent::DOWN) 
	{
			SoRayPickAction pick(viewer->getViewportRegion());
			pick.setPoint(pos);
			pick.apply(viewer->getSceneManager()->getSceneGraph());
			SoPickedPoint *pp = pick.getPickedPoint();
			if (pp) 
			{
				const SoPath *path = pp->getPath();
				SbVec3f p = pp->getPoint();
				SoNode *node = path->getTail();
				printf("Picked shape: %s (%s), point: (%f %f %f)\n", 
					node->getName().getString(), 
					node->getTypeId().getName().getString(),
					p[0], p[1], p[2]);
			}
	}
}

int main (int argc, char ** argv)
{
	if (argc != 2) 
	{
		fprintf(stderr, "Usage: %s <file.iv>\n", argv[0]);
		exit(1);
	}

	// Initialize Coin & SoWin
	HWND win = SoWin::init(argv[0]);
	if (win == NULL) exit(1);

	// Read scene graph from file
	SoInput in;
	if (!in.openFile(argv[1])) 
	{
		fprintf(stderr, "Unable to open file \"%s\"\n",argv[1]);
		exit(1);
	}
	SoSeparator *fileroot = SoDB::readAll(&in);
	in.closeFile();

	root = new SoSeparator;
	root->ref();

	SoEventCallback *cb = new SoEventCallback;
	cb->addEventCallback(SoMouseButtonEvent::getClassTypeId(), button_event_cb, NULL);
	root->addChild(cb);
	root->addChild(fileroot);

	// Create the viewer
	viewer = new SoWinExaminerViewer(win);
	viewer->setSceneGraph(root);
	viewer->setTitle("picking example");
	viewer->setViewing(FALSE);
	viewer->setDecoration(FALSE);

	// Show the window
	viewer->show();
	SoWin::show(win);

	// Enter the application event loop
	SoWin::mainLoop();

	// Free scene graph memory
	root->unref();

	return 0;
}

iv文件如下：

#Inventor V2.1 ascii

# open this file using the "raypick" demo program

Separator {
  DEF A Separator {
    DEF D Translation {
      translation -5 -5 0
    }
    DEF E Material {
      diffuseColor 0 1 1
    }
    DEF E2 MaterialBinding {
      value PER_PART
    }
    DEF F Cube {
    }
  }
  DEF B SoSphere {
  }
  DEF C Separator {
    DEF G Translation {
      translation 5 0 0
    }
    DEF H Cylinder {
    }
  }
}

运行效果如下