#include <Inventor/engines/SoCalculator.h>
#include <Inventor/engines/SoElapsedTime.h>
#include <Inventor/nodekits/SoShapeKit.h>
#include <Inventor/nodes/SoMaterial.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoText3.h>
#include <Inventor/nodes/SoTransform.h>

#include <Inventor/Xt/SoXt.h>
#include <Inventor/Xt/viewers/SoXtExaminerViewer.h>

main(int , char **argv)
{
   Widget myWindow = SoXt::init(argv[0]);
   if (myWindow == NULL) exit(1);

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

   // Create shape kits with the words "HAPPY" and "NICE"
   SoShapeKit *happyKit = new SoShapeKit;
   root->addChild(happyKit);
   happyKit->setPart("shape", new SoText3);
   happyKit->set("shape { parts ALL string \"HAPPY\"}");
   happyKit->set("font { size 2}");

   SoShapeKit *niceKit = new SoShapeKit;
   root->addChild(niceKit);
   niceKit->setPart("shape", new SoText3);
   niceKit->set("shape { parts ALL string \"NICE\"}");
   niceKit->set("font { size 2}");

   // Create the Elapsed Time engine
   SoElapsedTime *myTimer = new SoElapsedTime;
   myTimer->ref();
  

#include <Inventor/SoDB.h>
#include <Inventor/SoInput.h>
#include <Inventor/nodekits/SoCameraKit.h>
#include <Inventor/nodekits/SoLightKit.h>
#include <Inventor/nodekits/SoSceneKit.h>
#include <Inventor/nodekits/SoWrapperKit.h>
#include <Inventor/nodes/SoMaterial.h>
#include <Inventor/nodes/SoPerspectiveCamera.h>
#include <Inventor/nodes/SoSeparator.h>

#include <Inventor/Xt/SoXt.h>
#include <Inventor/Xt/SoXtDirectionalLightEditor.h>
#include <Inventor/Xt/SoXtMaterialEditor.h>
#include <Inventor/Xt/SoXtRenderArea.h>
  

// This example illustrates the creation of motion hierarchies
// using nodekits by creating a model of a balance-style scale.

// It adds an SoEventCallback to the "callback" list in the 
// nodekit called 'support.'
// The callback will have the following response to events:
// Pressing right arrow key == lower the right pan
// Pressing left arrow key  == lower the left pan
// The pans are lowered by animating three rotations in the 
// motion hierarchy.
// Use an SoText2Kit to print instructions to the user as part
// of the scene.

#include <Inventor/events/SoKeyboardEvent.h>
#include <Inventor/nodekits/SoCameraKit.h>
#include <Inventor/nodekits/SoLightKit.h>
#include <Inventor/nodekits/SoSceneKit.h>
#include <Inventor/nodekits/SoShapeKit.h>
#include <Inventor/nodes/SoCone.h>
#include <Inventor/nodes/SoCube.h>
#include <Inventor/nodes/SoCylinder.h>
#include <Inventor/nodes/SoEventCallback.h>
#include <Inventor/nodes/SoText2.h>
#include <Inventor/nodes/SoTransform.h>
#include <Inventor/nodes/SoPerspectiveCamera.h>

#include <Inventor/Xt/SoXt.h>
#include <Inventor/Xt/SoXtRenderArea.h>

// Callback Function for Animating the Balance Scale.
// --used to make the balance tip back and forth
// --Note: this routine is only called in response to KeyPress
//   events since the call 'setEventInterest(KeyPressMask)' is
//   made on the SoEventCallback node that uses it.
// --The routine checks if the key pressed was left arrow (which
//   is XK_Left in X-windows talk), or right arrow (which is
//   XK_Right)
// --The balance is made to tip by rotating the beam part of the
//   scale (to tip it) and then compensating (making the strings
//   vertical again) by rotating the string parts in the opposite
//   direction.
void
tipTheBalance(
   void *userData, // The nodekit representing 'support', the
                   // fulcrum of the balance. Passed in during
                   // main routine, below. 
   SoEventCallback *eventCB)
{
   const SoEvent *ev = eventCB->getEvent();
   
   // Which Key was pressed?
   // If Right or Left Arrow key, then continue...
   if (SO_KEY_PRESS_EVENT(ev, RIGHT_ARROW) || 
        SO_KEY_PRESS_EVENT(ev, LEFT_ARROW)) {
      SoShapeKit  *support, *beam1, *string1, *string2;
      SbRotation  startRot, beamIncrement, stringIncrement;

      // Get the different nodekits from the userData.
      support = (SoShapeKit *) userData;

    // These three parts are extracted based on knowledge of
    // the motion hierarchy (see the diagram in the main
    // routine.
      beam1   = (SoShapeKit *)support->getPart("childList[0]",TRUE);
      string1 = (SoShapeKit *)  beam1->getPart("childList[0]",TRUE);
      string2 = (SoShapeKit *)  beam1->getPart("childList[1]",TRUE);

      //Set angular increments to be .1 Radians about the Z-Axis
      //The strings rotate opposite the beam, and the two types
      //of key press produce opposite effects.
      if (SO_KEY_PRESS_EVENT(ev, RIGHT_ARROW)) {
         beamIncrement.setValue(SbVec3f(0, 0, 1), -.1);
         stringIncrement.setValue(SbVec3f(0, 0, 1), .1);
      } 
      else {
         beamIncrement.setValue(SbVec3f(0, 0, 1), .1);
         stringIncrement.setValue(SbVec3f(0, 0, 1), -.1);
      }

      // Use SO_GET_PART to find the transform for each of the 
      // rotating parts and modify their rotations.

      SoTransform *xf;
      xf = SO_GET_PART(beam1, "transform", SoTransform);
      startRot = xf->rotation.getValue();
      xf->rotation.setValue(startRot *  beamIncrement);

      xf = SO_GET_PART(string1, "transform", SoTransform);
      startRot = xf->rotation.getValue();
      xf->rotation.setValue(startRot *  stringIncrement);

      xf = SO_GET_PART(string2, "transform", SoTransform);
      startRot = xf->rotation.getValue();
      xf->rotation.setValue(startRot *  stringIncrement);

      eventCB->setHandled();
   }
}

main(int , char **argv)
{
   Widget myWindow = SoXt::init(argv[0]);
   if (myWindow == NULL) exit(1);

   SoSceneKit *myScene = new SoSceneKit;
   myScene->ref();

   myScene->setPart("lightList[0]", new SoLightKit);
   myScene->setPart("cameraList[0]", new SoCameraKit);
   myScene->setCameraNumber(0);

   // Create the Balance Scale -- put each part in the 
   // childList of its parent, to build up this hierarchy:
   //
   //                    myScene
   //                       |
   //                     support
   //                       |
   //                     beam
   //                       |
   //                   --------
   //                   |       |
   //                string1  string2
   //                   |       |
   //                tray1     tray2

   SoShapeKit *support = new SoShapeKit();
   support->setPart("shape", new SoCone);
   support->set("shape { height 3 bottomRadius .3 }");
   myScene->setPart("childList[0]", support);

   SoShapeKit *beam = new SoShapeKit();
   beam->setPart("shape", new SoCube);
   beam->set("shape { width 3 height .2 depth .2 }");
   beam->set("transform { translation 0 1.5 0 } ");
   support->setPart("childList[0]", beam);

   SoShapeKit *string1 = new SoShapeKit;
   string1->setPart("shape", new SoCylinder);
   string1->set("shape { radius .05 height 2}");
   string1->set("transform { translation -1.5 -1 0 }");
   string1->set("transform { center 0 1 0 }");
   beam->setPart("childList[0]", string1);

   SoShapeKit *string2 = new SoShapeKit;
   string2->setPart("shape", new SoCylinder);
   string2->set("shape { radius .05 height 2}");
   string2->set("transform { translation 1.5 -1 0 } ");
   string2->set("transform { center 0 1 0 } ");
   beam->setPart("childList[1]", string2);

   SoShapeKit *tray1 = new SoShapeKit;
   tray1->setPart("shape", new SoCylinder);
   tray1->set("shape { radius .75 height .1 }");
   tray1->set("transform { translation 0 -1 0 } ");
   string1->setPart("childList[0]", tray1);

   SoShapeKit *tray2 = new SoShapeKit;
   tray2->setPart("shape", new SoCylinder);
   tray2->set("shape { radius .75 height .1 }");
   tray2->set("transform { translation 0 -1 0 } ");
   string2->setPart("childList[0]", tray2);

   // Add EventCallback so Balance Responds to Events
   SoEventCallback *myCallbackNode = new SoEventCallback;
   myCallbackNode->addEventCallback(
        SoKeyboardEvent::getClassTypeId(), 
            	tipTheBalance, support); 
   support->setPart("callbackList[0]", myCallbackNode);

   // Add Instructions as Text in the Scene...
   SoShapeKit *myText = new SoShapeKit;
   myText->setPart("shape", new SoText2);
   myText->set("shape { string \"Press Left or Right Arrow Key\" }");
   myText->set("shape { justification CENTER }");
   myText->set("font { name \"Helvetica-Bold\" }");
   myText->set("font { size 16.0 }");
   myText->set("transform { translation 0 -2 0 }");
   myScene->setPart("childList[1]", myText);

   SoXtRenderArea *myRenderArea = new SoXtRenderArea(myWindow);

   // Get camera from scene and tell it to viewAll...
   SbViewportRegion myRegion(myRenderArea->getSize());
   SoPerspectiveCamera *myCamera = SO_GET_PART(myScene,
      "cameraList[0].camera", SoPerspectiveCamera);
   myCamera->viewAll(myScene, myRegion);

   myRenderArea->setSceneGraph(myScene);
   myRenderArea->setTitle("Balance Scale Made of Nodekits");
   myRenderArea->show();

   SoXt::show(myWindow);
   SoXt::mainLoop();
}