4.18 How to render multiple materialized shapes in OpenGL?

In this example, we have used the following classes:

OpenGLObject

  OpenGLMateria

  OpenGLGeometry
   
    OpenGLSolidSphere

    OpenGLWireSphere

Please note that OpenGLGeometry class is based on geometry APIs of OpenGL GLUT, and furthermore it has a OpenGLMateria member variable to store material properties of the geometrical shape.




/*
 * MaterializedSpheresRotationByTimerThread.cpp 
 * Copyright (c) 2015 Antillia.com TOSHIYUKI ARAI. ALL RIGHTS RESERVED. 
 */


#include <sol/opengl/OpenGLMainView.h>
#include <sol/opengl/OpenGLView.h>
#include <sol/opengl/OpenGLGC.h>
#include <sol/opengl/OpenGLLight.h>
#include <sol/opengl/OpenGLMaterial.h>
#include <sol/opengl/OpenGLSolidSphere.h>
#include <sol/opengl/OpenGLWireSphere.h>
#include <sol/opengl/OpenGLTimerThread.h>
#include <sol/CriticalSection.h>

#include "resource.h"

namespace SOL {

class MainView :public OpenGLMainView {
private:
  //Inner class starts
  class SimpleView: public OpenGLView {
  private:
    static const int        SPHERES=4;
    SmartPtr<OpenGLGC>      gc;
    SmartPtr<OpenGLGeometry>  sphere[SPHERES];
    SmartPtr<OpenGLTimerThread>       timerThread;
    float                   angle;
    int                     renderingInterval;
    CriticalSection         criticalSection;
    
  public:
   virtual void display()
    {
      angle += 0.2f;
      criticalSection.enter();
      
      if (gc && sphere[0]) {
        gc -> clear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        gc -> loadIdentity();
        gc -> lookAt(4.0, 6.0, 10.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);

        gc -> clearColor(0.0, 0.0, 0.0, 1.0);
        gc -> enable(GL_CULL_FACE); 
        gc -> enable(GL_LIGHTING);

        OpenGLLight light(GL_LIGHT0);
        GLfloat lightPosition[] = {10, 10, 10, 1.0};  
        light.position(lightPosition);

        for (int i = 0; i<SPHERES; i++) {
          gc->pushMatrix();
          gc->rotate(angle, 0.0f, 1.0f, 0.0f);
          sphere[i]->draw(gc, -2.0f+1.3f*i, 0.5f,  0.0f+ 0.3f*i);
          gc->popMatrix();
        }
      }
      criticalSection.leave();
    }
  
    virtual void resize(int w, int h)
    {
      if (w == 0 || h == 0) {
          return;
      }
      if (gc) {
        gc -> matrixMode(GL_PROJECTION);
        gc -> loadIdentity();
        gc -> perspective(16.0, (double)w / (double)h, 0.5, 40.0); 

        gc -> matrixMode(GL_MODELVIEW);
      }
    }


    virtual void initialize()
    {
      gc = new OpenGLGC();
      
      Color4  black         = { 0.0, 0.0, 0.0, 1.0 };
      Color4  ambient       = { 0.5, 0.5, 0.5, 1.0 };
      Color4  diffuse       = { 0.2, 0.4, 0.8, 1.0 };
      Color4  specular      = { 1.0, 1.0, 1.0, 1.0 };
      Color4  emission      = { 0.8, 0.0, 0.0, 0.0 };
      GLfloat lowShining    = { 10.0 };
      GLfloat highShining   = {100.0 };

      OpenGLMateria mat1(GL_FRONT, ambient, diffuse, specular, emission, lowShining);
      OpenGLMateria mat2(GL_FRONT, black,   diffuse, specular, emission, lowShining);
      OpenGLMateria mat3(GL_FRONT, black,   diffuse, black,    emission, highShining);
      OpenGLMateria mat4(GL_FRONT, ambient, diffuse, specular, black,    highShining);
      OpenGLMateria materias[] = {mat1, mat2, mat3, mat4};
      for (int i = 0; i<SPHERES; i++) {
        if (i%2 ==0) {
          sphere[i] = new OpenGLWireSphere(materias[i], 0.5f,  40, 40);
        } else {
          sphere[i] = new OpenGLSolidSphere(materias[i], 0.5f,  40, 40);
        }
      }
      timerThread = new OpenGLTimerThread(this, renderingInterval);
      timerThread->start(); 
    }

  public:
    SimpleView(View* parent, const char* name, Args& args)
    :OpenGLView(parent, name, args),
    angle(2.0f),
    renderingInterval(20)
    {
    } 

    ~SimpleView()
    {
    }
  };
  //Inner class ends
  
private:
  SmartPtr<SimpleView>  view;

 long size(Event& event)
  {
    int width  = 0;
    int height = 0;
    event.getSize(width, height);
    if (view) {
      view -> reshape(0, 0, width, height);
      view -> postResizeRequest(width, height);
    }
    
    return 0L;
  }
  
public:
  MainView(Application& applet, const char* name, Args& args)
  :OpenGLMainView(applet, name, args)
  {
    Args ar;
    view = new SimpleView(this, "", ar);
  }
  
  ~MainView()
  {
  }
};

}

//
void Main(int argc, char** argv) 
{
  try {
    glutInit(&argc, argv);
    
    const char*  name = appName(argv[0]);
    Application applet(name, argc, argv);

    Args args;
    args.set(XmNwidth,  640);
    args.set(XmNheight, 480);
    MainView view(applet, name, args);
    view.realize();

    applet.run();
    
  } catch (Exception& ex) {
    caught(ex);
  }
}


Last modified: 25 Feb 2017

Copyright (c) 2017 Antillia.com ALL RIGHTS RESERVED.