JOGLでピラミッドを描画する

JOGLでピラミッドを描画するには、以下のコードを実行します。

import java.io.*;
import javax.media.opengl.*;
import com.sun.opengl.util.*;

public class JoglSample56
{
   // 出力画像サイズ
   private static int width = 300;
   private static int height = 300;

   public static void main(String args[])
       throws IOException
   {
       GLDrawableFactory gldf =
           GLDrawableFactory.getFactory();
       GLCapabilities glc = new GLCapabilities();
       glc.setDoubleBuffered(false);
       GLPbuffer buf = gldf.createGLPbuffer(
          glc, null, width, height, null);

       buf.addGLEventListener(
           new GLEventListener(){
           // 初期化
           public void init(GLAutoDrawable dr)
           {
               GL gl = dr.getGL();
               // 背景色
               gl.glClearColor(
                   (float)0xf0/(float)0xf0,
                   (float)0xf0/(float)0xf0,
                   (float)0xf0/(float)0xf0,
                   1f);

           }

           public void display(GLAutoDrawable dr)
           {
               GL gl = dr.getGL();
               gl.glViewport(0, 0, width, height);

               // 透視投影
               gl.glMatrixMode(GL.GL_PROJECTION);
               gl.glLoadIdentity();
               float ratio = (float)height/(float)width;
               gl.glFrustum(-1.0f, 1.0f, -ratio, ratio,
                   5.0f, 40.0f);

               gl.glMatrixMode(GL.GL_MODELVIEW);
               gl.glLoadIdentity();
               gl.glTranslatef(0.0f, -1.0f, -12.0f);

               gl.glEnable(GL.GL_LIGHTING);
               gl.glEnable(GL.GL_LIGHT0);
               gl.glEnable(gl.GL_COLOR_MATERIAL);
               gl.glEnable(GL.GL_NORMALIZE);
               gl.glEnable(GL.GL_AUTO_NORMAL);
               gl.glEnable(GL.GL_DEPTH_TEST);
               gl.glEnable(GL.GL_CULL_FACE);
               gl.glClear(GL.GL_COLOR_BUFFER_BIT |GL.GL_DEPTH_BUFFER_BIT );

               gl.glPushMatrix();
               // 面の色を設定
               gl.glColor3f(
                   (float)0x77/(float)0xff,
                   (float)0x99/(float)0xff,
                   (float)0xff/(float)0xff
               );
               // X軸回転
               gl.glRotatef(40.0f, 1.0f, 0.0f, 0.0f);
               // Y軸回転
               gl.glRotatef(20.0f, 0.0f, 1.0f, 0.0f);

               // ピラミッドサイズ
               double ph = 2.0;
               double ps = 3.0;

               drawTriangle(gl,
                 0.0, ph, 0.0,
                 ps/2.0, 0.0, -ps/2.0,
                 -ps/2.0, 0.0, -ps/2.0);

               drawTriangle(gl,
                 0.0, ph, 0.0,
                 -ps/2.0, 0.0, ps/2.0,
                 ps/2.0, 0.0, ps/2.0);

               drawTriangle(gl,
                 0.0, ph, 0.0,
                 -ps/2.0, 0.0, -ps/2.0,
                 -ps/2.0, 0.0, ps/2.0);

               drawTriangle(gl,
                 0.0, ph, 0.0,
                 ps/2.0, 0.0, ps/2.0,
                 ps/2.0, 0.0, -ps/2.0);

               gl.glBegin(GL.GL_POLYGON);
               gl.glNormal3d(0,-1,0);
               gl.glVertex3d(-ps/2, 0.0, ps/2);
               gl.glVertex3d(-ps/2, 0.0, -ps/2);
               gl.glVertex3d(ps/2, 0.0, -ps/2);
               gl.glVertex3d(ps/2, 0.0, ps/2);
               gl.glEnd();

               gl.glPopMatrix();
           }

           public void reshape(
               GLAutoDrawable dr,
               int x, int y,
               int width, int height){}

           public void displayChanged(
               GLAutoDrawable dr,
               boolean modeChanged,
               boolean deviceChanged){}

           private void drawTriangle(GL gl,
               double p1x, double p1y, double p1z,
               double p2x, double p2y, double p2z,
               double p3x, double p3y, double p3z)
           {
               gl.glBegin(GL.GL_POLYGON);

               gl.glNormal3d((p1x+p2x+p3x)/3,
                   1, (p1z+p2z+p3z)/3);
               gl.glVertex3d(p1x, p1y, p1z);
               gl.glNormal3d((p1x+p2x+p3x)/3,
                   0, (p1z+p2z+p3z)/3);
               gl.glVertex3d(p2x, p2y, p2z);
               gl.glNormal3d((p1x+p2x+p3x)/3,
                   0, (p1z+p2z+p3z)/3);
               gl.glVertex3d(p3x, p3y, p3z);

               gl.glEnd();
           }
         }
       );

       GLContext context =  buf.createContext(null);
       context.makeCurrent();
       buf.display();
       Screenshot.writeToFile(
           new File("sample1214a.png"), width, height, true);
       context.release();
       context.destroy();
   }
}

出力画像(sample1214a.png)


動作環境
JDK6 Upadate13, JOGL 1.1.1