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/*                                                                                           */
/*  Java 3D Engine Basics Tutorials - Tut Solid Triangle                                     */
/*  Auth: bkenwright@xbdev.net                                                               */
/*  URL:  www.xbdev.net                                                                      */
/*                                                                                           */
/*  Drawing our own solid triangle using linear interplation                                 */
/*                                                                                           */
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import java.awt.image.*;
import java.awt.*;
import java.applet.*;

public class solidtriangle extends Applet 
{
  public void paint(Graphics g) 
  {      SolidTriangle(g,  mouse_x_right, mouse_y_right,             
                           mouse_x_left,  mouse_y_left,
													 90, 230, Color.green);                        
  }// End of paint(..)

  public void setPixel(Graphics g, int x, int y, Color color ) 
  {           g.setColor( color );
              g.fillRect( x, y, 1, 1 );
  }// End of setPixel(..)
  
  int mouse_x_right= 10;
  int mouse_y_right= 10;
  
  int mouse_x_left= 100;
  int mouse_y_left= 100;
  
	public boolean mouseDown(Event evt, int x, int y)
  {
  	  if(evt.id == Event.MOUSE_DOWN)
      {
          // Right mouse button
      		if( evt.metaDown() == true )
      		{
      				System.out.println( "Right MouseDown" );
      				mouse_x_right = x;
     					mouse_y_right = y;
      		}
      		else // right mouse button
      		{
      				System.out.println( "Left MouseDown" );
      				mouse_x_left = x;
     					mouse_y_left = y;
      		}
      }// End if
    
		 repaint();
		 return true;
	}// End of mouseDown(..)
	

	void SolidTriangle( Graphics g,
                      float x0, float y0,
                      float x1, float y1,
                      float x2, float y2,
                      Color colour )
{
   //Sort into order y0 -> y1 -> y2
   float temp;
   if( y1 < y0 )
   {
      temp=y1; y1=y0; y0=temp;
      temp=x1; x1=x0; x0=temp;
   }
   if( y2 < y0 )
   {
      temp=y2; y2=y0; y0=temp;
      temp=x2; x2=x0; x0=temp;
   }
   if( y2 < y1 )
   {
      temp=y2; y2=y1; y1=temp;
      temp=x2; x2=x1; x1=temp;
   }

   // Draw Top Half Triangle
   float x_left  = x0;
	 float x_right = x0;
	   
   float dx_left  = x1 - x0;   // to the middle then we change it
   float dx_right = x2 - x0;   // all the way to the bottom :)

	   
   dx_left  = (x1 - x0) / (y1 - y0);
   dx_right = (x2 - x0) / (y2 - y0);
	   
   int s = 0;
   float t; // temp variable
   if( dx_left > dx_right )
   {
      t     = dx_left;
      dx_left  = dx_right;
      dx_right = t;
      s=1;
   }//End if
	   
   for(float y=y0; y<y1; y++)
   {
      for(float x=x_left; x<x_right; x++)
      {
         setPixel(g, (int)x, (int)y, colour );
      }// End inner for loop
      x_left  += dx_left;
      x_right += dx_right;
   }// End outer for loop
	

   // Now for the bottom of the triangle
   // Whats the s==0 for?  Well we made the assumption that dx_left
   // goes all the way to p2 (the bottom) if now we set s to 1, and then
   // dx_right goes all the way to the bottom.
   if( s == 0 )
   {
      dx_left = (x2 - x1) / (y2 - y1);
   }
   else
   {
      dx_right = (x2 - x1) / (y2 - y1);
   }
	   
	   
   for(float y=y1; y<y2; y++)
   {
      for(float x=x_left; x<x_right; x++)
      {
         setPixel(g, (int)x, (int)y, colour);
      }
      x_left  += dx_left;
      x_right += dx_right;
   }// End outer for loop
   
}// End SolidTriangle(..)
	
}// End of our Applet