/*********************************************************************************************/ /* */ /* Java 3D Simple - 3D Wire Cube (with mouse input) */ /* Auth: bkenwright@xbdev.net */ /* URL: www.xbdev.net */ /* */ /* Creating a simple wireframe 3D demo */ /* It looks like a lot...but its mostly comments believe me. The only code in 3D here */ /* that may be a bit tricky to understand...well thats if your not from a 3D background */ /* is the rotation equations...everything else is pretty much simple...just a matter of */ /* arranging the data into nice tidy parts. For example, we have 8 corners of a cube...and */ /* those 8 corners are used to create 12 lines which make up the wire cube!..ta-daaAA. */ /* And thats it :) */ /* We use a bit of mouse input and of course...the rotation equations and translation etc */ /* so it looks better. */ /* Just drag the mouse and watch it move around...coOOoool. */ /* */ /*********************************************************************************************/ import java.awt.image.*; import java.awt.*; import java.applet.*; /*********************************************************************************************/ class Point3 { public float x, y, z; public Point3( int xx, int yy, int zz ) { x = xx; y = yy; z = zz; }// End constructor }// End Point3 class /*********************************************************************************************/ class Line { public int p0, p1; public Line( int a, int b ) { p0 = a; p1 = b; }// End constructor }// End class Edge /*********************************************************************************************/ /* */ /* Program Entry Point! */ /* Let the coding begin.... */ /* */ /*********************************************************************************************/ public class wire_cube extends Applet { Point3[] vertices; Line[] lines; int scr_width; int scr_height; // We'll only rotate around the x and y for simplicity :) float angle_y = 1.0f; float angle_x = 1.0f; // Mouse coords int mx; int my; int mb; public void init() { scr_width = getSize().width; scr_height = getSize().height; vertices = new Point3[ 8 ]; vertices[0] = new Point3( -1, -1, -1 ); vertices[1] = new Point3( -1, -1, 1 ); vertices[2] = new Point3( -1, 1, -1 ); vertices[3] = new Point3( -1, 1, 1 ); vertices[4] = new Point3( 1, -1, -1 ); vertices[5] = new Point3( 1, -1, 1 ); vertices[6] = new Point3( 1, 1, -1 ); vertices[7] = new Point3( 1, 1, 1 ); lines = new Line[ 12 ]; lines[ 0] = new Line( 0, 1 ); lines[ 1] = new Line( 0, 2 ); lines[ 2] = new Line( 0, 4 ); lines[ 3] = new Line( 1, 3 ); lines[ 4] = new Line( 1, 5 ); lines[ 5] = new Line( 2, 3 ); lines[ 6] = new Line( 2, 6 ); lines[ 7] = new Line( 3, 7 ); lines[ 8] = new Line( 4, 5 ); lines[ 9] = new Line( 4, 6 ); lines[10] = new Line( 5, 7 ); lines[11] = new Line( 6, 7 ); //backbuffer = createImage( width, height ); //backg = backbuffer.getGraphics(); //drawWireframe( backg ); repaint(); }// End init(..) void renderWireCube( Graphics g ) { float cosY = (float)Math.cos(angle_y); float sinY = (float)Math.sin(angle_y); float cosX = (float)Math.cos(angle_x); float sinX = (float)Math.sin(angle_x); Point[] points = new Point[8]; // Transformed start and end point Point3 tpA = new Point3(0,0,0); Point3 tp = new Point3(0,0,0); // Lets loop through all the lines and transform them for(int i=0; i<8; i++) { Point3 p = vertices[i]; //Rotate around the X axis tp.x = p.x; tp.y = cosX*p.y - sinX*p.z; tp.z = sinX*p.y + cosX*p.z; //Rotate around the Y axis tpA.x = cosY*tp.x + sinY*tp.z; tpA.y = tp.y; tpA.z = -sinY*tp.x + cosY*tp.z; // Translate (e.g move) our Cube away from us (into the z background) tpA.z += 3; float scr_x = tpA.x / tpA.z; float scr_y = tpA.y / tpA.z; scr_x += 1; scr_y += 1; scr_x *=0.5f; scr_y *= 0.5f; scr_x *= scr_width; scr_y *= scr_height; points[i] = new Point( (int)scr_x, (int)scr_y ); }// End for loop i // Clear the screen g.setColor( Color.black ); g.fillRect( 0, 0, scr_width, scr_height ); for(int j=0; j<12; j++) { int p0 = lines[j].p0; int p1 = lines[j].p1; g.setColor( Color.white ); g.drawLine( points[p0].x, points[p0].y, points[p1].x, points[p1].y ); }// End for loop j }// End renderWireCube(..) public void update( Graphics g ) { renderWireCube( g ); showStatus("y angle " + (angle_y * (180.0f/3.14f))%180 ); }// End update(..) public void paint( Graphics g ) { update( g ); }// End paint(..) /*********************************************************************************************/ /* */ /* Capture event when mouse is pressed */ /* Parameters: */ /* evt is The event... */ /* x is the x mouse position */ /* y is the y mouse position */ /* return whether or not we handled the event */ /* */ /*********************************************************************************************/ public boolean mouseDown(Event evt, int x, int y) { mb = 1; return true; }// End of mouseDown(..) /*********************************************************************************************/ /* */ /* Capture mouse release */ /* Parameters: */ /* evt is The event... */ /* x is the x mouse position */ /* y is the y mouse position */ /* return whether or not we handled the event */ /* */ /*********************************************************************************************/ public boolean mouseUp(Event evt, int x, int y) { mb=0; return false; }// End of mouseUp(..) /*********************************************************************************************/ /* */ /* Captures mouse movement */ /* -> Was added so that the dagging of the wire cube was more smooth...as if you click at a */ /* new place on the screen, there would be a sudden jump...this way its smooth right from */ /* your first click with the mouse :) */ /* */ /*********************************************************************************************/ public boolean mouseMove(Event evt, int x, int y) { // Update our old mouse pos mx = x; my = y; return true; }// End mouseMove(..) /*********************************************************************************************/ /* */ /* Capture mouse drags */ /* Parameters: */ /* evt is The event... */ /* x is the x mouse position */ /* y is the y mouse position */ /* return whether or not we handled the event */ /* */ /*********************************************************************************************/ public boolean mouseDrag(Event evt, int x, int y) { if( mb == 1 ) { int xnew = my - y; int ynew = mx - x; angle_y += ynew*0.05f; angle_x += xnew*0.05f; // Update the screen repaint(); }// End if(..) // Update our old mouse pos mx = x; my = y; return true; }// End of mouseDrag(..) }// End of Applet