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jPCT - a 3d engine for Java => Support => Topic started by: AGP on February 07, 2025, 11:08:25 PM

Title: Software Render Color Depth
Post by: AGP on February 07, 2025, 11:08:25 PM
If I'm not mistaken, the software renderer works with 16 bits for color (and a third byte for transparency?). Is it trivial giving it all 24 bits (plus a byte for transparency). If so, would you?
Title: Re: Software Render Color Depth
Post by: EgonOlsen on February 08, 2025, 11:23:37 AM
No, it's working on full 24 bit color depth.
Title: Re: Software Render Color Depth
Post by: AGP on February 08, 2025, 10:06:59 PM
I thought that it was a color thing that nothing I do makes an object fade in or out with the software render. This is a basic test I wrote (several different attempts in there, none of which work):


import java.awt.*;
import java.awt.event.*;
import com.threed.jpct.*;

public class Transparency extends Frame implements WindowListener {
    private World theWorld;
    private FrameBuffer buffer;
    private Camera cam;
    private Object3D obj;
    private boolean keepGoing, turnRight, turnLeft;
    private com.threed.jpct.util.KeyMapper keyMapper;
    private Texture boxMap;
    private int transparency = 0;
    private FadeoutEffect effect;

    public Transparency() {
       this.setTitle("BR's");
       theWorld = new World();
       buffer = new FrameBuffer(1440, 900, FrameBuffer.SAMPLINGMODE_NORMAL);
       obj = com.threed.jpct.util.ExtendedPrimitives.createBox(new SimpleVector(2f, 2f, 2f));//Primitives.getCube(1f);
       TextureManager.getInstance().addTexture("boxMap", (boxMap=new Texture("BoxMap.png", true)));
       boxMap.setEffect((effect=new FadeoutEffect()));
       obj.setTexture("boxMap");
       obj.build();
       obj.setTransparencyMode(Object3D.TRANSPARENCY_MODE_DEFAULT);
       obj.setTransparency(transparency);
       Object3D backgroundPlane = Primitives.getPlane(1, 4f);
       backgroundPlane.build();
       backgroundPlane.translate(0f, -2f, 0f);
       theWorld.addObject(backgroundPlane);
       cam = theWorld.getCamera();
       cam.moveCamera(Camera.CAMERA_MOVEOUT, 8f);
       theWorld.addObject(obj);
       obj.setLighting( Object3D.LIGHTING_NO_LIGHTS );
       keyMapper = new com.threed.jpct.util.KeyMapper(this);
       this.addWindowListener(this);
       this.setSize(buffer.getWidth(), buffer.getHeight());
       this.setVisible(true);
       loop();
    }

    public void loop() {
       keepGoing = true;
       while (keepGoing) {
           buffer.clear();
           com.threed.jpct.util.KeyState keyState = keyMapper.poll();
           if (keyState.getState() == com.threed.jpct.util.KeyState.PRESSED)
              keyPressed(keyState.getKeyCode());
           else if (keyState.getState() == com.threed.jpct.util.KeyState.RELEASED)
              keyReleased(keyState.getKeyCode());
           if (turnRight)
              obj.rotateY(-.01f);
           if (turnLeft)
              obj.rotateY(.01f);
           theWorld.renderScene(buffer);
           theWorld.draw(buffer);
           //theWorld.drawWireframe(buffer, Color.yellow);
           buffer.display(this.getGraphics());
           Thread.yield();
       }
       buffer.dispose();
       this.dispose();
       System.exit(0);
    }

    private void keyPressed(int keyCode) {
       if (keyCode == KeyEvent.VK_RIGHT)
           turnRight = true;
       if (keyCode == KeyEvent.VK_LEFT)
           turnLeft = true;
    }
    private void keyReleased(int keyCode) {
       if (keyCode == KeyEvent.VK_RIGHT)
           turnRight = false;
       if (keyCode == KeyEvent.VK_LEFT)
           turnLeft = false;
       if (keyCode == KeyEvent.VK_T) {
           float fade = 1.00f;
           if (transparency < 255)
              fade = (float)((transparency+=8)/255f);
           effect.transparency = 255-transparency;
           obj.setTransparency(255-transparency);
           //boxMap.setAlpha(255-transparency);
           TextureManager.getInstance().replaceTexture("boxMap", boxMap);
           //obj.setAdditionalColor(intensity(boxColor, fade));
           //boxMap.applyEffect();
           Logger.log("Transparency: "+transparency, Logger.MESSAGE);
       }
    }
    public void windowClosing(WindowEvent e) {
       keepGoing = false;
    }
    public void windowClosed(WindowEvent e) {}
    public void windowOpened(WindowEvent e) {}
    public void windowActivated(WindowEvent e) {}
    public void windowDeactivated(WindowEvent e) {}
    public void windowIconified(WindowEvent e) {}
    public void windowDeiconified(WindowEvent e) {}

    public static void main(String[] args) {
       new Transparency();
    }
}
class FadeoutEffect implements ITextureEffect {
    public int transparency;
    private Texture tex;
    public FadeoutEffect() {
    }

    public void init(Texture texture) {
       this.tex = texture;
    }

    public void apply(int[] dest, int[] src) {
       /*for (int y =0; y < 512;y++) {
              for (int x = 0; x < 512; x++) {
                     dest[y*x] = transparency;
              }
       }*/
       tex.setAlpha(transparency);
    }

    public boolean containsAlpha() {
       return false;
    }
}
Title: Re: Software Render Color Depth
Post by: EgonOlsen on February 09, 2025, 02:07:09 PM
That's because the usage of alpha in the texture itself overrides the global transparency setting. Or in other words, if a texture uses an alpha channel, it doesn't allow for setting the global transparency using setTransparency(). IIRC, this is a limitation of the software renderer. However, transpancy using setTransparency is pretty coarse anyway. But that's not related to color depth but to the way in which it's applied.
Title: Re: Software Render Color Depth
Post by: AGP on February 09, 2025, 08:47:48 PM
So is there no way to do a proper fadeout?
Title: Re: Software Render Color Depth
Post by: EgonOlsen on February 10, 2025, 06:48:51 AM
Either use a texture with no alpha channel and do setTransparency()...but that might look a bit coarse. Or use a texture with alpha and use Texture.setAlpha(). But that will alter the texture, which is slower and might not be feasible if you intend to do that on objects of which some are supposed to fade out while others won't.
Title: Re: Software Render Color Depth
Post by: AGP on February 12, 2025, 07:21:56 AM
I tried texture.setAlpha(). Even tried replacing the texture in the texture manager. It doesn't change the object's opacity in any way.
Title: Re: Software Render Color Depth
Post by: EgonOlsen on February 13, 2025, 07:54:51 AM
setAlpha really means the alpha value as it's represented in the texture, i.e. shifted up by 24. Here's an example of how it works:

import java.awt.*;
import java.awt.event.*;
import com.threed.jpct.*;

public class Transparency extends Frame implements WindowListener {
    private World theWorld;
    private FrameBuffer buffer;
    private Camera cam;
    private Object3D obj;
    private boolean keepGoing, turnRight, turnLeft;
    private com.threed.jpct.util.KeyMapper keyMapper;
    private Texture boxMap;
    private int transparency = 0;

    public Transparency() {
      this.setTitle("BR's");
      theWorld = new World();
      buffer = new FrameBuffer(1440, 900, FrameBuffer.SAMPLINGMODE_NORMAL);
      obj = com.threed.jpct.util.ExtendedPrimitives.createBox(new SimpleVector(2f, 2f, 2f));//Primitives.getCube(1f);
      TextureManager.getInstance().addTexture("boxMap", (boxMap=new Texture("test.jpg", true)));
      obj.setTexture("boxMap");
      obj.setTransparency(0);
      //obj.setTransparencyMode(Object3D.TRANSPARENCY_MODE_ADD);
      obj.build();
      Object3D backgroundPlane = Primitives.getPlane(1, 4f);
      backgroundPlane.build();
      backgroundPlane.translate(0f, -2f, 0f);
      theWorld.addObject(backgroundPlane);
      cam = theWorld.getCamera();
      cam.moveCamera(Camera.CAMERA_MOVEOUT, 8f);
      theWorld.addObject(obj);
      theWorld.setAmbientLight(255, 255, 255);
      keyMapper = new com.threed.jpct.util.KeyMapper(this);
      this.addWindowListener(this);
      this.setSize(buffer.getWidth(), buffer.getHeight());
      this.setVisible(true);
      loop();
    }

    public void loop() {
      keepGoing = true;
      transparency=0;
      int dir = 1;
      int its= 0;
      while (keepGoing) {
          buffer.clear();
          com.threed.jpct.util.KeyState keyState = keyMapper.poll();
          if (keyState.getState() == com.threed.jpct.util.KeyState.PRESSED)
              keyPressed(keyState.getKeyCode());
          else if (keyState.getState() == com.threed.jpct.util.KeyState.RELEASED)
              keyReleased(keyState.getKeyCode());
          if (turnRight)
              obj.rotateY(-.01f);
          if (turnLeft)
              obj.rotateY(.01f);
          theWorld.renderScene(buffer);
          theWorld.draw(buffer);
          //theWorld.drawWireframe(buffer, Color.yellow);
          buffer.display(this.getGraphics());
          its++;
              if (its>10)  {
              transparency+=dir;
              if (Math.abs(transparency)>255 || transparency==0) {
                  dir*=-1;
              }
              //obj.setTransparency(transparency);
              TextureManager.getInstance().getTexture("boxMap").setAlpha(transparency<<24);
              System.out.println("Trans: "+transparency);
              its = 0;
          }
          Thread.yield();
      }
      buffer.dispose();
      this.dispose();
      System.exit(0);
    }

    private void keyPressed(int keyCode) {
      if (keyCode == KeyEvent.VK_RIGHT)
          turnRight = true;
      if (keyCode == KeyEvent.VK_LEFT)
          turnLeft = true;
    }
    private void keyReleased(int keyCode) {
      if (keyCode == KeyEvent.VK_RIGHT)
          turnRight = false;
      if (keyCode == KeyEvent.VK_LEFT)
          turnLeft = false;
    }
    public void windowClosing(WindowEvent e) {
      keepGoing = false;
    }
    public void windowClosed(WindowEvent e) {}
    public void windowOpened(WindowEvent e) {}
    public void windowActivated(WindowEvent e) {}
    public void windowDeactivated(WindowEvent e) {}
    public void windowIconified(WindowEvent e) {}
    public void windowDeiconified(WindowEvent e) {}

    public static void main(String[] args) {
      new Transparency();
    }
}

Title: Re: Software Render Color Depth
Post by: AGP on February 16, 2025, 09:52:21 PM
Thanks a lot. It is unnecessarily complicated, though, isn't it?
Title: Re: Software Render Color Depth
Post by: EgonOlsen on February 19, 2025, 06:58:07 AM
Yes, a little bit...  ;) It's actually a performance issue. The "old" transparency code is optimized for speed and not accuracy, which is why its results are  not on par with what the GL renderer could do. The alpha stuff has been added much later. It's more flexible but also slower.
Title: Re: Software Render Color Depth
Post by: AGP on February 26, 2025, 02:38:36 AM
Now I want the same code to also work with OpenGL. But I'm getting:
QuoteException in thread "main" java.lang.NullPointerException: Cannot read the array length because "this.texels" is null
Title: Re: Software Render Color Depth
Post by: EgonOlsen on February 26, 2025, 06:29:10 AM
That's because the GL renderer discards a texture's actual pixel data once it has been uploaded to the GPU. There's a 'keepPixelData()' method in Texture to prevent this.