Hi,

I'm working in a 2D editor ( polygons, rectangles, circles, lines, images, etc). Images are represented by textured polygons.
To translate the shapes fast I use the xor operation. My problem is when I translating a masked image.

The xor operation don't respect the alpha channel, and  the masked area from image appear white.

Any idea?

Thank's.

Stiva

I am developing a 2d editor. In some cases, is necessary render specific regions of the model, instead of render it all.  This is possible?

To use GLCanvas with swt, I do this:

- First I extend a Panel and add a GLCanvas:

public class GLPanel extends Panel{
   private GLCanvas canvas = null;
   private GL gl;
   private GLU glu;

   public GLPanel(){
     GLCapabilities cap = new GLCapabilities();
     this.canvas = GLDrawableFactory.getFactory().createGLCanvas(cap);
     this.setLayout(new BorderLayout());
     this.add(canvas);
     }

     .....
}


- Then I add the GLCanvas to a SWT Composite, with SWT_AWT bridje.

private void addGlCanvas(Composite parent)
     {
     FillLayout fl = new FillLayout();
         parent.setLayout(fl);
         Composite glCompo = new Composite(parent, SWT.EMBEDDED);
     // bridje swt -> awt
     fDrawSurface = new GLPanel();
     fDrawSurface.addAdjustmentListener(this);
           

     Frame awtFrame = SWT_AWT.new_Frame(glCompo);
     awtFrame.add(fDrawSurface);
     }

Work's fine.

Hi,

I need to draw elements of feedback with the user as marquee of selection, mouse cursors , etc...  I do not want to render all drawing to each movement of mouse.  Exists some more performatic alternative, as xor operation (to invert pixels)?

thanks

I have two GLCanvas in my application.  I can share textures and DisplayLists created from one between the two?

I get good results applying a contour to the polygons with 50% of transparency. Work like a antialias.

Hi,

I am drawing characters from poligonos returned from the Freetype library.  I am having problem when apply zoom out, because the text is unreadable.  The fine poligonos disappear or are distorted.

Exists some filter that improves the quality to the poligonos?

Can you write a simple code with the skeleton of sugestion?

Hi,

I have a problem to get values for modelMatrix, projectionMatrix and viewport.  I only obtain the values for this matrices if the respective init function are called in Display() method.

Follows the code:

     private YxxfGfxPointW DCStoMCS(YxxfGfxPointS pt) {
           int[] viewport = new int[4];
           double[] matrizModelo = new double[16];
           double[] matrizProjecao = new double[16];
           int winY;
           double[] x = new double[1];
           double[] y = new double[1];
           double[] z = new double[1];
           
           // get the matrix values
           gl.glGetIntegerv(GL.GL_VIEWPORT, viewport);
           winY = viewport[3] - pt.y - 1;
           gl.glGetDoublev(GL.GL_MODELVIEW_MATRIX, matrizModelo);
           gl.glGetDoublev(GL.GL_PROJECTION_MATRIX, matrizProjecao);
...

somebody knows the reason?

Maurício