The code below demonstrates what may be a bug in immediate-mode rendering of
a texture with image data set by reference. I tested this on:
Java3D 1.2 Maintenance Release Implementation
JDK 1.3
Windows NT 4.0
PentiumIII laptop (Dell Inspiron 7500) with ATI Rage Mobility P OpenGL
Also, despite statements in Java3D demos (and this mailing list) that a
BufferedImage of TYPE_3BYTE_BGR enables images by reference, I have not
found this to be true. Therefore, the code below uses a BufferedImage of
TYPE_CUSTOM, which is the only way I know of (on Windows) to avoid copying
from a BufferedImage to an ImageComponent2D.
Finally, if someone can point me to a better place to submit a Java3D bug,
I'd appreciate it. I noticed that I can view Java3D bugs in the Developer
Connection Bug Database, but I could not find a category for Java3D in the
"submit bug" form.
Regards,
Dave
---
import java.applet.Applet;
import java.awt.*;
import java.awt.color.*;
import java.awt.image.*;
import com.sun.j3d.utils.applet.MainFrame;
import com.sun.j3d.utils.universe.*;
import javax.media.j3d.*;
import javax.vecmath.*;
/**
* Demonstrates a bug in Java3D 1.2.
*
* Immediate-mode rendering of texture with image data set by reference
* yields an (incorrect) all-white image. When by reference is not
specified,
* the displayed image is (correct) shades of gray. Search for byReference
* below.
*
* @author Dave Hale, Landmark Graphics
* @version 06/14/2000
*/
public class ImmTexByRefBug extends Applet implements Runnable {
public ImmTexByRefBug() {
setLayout(new BorderLayout());
GraphicsConfiguration config =
SimpleUniverse.getPreferredConfiguration();
canvas = new Canvas3D(config);
canvas.stopRenderer();
add("Center",canvas);
SimpleUniverse u = new SimpleUniverse(canvas);
u.getViewingPlatform().setNominalViewingTransform();
new Thread(this).start();
}
public void render() {
if (gc == null) {
gc = canvas.getGraphicsContext3D();
gc.setAppearance(new Appearance());
tc = new TexturedQuad();
}
gc.clear();
gc.draw(tc);
canvas.swap();
}
public void run() {
while (true) {
render();
Thread.yield();
}
}
public static void main(String[] args) {
new MainFrame(new ImmTexByRefBug(),256,256);
}
private Canvas3D canvas;
private GraphicsContext3D gc = null;
private TexturedQuad tc = null;
private class TexturedQuad extends Shape3D {
public TexturedQuad() {
QuadArray qa = new QuadArray(
4,QuadArray.COORDINATES|QuadArray.TEXTURE_COORDINATE_2);
this.setGeometry(qa);
float[] coords = {
-0.5f, -0.5f, 0.0f,
0.5f, -0.5f, 0.0f,
0.5f, 0.5f, 0.0f,
-0.5f, 0.5f, 0.0f,
};
qa.setCoordinates(0,coords);
int w = 256;
int h = 256;
float dw = 0.5f/(float)w;
float dh = 0.5f/(float)h;
float[] txcoords = {
dw, dh,
1.0f-dw, dh,
1.0f-dw, 1.0f-dh,
dw, 1.0f-dh,
};
qa.setTextureCoordinates(0,0,txcoords);
Appearance a = new Appearance();
this.setAppearance(a);
// If byReference==true, then textured quad is white (WRONG!).
// If byReference==false, then textured quad is shades of gray
(RIGHT).
boolean byReference = true;
boolean yUp = true;
// This is the only way I've found to avoid the copy for RGB images.
// Documentation says TYPE_3BYTE_BGR will also avoid the copy, but
// it does not (another bug?).
ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_sRGB);
int[] nbits = {8,8,8};
ColorModel cm = new ComponentColorModel(
cs,nbits,false,false,Transparency.OPAQUE,0);
int[] bandoffset = {0,1,2};
WritableRaster wr = java.awt.image.Raster.createInterleavedRaster(
DataBuffer.TYPE_BYTE,w,h,w*3,3,bandoffset,null);
BufferedImage bi = new BufferedImage(cm,wr,false,null);
byte[] data =
((DataBufferByte)bi.getRaster().getDataBuffer()).getData();
for (int i=0,k=0; i<h; ++i) {
for (int j=0; j<w; ++j) {
byte c = (byte)((i+j)*255/(w+h-2));
data[k++] = c;
data[k++] = c;
data[k++] = c;
}
}
ImageComponent2D ic = new ImageComponent2D(
ImageComponent.FORMAT_RGB8,w,h,byReference,yUp);
ic.set(bi);
Texture2D tx = new Texture2D(Texture.BASE_LEVEL,Texture.RGB,w,h);
tx.setMagFilter(Texture.BASE_LEVEL_LINEAR);
tx.setMinFilter(Texture.BASE_LEVEL_LINEAR);
tx.setImage(0,ic);
tx.setEnable(true);
a.setTexture(tx);
}
}
}
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