DEar Vincent,
Thank you for you help!
But I think I should talk about my problem that I'm facing. I'm
writing a 3D maze applet. I need to do the texture mapping on the walls.
The far walls will darker than the near walls. I can put the GIF picture
on the walls. But when I use the JPEG instead. Exception came out and
nothing to see on the applet. I think the problem is in the color model.
The following is the class to read the image, reference from a book:
public class ImageBytes implements ImageConsumer {
public int width, height;
public byte[] iData;
public ColorModel cModel = null;
private ImageProducer pro;
private boolean done = false;
ImageBytes (Image img) {
synchronized (this) {
pro = img.getSource();
pro.addConsumer(this);
pro.startProduction(this);
while (!done)
try { wait(); }
catch (InterruptedException e) { }
}
}
public synchronized void imageComplete (int status) {
pro.removeConsumer(this);
done = true;
notifyAll();
}
public void setColorModel (ColorModel model) {
if (model instanceof IndexColorModel && cModel == null)
cModel = model;
}
public void setDimensions (int width, int height) {
this.width = width;
this.height = height;
iData = new byte [width * height];
}
public void setHints (int hintflags) {
}
public void setPixels (int x, int y, int w, int h, ColorModel model,
byte pixels[], int off, int scansize) {
int doff = (y * width) + x;
if (w == scansize && w == width) {
System.arraycopy(pixels, off, iData, doff, h * w);
}
else {
for (int row = 0; row < h; row++) {
System.arraycopy(pixels, off, iData, doff, w);
doff += width;
off += scansize;
}
}
}
public void setPixels (int x, int y, int w, int h, ColorModel model,
int pixels[], int off, int scansize) {
}
public void setProperties (Hashtable props) {
}
}
The following is the implementation of the class:
public class TexView extends GridView {
protected ImageBytes[] iData = new ImageBytes[2];
protected int ix = 0;
protected Component ap;
protected float hWidth;
protected IndexColorModel[][] shades;
private int sDark = 3;
public TexView (Dimension window, int maxZ, Image wA, Image wB,
Component ap) {
super(window, maxZ);
iData[0] = new ImageBytes(wA);
iData[1] = new ImageBytes(wB);
this.ap = ap;
hWidth = window.width / 2f;
// Generate array of darkened color tables
int steps = maxZ + sDark + 1;
shades = new IndexColorModel[2][steps];
for (int jj = 0; jj < 2; jj++) {
for (int ii = 0; ii < steps; ii++)
shades[jj][ii] = darker((IndexColorModel)
iData[jj].cModel,
(float) (steps - ii) / steps);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
problem came out! (my guess)
}
}
protected IndexColorModel darker (IndexColorModel pal, float inten) {
int colors = pal.getMapSize();
byte[] reds = new byte[colors];
byte[] grns = new byte[colors];
byte[] blus = new byte[colors];
for (int ii = 0; ii < colors; ii++) {
int rgb = pal.getRGB(ii);
int red = (rgb >> 16) & 0xFF;
int grn = (rgb >> 8) & 0xFF;
int blu = rgb & 0xFF;
// Convert to HSB to darken and then back to RGB
float[] vals = Color.RGBtoHSB(red, grn, blu, null);
rgb = Color.HSBtoRGB(vals[0], vals[1], vals[2] * inten);
reds[ii] = (byte) (rgb >> 16);
grns[ii] = (byte) (rgb >> 8);
blus[ii] = (byte) rgb;
}
return new IndexColorModel(8, colors, reds, grns, blus);
}
protected Image makePic (byte[] buf, int width, int height, int z) {
return ap.createImage(new MemoryImageSource(width, height,
shades[ix][z], buf, 0,
width));
}
protected void getPoint (int idx, int z, int x, boolean b) {
super.getPoint(idx, z, x, b);
yy[idx] = Math.max(0, Math.min(window.height, yy[idx]));
xx[idx] = Math.max(0, Math.min(window.width, xx[idx]));
}
protected float frontOff (float x, int z) {
float height = ((eyeDist + vOff + z - 1) / eyeDist);
return (((x + .5f) / window.width) - .5f) * height + .5f;
}
protected float sideOff (float xOff, int z) {
float sRatio = eyeDist / (Math.abs(xOff - hWidth) / window.width);
return (Math.abs(frontOff(xOff, z)) * sRatio) % 1f;
}
protected void colSlice (byte[] dst, int dstIdx, float texOff,
int width, int height) {
int sIdx = (int) (texOff * iData[ix].width);
byte[] src = iData[ix].iData;
int sWidth = iData[ix].width;
int sHeight = iData[ix].height;
int end = dstIdx + width * height;
int sNum = 0;
int sInc = sHeight * 2;
int sDec = height * 2;
for (int ii = dstIdx; ii < end; ii += width) {
dst[ii] = src[sIdx];
for (sNum += sInc; sNum > height; sNum -= sDec)
sIdx += sWidth;
}
}
protected void textureSide (Graphics g, int x, int z) {
int x2 = x < 1 ? x : x - 1;
getPoint(0, z, x2, false); // top front
getPoint(1, z + 1, x2, false); // top rear
getPoint(2, z + 1, x2, true); // bottom rear
getPoint(3, z, x2, true); // bottom front
int wallX = Math.min(xx[0], xx[1]);
int wallY = Math.min(yy[0], yy[1]);
int width = Math.abs(xx[1] - xx[0]);
int height = yy[3] - yy[0];
byte[] dst = new byte[width * height];
// Setup ratio counters
int dec = width * 2;
int topNum = 0;
int topInc = (yy[1] - yy[0]) * 2;
int botNum = 0;
int botInc = (yy[3] - yy[2]) * 2;
int top = yy[0] - wallY;
int bot = height + top;
int topStep = 1;
int botStep = -topStep;
for (int ii = 0; ii < width; ii++) {
int dx = x < 0 ? ii : width - ii - 1;
float tx = sideOff(x < 0 ? xx[0] + ii :
window.width - xx[0] + ii, z);
colSlice(dst, dx + top * width, x < 0 ? tx : 1f - tx,
width, bot - top);
for (topNum += topInc; topNum > width; topNum -= dec)
top += topStep;
for (botNum += botInc; botNum > width; botNum -= dec)
bot += botStep;
}
g.drawImage(makePic(dst, width, height, z + sDark), wallX,
wallY, null);
}
protected void textureFront (Graphics g, int x, int z) {
getPoint(0, z, x - 1, false);
getPoint(1, z, x, true);
int height = yy[1] - yy[0];
int width = xx[1] - xx[0];
byte[] dst = new byte[width * height];
for (int ii = 0; ii < width; ii++) {
float tx = Math.abs(frontOff(xx[0] + ii, z)) % 1f;
colSlice(dst, ii, x < 0 ? 1f - tx : tx, width, height);
}
g.drawImage(makePic(dst, width, height, z), xx[0], yy[0], null);
}
protected void drawSq (Graphics g, MazeMap map, int x, int z) {
if (map.isWall(x, z)) {
ix = map.isOdd(x, z) ? 0 : 1;
if (z > 0 && !map.isWall(x, z - 1))
textureFront(g, x, z);
if (x != 0 && !map.isWall(x < 0 ? x + 1 : x - 1, z))
textureSide(g, x, z);
}
else
drawFloorCeil(g, map, x, z);
}
}
=====================================================================
To subscribe/unsubscribe, send mail to [EMAIL PROTECTED]
Java 2D Home Page: http://java.sun.com/products/java-media/2D/
