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-rwxr-xr-xsrc/classes/com/sun/opengl/utils/SGIImage.java283
1 files changed, 282 insertions, 1 deletions
diff --git a/src/classes/com/sun/opengl/utils/SGIImage.java b/src/classes/com/sun/opengl/utils/SGIImage.java
index d115604b1..f06c10b56 100755
--- a/src/classes/com/sun/opengl/utils/SGIImage.java
+++ b/src/classes/com/sun/opengl/utils/SGIImage.java
@@ -47,7 +47,7 @@ import com.sun.opengl.utils.*;
import java.awt.image.*;
import javax.swing.*;
-/** <p> Reads SGI RGB/RGBA images. </p>
+/** <p> Reads and writes SGI RGB/RGBA images. </p>
<p> Written from <a href =
"http://astronomy.swin.edu.au/~pbourke/dataformats/sgirgb/">Paul
@@ -104,6 +104,10 @@ public class SGIImage {
// 404 bytes char DUMMY Ignored
// Should be set to 0, makes the header 512 bytes.
+ Header() {
+ magic = MAGIC;
+ }
+
Header(DataInputStream in) throws IOException {
magic = in.readShort();
storage = in.readByte();
@@ -159,6 +163,35 @@ public class SGIImage {
return res;
}
+ /** Writes this SGIImage to the specified file name. If
+ flipVertically is set, outputs the scanlines from top to bottom
+ rather than the default bottom to top order. */
+ public void write(String filename, boolean flipVertically) throws IOException {
+ write(new File(filename), flipVertically);
+ }
+
+ /** Writes this SGIImage to the specified file. If flipVertically is
+ set, outputs the scanlines from top to bottom rather than the
+ default bottom to top order. */
+ public void write(File file, boolean flipVertically) throws IOException {
+ writeImage(file, data, header.xsize, header.ysize, header.zsize, flipVertically);
+ }
+
+ /** Creates an SGIImage from the specified data in either RGB or
+ RGBA format. */
+ public static SGIImage createFromData(int width,
+ int height,
+ boolean hasAlpha,
+ byte[] data) {
+ Header header = new Header();
+ header.xsize = (short) width;
+ header.ysize = (short) height;
+ header.zsize = (short) (hasAlpha ? 4 : 3);
+ SGIImage image = new SGIImage(header);
+ image.data = data;
+ return image;
+ }
+
/** Determines from the magic number whether the given InputStream
points to an SGI RGB image. The given InputStream must return
true from markSupported() and support a minimum of two bytes
@@ -258,6 +291,7 @@ public class SGIImage {
tmpData = null;
tmpRead = null;
format = GL.GL_RGBA;
+ header.zsize = 4;
}
private void getRow(byte[] buf, int y, int z) {
@@ -325,6 +359,250 @@ public class SGIImage {
}
}
+ private static byte imgref(byte[] i,
+ int x,
+ int y,
+ int z,
+ int xs,
+ int ys,
+ int zs) {
+ return i[(xs*ys*z)+(xs*y)+x];
+ }
+
+
+ private void writeHeader(DataOutputStream stream,
+ int xsize, int ysize, int zsize, boolean rle) throws IOException {
+ // effects: outputs the 512-byte IRIS RGB header to STREAM, using xsize,
+ // ysize, and depth as the dimensions of the image. NOTE that
+ // the following defaults are used:
+ // STORAGE = 1 (storage format = RLE)
+ // BPC = 1 (# bytes/channel)
+ // DIMENSION = 3
+ // PIXMIN = 0
+ // PIXMAX = 255
+ // IMAGENAME = <80 nulls>
+ // COLORMAP = 0
+ // See ftp://ftp.sgi.com/pub/sgi/SGIIMAGESPEC for more details.
+
+ // write out MAGIC, STORAGE, BPC
+ stream.writeShort(474);
+ stream.write((rle ? 1 : 0));
+ stream.write(1);
+
+ // write out DIMENSION
+ stream.writeShort(3);
+
+ // write XSIZE, YSIZE, ZSIZE
+ stream.writeShort(xsize);
+ stream.writeShort(ysize);
+ stream.writeShort(zsize);
+
+ // write PIXMIN, PIXMAX
+ stream.writeInt(0);
+ stream.writeInt(255);
+
+ // write DUMMY
+ stream.writeInt(0);
+
+ // write IMAGENAME
+ for (int i = 0; i < 80; i++)
+ stream.write(0);
+
+ // write COLORMAP
+ stream.writeInt(0);
+
+ // write DUMMY (404 bytes)
+ for (int i = 0; i < 404; i++)
+ stream.write(0);
+ }
+
+ private void writeImage(File file,
+ byte[] data,
+ int xsize,
+ int ysize,
+ int zsize,
+ boolean yflip) throws IOException {
+ // Input data is in RGBRGBRGB or RGBARGBARGBA format; first unswizzle it
+ byte[] tmpData = new byte[xsize * ysize * zsize];
+ int dest = 0;
+ for (int i = 0; i < zsize; i++) {
+ for (int j = i; j < (xsize * ysize * zsize); j += zsize) {
+ tmpData[dest++] = data[j];
+ }
+ }
+ data = tmpData;
+
+ // requires: DATA must be an array of size XSIZE * YSIZE * ZSIZE,
+ // indexed in the following manner:
+ // data[0] ...data[xsize-1] == first row of first channel
+ // data[xsize]...data[2*xsize-1] == second row of first channel
+ // ... data[(ysize - 1) * xsize]...data[(ysize * xsize) - 1] ==
+ // last row of first channel
+ // Later channels follow the same format.
+ // *** NOTE that "first row" is defined by the BOTTOM ROW of
+ // the image. That is, the origin is in the lower left corner.
+ // effects: writes out an SGI image to FILE, RLE-compressed, INCLUDING
+ // header, of dimensions (xsize, ysize, zsize), and containing
+ // the data in DATA. If YFLIP is set, outputs the data in DATA
+ // in reverse order vertically (equivalent to a flip about the
+ // x axis).
+
+ // Build the offset tables
+ int[] starttab = new int[ysize * zsize];
+ int[] lengthtab = new int[ysize * zsize];
+
+ // Temporary buffer for holding RLE data.
+ // Note that this makes the assumption that RLE-compressed data will
+ // never exceed twice the size of the input data.
+ // There are surely formal proofs about how big the RLE buffer should
+ // be, as well as what the optimal look-ahead size is (i.e. don't switch
+ // copy/repeat modes for less than N repeats). However, I'm going from
+ // empirical evidence here; the break-even point seems to be a look-
+ // ahead of 3. (That is, if the three values following this one are all
+ // the same as the current value, switch to repeat mode.)
+ int lookahead = 3;
+ byte[] rlebuf = new byte[2 * xsize * ysize * zsize];
+
+ int cur_loc = 0; // current offset location.
+ int ptr = 0;
+ int total_size = 0;
+ int ystart = 0;
+ int yincr = 1;
+ int yend = ysize;
+
+ if (yflip) {
+ ystart = ysize - 1;
+ yend = -1;
+ yincr = -1;
+ }
+
+ boolean DEBUG = false;
+
+ for (int z = 0; z < zsize; z++) {
+ for (int y = ystart; y != yend; y += yincr) {
+ // RLE-compress each row.
+
+ int x = 0;
+ byte count = 0;
+ boolean repeat_mode = false;
+ boolean should_switch = false;
+ int start_ptr = ptr;
+ int num_ptr = ptr++;
+ byte repeat_val = 0;
+
+ while (x < xsize) {
+ // see if we should switch modes
+ should_switch = false;
+ if (repeat_mode) {
+ if (imgref(data, x, y, z, xsize, ysize, zsize) != repeat_val) {
+ should_switch = true;
+ }
+ } else {
+ // look ahead to see if we should switch to repeat mode.
+ // stay within the scanline for the lookahead
+ if ((x + lookahead) < xsize) {
+ should_switch = true;
+ for (int i = 1; i <= lookahead; i++) {
+ if (DEBUG)
+ System.err.println("left side was " + ((int) imgref(data, x, y, z, xsize, ysize, zsize)) +
+ ", right side was " + (int)imgref(data, x+i, y, z, xsize, ysize, zsize));
+
+ if (imgref(data, x, y, z, xsize, ysize, zsize) !=
+ imgref(data, x+i, y, z, xsize, ysize, zsize))
+ should_switch = false;
+ }
+ }
+ }
+
+ if (should_switch || (count == 127)) {
+ // update the number of elements we repeated/copied
+ if (x > 0) {
+ if (repeat_mode)
+ rlebuf[num_ptr] = count;
+ else
+ rlebuf[num_ptr] = (byte) (count | 0x80);
+ }
+ // perform mode switch if necessary; output repeat_val if
+ // switching FROM repeat mode, and set it if switching
+ // TO repeat mode.
+ if (repeat_mode) {
+ if (should_switch)
+ repeat_mode = false;
+ rlebuf[ptr++] = repeat_val;
+ } else {
+ if (should_switch)
+ repeat_mode = true;
+ repeat_val = imgref(data, x, y, z, xsize, ysize, zsize);
+ }
+
+ if (x > 0) {
+ // reset the number pointer
+ num_ptr = ptr++;
+ // reset number of bytes copied
+ count = 0;
+ }
+ }
+
+ // if not in repeat mode, copy element to ptr
+ if (!repeat_mode) {
+ rlebuf[ptr++] = imgref(data, x, y, z, xsize, ysize, zsize);
+ }
+ count++;
+
+ if (x == xsize - 1) {
+ // Need to store the number of pixels we copied/repeated.
+ if (repeat_mode) {
+ rlebuf[num_ptr] = count;
+ // If we ended the row in repeat mode, store the
+ // repeated value
+ rlebuf[ptr++] = repeat_val;
+ }
+ else
+ rlebuf[num_ptr] = (byte) (count | 0x80);
+
+ // output zero counter for the last value in the row
+ rlebuf[ptr++] = 0;
+ }
+
+ x++;
+ }
+ // output this row's length into the length table
+ int rowlen = ptr - start_ptr;
+ if (yflip)
+ lengthtab[ysize*z+(ysize-y-1)] = rowlen;
+ else
+ lengthtab[ysize*z+y] = rowlen;
+ // add to the start table, and update the current offset
+ if (yflip)
+ starttab[ysize*z+(ysize-y-1)] = cur_loc;
+ else
+ starttab[ysize*z+y] = cur_loc;
+ cur_loc += rowlen;
+ }
+ }
+
+ // Now we have the offset tables computed, as well as the RLE data.
+ // Output this information to the file.
+ total_size = ptr;
+
+ if (DEBUG)
+ System.err.println("total_size was " + total_size);
+
+ DataOutputStream stream = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(file)));
+
+ writeHeader(stream, xsize, ysize, zsize, true);
+
+ int SIZEOF_INT = 4;
+ for (int i = 0; i < (ysize * zsize); i++)
+ stream.writeInt(starttab[i] + 512 + (2 * ysize * zsize * SIZEOF_INT));
+ for (int i = 0; i < (ysize * zsize); i++)
+ stream.writeInt(lengthtab[i]);
+ for (int i = 0; i < total_size; i++)
+ stream.write(rlebuf[i]);
+
+ stream.close();
+ }
+
private byte[] readAll(DataInputStream in) throws IOException {
byte[] dest = new byte[16384];
int pos = 0;
@@ -357,6 +635,8 @@ public class SGIImage {
return dest;
}
+ // Test case
+ /*
public static void main(String[] args) {
for (int i = 0; i < args.length; i++) {
try {
@@ -387,4 +667,5 @@ public class SGIImage {
}
}
}
+ */
}
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