> Awesome. That's just what I needed to know. Implementation
> sounds straightforward but time is of the essence. I don't
> suppose you would be willing to share your code?
ok.. :P here it is:
BMPExtractor.java
---
import java.io.*;
public class BMPExtractor
{
public static void main(String args[])
throws Exception
{
RandomAccessFile in = new RandomAccessFile(args[0] + ".bmp", "r");
long offset = in.length();
// read in the file dimensions
in.seek(0x12);
int width = in.readUnsignedByte() | (in.readUnsignedByte() << 8);
in.seek(0x16);
int height = in.readUnsignedByte() | (in.readUnsignedByte() << 8);
byte[] image = new byte[(width*height) >> 2];
int count = 0;
offset -= (width >> 1);
while (offset > 0x75) {
in.seek(offset);
for (int i=0; i<(width >> 2); i++) {
byte b1 = in.readByte();
byte b2 = in.readByte();
image[count++] = (byte)
((((b1 & 0x80) == 0x00) ? 0x40 : 0x00) |
(((b1 & 0x08) == 0x00) ? 0x10 : 0x00) |
(((b2 & 0x80) == 0x00) ? 0x04 : 0x00) |
(((b2 & 0x08) == 0x00) ? 0x01 : 0x00)
);
}
// next line
offset -= (width >> 1);
}
in.close();
FileOutputStream out = new FileOutputStream(args[0] + ".rle");
out.write((width & 0xff00) >> 8);
out.write(width & 0x00ff);
out.write((height & 0xff00) >> 8);
out.write(height & 0x00ff);
for (int i=0; i<count; ) {
byte val = image[i++];
short num = 1;
while ((num < 255) && (i < count) && (image[i] == val)) {
num++; i++;
}
out.write(val);
out.write(num & 0xFF);
}
out.close();
}
}
---
basically, this creates a .rle file from a 16 color windows BMP
file (i know, hardcoding - but it does the job) :P it works well,
and i did not want to spend more than 1 hour on it :)
somehow get it in as a resource to your program and then you can
display it taking advantage of the RLE compression.. this code above
is used to generate a file that is for 2bpp display - in this
code, the use of more than one color is ignored (it is a background
bitmap).. download CitiKey and you will see how it is used.
windows BMP files are stored in a bizzare manner too.. from what
i saw, they were bottom row first, left to right.. my original
images were upside down :P
http://www.citikey.com/
it took me a few days to figure out how to do this :) however
i give you a hint - use MemSet() wherever you can.. take advantage
of screen memory (or in 3.5, bitmap memory) and write huge chunks
of data at a time. i cannot supply the palmos code as i developed
it under contract and i no longer own it.
the display of my bitmaps are REAL time.. very very very fast :)
cheers
az.
--
Aaron Ardiri
Java Certified Programmer http://www.hig.se/~ardiri/
University-College i G�vle mailto:[EMAIL PROTECTED]
SE 801 76 G�vle SWEDEN
Tel: +46 26 64 87 38 Fax: +46 26 64 87 88
Mob: +46 70 656 1143 A/H: +46 26 10 16 11
