| Index: bower_components/gif.js/src/LZWEncoder.js
|
| diff --git a/bower_components/gif.js/src/LZWEncoder.js b/bower_components/gif.js/src/LZWEncoder.js
|
| deleted file mode 100644
|
| index b12edc9d2e01369226859f9d4896b4fdf926f10d..0000000000000000000000000000000000000000
|
| --- a/bower_components/gif.js/src/LZWEncoder.js
|
| +++ /dev/null
|
| @@ -1,209 +0,0 @@
|
| -/*
|
| - LZWEncoder.js
|
| -
|
| - Authors
|
| - Kevin Weiner (original Java version - kweiner@fmsware.com)
|
| - Thibault Imbert (AS3 version - bytearray.org)
|
| - Johan Nordberg (JS version - code@johan-nordberg.com)
|
| -
|
| - Acknowledgements
|
| - GIFCOMPR.C - GIF Image compression routines
|
| - Lempel-Ziv compression based on 'compress'. GIF modifications by
|
| - David Rowley (mgardi@watdcsu.waterloo.edu)
|
| - GIF Image compression - modified 'compress'
|
| - Based on: compress.c - File compression ala IEEE Computer, June 1984.
|
| - By Authors: Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!thomas)
|
| - Jim McKie (decvax!mcvax!jim)
|
| - Steve Davies (decvax!vax135!petsd!peora!srd)
|
| - Ken Turkowski (decvax!decwrl!turtlevax!ken)
|
| - James A. Woods (decvax!ihnp4!ames!jaw)
|
| - Joe Orost (decvax!vax135!petsd!joe)
|
| -*/
|
| -
|
| -var EOF = -1;
|
| -var BITS = 12;
|
| -var HSIZE = 5003; // 80% occupancy
|
| -var masks = [0x0000, 0x0001, 0x0003, 0x0007, 0x000F, 0x001F,
|
| - 0x003F, 0x007F, 0x00FF, 0x01FF, 0x03FF, 0x07FF,
|
| - 0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF];
|
| -
|
| -function LZWEncoder(width, height, pixels, colorDepth) {
|
| - var initCodeSize = Math.max(2, colorDepth);
|
| -
|
| - var accum = new Uint8Array(256);
|
| - var htab = new Int32Array(HSIZE);
|
| - var codetab = new Int32Array(HSIZE);
|
| -
|
| - var cur_accum, cur_bits = 0;
|
| - var a_count;
|
| - var free_ent = 0; // first unused entry
|
| - var maxcode;
|
| -
|
| - // block compression parameters -- after all codes are used up,
|
| - // and compression rate changes, start over.
|
| - var clear_flg = false;
|
| -
|
| - // Algorithm: use open addressing double hashing (no chaining) on the
|
| - // prefix code / next character combination. We do a variant of Knuth's
|
| - // algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
|
| - // secondary probe. Here, the modular division first probe is gives way
|
| - // to a faster exclusive-or manipulation. Also do block compression with
|
| - // an adaptive reset, whereby the code table is cleared when the compression
|
| - // ratio decreases, but after the table fills. The variable-length output
|
| - // codes are re-sized at this point, and a special CLEAR code is generated
|
| - // for the decompressor. Late addition: construct the table according to
|
| - // file size for noticeable speed improvement on small files. Please direct
|
| - // questions about this implementation to ames!jaw.
|
| - var g_init_bits, ClearCode, EOFCode;
|
| -
|
| - // Add a character to the end of the current packet, and if it is 254
|
| - // characters, flush the packet to disk.
|
| - function char_out(c, outs) {
|
| - accum[a_count++] = c;
|
| - if (a_count >= 254) flush_char(outs);
|
| - }
|
| -
|
| - // Clear out the hash table
|
| - // table clear for block compress
|
| - function cl_block(outs) {
|
| - cl_hash(HSIZE);
|
| - free_ent = ClearCode + 2;
|
| - clear_flg = true;
|
| - output(ClearCode, outs);
|
| - }
|
| -
|
| - // Reset code table
|
| - function cl_hash(hsize) {
|
| - for (var i = 0; i < hsize; ++i) htab[i] = -1;
|
| - }
|
| -
|
| - function compress(init_bits, outs) {
|
| - var fcode, c, i, ent, disp, hsize_reg, hshift;
|
| -
|
| - // Set up the globals: g_init_bits - initial number of bits
|
| - g_init_bits = init_bits;
|
| -
|
| - // Set up the necessary values
|
| - clear_flg = false;
|
| - n_bits = g_init_bits;
|
| - maxcode = MAXCODE(n_bits);
|
| -
|
| - ClearCode = 1 << (init_bits - 1);
|
| - EOFCode = ClearCode + 1;
|
| - free_ent = ClearCode + 2;
|
| -
|
| - a_count = 0; // clear packet
|
| -
|
| - ent = nextPixel();
|
| -
|
| - hshift = 0;
|
| - for (fcode = HSIZE; fcode < 65536; fcode *= 2) ++hshift;
|
| - hshift = 8 - hshift; // set hash code range bound
|
| - hsize_reg = HSIZE;
|
| - cl_hash(hsize_reg); // clear hash table
|
| -
|
| - output(ClearCode, outs);
|
| -
|
| - outer_loop: while ((c = nextPixel()) != EOF) {
|
| - fcode = (c << BITS) + ent;
|
| - i = (c << hshift) ^ ent; // xor hashing
|
| - if (htab[i] === fcode) {
|
| - ent = codetab[i];
|
| - continue;
|
| - } else if (htab[i] >= 0) { // non-empty slot
|
| - disp = hsize_reg - i; // secondary hash (after G. Knott)
|
| - if (i === 0) disp = 1;
|
| - do {
|
| - if ((i -= disp) < 0) i += hsize_reg;
|
| - if (htab[i] === fcode) {
|
| - ent = codetab[i];
|
| - continue outer_loop;
|
| - }
|
| - } while (htab[i] >= 0);
|
| - }
|
| - output(ent, outs);
|
| - ent = c;
|
| - if (free_ent < 1 << BITS) {
|
| - codetab[i] = free_ent++; // code -> hashtable
|
| - htab[i] = fcode;
|
| - } else {
|
| - cl_block(outs);
|
| - }
|
| - }
|
| -
|
| - // Put out the final code.
|
| - output(ent, outs);
|
| - output(EOFCode, outs);
|
| - }
|
| -
|
| - function encode(outs) {
|
| - outs.writeByte(initCodeSize); // write "initial code size" byte
|
| - remaining = width * height; // reset navigation variables
|
| - curPixel = 0;
|
| - compress(initCodeSize + 1, outs); // compress and write the pixel data
|
| - outs.writeByte(0); // write block terminator
|
| - }
|
| -
|
| - // Flush the packet to disk, and reset the accumulator
|
| - function flush_char(outs) {
|
| - if (a_count > 0) {
|
| - outs.writeByte(a_count);
|
| - outs.writeBytes(accum, 0, a_count);
|
| - a_count = 0;
|
| - }
|
| - }
|
| -
|
| - function MAXCODE(n_bits) {
|
| - return (1 << n_bits) - 1;
|
| - }
|
| -
|
| - // Return the next pixel from the image
|
| - function nextPixel() {
|
| - if (remaining === 0) return EOF;
|
| - --remaining;
|
| - var pix = pixels[curPixel++];
|
| - return pix & 0xff;
|
| - }
|
| -
|
| - function output(code, outs) {
|
| - cur_accum &= masks[cur_bits];
|
| -
|
| - if (cur_bits > 0) cur_accum |= (code << cur_bits);
|
| - else cur_accum = code;
|
| -
|
| - cur_bits += n_bits;
|
| -
|
| - while (cur_bits >= 8) {
|
| - char_out((cur_accum & 0xff), outs);
|
| - cur_accum >>= 8;
|
| - cur_bits -= 8;
|
| - }
|
| -
|
| - // If the next entry is going to be too big for the code size,
|
| - // then increase it, if possible.
|
| - if (free_ent > maxcode || clear_flg) {
|
| - if (clear_flg) {
|
| - maxcode = MAXCODE(n_bits = g_init_bits);
|
| - clear_flg = false;
|
| - } else {
|
| - ++n_bits;
|
| - if (n_bits == BITS) maxcode = 1 << BITS;
|
| - else maxcode = MAXCODE(n_bits);
|
| - }
|
| - }
|
| -
|
| - if (code == EOFCode) {
|
| - // At EOF, write the rest of the buffer.
|
| - while (cur_bits > 0) {
|
| - char_out((cur_accum & 0xff), outs);
|
| - cur_accum >>= 8;
|
| - cur_bits -= 8;
|
| - }
|
| - flush_char(outs);
|
| - }
|
| - }
|
| -
|
| - this.encode = encode;
|
| -}
|
| -
|
| -module.exports = LZWEncoder;
|
|
|