--- /dev/null
+/**
+* A handy class to calculate color values.
+*
+* @version 1.0
+* @author Robert Eisele <robert@xarg.org>
+* @copyright Copyright (c) 2010, Robert Eisele
+* @link http://www.xarg.org/2010/03/generate-client-side-png-files-using-javascript/
+* @license http://www.opensource.org/licenses/bsd-license.php BSD License
+*
+*/
+
+(function() {
+
+ // helper functions for that ctx
+ function write(buffer, offs) {
+ for (var i = 2; i < arguments.length; i++) {
+ for (var j = 0; j < arguments[i].length; j++) {
+ buffer[offs++] = arguments[i].charAt(j);
+ }
+ }
+ }
+
+ function byte2(w) {
+ return String.fromCharCode((w >> 8) & 255, w & 255);
+ }
+
+ function byte4(w) {
+ return String.fromCharCode((w >> 24) & 255, (w >> 16) & 255, (w >> 8) & 255, w & 255);
+ }
+
+ function byte2lsb(w) {
+ return String.fromCharCode(w & 255, (w >> 8) & 255);
+ }
+
+ window.PNGlib = function(width,height,depth) {
+
+ this.width = width;
+ this.height = height;
+ this.depth = depth;
+
+ // pixel data and row filter identifier size
+ this.pix_size = height * (width + 1);
+
+ // deflate header, pix_size, block headers, adler32 checksum
+ this.data_size = 2 + this.pix_size + 5 * Math.floor((0xfffe + this.pix_size) / 0xffff) + 4;
+
+ // offsets and sizes of Png chunks
+ this.ihdr_offs = 0; // IHDR offset and size
+ this.ihdr_size = 4 + 4 + 13 + 4;
+ this.plte_offs = this.ihdr_offs + this.ihdr_size; // PLTE offset and size
+ this.plte_size = 4 + 4 + 3 * depth + 4;
+ this.trns_offs = this.plte_offs + this.plte_size; // tRNS offset and size
+ this.trns_size = 4 + 4 + depth + 4;
+ this.idat_offs = this.trns_offs + this.trns_size; // IDAT offset and size
+ this.idat_size = 4 + 4 + this.data_size + 4;
+ this.iend_offs = this.idat_offs + this.idat_size; // IEND offset and size
+ this.iend_size = 4 + 4 + 4;
+ this.buffer_size = this.iend_offs + this.iend_size; // total PNG size
+
+ this.buffer = new Array();
+ this.palette = new Object();
+ this.pindex = 0;
+
+ var _crc32 = new Array();
+
+ // initialize buffer with zero bytes
+ for (var i = 0; i < this.buffer_size; i++) {
+ this.buffer[i] = "\x00";
+ }
+
+ // initialize non-zero elements
+ write(this.buffer, this.ihdr_offs, byte4(this.ihdr_size - 12), 'IHDR', byte4(width), byte4(height), "\x08\x03");
+ write(this.buffer, this.plte_offs, byte4(this.plte_size - 12), 'PLTE');
+ write(this.buffer, this.trns_offs, byte4(this.trns_size - 12), 'tRNS');
+ write(this.buffer, this.idat_offs, byte4(this.idat_size - 12), 'IDAT');
+ write(this.buffer, this.iend_offs, byte4(this.iend_size - 12), 'IEND');
+
+ // initialize deflate header
+ var header = ((8 + (7 << 4)) << 8) | (3 << 6);
+ header+= 31 - (header % 31);
+
+ write(this.buffer, this.idat_offs + 8, byte2(header));
+
+ // initialize deflate block headers
+ for (var i = 0; (i << 16) - 1 < this.pix_size; i++) {
+ var size, bits;
+ if (i + 0xffff < this.pix_size) {
+ size = 0xffff;
+ bits = "\x00";
+ } else {
+ size = this.pix_size - (i << 16) - i;
+ bits = "\x01";
+ }
+ write(this.buffer, this.idat_offs + 8 + 2 + (i << 16) + (i << 2), bits, byte2lsb(size), byte2lsb(~size));
+ }
+
+ /* Create crc32 lookup table */
+ for (var i = 0; i < 256; i++) {
+ var c = i;
+ for (var j = 0; j < 8; j++) {
+ if (c & 1) {
+ c = -306674912 ^ ((c >> 1) & 0x7fffffff);
+ } else {
+ c = (c >> 1) & 0x7fffffff;
+ }
+ }
+ _crc32[i] = c;
+ }
+
+ // compute the index into a png for a given pixel
+ this.index = function(x,y) {
+ var i = y * (this.width + 1) + x + 1;
+ var j = this.idat_offs + 8 + 2 + 5 * Math.floor((i / 0xffff) + 1) + i;
+ return j;
+ }
+
+ // convert a color and build up the palette
+ this.color = function(red, green, blue, alpha) {
+
+ alpha = alpha >= 0 ? alpha : 255;
+ var color = (((((alpha << 8) | red) << 8) | green) << 8) | blue;
+
+ if (typeof this.palette[color] == "undefined") {
+ if (this.pindex == this.depth) return "\x00";
+
+ var ndx = this.plte_offs + 8 + 3 * this.pindex;
+
+ this.buffer[ndx + 0] = String.fromCharCode(red);
+ this.buffer[ndx + 1] = String.fromCharCode(green);
+ this.buffer[ndx + 2] = String.fromCharCode(blue);
+ this.buffer[this.trns_offs+8+this.pindex] = String.fromCharCode(alpha);
+
+ this.palette[color] = String.fromCharCode(this.pindex++);
+ }
+ return this.palette[color];
+ }
+
+ // output a PNG string, Base64 encoded
+ this.getBase64 = function() {
+
+ var s = this.getDump();
+
+ // If the current browser supports the Base64 encoding
+ // function, then offload the that to the browser as it
+ // will be done in native code.
+ if ((typeof window.btoa !== 'undefined') && (window.btoa !== null)) {
+ return window.btoa(s);
+ }
+
+ var ch = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
+ var c1, c2, c3, e1, e2, e3, e4;
+ var l = s.length;
+ var i = 0;
+ var r = "";
+
+ do {
+ c1 = s.charCodeAt(i);
+ e1 = c1 >> 2;
+ c2 = s.charCodeAt(i+1);
+ e2 = ((c1 & 3) << 4) | (c2 >> 4);
+ c3 = s.charCodeAt(i+2);
+ if (l < i+2) { e3 = 64; } else { e3 = ((c2 & 0xf) << 2) | (c3 >> 6); }
+ if (l < i+3) { e4 = 64; } else { e4 = c3 & 0x3f; }
+ r+= ch.charAt(e1) + ch.charAt(e2) + ch.charAt(e3) + ch.charAt(e4);
+ } while ((i+= 3) < l);
+ return r;
+ }
+
+ // output a PNG string
+ this.getDump = function() {
+
+ // compute adler32 of output pixels + row filter bytes
+ var BASE = 65521; /* largest prime smaller than 65536 */
+ var NMAX = 5552; /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
+ var s1 = 1;
+ var s2 = 0;
+ var n = NMAX;
+
+ for (var y = 0; y < this.height; y++) {
+ for (var x = -1; x < this.width; x++) {
+ s1+= this.buffer[this.index(x, y)].charCodeAt(0);
+ s2+= s1;
+ if ((n-= 1) == 0) {
+ s1%= BASE;
+ s2%= BASE;
+ n = NMAX;
+ }
+ }
+ }
+ s1%= BASE;
+ s2%= BASE;
+ write(this.buffer, this.idat_offs + this.idat_size - 8, byte4((s2 << 16) | s1));
+
+ // compute crc32 of the PNG chunks
+ function crc32(png, offs, size) {
+ var crc = -1;
+ for (var i = 4; i < size-4; i += 1) {
+ crc = _crc32[(crc ^ png[offs+i].charCodeAt(0)) & 0xff] ^ ((crc >> 8) & 0x00ffffff);
+ }
+ write(png, offs+size-4, byte4(crc ^ -1));
+ }
+
+ crc32(this.buffer, this.ihdr_offs, this.ihdr_size);
+ crc32(this.buffer, this.plte_offs, this.plte_size);
+ crc32(this.buffer, this.trns_offs, this.trns_size);
+ crc32(this.buffer, this.idat_offs, this.idat_size);
+ crc32(this.buffer, this.iend_offs, this.iend_size);
+
+ // convert PNG to string
+ return "\211PNG\r\n\032\n"+this.buffer.join('');
+ }
+ }
+
+})();
--- /dev/null
+
+// okay, not really sure how to output pngs yet
+
+function get_matrix(s,w,t,z) {
+ // Takes string s and width w and output an appropriate-sized matrix with
+ // width w and zeroes where there is a printed character and ones
+ // elsewhere if z is null or undefined. Tabs are the equivalent of t spaces
+ // I think it's pretty much ascii-only at this point
+ if(typeof z === "undefined") {
+ z = null;
+ }
+ wsfill = 0;
+ fill = 1;
+ if(z!=null) {
+ wsfill = 1;
+ fill = 0;
+ }
+ mat = [];
+ mat[0] = new Array(w);
+ numRows = 1;
+ currCol = 0;
+ extravar = fill;
+ for(i=0;i<s.length;i++) {
+ //console.log(s[i]);
+ // set up new row if needed
+ if(currCol==w) {
+ currCol = 0;
+ mat[numRows] = new Array(w);
+ numRows++;
+ }
+
+ switch (s[i]) {
+ case '\n':
+ while(currCol<w) {
+ mat[numRows-1][currCol] = wsfill;
+ currCol++;
+ }
+ currCol = 0;
+ mat[numRows] = new Array(w);
+ numRows++;
+ break;
+ case '\t':
+ // okay, no wraparound, just finish off the line if need be,
+ // else t spaces
+ left = w-currCol;
+ if(t>left) {
+ // do same for newline
+ while(currCol<w) {
+ mat[numRows-1][currCol] = wsfill;
+ currCol++;
+ }
+ currCol = 0;
+ mat[numRows] = new Array(w);
+ numRows++;
+ }
+ else {
+ // just put t spaces
+ for(j=0;j<t;j++) {
+ mat[numRows-1][currCol] = wsfill;
+ currCol++;
+ }
+ }
+ break;
+ case ' ':
+ extravar = wsfill;
+ default:
+ mat[numRows-1][currCol] = extravar;
+ currCol++;
+ extravar = fill;
+ }
+ }
+ while(currCol<w) {
+ mat[numRows-1][currCol] = wsfill;
+ currCol++;
+ }
+ return transpose(mat);
+}
+
+function transpose(mat) {
+ l = mat.length;
+ w = mat[0].length;
+ newmat = [];
+ for(i=0;i<w;i++) {
+ newmat[i] = new Array(l);
+ for(j=0;j<l;j++) {
+ newmat[i][j] = mat[j][i];
+ }
+ }
+ return newmat;
+}
+
+function mat_to_png(mat) {
+ // requires mat to be properly dimensioned and full
+ // returns PNGlib object
+ var p = new PNGlib(mat.length,mat[0].length,256);
+ var background = p.color(0xff,0xff,0xff,0xff);
+
+ for(i=0;i<mat.length;i++) {
+ for(j=0;j<mat[0].length;j++) {
+ if(mat[i][j] == 1) {
+ p.buffer[p.index(i,j)] = p.color(0x00,0x00,0x00);
+ }
+ }
+ }
+ return p;
+}
+
+
+function go() {
+ s = document.getElementById("txt").value;
+ w = document.getElementById("w").value;
+ t = document.getElementById("t").value;
+ scl = document.getElementById("scale").value;
+ console.log(w);
+ console.log(t);
+ p = mat_to_png(get_matrix(s,w,t));
+ document.getElementById("img_zone").innerHTML = '<img src="data:image/png;base64,'+p.getBase64()+'">';
+ //d = document.createElement('div');
+ //d.innerHTML =
+ //document.getElementById("img_zone").appendChild(d);
+}
home / projects / textrivers / commitdiff