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compileType3Glyph cleanup

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fkaelberer 2013-06-11 21:01:10 +02:00
parent 220627b135
commit 2cdd8de25a
1 changed files with 28 additions and 28 deletions
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56
src/canvas.js
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@ -191,13 +191,13 @@ var CachedCanvases = (function CachedCanvasesClosure() {
})();
function compileType3Glyph(imgData) {
var t1 = window.performance.now();
var POINT_TO_PROCESS_LIMIT = 1000;
var width = imgData.width, height = imgData.height;
var i, j, width1 = width+1;
var points = new Uint8Array(width1*(height+1));
var TYPES = [0, 2, 4, 0, 1, 0, 5, 4, 8, 10, 0, 8, 0, 2, 1, 0];
var i, j, j0, width1 = width + 1;
var points = new Uint8Array(width1 * (height + 1));
var POINT_TYPES =
new Uint8Array([0, 2, 4, 0, 1, 0, 5, 4, 8, 10, 0, 8, 0, 2, 1, 0]);
// finding iteresting points: every point is located between mask pixels,
// so there will be points of the (width + 1)x(height + 1) grid. Every point
// will have flags assigned based on neighboring mask pixels:
@ -226,20 +226,19 @@ function compileType3Glyph(imgData) {
}
pos += 4;
for (i = 1; i < height; i++) {
var j0 = i * width1;
j0 = i * width1;
if (data[pos - lineSize] !== data[pos]) {
points[j0] = data[pos] ? 1 : 8;
++count;
}
// 'sum' is the position of the current pixel configuration in the 'TYPES'
// array (in order 8-1-2-4, so we can use '>>2' to shift the column).
var sum = (data[pos] ? 4 : 0) + (data[pos - lineSize] ? 8 : 0);
for (j = 1; j < width; j++) {
sum = (sum >> 2) + (data[pos + 4] ? 4 : 0) +
(data[pos - lineSize + 4] ? 8 : 0);
if (TYPES[sum]) {
points[j0 + j] = TYPES[sum];
if (POINT_TYPES[sum]) {
points[j0 + j] = POINT_TYPES[sum];
++count;
}
pos += 4;
@ -254,20 +253,22 @@ function compileType3Glyph(imgData) {
return null;
}
}
pos -= lineSize;
j0 = i * width1;
if (data[pos] !== 0) {
points[i * width1] = 8;
points[j0] = 8;
++count;
}
for (j = 1; j < width; j++) {
if (data[pos] !== data[pos + 4]) {
points[i * width1 + j] = data[pos] ? 4 : 8;
points[j0 + j] = data[pos] ? 4 : 8;
++count;
}
pos += 4;
}
if (data[pos] !== 0) {
points[i * width1 + j] = 4;
points[j0 + j] = 4;
++count;
}
if (count > POINT_TO_PROCESS_LIMIT) {
@ -275,8 +276,8 @@ function compileType3Glyph(imgData) {
}
// building outlines
var steps = new Int32Array([0, width1, -1, 0, -width1, 0, 0, 0, 1]);
var outlines = [];
var steps = [0, width1, -1, 0, -width1, 0, 0, 0, 1];
for (i = 0; count && i <= height; i++) {
var p = i * width1;
var end = p + width;
@ -286,31 +287,31 @@ function compileType3Glyph(imgData) {
if (p === end) {
continue;
}
var from = [p % width1];
var to = [i];
var coords = [p % width1, i];
var type = points[p], p0 = p;
var type = points[p], p0 = p, pp;
do {
var step = steps[type];
do { p += step; } while (!points[p]);
if (points[p] % 5) {
pp = points[p];
if (pp !== 5 && pp !== 10) {
// set new direction
type = points[p];
type = pp;
// delete mark
points[p] = 0;
} else { // type is 5 or 10, ie, a crossing
// set new direction
type = points[p] & ((0x33 * type) >> 4);
type = pp & ((0x33 * type) >> 4);
// set new type for "future hit"
points[p] &= (type >> 2 | type << 2);
}
from.push(p % width1);
to.push((p / width1) | 0);
coords.push(p % width1);
coords.push((p / width1) | 0);
--count;
} while (p0 !== p);
outlines.push([from, to]);
outlines.push(coords);
--i;
}
@ -320,12 +321,11 @@ function compileType3Glyph(imgData) {
c.scale(1 / width, -1 / height);
c.translate(0, -height);
c.beginPath();
for (var i=0; i<outlines.length; i++) {
var f = outlines[i][0];
var t = outlines[i][1];
c.moveTo(f[0], t[0]);
for (var j=1; j<f.length; j++) {
c.lineTo(f[j], t[j]);
for (var i = 0, ii = outlines.length; i < ii; i++) {
var o = outlines[i];
c.moveTo(o[0], o[1]);
for (var j = 2, jj = o.length; j < jj; j += 2) {
c.lineTo(o[j], o[j+1]);
}
}
c.fill();