Icard/angular-clarity-master(work.../node_modules/pngjs/lib/interlace.js

96 lines
2.0 KiB
JavaScript

"use strict";
// Adam 7
// 0 1 2 3 4 5 6 7
// 0 x 6 4 6 x 6 4 6
// 1 7 7 7 7 7 7 7 7
// 2 5 6 5 6 5 6 5 6
// 3 7 7 7 7 7 7 7 7
// 4 3 6 4 6 3 6 4 6
// 5 7 7 7 7 7 7 7 7
// 6 5 6 5 6 5 6 5 6
// 7 7 7 7 7 7 7 7 7
let imagePasses = [
{
// pass 1 - 1px
x: [0],
y: [0],
},
{
// pass 2 - 1px
x: [4],
y: [0],
},
{
// pass 3 - 2px
x: [0, 4],
y: [4],
},
{
// pass 4 - 4px
x: [2, 6],
y: [0, 4],
},
{
// pass 5 - 8px
x: [0, 2, 4, 6],
y: [2, 6],
},
{
// pass 6 - 16px
x: [1, 3, 5, 7],
y: [0, 2, 4, 6],
},
{
// pass 7 - 32px
x: [0, 1, 2, 3, 4, 5, 6, 7],
y: [1, 3, 5, 7],
},
];
exports.getImagePasses = function (width, height) {
let images = [];
let xLeftOver = width % 8;
let yLeftOver = height % 8;
let xRepeats = (width - xLeftOver) / 8;
let yRepeats = (height - yLeftOver) / 8;
for (let i = 0; i < imagePasses.length; i++) {
let pass = imagePasses[i];
let passWidth = xRepeats * pass.x.length;
let passHeight = yRepeats * pass.y.length;
for (let j = 0; j < pass.x.length; j++) {
if (pass.x[j] < xLeftOver) {
passWidth++;
} else {
break;
}
}
for (let j = 0; j < pass.y.length; j++) {
if (pass.y[j] < yLeftOver) {
passHeight++;
} else {
break;
}
}
if (passWidth > 0 && passHeight > 0) {
images.push({ width: passWidth, height: passHeight, index: i });
}
}
return images;
};
exports.getInterlaceIterator = function (width) {
return function (x, y, pass) {
let outerXLeftOver = x % imagePasses[pass].x.length;
let outerX =
((x - outerXLeftOver) / imagePasses[pass].x.length) * 8 +
imagePasses[pass].x[outerXLeftOver];
let outerYLeftOver = y % imagePasses[pass].y.length;
let outerY =
((y - outerYLeftOver) / imagePasses[pass].y.length) * 8 +
imagePasses[pass].y[outerYLeftOver];
return outerX * 4 + outerY * width * 4;
};
};