html2canvas
Version:
Screenshots with JavaScript
165 lines • 7.59 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.calculateRadius = exports.calculateGradientDirection = exports.processColorStops = exports.parseColorStop = void 0;
var color_1 = require("../color");
var length_percentage_1 = require("../length-percentage");
var parseColorStop = function (context, args) {
var color = color_1.color.parse(context, args[0]);
var stop = args[1];
return stop && length_percentage_1.isLengthPercentage(stop) ? { color: color, stop: stop } : { color: color, stop: null };
};
exports.parseColorStop = parseColorStop;
var processColorStops = function (stops, lineLength) {
var first = stops[0];
var last = stops[stops.length - 1];
if (first.stop === null) {
first.stop = length_percentage_1.ZERO_LENGTH;
}
if (last.stop === null) {
last.stop = length_percentage_1.HUNDRED_PERCENT;
}
var processStops = [];
var previous = 0;
for (var i = 0; i < stops.length; i++) {
var stop_1 = stops[i].stop;
if (stop_1 !== null) {
var absoluteValue = length_percentage_1.getAbsoluteValue(stop_1, lineLength);
if (absoluteValue > previous) {
processStops.push(absoluteValue);
}
else {
processStops.push(previous);
}
previous = absoluteValue;
}
else {
processStops.push(null);
}
}
var gapBegin = null;
for (var i = 0; i < processStops.length; i++) {
var stop_2 = processStops[i];
if (stop_2 === null) {
if (gapBegin === null) {
gapBegin = i;
}
}
else if (gapBegin !== null) {
var gapLength = i - gapBegin;
var beforeGap = processStops[gapBegin - 1];
var gapValue = (stop_2 - beforeGap) / (gapLength + 1);
for (var g = 1; g <= gapLength; g++) {
processStops[gapBegin + g - 1] = gapValue * g;
}
gapBegin = null;
}
}
return stops.map(function (_a, i) {
var color = _a.color;
return { color: color, stop: Math.max(Math.min(1, processStops[i] / lineLength), 0) };
});
};
exports.processColorStops = processColorStops;
var getAngleFromCorner = function (corner, width, height) {
var centerX = width / 2;
var centerY = height / 2;
var x = length_percentage_1.getAbsoluteValue(corner[0], width) - centerX;
var y = centerY - length_percentage_1.getAbsoluteValue(corner[1], height);
return (Math.atan2(y, x) + Math.PI * 2) % (Math.PI * 2);
};
var calculateGradientDirection = function (angle, width, height) {
var radian = typeof angle === 'number' ? angle : getAngleFromCorner(angle, width, height);
var lineLength = Math.abs(width * Math.sin(radian)) + Math.abs(height * Math.cos(radian));
var halfWidth = width / 2;
var halfHeight = height / 2;
var halfLineLength = lineLength / 2;
var yDiff = Math.sin(radian - Math.PI / 2) * halfLineLength;
var xDiff = Math.cos(radian - Math.PI / 2) * halfLineLength;
return [lineLength, halfWidth - xDiff, halfWidth + xDiff, halfHeight - yDiff, halfHeight + yDiff];
};
exports.calculateGradientDirection = calculateGradientDirection;
var distance = function (a, b) { return Math.sqrt(a * a + b * b); };
var findCorner = function (width, height, x, y, closest) {
var corners = [
[0, 0],
[0, height],
[width, 0],
[width, height]
];
return corners.reduce(function (stat, corner) {
var cx = corner[0], cy = corner[1];
var d = distance(x - cx, y - cy);
if (closest ? d < stat.optimumDistance : d > stat.optimumDistance) {
return {
optimumCorner: corner,
optimumDistance: d
};
}
return stat;
}, {
optimumDistance: closest ? Infinity : -Infinity,
optimumCorner: null
}).optimumCorner;
};
var calculateRadius = function (gradient, x, y, width, height) {
var rx = 0;
var ry = 0;
switch (gradient.size) {
case 0 /* CLOSEST_SIDE */:
// The ending shape is sized so that that it exactly meets the side of the gradient box closest to the gradient’s center.
// If the shape is an ellipse, it exactly meets the closest side in each dimension.
if (gradient.shape === 0 /* CIRCLE */) {
rx = ry = Math.min(Math.abs(x), Math.abs(x - width), Math.abs(y), Math.abs(y - height));
}
else if (gradient.shape === 1 /* ELLIPSE */) {
rx = Math.min(Math.abs(x), Math.abs(x - width));
ry = Math.min(Math.abs(y), Math.abs(y - height));
}
break;
case 2 /* CLOSEST_CORNER */:
// The ending shape is sized so that that it passes through the corner of the gradient box closest to the gradient’s center.
// If the shape is an ellipse, the ending shape is given the same aspect-ratio it would have if closest-side were specified.
if (gradient.shape === 0 /* CIRCLE */) {
rx = ry = Math.min(distance(x, y), distance(x, y - height), distance(x - width, y), distance(x - width, y - height));
}
else if (gradient.shape === 1 /* ELLIPSE */) {
// Compute the ratio ry/rx (which is to be the same as for "closest-side")
var c = Math.min(Math.abs(y), Math.abs(y - height)) / Math.min(Math.abs(x), Math.abs(x - width));
var _a = findCorner(width, height, x, y, true), cx = _a[0], cy = _a[1];
rx = distance(cx - x, (cy - y) / c);
ry = c * rx;
}
break;
case 1 /* FARTHEST_SIDE */:
// Same as closest-side, except the ending shape is sized based on the farthest side(s)
if (gradient.shape === 0 /* CIRCLE */) {
rx = ry = Math.max(Math.abs(x), Math.abs(x - width), Math.abs(y), Math.abs(y - height));
}
else if (gradient.shape === 1 /* ELLIPSE */) {
rx = Math.max(Math.abs(x), Math.abs(x - width));
ry = Math.max(Math.abs(y), Math.abs(y - height));
}
break;
case 3 /* FARTHEST_CORNER */:
// Same as closest-corner, except the ending shape is sized based on the farthest corner.
// If the shape is an ellipse, the ending shape is given the same aspect ratio it would have if farthest-side were specified.
if (gradient.shape === 0 /* CIRCLE */) {
rx = ry = Math.max(distance(x, y), distance(x, y - height), distance(x - width, y), distance(x - width, y - height));
}
else if (gradient.shape === 1 /* ELLIPSE */) {
// Compute the ratio ry/rx (which is to be the same as for "farthest-side")
var c = Math.max(Math.abs(y), Math.abs(y - height)) / Math.max(Math.abs(x), Math.abs(x - width));
var _b = findCorner(width, height, x, y, false), cx = _b[0], cy = _b[1];
rx = distance(cx - x, (cy - y) / c);
ry = c * rx;
}
break;
}
if (Array.isArray(gradient.size)) {
rx = length_percentage_1.getAbsoluteValue(gradient.size[0], width);
ry = gradient.size.length === 2 ? length_percentage_1.getAbsoluteValue(gradient.size[1], height) : rx;
}
return [rx, ry];
};
exports.calculateRadius = calculateRadius;
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