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/**
* @author Kener (@Kener-林峰, kener.linfeng@gmail.com)
* pissang(https://github.com/pissang)
* errorrik (errorrik@gmail.com)
*/
define(
function (require) {
var vec2 = require('./vector');
var curve = require('./curve');
/**
* 从顶点数组中计算出最小包围盒，写入`min`和`max`中
* @module zrender/tool/computeBoundingBox
* @param {Array<Object>} points 顶点数组
* @param {number} min
* @param {number} max
*/
function computeBoundingBox(points, min, max) {
if (points.length === 0) {
return;
}
var left = points[0][0];
var right = points[0][0];
var top = points[0][1];
var bottom = points[0][1];
for (var i = 1; i < points.length; i++) {
var p = points[i];
if (p[0] < left) {
left = p[0];
}
if (p[0] > right) {
right = p[0];
}
if (p[1] < top) {
top = p[1];
}
if (p[1] > bottom) {
bottom = p[1];
}
}
min[0] = left;
min[1] = top;
max[0] = right;
max[1] = bottom;
}
/**
* 从三阶贝塞尔曲线(p0, p1, p2, p3)中计算出最小包围盒，写入`min`和`max`中
* @memberOf module:zrender/tool/computeBoundingBox
* @param {Array.<number>} p0
* @param {Array.<number>} p1
* @param {Array.<number>} p2
* @param {Array.<number>} p3
* @param {Array.<number>} min
* @param {Array.<number>} max
*/
function computeCubeBezierBoundingBox(p0, p1, p2, p3, min, max) {
var xDim = [];
curve.cubicExtrema(p0[0], p1[0], p2[0], p3[0], xDim);
for (var i = 0; i < xDim.length; i++) {
xDim[i] = curve.cubicAt(p0[0], p1[0], p2[0], p3[0], xDim[i]);
}
var yDim = [];
curve.cubicExtrema(p0[1], p1[1], p2[1], p3[1], yDim);
for (var i = 0; i < yDim.length; i++) {
yDim[i] = curve.cubicAt(p0[1], p1[1], p2[1], p3[1], yDim[i]);
}
xDim.push(p0[0], p3[0]);
yDim.push(p0[1], p3[1]);
var left = Math.min.apply(null, xDim);
var right = Math.max.apply(null, xDim);
var top = Math.min.apply(null, yDim);
var bottom = Math.max.apply(null, yDim);
min[0] = left;
min[1] = top;
max[0] = right;
max[1] = bottom;
}
/**
* 从二阶贝塞尔曲线(p0, p1, p2)中计算出最小包围盒，写入`min`和`max`中
* @memberOf module:zrender/tool/computeBoundingBox
* @param {Array.<number>} p0
* @param {Array.<number>} p1
* @param {Array.<number>} p2
* @param {Array.<number>} min
* @param {Array.<number>} max
*/
function computeQuadraticBezierBoundingBox(p0, p1, p2, min, max) {
// Find extremities, where derivative in x dim or y dim is zero
var t1 = curve.quadraticExtremum(p0[0], p1[0], p2[0]);
var t2 = curve.quadraticExtremum(p0[1], p1[1], p2[1]);
t1 = Math.max(Math.min(t1, 1), 0);
t2 = Math.max(Math.min(t2, 1), 0);
var ct1 = 1 - t1;
var ct2 = 1 - t2;
var x1 = ct1 * ct1 * p0[0]
+ 2 * ct1 * t1 * p1[0]
+ t1 * t1 * p2[0];
var y1 = ct1 * ct1 * p0[1]
+ 2 * ct1 * t1 * p1[1]
+ t1 * t1 * p2[1];
var x2 = ct2 * ct2 * p0[0]
+ 2 * ct2 * t2 * p1[0]
+ t2 * t2 * p2[0];
var y2 = ct2 * ct2 * p0[1]
+ 2 * ct2 * t2 * p1[1]
+ t2 * t2 * p2[1];
min[0] = Math.min(p0[0], p2[0], x1, x2);
min[1] = Math.min(p0[1], p2[1], y1, y2);
max[0] = Math.max(p0[0], p2[0], x1, x2);
max[1] = Math.max(p0[1], p2[1], y1, y2);
}
var start = vec2.create();
var end = vec2.create();
var extremity = vec2.create();
/**
* 从圆弧中计算出最小包围盒，写入`min`和`max`中
* @method
* @memberOf module:zrender/tool/computeBoundingBox
* @param {Array.<number>} center 圆弧中心点
* @param {number} radius 圆弧半径
* @param {number} startAngle 圆弧开始角度
* @param {number} endAngle 圆弧结束角度
* @param {number} anticlockwise 是否是顺时针
* @param {Array.<number>} min
* @param {Array.<number>} max
*/
var computeArcBoundingBox = function (
x, y, r, startAngle, endAngle, anticlockwise, min, max
) {
if (Math.abs(startAngle - endAngle) >= Math.PI * 2) {
// Is a circle
min[0] = x - r;
min[1] = y - r;
max[0] = x + r;
max[1] = y + r;
return;
}
start[0] = Math.cos(startAngle) * r + x;
start[1] = Math.sin(startAngle) * r + y;
end[0] = Math.cos(endAngle) * r + x;
end[1] = Math.sin(endAngle) * r + y;
vec2.min(min, start, end);
vec2.max(max, start, end);
// Thresh to [0, Math.PI * 2]
startAngle = startAngle % (Math.PI * 2);
if (startAngle < 0) {
startAngle = startAngle + Math.PI * 2;
}
endAngle = endAngle % (Math.PI * 2);
if (endAngle < 0) {
endAngle = endAngle + Math.PI * 2;
}
if (startAngle > endAngle && !anticlockwise) {
endAngle += Math.PI * 2;
} else if (startAngle < endAngle && anticlockwise) {
startAngle += Math.PI * 2;
}
if (anticlockwise) {
var tmp = endAngle;
endAngle = startAngle;
startAngle = tmp;
}
// var number = 0;
// var step = (anticlockwise ? -Math.PI : Math.PI) / 2;
for (var angle = 0; angle < endAngle; angle += Math.PI / 2) {
if (angle > startAngle) {
extremity[0] = Math.cos(angle) * r + x;
extremity[1] = Math.sin(angle) * r + y;
vec2.min(min, extremity, min);
vec2.max(max, extremity, max);
}
}
};
computeBoundingBox.cubeBezier = computeCubeBezierBoundingBox;
computeBoundingBox.quadraticBezier = computeQuadraticBezierBoundingBox;
computeBoundingBox.arc = computeArcBoundingBox;
return computeBoundingBox;
}
);