phaser-ce
Version:
Phaser CE (Community Edition) is a fast, free and fun HTML5 Game Framework for Desktop and Mobile web browsers.
708 lines (566 loc) • 19.3 kB
JavaScript
/*
* Copyright (c) 2016, Mapbox
*
* Permission to use, copy, modify, and/or distribute this software for any purpose
* with or without fee is hereby granted, provided that the above copyright notice
* and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
* OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
* THIS SOFTWARE.
*/
/**
* @class EarCut
*/
Phaser.EarCut = {};
Phaser.EarCut.Triangulate = function (data, holeIndices, dim)
{
dim = dim || 2;
var hasHoles = holeIndices && holeIndices.length,
outerLen = hasHoles ? holeIndices[0] * dim : data.length,
outerNode = Phaser.EarCut.linkedList(data, 0, outerLen, dim, true),
triangles = [];
if (!outerNode) { return triangles; }
var minX, minY, maxX, maxY, x, y, size;
if (hasHoles) { outerNode = Phaser.EarCut.eliminateHoles(data, holeIndices, outerNode, dim); }
// if the shape is not too simple, we'll use z-order curve hash later; calculate polygon bbox
if (data.length > 80 * dim)
{
minX = maxX = data[0];
minY = maxY = data[1];
for (var i = dim; i < outerLen; i += dim)
{
x = data[i];
y = data[i + 1];
if (x < minX) { minX = x; }
if (y < minY) { minY = y; }
if (x > maxX) { maxX = x; }
if (y > maxY) { maxY = y; }
}
// minX, minY and size are later used to transform coords into integers for z-order calculation
size = Math.max(maxX - minX, maxY - minY);
}
Phaser.EarCut.earcutLinked(outerNode, triangles, dim, minX, minY, size);
return triangles;
};
// create a circular doubly linked list from polygon points in the specified winding order
Phaser.EarCut.linkedList = function (data, start, end, dim, clockwise)
{
var sum = 0,
i, j, last;
// calculate original winding order of a polygon ring
for (i = start, j = end - dim; i < end; i += dim)
{
sum += (data[j] - data[i]) * (data[i + 1] + data[j + 1]);
j = i;
}
// link points into circular doubly-linked list in the specified winding order
if (clockwise === (sum > 0))
{
for (i = start; i < end; i += dim) { last = Phaser.EarCut.insertNode(i, data[i], data[i + 1], last); }
}
else
{
for (i = end - dim; i >= start; i -= dim) { last = Phaser.EarCut.insertNode(i, data[i], data[i + 1], last); }
}
return last;
};
// eliminate colinear or duplicate points
Phaser.EarCut.filterPoints = function (start, end)
{
if (!start) { return start; }
if (!end) { end = start; }
var p = start,
again;
do
{
again = false;
if (!p.steiner && (Phaser.EarCut.equals(p, p.next) || Phaser.EarCut.area(p.prev, p, p.next) === 0))
{
Phaser.EarCut.removeNode(p);
p = end = p.prev;
if (p === p.next) { return null; }
again = true;
}
else
{
p = p.next;
}
} while (again || p !== end);
return end;
};
// main ear slicing loop which triangulates a polygon (given as a linked list)
Phaser.EarCut.earcutLinked = function (ear, triangles, dim, minX, minY, size, pass)
{
if (!ear) { return; }
// interlink polygon nodes in z-order
if (!pass && size) { Phaser.EarCut.indexCurve(ear, minX, minY, size); }
var stop = ear,
prev, next;
// iterate through ears, slicing them one by one
while (ear.prev !== ear.next)
{
prev = ear.prev;
next = ear.next;
if (size ? Phaser.EarCut.isEarHashed(ear, minX, minY, size) : Phaser.EarCut.isEar(ear))
{
// cut off the triangle
triangles.push(prev.i / dim);
triangles.push(ear.i / dim);
triangles.push(next.i / dim);
Phaser.EarCut.removeNode(ear);
// skipping the next vertice leads to less sliver triangles
ear = next.next;
stop = next.next;
continue;
}
ear = next;
// if we looped through the whole remaining polygon and can't find any more ears
if (ear === stop)
{
// try filtering points and slicing again
if (!pass)
{
Phaser.EarCut.earcutLinked(Phaser.EarCut.filterPoints(ear), triangles, dim, minX, minY, size, 1);
// if this didn't work, try curing all small self-intersections locally
}
else if (pass === 1)
{
ear = Phaser.EarCut.cureLocalIntersections(ear, triangles, dim);
Phaser.EarCut.earcutLinked(ear, triangles, dim, minX, minY, size, 2);
// as a last resort, try splitting the remaining polygon into two
}
else if (pass === 2)
{
Phaser.EarCut.splitEarcut(ear, triangles, dim, minX, minY, size);
}
break;
}
}
};
// check whether a polygon node forms a valid ear with adjacent nodes
Phaser.EarCut.isEar = function (ear)
{
var a = ear.prev,
b = ear,
c = ear.next;
if (Phaser.EarCut.area(a, b, c) >= 0) { return false; } // reflex, can't be an ear
// now make sure we don't have other points inside the potential ear
var p = ear.next.next;
while (p !== ear.prev)
{
if (Phaser.EarCut.pointInTriangle(a.x, a.y, b.x, b.y, c.x, c.y, p.x, p.y) &&
Phaser.EarCut.area(p.prev, p, p.next) >= 0) { return false; }
p = p.next;
}
return true;
};
Phaser.EarCut.isEarHashed = function (ear, minX, minY, size)
{
var a = ear.prev,
b = ear,
c = ear.next;
if (Phaser.EarCut.area(a, b, c) >= 0) { return false; } // reflex, can't be an ear
// triangle bbox; min & max are calculated like this for speed
var minTX = a.x < b.x ? (a.x < c.x ? a.x : c.x) : (b.x < c.x ? b.x : c.x),
minTY = a.y < b.y ? (a.y < c.y ? a.y : c.y) : (b.y < c.y ? b.y : c.y),
maxTX = a.x > b.x ? (a.x > c.x ? a.x : c.x) : (b.x > c.x ? b.x : c.x),
maxTY = a.y > b.y ? (a.y > c.y ? a.y : c.y) : (b.y > c.y ? b.y : c.y);
// z-order range for the current triangle bbox;
var minZ = Phaser.EarCut.zOrder(minTX, minTY, minX, minY, size),
maxZ = Phaser.EarCut.zOrder(maxTX, maxTY, minX, minY, size);
// first look for points inside the triangle in increasing z-order
var p = ear.nextZ;
while (p && p.z <= maxZ)
{
if (p !== ear.prev && p !== ear.next &&
Phaser.EarCut.pointInTriangle(a.x, a.y, b.x, b.y, c.x, c.y, p.x, p.y) &&
Phaser.EarCut.area(p.prev, p, p.next) >= 0) { return false; }
p = p.nextZ;
}
// then look for points in decreasing z-order
p = ear.prevZ;
while (p && p.z >= minZ)
{
if (p !== ear.prev && p !== ear.next &&
Phaser.EarCut.pointInTriangle(a.x, a.y, b.x, b.y, c.x, c.y, p.x, p.y) &&
Phaser.EarCut.area(p.prev, p, p.next) >= 0) { return false; }
p = p.prevZ;
}
return true;
};
// go through all polygon nodes and cure small local self-intersections
Phaser.EarCut.cureLocalIntersections = function (start, triangles, dim)
{
var p = start;
do
{
var a = p.prev,
b = p.next.next;
// a self-intersection where edge (v[i-1],v[i]) intersects (v[i+1],v[i+2])
if (Phaser.EarCut.intersects(a, p, p.next, b) && Phaser.EarCut.locallyInside(a, b) && Phaser.EarCut.locallyInside(b, a))
{
triangles.push(a.i / dim);
triangles.push(p.i / dim);
triangles.push(b.i / dim);
// remove two nodes involved
Phaser.EarCut.removeNode(p);
Phaser.EarCut.removeNode(p.next);
p = start = b;
}
p = p.next;
} while (p !== start);
return p;
};
// try splitting polygon into two and triangulate them independently
Phaser.EarCut.splitEarcut = function (start, triangles, dim, minX, minY, size)
{
// look for a valid diagonal that divides the polygon into two
var a = start;
do
{
var b = a.next.next;
while (b !== a.prev)
{
if (a.i !== b.i && Phaser.EarCut.isValidDiagonal(a, b))
{
// split the polygon in two by the diagonal
var c = Phaser.EarCut.splitPolygon(a, b);
// filter colinear points around the cuts
a = Phaser.EarCut.filterPoints(a, a.next);
c = Phaser.EarCut.filterPoints(c, c.next);
// run earcut on each half
Phaser.EarCut.earcutLinked(a, triangles, dim, minX, minY, size);
Phaser.EarCut.earcutLinked(c, triangles, dim, minX, minY, size);
return;
}
b = b.next;
}
a = a.next;
} while (a !== start);
};
// link every hole into the outer loop, producing a single-ring polygon without holes
Phaser.EarCut.eliminateHoles = function (data, holeIndices, outerNode, dim)
{
var queue = [],
i, len, start, end, list;
for (i = 0, len = holeIndices.length; i < len; i++)
{
start = holeIndices[i] * dim;
end = i < len - 1 ? holeIndices[i + 1] * dim : data.length;
list = Phaser.EarCut.linkedList(data, start, end, dim, false);
if (list === list.next) { list.steiner = true; }
queue.push(Phaser.EarCut.getLeftmost(list));
}
queue.sort(Phaser.EarCut.compareX);
// process holes from left to right
for (i = 0; i < queue.length; i++)
{
Phaser.EarCut.eliminateHole(queue[i], outerNode);
outerNode = Phaser.EarCut.filterPoints(outerNode, outerNode.next);
}
return outerNode;
};
Phaser.EarCut.compareX = function (a, b)
{
return a.x - b.x;
};
// find a bridge between vertices that connects hole with an outer ring and and link it
Phaser.EarCut.eliminateHole = function (hole, outerNode)
{
outerNode = Phaser.EarCut.findHoleBridge(hole, outerNode);
if (outerNode)
{
var b = Phaser.EarCut.splitPolygon(outerNode, hole);
Phaser.EarCut.filterPoints(b, b.next);
}
};
// David Eberly's algorithm for finding a bridge between hole and outer polygon
Phaser.EarCut.findHoleBridge = function (hole, outerNode)
{
var p = outerNode,
hx = hole.x,
hy = hole.y,
qx = -Infinity,
m;
/*
* find a segment intersected by a ray from the hole's leftmost point to the left;
* segment's endpoint with lesser x will be potential connection point
*/
do
{
if (hy <= p.y && hy >= p.next.y)
{
var x = p.x + (hy - p.y) * (p.next.x - p.x) / (p.next.y - p.y);
if (x <= hx && x > qx)
{
qx = x;
m = p.x < p.next.x ? p : p.next;
}
}
p = p.next;
} while (p !== outerNode);
if (!m) { return null; }
if (hole.x === m.x) { return m.prev; } // hole touches outer segment; pick lower endpoint
/*
* look for points inside the triangle of hole point, segment intersection and endpoint;
* if there are no points found, we have a valid connection;
* otherwise choose the point of the minimum angle with the ray as connection point
*/
var stop = m,
tanMin = Infinity,
tan;
p = m.next;
while (p !== stop)
{
if (hx >= p.x && p.x >= m.x &&
Phaser.EarCut.pointInTriangle(hy < m.y ? hx : qx, hy, m.x, m.y, hy < m.y ? qx : hx, hy, p.x, p.y))
{
tan = Math.abs(hy - p.y) / (hx - p.x); // tangential
if ((tan < tanMin || (tan === tanMin && p.x > m.x)) && Phaser.EarCut.locallyInside(p, hole))
{
m = p;
tanMin = tan;
}
}
p = p.next;
}
return m;
};
// interlink polygon nodes in z-order
Phaser.EarCut.indexCurve = function (start, minX, minY, size)
{
var p = start;
do
{
if (p.z === null) { p.z = Phaser.EarCut.zOrder(p.x, p.y, minX, minY, size); }
p.prevZ = p.prev;
p.nextZ = p.next;
p = p.next;
} while (p !== start);
p.prevZ.nextZ = null;
p.prevZ = null;
Phaser.EarCut.sortLinked(p);
};
/*
* Simon Tatham's linked list merge sort algorithm
* http://www.chiark.greenend.org.uk/~sgtatham/algorithms/listsort.html
*/
Phaser.EarCut.sortLinked = function (list)
{
var i, p, q, e, tail, numMerges, pSize, qSize,
inSize = 1;
do
{
p = list;
list = null;
tail = null;
numMerges = 0;
while (p)
{
numMerges++;
q = p;
pSize = 0;
for (i = 0; i < inSize; i++)
{
pSize++;
q = q.nextZ;
if (!q) { break; }
}
qSize = inSize;
while (pSize > 0 || (qSize > 0 && q))
{
if (pSize === 0)
{
e = q;
q = q.nextZ;
qSize--;
}
else if (qSize === 0 || !q)
{
e = p;
p = p.nextZ;
pSize--;
}
else if (p.z <= q.z)
{
e = p;
p = p.nextZ;
pSize--;
}
else
{
e = q;
q = q.nextZ;
qSize--;
}
if (tail) { tail.nextZ = e; }
else { list = e; }
e.prevZ = tail;
tail = e;
}
p = q;
}
tail.nextZ = null;
inSize *= 2;
} while (numMerges > 1);
return list;
};
// z-order of a point given coords and size of the data bounding box
Phaser.EarCut.zOrder = function (x, y, minX, minY, size)
{
// coords are transformed into non-negative 15-bit integer range
x = 32767 * (x - minX) / size;
y = 32767 * (y - minY) / size;
x = (x | (x << 8)) & 0x00FF00FF;
x = (x | (x << 4)) & 0x0F0F0F0F;
x = (x | (x << 2)) & 0x33333333;
x = (x | (x << 1)) & 0x55555555;
y = (y | (y << 8)) & 0x00FF00FF;
y = (y | (y << 4)) & 0x0F0F0F0F;
y = (y | (y << 2)) & 0x33333333;
y = (y | (y << 1)) & 0x55555555;
return x | (y << 1);
};
// find the leftmost node of a polygon ring
Phaser.EarCut.getLeftmost = function (start)
{
var p = start,
leftmost = start;
do
{
if (p.x < leftmost.x) { leftmost = p; }
p = p.next;
} while (p !== start);
return leftmost;
};
// check if a point lies within a convex triangle
Phaser.EarCut.pointInTriangle = function (ax, ay, bx, by, cx, cy, px, py)
{
return (cx - px) * (ay - py) - (ax - px) * (cy - py) >= 0 &&
(ax - px) * (by - py) - (bx - px) * (ay - py) >= 0 &&
(bx - px) * (cy - py) - (cx - px) * (by - py) >= 0;
};
// check if a diagonal between two polygon nodes is valid (lies in polygon interior)
Phaser.EarCut.isValidDiagonal = function (a, b)
{
return Phaser.EarCut.equals(a, b) || a.next.i !== b.i && a.prev.i !== b.i && !Phaser.EarCut.intersectsPolygon(a, b) &&
Phaser.EarCut.locallyInside(a, b) && Phaser.EarCut.locallyInside(b, a) && Phaser.EarCut.middleInside(a, b);
};
// signed area of a triangle
Phaser.EarCut.area = function (p, q, r)
{
return (q.y - p.y) * (r.x - q.x) - (q.x - p.x) * (r.y - q.y);
};
// check if two points are equal
Phaser.EarCut.equals = function (p1, p2)
{
return p1.x === p2.x && p1.y === p2.y;
};
// check if two segments intersect
Phaser.EarCut.intersects = function (p1, q1, p2, q2)
{
return Phaser.EarCut.area(p1, q1, p2) > 0 !== Phaser.EarCut.area(p1, q1, q2) > 0 &&
Phaser.EarCut.area(p2, q2, p1) > 0 !== Phaser.EarCut.area(p2, q2, q1) > 0;
};
// check if a polygon diagonal intersects any polygon segments
Phaser.EarCut.intersectsPolygon = function (a, b)
{
var p = a;
do
{
if (p.i !== a.i && p.next.i !== a.i && p.i !== b.i && p.next.i !== b.i &&
Phaser.EarCut.intersects(p, p.next, a, b)) { return true; }
p = p.next;
} while (p !== a);
return false;
};
// check if a polygon diagonal is locally inside the polygon
Phaser.EarCut.locallyInside = function (a, b)
{
return Phaser.EarCut.area(a.prev, a, a.next) < 0 ?
Phaser.EarCut.area(a, b, a.next) >= 0 && Phaser.EarCut.area(a, a.prev, b) >= 0 :
Phaser.EarCut.area(a, b, a.prev) < 0 || Phaser.EarCut.area(a, a.next, b) < 0;
};
// check if the middle point of a polygon diagonal is inside the polygon
Phaser.EarCut.middleInside = function (a, b)
{
var p = a,
inside = false,
px = (a.x + b.x) / 2,
py = (a.y + b.y) / 2;
do
{
if (((p.y > py) !== (p.next.y > py)) && (px < (p.next.x - p.x) * (py - p.y) / (p.next.y - p.y) + p.x))
{ inside = !inside; }
p = p.next;
} while (p !== a);
return inside;
};
/*
* link two polygon vertices with a bridge; if the vertices belong to the same ring, it splits polygon into two;
* if one belongs to the outer ring and another to a hole, it merges it into a single ring
*/
Phaser.EarCut.splitPolygon = function (a, b)
{
var a2 = new Phaser.EarCut.Node(a.i, a.x, a.y),
b2 = new Phaser.EarCut.Node(b.i, b.x, b.y),
an = a.next,
bp = b.prev;
a.next = b;
b.prev = a;
a2.next = an;
an.prev = a2;
b2.next = a2;
a2.prev = b2;
bp.next = b2;
b2.prev = bp;
return b2;
};
// create a node and optionally link it with previous one (in a circular doubly linked list)
Phaser.EarCut.insertNode = function (i, x, y, last)
{
var p = new Phaser.EarCut.Node(i, x, y);
if (!last)
{
p.prev = p;
p.next = p;
}
else
{
p.next = last.next;
p.prev = last;
last.next.prev = p;
last.next = p;
}
return p;
};
Phaser.EarCut.removeNode = function (p)
{
p.next.prev = p.prev;
p.prev.next = p.next;
if (p.prevZ) { p.prevZ.nextZ = p.nextZ; }
if (p.nextZ) { p.nextZ.prevZ = p.prevZ; }
};
Phaser.EarCut.Node = function (i, x, y)
{
// vertice index in coordinates array
this.i = i;
// vertex coordinates
this.x = x;
this.y = y;
// previous and next vertice nodes in a polygon ring
this.prev = null;
this.next = null;
// z-order curve value
this.z = null;
// previous and next nodes in z-order
this.prevZ = null;
this.nextZ = null;
// indicates whether this is a steiner point
this.steiner = false;
};