File: src/factory/Composites.js
/**
* The `Matter.Composites` module contains factory methods for creating composite bodies
* with commonly used configurations (such as stacks and chains).
*
* See the included usage [examples](https://github.com/liabru/matter-js/tree/master/examples).
*
* @class Composites
*/
var Composites = {};
module.exports = Composites;
var Composite = require('../body/Composite');
var Constraint = require('../constraint/Constraint');
var Common = require('../core/Common');
var Body = require('../body/Body');
var Bodies = require('./Bodies');
var deprecated = Common.deprecated;
(function() {
/**
* Create a new composite containing bodies created in the callback in a grid arrangement.
* This function uses the body's bounds to prevent overlaps.
* @method stack
* @param {number} x Starting position in X.
* @param {number} y Starting position in Y.
* @param {number} columns
* @param {number} rows
* @param {number} columnGap
* @param {number} rowGap
* @param {function} callback
* @return {composite} A new composite containing objects created in the callback
*/
Composites.stack = function(x, y, columns, rows, columnGap, rowGap, callback) {
var stack = Composite.create({ label: 'Stack' }),
currentX = x,
currentY = y,
lastBody,
i = 0;
for (var row = 0; row < rows; row++) {
var maxHeight = 0;
for (var column = 0; column < columns; column++) {
var body = callback(currentX, currentY, column, row, lastBody, i);
if (body) {
var bodyHeight = body.bounds.max.y - body.bounds.min.y,
bodyWidth = body.bounds.max.x - body.bounds.min.x;
if (bodyHeight > maxHeight)
maxHeight = bodyHeight;
Body.translate(body, { x: bodyWidth * 0.5, y: bodyHeight * 0.5 });
currentX = body.bounds.max.x + columnGap;
Composite.addBody(stack, body);
lastBody = body;
i += 1;
} else {
currentX += columnGap;
}
}
currentY += maxHeight + rowGap;
currentX = x;
}
return stack;
};
/**
* Chains all bodies in the given composite together using constraints.
* @method chain
* @param {composite} composite
* @param {number} xOffsetA
* @param {number} yOffsetA
* @param {number} xOffsetB
* @param {number} yOffsetB
* @param {object} options
* @return {composite} A new composite containing objects chained together with constraints
*/
Composites.chain = function(composite, xOffsetA, yOffsetA, xOffsetB, yOffsetB, options) {
var bodies = composite.bodies;
for (var i = 1; i < bodies.length; i++) {
var bodyA = bodies[i - 1],
bodyB = bodies[i],
bodyAHeight = bodyA.bounds.max.y - bodyA.bounds.min.y,
bodyAWidth = bodyA.bounds.max.x - bodyA.bounds.min.x,
bodyBHeight = bodyB.bounds.max.y - bodyB.bounds.min.y,
bodyBWidth = bodyB.bounds.max.x - bodyB.bounds.min.x;
var defaults = {
bodyA: bodyA,
pointA: { x: bodyAWidth * xOffsetA, y: bodyAHeight * yOffsetA },
bodyB: bodyB,
pointB: { x: bodyBWidth * xOffsetB, y: bodyBHeight * yOffsetB }
};
var constraint = Common.extend(defaults, options);
Composite.addConstraint(composite, Constraint.create(constraint));
}
composite.label += ' Chain';
return composite;
};
/**
* Connects bodies in the composite with constraints in a grid pattern, with optional cross braces.
* @method mesh
* @param {composite} composite
* @param {number} columns
* @param {number} rows
* @param {boolean} crossBrace
* @param {object} options
* @return {composite} The composite containing objects meshed together with constraints
*/
Composites.mesh = function(composite, columns, rows, crossBrace, options) {
var bodies = composite.bodies,
row,
col,
bodyA,
bodyB,
bodyC;
for (row = 0; row < rows; row++) {
for (col = 1; col < columns; col++) {
bodyA = bodies[(col - 1) + (row * columns)];
bodyB = bodies[col + (row * columns)];
Composite.addConstraint(composite, Constraint.create(Common.extend({ bodyA: bodyA, bodyB: bodyB }, options)));
}
if (row > 0) {
for (col = 0; col < columns; col++) {
bodyA = bodies[col + ((row - 1) * columns)];
bodyB = bodies[col + (row * columns)];
Composite.addConstraint(composite, Constraint.create(Common.extend({ bodyA: bodyA, bodyB: bodyB }, options)));
if (crossBrace && col > 0) {
bodyC = bodies[(col - 1) + ((row - 1) * columns)];
Composite.addConstraint(composite, Constraint.create(Common.extend({ bodyA: bodyC, bodyB: bodyB }, options)));
}
if (crossBrace && col < columns - 1) {
bodyC = bodies[(col + 1) + ((row - 1) * columns)];
Composite.addConstraint(composite, Constraint.create(Common.extend({ bodyA: bodyC, bodyB: bodyB }, options)));
}
}
}
}
composite.label += ' Mesh';
return composite;
};
/**
* Create a new composite containing bodies created in the callback in a pyramid arrangement.
* This function uses the body's bounds to prevent overlaps.
* @method pyramid
* @param {number} x Starting position in X.
* @param {number} y Starting position in Y.
* @param {number} columns
* @param {number} rows
* @param {number} columnGap
* @param {number} rowGap
* @param {function} callback
* @return {composite} A new composite containing objects created in the callback
*/
Composites.pyramid = function(x, y, columns, rows, columnGap, rowGap, callback) {
return Composites.stack(x, y, columns, rows, columnGap, rowGap, function(stackX, stackY, column, row, lastBody, i) {
var actualRows = Math.min(rows, Math.ceil(columns / 2)),
lastBodyWidth = lastBody ? lastBody.bounds.max.x - lastBody.bounds.min.x : 0;
if (row > actualRows)
return;
// reverse row order
row = actualRows - row;
var start = row,
end = columns - 1 - row;
if (column < start || column > end)
return;
// retroactively fix the first body's position, since width was unknown
if (i === 1) {
Body.translate(lastBody, { x: (column + (columns % 2 === 1 ? 1 : -1)) * lastBodyWidth, y: 0 });
}
var xOffset = lastBody ? column * lastBodyWidth : 0;
return callback(x + xOffset + column * columnGap, stackY, column, row, lastBody, i);
});
};
/**
* This has now moved to the [newtonsCradle example](https://github.com/liabru/matter-js/blob/master/examples/newtonsCradle.js), follow that instead as this function is deprecated here.
* @deprecated moved to newtonsCradle example
* @method newtonsCradle
* @param {number} x Starting position in X.
* @param {number} y Starting position in Y.
* @param {number} number
* @param {number} size
* @param {number} length
* @return {composite} A new composite newtonsCradle body
*/
Composites.newtonsCradle = function(x, y, number, size, length) {
var newtonsCradle = Composite.create({ label: 'Newtons Cradle' });
for (var i = 0; i < number; i++) {
var separation = 1.9,
circle = Bodies.circle(x + i * (size * separation), y + length, size,
{ inertia: Infinity, restitution: 1, friction: 0, frictionAir: 0.0001, slop: 1 }),
constraint = Constraint.create({ pointA: { x: x + i * (size * separation), y: y }, bodyB: circle });
Composite.addBody(newtonsCradle, circle);
Composite.addConstraint(newtonsCradle, constraint);
}
return newtonsCradle;
};
deprecated(Composites, 'newtonsCradle', 'Composites.newtonsCradle ➤ moved to newtonsCradle example');
/**
* This has now moved to the [car example](https://github.com/liabru/matter-js/blob/master/examples/car.js), follow that instead as this function is deprecated here.
* @deprecated moved to car example
* @method car
* @param {number} x Starting position in X.
* @param {number} y Starting position in Y.
* @param {number} width
* @param {number} height
* @param {number} wheelSize
* @return {composite} A new composite car body
*/
Composites.car = function(x, y, width, height, wheelSize) {
var group = Body.nextGroup(true),
wheelBase = 20,
wheelAOffset = -width * 0.5 + wheelBase,
wheelBOffset = width * 0.5 - wheelBase,
wheelYOffset = 0;
var car = Composite.create({ label: 'Car' }),
body = Bodies.rectangle(x, y, width, height, {
collisionFilter: {
group: group
},
chamfer: {
radius: height * 0.5
},
density: 0.0002
});
var wheelA = Bodies.circle(x + wheelAOffset, y + wheelYOffset, wheelSize, {
collisionFilter: {
group: group
},
friction: 0.8
});
var wheelB = Bodies.circle(x + wheelBOffset, y + wheelYOffset, wheelSize, {
collisionFilter: {
group: group
},
friction: 0.8
});
var axelA = Constraint.create({
bodyB: body,
pointB: { x: wheelAOffset, y: wheelYOffset },
bodyA: wheelA,
stiffness: 1,
length: 0
});
var axelB = Constraint.create({
bodyB: body,
pointB: { x: wheelBOffset, y: wheelYOffset },
bodyA: wheelB,
stiffness: 1,
length: 0
});
Composite.addBody(car, body);
Composite.addBody(car, wheelA);
Composite.addBody(car, wheelB);
Composite.addConstraint(car, axelA);
Composite.addConstraint(car, axelB);
return car;
};
deprecated(Composites, 'car', 'Composites.car ➤ moved to car example');
/**
* This has now moved to the [softBody example](https://github.com/liabru/matter-js/blob/master/examples/softBody.js)
* and the [cloth example](https://github.com/liabru/matter-js/blob/master/examples/cloth.js), follow those instead as this function is deprecated here.
* @deprecated moved to softBody and cloth examples
* @method softBody
* @param {number} x Starting position in X.
* @param {number} y Starting position in Y.
* @param {number} columns
* @param {number} rows
* @param {number} columnGap
* @param {number} rowGap
* @param {boolean} crossBrace
* @param {number} particleRadius
* @param {} particleOptions
* @param {} constraintOptions
* @return {composite} A new composite softBody
*/
Composites.softBody = function(x, y, columns, rows, columnGap, rowGap, crossBrace, particleRadius, particleOptions, constraintOptions) {
particleOptions = Common.extend({ inertia: Infinity }, particleOptions);
constraintOptions = Common.extend({ stiffness: 0.2, render: { type: 'line', anchors: false } }, constraintOptions);
var softBody = Composites.stack(x, y, columns, rows, columnGap, rowGap, function(stackX, stackY) {
return Bodies.circle(stackX, stackY, particleRadius, particleOptions);
});
Composites.mesh(softBody, columns, rows, crossBrace, constraintOptions);
softBody.label = 'Soft Body';
return softBody;
};
deprecated(Composites, 'softBody', 'Composites.softBody ➤ moved to softBody and cloth examples');
})();