spaces style

This commit is contained in:
Adam Bradley
2015-04-25 10:23:35 -05:00
parent e67ff15e08
commit 4473463909

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@@ -17,214 +17,214 @@ function generateStep (steps) {
/* Bezier curve function generator. Copyright Gaetan Renaudeau. MIT License: http://en.wikipedia.org/wiki/MIT_License */
function generateBezier (mX1, mY1, mX2, mY2) {
var NEWTON_ITERATIONS = 4,
NEWTON_MIN_SLOPE = 0.001,
SUBDIVISION_PRECISION = 0.0000001,
SUBDIVISION_MAX_ITERATIONS = 10,
kSplineTableSize = 11,
kSampleStepSize = 1.0 / (kSplineTableSize - 1.0),
float32ArraySupported = "Float32Array" in window;
var NEWTON_ITERATIONS = 4,
NEWTON_MIN_SLOPE = 0.001,
SUBDIVISION_PRECISION = 0.0000001,
SUBDIVISION_MAX_ITERATIONS = 10,
kSplineTableSize = 11,
kSampleStepSize = 1.0 / (kSplineTableSize - 1.0),
float32ArraySupported = "Float32Array" in window;
/* Must contain four arguments. */
if (arguments.length !== 4) {
return false;
/* Must contain four arguments. */
if (arguments.length !== 4) {
return false;
}
/* Arguments must be numbers. */
for (var i = 0; i < 4; ++i) {
if (typeof arguments[i] !== "number" || isNaN(arguments[i]) || !isFinite(arguments[i])) {
return false;
}
}
/* X values must be in the [0, 1] range. */
mX1 = Math.min(mX1, 1);
mX2 = Math.min(mX2, 1);
mX1 = Math.max(mX1, 0);
mX2 = Math.max(mX2, 0);
var mSampleValues = float32ArraySupported ? new Float32Array(kSplineTableSize) : new Array(kSplineTableSize);
function A (aA1, aA2) { return 1.0 - 3.0 * aA2 + 3.0 * aA1; }
function B (aA1, aA2) { return 3.0 * aA2 - 6.0 * aA1; }
function C (aA1) { return 3.0 * aA1; }
function calcBezier (aT, aA1, aA2) {
return ((A(aA1, aA2)*aT + B(aA1, aA2))*aT + C(aA1))*aT;
}
function getSlope (aT, aA1, aA2) {
return 3.0 * A(aA1, aA2)*aT*aT + 2.0 * B(aA1, aA2) * aT + C(aA1);
}
function newtonRaphsonIterate (aX, aGuessT) {
for (var i = 0; i < NEWTON_ITERATIONS; ++i) {
var currentSlope = getSlope(aGuessT, mX1, mX2);
if (currentSlope === 0.0) return aGuessT;
var currentX = calcBezier(aGuessT, mX1, mX2) - aX;
aGuessT -= currentX / currentSlope;
}
/* Arguments must be numbers. */
for (var i = 0; i < 4; ++i) {
if (typeof arguments[i] !== "number" || isNaN(arguments[i]) || !isFinite(arguments[i])) {
return false;
}
return aGuessT;
}
function calcSampleValues () {
for (var i = 0; i < kSplineTableSize; ++i) {
mSampleValues[i] = calcBezier(i * kSampleStepSize, mX1, mX2);
}
}
function binarySubdivide (aX, aA, aB) {
var currentX, currentT, i = 0;
do {
currentT = aA + (aB - aA) / 2.0;
currentX = calcBezier(currentT, mX1, mX2) - aX;
if (currentX > 0.0) {
aB = currentT;
} else {
aA = currentT;
}
} while (Math.abs(currentX) > SUBDIVISION_PRECISION && ++i < SUBDIVISION_MAX_ITERATIONS);
return currentT;
}
function getTForX (aX) {
var intervalStart = 0.0,
currentSample = 1,
lastSample = kSplineTableSize - 1;
for (; currentSample != lastSample && mSampleValues[currentSample] <= aX; ++currentSample) {
intervalStart += kSampleStepSize;
}
/* X values must be in the [0, 1] range. */
mX1 = Math.min(mX1, 1);
mX2 = Math.min(mX2, 1);
mX1 = Math.max(mX1, 0);
mX2 = Math.max(mX2, 0);
--currentSample;
var mSampleValues = float32ArraySupported ? new Float32Array(kSplineTableSize) : new Array(kSplineTableSize);
var dist = (aX - mSampleValues[currentSample]) / (mSampleValues[currentSample+1] - mSampleValues[currentSample]),
guessForT = intervalStart + dist * kSampleStepSize,
initialSlope = getSlope(guessForT, mX1, mX2);
function A (aA1, aA2) { return 1.0 - 3.0 * aA2 + 3.0 * aA1; }
function B (aA1, aA2) { return 3.0 * aA2 - 6.0 * aA1; }
function C (aA1) { return 3.0 * aA1; }
function calcBezier (aT, aA1, aA2) {
return ((A(aA1, aA2)*aT + B(aA1, aA2))*aT + C(aA1))*aT;
if (initialSlope >= NEWTON_MIN_SLOPE) {
return newtonRaphsonIterate(aX, guessForT);
} else if (initialSlope == 0.0) {
return guessForT;
} else {
return binarySubdivide(aX, intervalStart, intervalStart + kSampleStepSize);
}
}
function getSlope (aT, aA1, aA2) {
return 3.0 * A(aA1, aA2)*aT*aT + 2.0 * B(aA1, aA2) * aT + C(aA1);
}
var _precomputed = false;
function newtonRaphsonIterate (aX, aGuessT) {
for (var i = 0; i < NEWTON_ITERATIONS; ++i) {
var currentSlope = getSlope(aGuessT, mX1, mX2);
function precompute() {
_precomputed = true;
if (mX1 != mY1 || mX2 != mY2) calcSampleValues();
}
if (currentSlope === 0.0) return aGuessT;
var f = function (aX) {
if (!_precomputed) precompute();
if (mX1 === mY1 && mX2 === mY2) return aX;
if (aX === 0) return 0;
if (aX === 1) return 1;
var currentX = calcBezier(aGuessT, mX1, mX2) - aX;
aGuessT -= currentX / currentSlope;
}
return calcBezier(getTForX(aX), mY1, mY2);
};
return aGuessT;
}
f.getControlPoints = function() { return [{ x: mX1, y: mY1 }, { x: mX2, y: mY2 }]; };
function calcSampleValues () {
for (var i = 0; i < kSplineTableSize; ++i) {
mSampleValues[i] = calcBezier(i * kSampleStepSize, mX1, mX2);
}
}
var str = "generateBezier(" + [mX1, mY1, mX2, mY2] + ")";
f.toString = function () { return str; };
function binarySubdivide (aX, aA, aB) {
var currentX, currentT, i = 0;
do {
currentT = aA + (aB - aA) / 2.0;
currentX = calcBezier(currentT, mX1, mX2) - aX;
if (currentX > 0.0) {
aB = currentT;
} else {
aA = currentT;
}
} while (Math.abs(currentX) > SUBDIVISION_PRECISION && ++i < SUBDIVISION_MAX_ITERATIONS);
return currentT;
}
function getTForX (aX) {
var intervalStart = 0.0,
currentSample = 1,
lastSample = kSplineTableSize - 1;
for (; currentSample != lastSample && mSampleValues[currentSample] <= aX; ++currentSample) {
intervalStart += kSampleStepSize;
}
--currentSample;
var dist = (aX - mSampleValues[currentSample]) / (mSampleValues[currentSample+1] - mSampleValues[currentSample]),
guessForT = intervalStart + dist * kSampleStepSize,
initialSlope = getSlope(guessForT, mX1, mX2);
if (initialSlope >= NEWTON_MIN_SLOPE) {
return newtonRaphsonIterate(aX, guessForT);
} else if (initialSlope == 0.0) {
return guessForT;
} else {
return binarySubdivide(aX, intervalStart, intervalStart + kSampleStepSize);
}
}
var _precomputed = false;
function precompute() {
_precomputed = true;
if (mX1 != mY1 || mX2 != mY2) calcSampleValues();
}
var f = function (aX) {
if (!_precomputed) precompute();
if (mX1 === mY1 && mX2 === mY2) return aX;
if (aX === 0) return 0;
if (aX === 1) return 1;
return calcBezier(getTForX(aX), mY1, mY2);
};
f.getControlPoints = function() { return [{ x: mX1, y: mY1 }, { x: mX2, y: mY2 }]; };
var str = "generateBezier(" + [mX1, mY1, mX2, mY2] + ")";
f.toString = function () { return str; };
return f;
return f;
}
/* Runge-Kutta spring physics function generator. Adapted from Framer.js, copyright Koen Bok. MIT License: http://en.wikipedia.org/wiki/MIT_License */
/* Given a tension, friction, and duration, a simulation at 60FPS will first run without a defined duration in order to calculate the full path. A second pass
then adjusts the time delta -- using the relation between actual time and duration -- to calculate the path for the duration-constrained animation. */
var generateSpringRK4 = (function () {
function springAccelerationForState (state) {
return (-state.tension * state.x) - (state.friction * state.v);
}
function springAccelerationForState (state) {
return (-state.tension * state.x) - (state.friction * state.v);
}
function springEvaluateStateWithDerivative (initialState, dt, derivative) {
var state = {
x: initialState.x + derivative.dx * dt,
v: initialState.v + derivative.dv * dt,
tension: initialState.tension,
friction: initialState.friction
};
return { dx: state.v, dv: springAccelerationForState(state) };
}
function springIntegrateState (state, dt) {
var a = {
dx: state.v,
dv: springAccelerationForState(state)
},
b = springEvaluateStateWithDerivative(state, dt * 0.5, a),
c = springEvaluateStateWithDerivative(state, dt * 0.5, b),
d = springEvaluateStateWithDerivative(state, dt, c),
dxdt = 1.0 / 6.0 * (a.dx + 2.0 * (b.dx + c.dx) + d.dx),
dvdt = 1.0 / 6.0 * (a.dv + 2.0 * (b.dv + c.dv) + d.dv);
state.x = state.x + dxdt * dt;
state.v = state.v + dvdt * dt;
return state;
}
return function springRK4Factory (tension, friction, duration) {
var initState = {
x: -1,
v: 0,
tension: null,
friction: null
},
path = [0],
time_lapsed = 0,
tolerance = 1 / 10000,
DT = 16 / 1000,
have_duration, dt, last_state;
tension = parseFloat(tension) || 500;
friction = parseFloat(friction) || 20;
duration = duration || null;
initState.tension = tension;
initState.friction = friction;
have_duration = duration !== null;
/* Calculate the actual time it takes for this animation to complete with the provided conditions. */
if (have_duration) {
/* Run the simulation without a duration. */
time_lapsed = springRK4Factory(tension, friction);
/* Compute the adjusted time delta. */
dt = time_lapsed / duration * DT;
} else {
dt = DT;
}
while (true) {
/* Next/step function .*/
last_state = springIntegrateState(last_state || initState, dt);
/* Store the position. */
path.push(1 + last_state.x);
time_lapsed += 16;
/* If the change threshold is reached, break. */
if (!(Math.abs(last_state.x) > tolerance && Math.abs(last_state.v) > tolerance)) {
break;
}
}
/* If duration is not defined, return the actual time required for completing this animation. Otherwise, return a closure that holds the
computed path and returns a snapshot of the position according to a given percentComplete. */
return !have_duration ? time_lapsed : function(percentComplete) { return path[ (percentComplete * (path.length - 1)) | 0 ]; };
function springEvaluateStateWithDerivative (initialState, dt, derivative) {
var state = {
x: initialState.x + derivative.dx * dt,
v: initialState.v + derivative.dv * dt,
tension: initialState.tension,
friction: initialState.friction
};
return { dx: state.v, dv: springAccelerationForState(state) };
}
function springIntegrateState (state, dt) {
var a = {
dx: state.v,
dv: springAccelerationForState(state)
},
b = springEvaluateStateWithDerivative(state, dt * 0.5, a),
c = springEvaluateStateWithDerivative(state, dt * 0.5, b),
d = springEvaluateStateWithDerivative(state, dt, c),
dxdt = 1.0 / 6.0 * (a.dx + 2.0 * (b.dx + c.dx) + d.dx),
dvdt = 1.0 / 6.0 * (a.dv + 2.0 * (b.dv + c.dv) + d.dv);
state.x = state.x + dxdt * dt;
state.v = state.v + dvdt * dt;
return state;
}
return function springRK4Factory (tension, friction, duration) {
var initState = {
x: -1,
v: 0,
tension: null,
friction: null
},
path = [0],
time_lapsed = 0,
tolerance = 1 / 10000,
DT = 16 / 1000,
have_duration, dt, last_state;
tension = parseFloat(tension) || 500;
friction = parseFloat(friction) || 20;
duration = duration || null;
initState.tension = tension;
initState.friction = friction;
have_duration = duration !== null;
/* Calculate the actual time it takes for this animation to complete with the provided conditions. */
if (have_duration) {
/* Run the simulation without a duration. */
time_lapsed = springRK4Factory(tension, friction);
/* Compute the adjusted time delta. */
dt = time_lapsed / duration * DT;
} else {
dt = DT;
}
while (true) {
/* Next/step function .*/
last_state = springIntegrateState(last_state || initState, dt);
/* Store the position. */
path.push(1 + last_state.x);
time_lapsed += 16;
/* If the change threshold is reached, break. */
if (!(Math.abs(last_state.x) > tolerance && Math.abs(last_state.v) > tolerance)) {
break;
}
}
/* If duration is not defined, return the actual time required for completing this animation. Otherwise, return a closure that holds the
computed path and returns a snapshot of the position according to a given percentComplete. */
return !have_duration ? time_lapsed : function(percentComplete) { return path[ (percentComplete * (path.length - 1)) | 0 ]; };
};
}());