好玩的Canvas射箭小游戏

<!DOCTYPE html>

<html>

<head>

<title>Canvas射箭小游戏</title>

</head>

body{

margin:0;

background:#222;

margin:20px;

}

svg{

width:100%;

height:100%;

position:fixed;

top:0;

left:0;

}

span{

color:white;

font-family:sans-serif;

opacity:.3;

}

</style>

<body>

</linearGradient>

<defs>

</g>

</defs>

</g>

</g>

</clipPath>

</g>

</g>

</g>

</g>

<!-- <line x1= "875", y1= "280", x2= "925", y2= "220" stroke="red"/>

</svg>

<span>点击弓然后射箭！</span>

</body>

var svg = document.querySelector("svg");

var cursor = svg.createSVGPoint();

var arrows = document.querySelector(".arrows");

var randomAngle = 0;

// center of target

var target = {

x: 900,

y: 249.5

};

// target intersection line segment

var lineSegment = {

x1: 875,

y1: 280,

x2: 925,

y2: 220

};

// bow rotation point

var pivot = {

x: 100,

y: 250

};

aim({

clientX: 320,

clientY: 300

});

// set up start drag event

window.addEventListener("mousedown", draw);

function draw(e) {

// pull back arrow

randomAngle = (Math.random() * Math.PI * 0.03) - 0.015;

TweenMax.to(".arrow-angle use", 0.3, {

opacity: 1

});

window.addEventListener("mousemove", aim);

window.addEventListener("mouseup", loose);

aim(e);

}

function aim(e) {

// get mouse position in relation to svg position and scale

var point = getMouseSVG(e);

point.x = Math.min(point.x, pivot.x - 7);

point.y = Math.max(point.y, pivot.y + 7);

var dx = point.x - pivot.x;

var dy = point.y - pivot.y;

// Make it more difficult by adding random angle each time

var angle = Math.atan2(dy, dx) + randomAngle;

var bowAngle = angle - Math.PI;

var distance = Math.min(Math.sqrt((dx * dx) + (dy * dy)), 50);

var scale = Math.min(Math.max(distance / 30, 1), 2);

TweenMax.to("#bow", 0.3, {

scaleX: scale,

rotation: bowAngle + "rad",

transformOrigin: "right center"

});

var arrowX = Math.min(pivot.x - ((1 / scale) * distance), 88);

TweenMax.to(".arrow-angle", 0.3, {

rotation: bowAngle + "rad",

svgOrigin: "100 250"

});

TweenMax.to(".arrow-angle use", 0.3, {

x: -distance

});

TweenMax.to("#bow polyline", 0.3, {

attr: {

points: "88,200 " + Math.min(pivot.x - ((1 / scale) * distance), 88) + ",250 88,300"

}

});

var radius = distance * 9;

var offset = {

x: (Math.cos(bowAngle) * radius),

y: (Math.sin(bowAngle) * radius)

};

var arcWidth = offset.x * 3;

TweenMax.to("#arc", 0.3, {

attr: {

d: "M100,250c" + offset.x + "," + offset.y + "," + (arcWidth - offset.x) + "," + (offset.y + 50) + "," + arcWidth + ",50"

autoAlpha: distance/60

});

}

function loose() {

// release arrow

window.removeEventListener("mousemove", aim);

window.removeEventListener("mouseup", loose);

TweenMax.to("#bow", 0.4, {

scaleX: 1,

transformOrigin: "right center",

ease: Elastic.easeOut

});

TweenMax.to("#bow polyline", 0.4, {

attr: {

points: "88,200 88,250 88,300"

ease: Elastic.easeOut

});

// duplicate arrow

var newArrow = document.createElementNS("SVG namespace", "use");

newArrow.setAttributeNS('XLink namespace', 'href', "#arrow");

arrows.appendChild(newArrow);

// animate arrow along path

var path = MorphSVGPlugin.pathDataToBezier("#arc");

TweenMax.to([newArrow], 0.5, {

force3D: true,

bezier: {

type: "cubic",

values: path,

autoRotate: ["x", "y", "rotation"]

onUpdate: hitTest,

onUpdateParams: ["{self}"],

onComplete: onMiss,

ease: Linear.easeNone

});

TweenMax.to("#arc", 0.3, {

opacity: 0

});

//hide previous arrow

TweenMax.set(".arrow-angle use", {

opacity: 0

});

}

function hitTest(tween) {

// check for collisions with arrow and target

var arrow = tween.target[0];

var transform = arrow._gsTransform;

var radians = transform.rotation * Math.PI / 180;

var arrowSegment = {

x1: transform.x,

y1: transform.y,

x2: (Math.cos(radians) * 60) + transform.x,

y2: (Math.sin(radians) * 60) + transform.y

}

var intersection = getIntersection(arrowSegment, lineSegment);

if (intersection.segment1 && intersection.segment2) {

tween.pause();

var dx = intersection.x - target.x;

var dy = intersection.y - target.y;

var distance = Math.sqrt((dx * dx) + (dy * dy));

var selector = ".hit";

if (distance < 7) {

selector = ".bullseye"

}

showMessage(selector);

}

function onMiss() {

// Damn!

showMessage(".miss");

}

function showMessage(selector) {

// handle all text animations by providing selector

TweenMax.killTweensOf(selector);

TweenMax.killChildTweensOf(selector);

TweenMax.set(selector, {

autoAlpha: 1

});

TweenMax.staggerFromTo(selector + " path", .5, {

rotation: -5,

scale: 0,

transformOrigin: "center"

}, {

scale: 1,

ease: Back.easeOut

}, .05);

TweenMax.staggerTo(selector + " path", .3, {

delay: 2,

rotation: 20,

scale: 0,

ease: Back.easeIn

}, .03);

}

function getMouseSVG(e) {

// normalize mouse position within svg coordinates

cursor.x = e.clientX;

cursor.y = e.clientY;

return cursor.matrixTransform(svg.getScreenCTM().inverse());

}

function getIntersection(segment1, segment2) {

// find intersection point of two line segments and whether or not the point is on either line segment

var dx1 = segment1.x2 - segment1.x1;

var dy1 = segment1.y2 - segment1.y1;

var dx2 = segment2.x2 - segment2.x1;

var dy2 = segment2.y2 - segment2.y1;

var cx = segment1.x1 - segment2.x1;

var cy = segment1.y1 - segment2.y1;

var denominator = dy2 * dx1 - dx2 * dy1;

if (denominator == 0) {

return null;

}

var ua = (dx2 * cy - dy2 * cx) / denominator;

var ub = (dx1 * cy - dy1 * cx) / denominator;

return {

x: segment1.x1 + ua * dx1,

y: segment1.y1 + ua * dy1,

segment1: ua >= 0 && ua <= 1,

segment2: ub >= 0 && ub <= 1

};

}

</script>

</html>

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posted @ 2017-04-20 13:13 倪殤阅读(260) 评论(0) 编辑收藏举报

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