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Algebraic Fractal was done #5

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Algebraic Fractal was done #5

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246 changes: 246 additions & 0 deletions AlgebrFrac.js
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Original file line number Diff line number Diff line change
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var Plane = {
left: -2,
top: -2,
right: 2,
bottom: 2,
};

var Fractal;
var Coloring;
var N;
var ConstJulia= {x: -0.12, y: 0.72};
var Scale = 2;
var Center = {x:0, y:0};

function run() {
Fractal = Form.fractal.options[Form.fractal.selectedIndex].value;
Coloring = Form.color.options[Form.color.selectedIndex].value;
N = parseInt(document.getElementById("n").value);
ConstJulia.x = parseFloat(document.getElementById("x").value);
ConstJulia.y = parseFloat(document.getElementById("y").value);
Plane.left = Center.x - Scale;
Plane.right = Center.x + Scale;
Plane.top = Center.y - Scale;
Plane.bottom = Center.y + Scale;
draw();
}

function draw() {
var canvas = document.getElementById("canvas");
var context = canvas.getContext('2d');
var canvasHeight = parseInt(canvas.getAttribute("height"));
var canvasWidth = parseInt(canvas.getAttribute("width"));
var imageData = context.createImageData(canvasWidth, canvasHeight);



for (var i = 0; i < canvasWidth; i++) {
for (var j = 0; j < canvasHeight; j++) {
var point = getRealCoordinates(i, j, canvasWidth, canvasHeight);

var atr = getAttractor(point);
var color = getColor(atr);

imageData.data[4 * (i + canvasWidth * j) + 0] = color[0];
imageData.data[4 * (i + canvasWidth * j) + 1] = color[1];
imageData.data[4 * (i + canvasWidth * j) + 2] = color[2];
imageData.data[4 * (i + canvasWidth * j) + 3] = color[3];
}
}
context.putImageData(imageData, 0, 0);
}

function getRealCoordinates(i, j, width, height) {
var X = Plane.left + i * (Plane.right - Plane.left) / (width - 1);
var Y = Plane.top + j * (Plane.bottom - Plane.top) / (height - 1);
return { x: X, y: Y };
}

function getAttractor(point) {
switch (Fractal) {
case '1':
return getNewtonAttr(point, N, 0);
break;
case '2':
return getMandelbrotAttr(point);
break;
case '3':
return getJuliaAttr(point);
break;

}
}

function getNewtonAttr(point, n, it) {
var sin = Math.sin(Math.PI / 3);
var cos = Math.cos(Math.PI / 3);
if (n == 0)
return { attr: 0, iter: it };
if (checkLimit(point, 1, 0))
return { attr: 1, iter: it };
if (checkLimit(point, -cos, sin))
return { attr: 2, iter: it };
if (checkLimit(point, -cos, -sin))
return { attr: 3, iter: it };

var x = point.x * point.x;
var y = point.y * point.y;
var newX = 2 * point.x/3 + (x - y) / (3 * (x + y) * (x + y));
var newY = 2 * point.y * (1 - point.x /Math.pow((x + y),2)) /3;
var newP = { x: newX, y: newY };
return getNewtonAttr(newP, n - 1, it + 1);

}

function checkLimit(start, endX, endY) {
var eps = 0.0001;
var deltaX = Math.abs(start.x - endX);
var deltaY = Math.abs(start.y - endY);
return deltaX <= eps && deltaY <= eps;
}

function getMandelbrotAttree(point) {
var x = 0;
var y = 0;
var newX=0;
var newY=0;
for (var i = 0; i < N; i++) {
newX = x * x - y * y + point.x;
newY = 2 * x * y + point.y;
if (newX * newX + newX * newY > 4)
return i;
x = newX;
y = newY;
}
return 0;
}

function getMandelbrotAttr(point) {
var x = point.x;
var y = point.y;
var newX = 0;
var newY = 0;
for (var i = 0; i < N; i++) {
if (x * x + y * y > 4)
return i;
newX = x * x - y * y + point.x;
newY = 2 * x * y + point.y;
x = newX;
y = newY;
}
return 0;
}

function getJuliaAttr(point) {
var x = point.x;
var y = point.y;
var newX = 0;
var newY = 0;
for (var i = 0; i < N; i++) {
if (x * x + y * y > 4)
return i;
newX = x * x - y * y + ConstJulia.x;
newY = 2 * x * y + ConstJulia.y;
x = newX;
y = newY;
}
return 0;
}

function getColor(atr) {
switch (Coloring) {
case '1':
return getClassicColor(atr);
case '2':
return getLevelColor(atr);
case '3':
return getZebraColor(atr);
}

}

function getClassicColor(atr) {
if (Fractal == '1') {
switch (atr.attr) {
case 0:
return [0, 0, 0, 0];
break;
case 1:
return [255, 0, 0, 255];
break;
case 2:
return [0, 255, 0, 255];
break;
case 3:
return [0, 0, 255, 255];
break;
}
}
else{
if (atr == 0)
return [0, 0, 0, 255]
else
return [255, 255, 255, 255];
}


}

function getLevelColor(atr) {

if (Fractal == '1') {
var it = atr.iter;
}
else{
var it = atr;
}
var bright = 255;
if (N > 1)
bright = bright * it * 4 / (N - 1);
return [bright, bright, bright, bright];

}

function getZebraColor(atr) {
if (Fractal == '1') {
var it = atr.iter;
}
else{
var it = atr;
}

if (it % 2 == 0)
return [0, 0, 0, 255];
return [255, 255, 255, 255];
}

function mouseDownHandler(canvas, e) {
var сoords = canvas.relMouseCoords(e);
var i = сoords.x * (Plane.right - Plane.left) / (canvas.width - 1) + Plane.left;
var j = сoords.y * (Plane.bottom - Plane.top) / (canvas.height - 1) + Plane.top;
if (e.button === 0) {
Scale /= 1.5;
}
if (e.button === 2) {
Scale *= 1.5;
}
Center.x = i;
Center.y = j;
run();
}

function mousePress() {
canvas.addEventListener("mousedown",
function (e) {
mouseDownHandler(canvas, e);
},
false);
}

function resetScale()
{
Scale = 2;
Center.x = 0;
Center.y = 0;
}

137 changes: 58 additions & 79 deletions index.html
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Original file line number Diff line number Diff line change
@@ -1,80 +1,59 @@
<!doctype html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta http-equiv="Cache-Control" content="no-cache"/>

<script>
HTMLCanvasElement.prototype.relMouseCoords = function (event) {
var totalOffsetX = 0;
var totalOffsetY = 0;
var canvasX = 0;
var canvasY = 0;
var currentElement = this;

do {
totalOffsetX += currentElement.offsetLeft;
totalOffsetY += currentElement.offsetTop;
}
while (currentElement = currentElement.offsetParent)

canvasX = event.pageX - totalOffsetX;
canvasY = event.pageY - totalOffsetY;

// Fix for variable canvas width
canvasX = Math.round( canvasX * (this.width / this.offsetWidth) );
canvasY = Math.round( canvasY * (this.height / this.offsetHeight) );

return {x:canvasX, y:canvasY}
}

//пример рисования произвольного множества точек
function example(canvas) {
var canvasHeight = parseInt(canvas.getAttribute("height"));
var canvasWidth = parseInt(canvas.getAttribute("width"));

//создаем 2d context
var context = canvas.getContext('2d');

//создаем "буфер" imageData, в который будем класть новую информацию о цветах
var imageData = context.createImageData(canvasWidth, canvasHeight);
for (var i = 0; i < canvasWidth; i++) {
for (var j = 0; j < canvasHeight; j++) {
var red = 0;
var green = 0;
var blue = (i + j) % 255;
if (i % 20 == 0)
red = 150;
if (j % 20 == 0)
green = 150;
var opacity = 255;

imageData.data[4*(i + canvasWidth*j) + 0] = red;
imageData.data[4*(i + canvasWidth*j) + 1] = green;
imageData.data[4*(i + canvasWidth*j) + 2] = blue;
imageData.data[4*(i + canvasWidth*j) + 3] = opacity;
}
}
//заполненный "буфер" imageData передаем в context для вывода на экран
context.putImageData(imageData, 0, 0);
}

function mouseDownHandler(canvas, e) {
var coords = canvas.relMouseCoords(e);
alert("x=" + coords.x + " " + "y=" + coords.y);
}

//вызывается после загрузки body
function run () {
var canvas = document.getElementById("canvas");
canvas.addEventListener("mousedown",
function(e) { mouseDownHandler(canvas, e); },
false);
example(canvas);
}
</script>

<body onload="run()">
<canvas height='200' width='200' id='canvas'></canvas>
</body>
<html>

<head>
<meta charset="utf-8">
<script src="AlgebrFrac.js" type="text/javascript" charset="utf-8"></script>
<script>
HTMLCanvasElement.prototype.relMouseCoords = function (event) {
var moveX = 0;
var moveY = 0;
var canvasX = 0;
var canvasY = 0;
var currentElement = this;

do {
moveX += currentElement.offsetLeft;
moveY += currentElement.offsetTop;
}
while (currentElement = currentElement.offsetParent)

canvasX = event.pageX - moveX;
canvasY = event.pageY - moveY;
canvasX = Math.round(canvasX * (this.width / this.offsetWidth));
canvasY = Math.round(canvasY * (this.height / this.offsetHeight));
return {
x: canvasX,
y: canvasY
}
}


</script>
</head>

<body onload="mousePress()">
<canvas oncontextmenu = "return false"; height='500' width='500' id='canvas'></canvas>
<div>
<div> <input id="n" type="text">N</div>
<div> <input id="x" type="text">Константа Жюлиа(х)</div>
<div> <input id="y" type="text">Константа Жюлиа(у)</div>
<form name="Form">
<select name="fractal">
<option value="1">Бассейн Ньютона</option>
<option value="2">Множество Мандельброта</option>
<option value="3">Множество Жюлиа</option>
</select>
<select name="color">
<option value="1">Классическая</option>
<option value="2">Уровни</option>
<option value="3">Зебра</option>
</select>
</form>

</div>
<div><button type="button" id='button' onclick=" resetScale(); run()">Нарисовать</button></div>


</body>

</html>