Kwadraty i spirala Fibonacciego
Listing
var cv = document.getElementById("canvas");
var ctx = cv.getContext("2d");
//x, y położenie pierwszego elementu
//len - długość boku pierwszego kwadratu w pikselach;
//n - liczba kwadratów
var rectFibo = function(ctx, x, y, len, n) {
var fibos = new Array(1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89,
144, 233);
if (n == 1) {
ctx.strokeRect(x + len, y, len * fibos[0], len * fibos[0]);
} else if (n == 2) {
ctx.strokeRect(x + len, y, len * fibos[0], len * fibos[0]);
ctx.strokeRect(x, y, len * fibos[1], len * fibos[1]);
} else {
ctx.strokeRect(x + len, y, len * fibos[0], len * fibos[0]);
ctx.strokeRect(x, y, len * fibos[1], len * fibos[1]);
//-
for (var i = 2; i < n; i = i + 4) {
ctx.strokeRect(x, y = y + len * fibos[i - 1], len
* fibos[i], len * fibos[i]);
ctx.strokeRect(x = x + len * fibos[i], y = y - len
* fibos[i - 1], len * fibos[i + 1], len
* fibos[i + 1]);
ctx.strokeRect(x = x - len * fibos[i], y = y - len
* fibos[i + 2], len * fibos[i + 2], len
* fibos[i + 2]);
ctx.strokeRect(x = x - len * fibos[i + 3], y, len
* fibos[i + 3], len * fibos[i + 3]);//8
}
}
};
var spiralFibo = function(ctx, x, y, len, n) {
var fibos = new Array(1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89,
144, 233);
if (n == 1) {
ctx.beginPath();
ctx.arc(x + len, y + len, fibos[0] * len - 1,
1.5 * Math.PI, Math.PI, true);
ctx.stroke();
} else if (n == 2) {
ctx.beginPath();
ctx.arc(x + len, y + len, fibos[0] * len - 1,
1.5 * Math.PI, Math.PI, true);
ctx.stroke();
ctx.beginPath();
ctx.arc(x + len, y + len, fibos[1] * len - 1, 0,
1.5 * Math.PI, true);
ctx.stroke();
} else {
ctx.beginPath();
ctx.arc(x + len, y + len, fibos[0] * len - 1,
1.5 * Math.PI, Math.PI, true);
ctx.stroke();
ctx.beginPath();
ctx.arc(x + len, y + len, fibos[1] * len - 1, 0,
1.5 * Math.PI, true);
ctx.stroke();
//-
for (var i = 2; i < n; i = i + 4) {
ctx.beginPath();
y=y+len*fibos[i-1];
ctx.arc(x + fibos[i] * len, y, fibos[i] * len - 1,
Math.PI, 0.5 * Math.PI, true);
ctx.stroke();
ctx.beginPath();
x=x+len*fibos[i];
y = y - len*fibos[i-1];
ctx.arc(x, y, fibos[i + 1] * len - 1, 0.5 * Math.PI, 0,
true);
ctx.stroke();
ctx.beginPath();
x = x - len * fibos[i];
y = y - len * fibos[i + 2];
ctx.arc(x, y + fibos[i + 2] * len, fibos[i + 2] * len
- 1, 0, 1.5 * Math.PI, true);
ctx.stroke();
ctx.beginPath();
x = x - len * fibos[i + 3];
ctx.arc(x + fibos[i + 3] * len, y + fibos[i + 3] * len,
fibos[i + 3] * len - 1, 1.5 * Math.PI, Math.PI,
true);
ctx.stroke()
}
}
};
ctx.strokeStyle = "green";
ctx.lineWidth = 1;
rectFibo(ctx,700,700,10,10);
ctx.strokeStyle="magenta";
spiralFibo(ctx, 700, 700, 10, 10);