gitea-simplematrix/public/js/theme-matrix.js

57 lines
1.8 KiB
JavaScript

//Matrix canvas
var c = document.getElementById("c");
var ctx = c.getContext("2d");
//Get client offsets
var my_height = document.getElementById("main_doc").offsetHeight;
var my_width = document.getElementById("home").offsetWidth;
//making the canvas full screen
c.height = my_height;
c.width = my_width;
//latin characters - taken from the unicode charset
var matrix = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ123456789@#$%^&*()*&^%+-/~{[|`]}";
//converting the string into an array of single characters
matrix = matrix.split("");
var font_size = 10;
var columns = c.width / font_size; //number of columns for the rain
//an array of drops - one per column
var drops = [];
//x below is the x coordinate
//1 = y co-ordinate of the drop(same for every drop initially)
for (var x = 0; x < columns; x++)
drops[x] = 1;
//drawing the characters
function draw() {
//Black BG for the canvas
//translucent BG to show trail
ctx.fillStyle = "rgba(0, 0, 0, 0.04)";
ctx.fillRect(0, 0, c.width, c.height);
ctx.fillStyle = "#5AA509"; // Gitea green
//ctx.fillStyle = "red";
ctx.font = font_size + "px arial";
//looping over drops
for (var i = 0; i < drops.length; i++) {
//a random chinese character to print
var text = matrix[Math.floor(Math.random() * matrix.length)];
//x = i*font_size, y = value of drops[i]*font_size
ctx.fillText(text, i * font_size, drops[i] * font_size);
//sending the drop back to the top randomly after it has crossed the screen
//adding a randomness to the reset to make the drops scattered on the Y axis
if (drops[i] * font_size > c.height && Math.random() > 0.975) {
drops[i] = 0;
}
//incrementing Y coordinate
drops[i]++;
}
}
setInterval(draw, 35);