// // snows.js // // // Snows will fall if you load this file at page top and call Start() // at page bottom. // // Checked browsers are: IE6 / Mozilla1.7.3 / Opera7.53. // // // // Configuration Variables MaxLayer = 16; // number of snows TimeSlice = 41; // time slice of updating snows Frequency = 0.015; // frequency of fluctuation of snows Amplitude = 0.5; // amplitude of fluctuation of snows SnowTypes = 4; // number of snow types SnowImage = new Array(); SnowImage[0] = "./snow0.gif"; // snow image file / slow SnowImage[1] = "./snow1.gif"; // snow image file SnowImage[2] = "./snow2.gif"; // snow image file SnowImage[3] = "./snow3.gif"; // snow image file / fast // Variable Arrays snow_element = new Array(); // snow layer element snow_type = new Array(); // snow type snow_left = new Array(); // snow left position snow_top = new Array(); // snow top position snow_width = new Array(); // snow layer width snow_height = new Array(); // snow layer height snow_radian = new Array(); // snow radian snow_amplitude = new Array(); // snow amplitude snow_frequency = new Array(); // snow frequency // Varaibles var loop; // temporary for loop var client_width, client_height; // client screen size var holizontal_offse, vertical_offse; // scroll offset positions var timer; // timer handler document.open(); for (loop = 0; loop < MaxLayer; loop++) { snow_type[loop] = Math.floor(Math.random() * SnowTypes); document.write('

'); document.write('

'); document.write('

'); } document.close(); // Start snows falling ! function Snows() { client_width = GetWidth(); client_height = GetHeight(); for (loop = 0; loop < MaxLayer; loop++) { snow_element[loop] = document.getElementById('Lay' + loop); snow_width[loop] = snow_element[loop].clientWidth; snow_height[loop] = snow_element[loop].clientHeight; snow_left[loop] = Math.floor(Math.random() * (client_width - snow_width[loop])); snow_top[loop] = Math.floor(Math.random() * (client_height - snow_height[loop])); snow_radian[loop] = Math.random() * (Math.PI * 2); snow_frequency[loop] = Frequency * (SnowTypes - snow_type[loop]); snow_amplitude[loop] = Amplitude * (snow_type[loop] + 1); snow_element[loop].style.visibility = 'visible'; snow_element[loop].style.zIndex = snow_type[loop]; snow_element[loop].style.left = snow_left[loop] + "px"; snow_element[loop].style.top = snow_top[loop] + "px"; } window.onresize = GetWindowSize; timer = setInterval("MoveSnows()", TimeSlice); } // Moving snows function MoveSnows() { holizontal_offse = document.documentElement.scrollLeft; vertical_offse = document.documentElement.scrollTop; for (loop = 0; loop < MaxLayer; loop++) { snow_radian[loop] += snow_frequency[loop]; snow_left[loop] += Math.sin(snow_radian[loop]) * snow_amplitude[loop]; snow_top[loop] += snow_type[loop] + 1; if (snow_top[loop] < vertical_offse) { snow_top[loop] += (client_height - snow_height[loop]); snow_left[loop] = Math.floor(Math.random() * (client_width - snow_width[loop])) + holizontal_offse; } if (snow_top[loop] >= (client_height + vertical_offse - snow_height[loop])) { snow_top[loop] -= (client_height - snow_height[loop]); snow_left[loop] = Math.floor(Math.random() * (client_width - snow_width[loop])) + holizontal_offse; } if (snow_left[loop] < holizontal_offse) { snow_left[loop] += (client_width - snow_width[loop]); } if (snow_left[loop] >= (client_width - snow_width[loop] + holizontal_offse)) { snow_left[loop] -= (client_width - snow_width[loop]); } snow_element[loop].style.left = snow_left[loop] + "px"; snow_element[loop].style.top = snow_top[loop] + "px"; } } // WindowResize Event Callback function GetWindowSize() { client_width = GetWidth(); client_height = GetHeight(); for (loop = 0; loop < MaxLayer; loop++) { snow_left[loop] = Math.floor(Math.random() * (client_width - snow_width[loop])) + holizontal_offse; snow_top[loop] = Math.floor(Math.random() * (client_height - snow_height[loop])) + vertical_offse; snow_radian[loop] = Math.random() * Math.PI; snow_element[loop].style.left = snow_left[loop] + "px"; snow_element[loop].style.top = snow_top[loop] + "px"; } } // Get client width function GetWidth() { if (window.opera) return document.body.clientWidth; else return document.documentElement.clientWidth; } // Get client height function GetHeight() { if (window.opera) return document.body.clientHeight; else return document.documentElement.clientHeight; }