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JavaScript - Canvas Grid Generating
Hello,
I have this idea, but I wouldn't want to reinvent the wheel if it's already been done. I want to generate perspective grid on canvas depending on browser window size, something like this, but without textures: http://www.123rf.com/photo_2651286_a...rspective.html Do someone of you guys know if some similar script already exists? Or at least some tips on how not to end up writing a 1000 lines script (At this point I would just drop the idea)? All thoughts appreciated. P.S. even an obscure algorithm would probably suffice, 'cause the main problem I'm struggling with is diminishing size perspective calculations Similar TutorialsHi I had a problem earlier with the dom, which I have resolved. I was just wondering if anyone new how to use the dom, to create a table styled effect, a 3x5 grid. I find that I can create div elements and add them to the document, but they are only added vertically and not in the horizontal. This is my code Code: <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<META name="generator" content="Free Script Editor, see www.freescripteditor.com">
<TITLE>Email Client</TITLE>
<link rel="stylesheet" type="text/css" href="http://localhost/email/styles/style1.css"/>
<script src="javascript/prototype.js" type="text/javascript"></script>
<script src="javascript/scriptaculous.js" type="text/javascript"></script>
<script src="javascript/dragdrop.js" type="text/javascript"></script>
<script src="javascript/controls.js" type="text/javascript"></script>
<script src="javascript/effects.js" type="text/javascript"></script>
<script src="javascript/builder.js" type="text/javascript"></script>
<script type="text/javascript">
var xmlhttp = false;
//check if we are using IE
try {
//If the javascript version is greater than 5.
xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
alert ("You are using Microsoft Internet Explorer.");
}
catch(e)
{
//if not, then use the older active x object.
try {
//if we are using Internet Explorer
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
alert("You are using Microsoft Internet Explorer");
}
catch (E)
{
xmlhttp = false;
}
}
//If we are using a non-IE browser, crea a javascript instance of the object
if(!xmlhttp && typeof XMLHttpRequest != 'undefined')
{
xmlhttp = new XMLHttpRequest();
alert ("You are not using Microsoft Internet Explorer");
}
function createTable()
{
var divright, div1, div2, div3, div4, div5, div6, div7, div8, div9, div10, div11, div12, div13, div14, div15;
divright = document.getElementById('right');
div1 = document.createElement('div');
div1.className = 'droparea';
div1.setAttribute('id', 'sortList1');
div2 = document.createElement('div');
div2.className = 'droparea';
div2.setAttribute('id', 'sortList2');
div3 = document.createElement('div');
div3.className = 'droparea';
div3.setAttribute('id', 'sortList3');
div4 = document.createElement('div');
div4.className = 'droparea';
div4.setAttribute('id', 'sortList4');
div5 = document.createElement('div');
div5.className = 'droparea';
div5.setAttribute('id', 'sortList5');
div6 = document.createElement('div');
div6.className = 'droparea';
div6.setAttribute('id', 'sortList6');
div7 = document.createElement('div');
div7.className = 'droparea';
div7.setAttribute('id', 'sortList7');
div8 = document.createElement('div');
div8.className = 'droparea';
div8.setAttribute('id', 'sortList8');
div9 = document.createElement('div');
div9.className = 'droparea';
div9.setAttribute('id', 'sortList9');
div10 = document.createElement('div');
div10.className = 'droparea';
div10.setAttribute('id', 'sortList10');
div11 = document.createElement('div');
div11.className = 'droparea';
div11.setAttribute('id', 'sortList11');
div12 = document.createElement('div');
div12.className = 'droparea';
div12.setAttribute('id', 'sortList12');
var div13 = document.createElement('div');
div13.className = 'droparea';
div13.setAttribute('id', 'sortList13');
div14 = document.createElement('div');
div14.className = 'droparea';
div14.setAttribute('id', 'sortList14');
div15 = document.createElement('div');
div15.className = 'droparea';
div15.setAttribute('id', 'sortList15');
divright.appendChild(div1);
divright.appendChild(div2);
}
function getmessage(inbox_id)
{
var object = document.getElementById('content');
var server = "getmessage.php?inbox_id=" +inbox_id;
xmlhttp.open("GET", server);
xmlhttp.onreadystatechange = function()
{
if(xmlhttp.readyState == 4 && xmlhttp.status == 200)
{
object.innerHTML = xmlhttp.responseText;
}
}
xmlhttp.send(null);
}
function createSortables()
{
Sortable.create('container1', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7' , 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList1', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList2', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList3', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList4', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList5', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList6', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList7', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList8', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList9', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList10', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList11', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList12', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList13', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList14', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
Sortable.create('sortList15', {tag: 'div', only: 'draggable', constraint: false,
containment: ['container1', 'sortList1', 'sortList2', 'sortList3', 'sortList4', 'sortList5', 'sortList6', 'sortList7', 'sortList8', 'sortList9', 'sortList10', 'sortList11', 'sortList12', 'sortList13', 'sortList14', 'sortList15'], dropOnEmpty: true});
}
window.onload = function()
{
this.createTable();
this.createSortables();
}
</script>
</HEAD>
<BODY>
<!--header div - for message 'new', 'reply' -->
<div class="container" id="container">
<div class="header">
</div>
<!-- end of header div-->
<!--Begin the div class left - this will hold the inbox emails for review-->
<div class="left" id='container1'>
<?PHP
include ($_SERVER['DOCUMENT_ROOT'].'\email\database_connect\connect.php');
$str = "id";
$i = 0;
$inbox_query = "select i.inbox_id, i.to, i.subject, i.sent, i.message from inbox as i";
$inbox_result = mysql_query($inbox_query);
while($row = mysql_fetch_array($inbox_result))
{//start while trainer query
$inbox_id = $row['0'];
$to = $row['1'];
$subject= $row['2'];
$sent = $row['3'];
$message = $row['4'];
$i++;
echo "<div class='draggable' id='$str$i'>
$inbox_id $to $sent <a href='#' onclick='getmessage($inbox_id)'>$subject</a>
</div>";
}//end while inbox query
?>
</div>
<!--end left div-->
<!--begin the right div - this is the right side of the screen frame for
postponed email area-->
<div class="right" id="right">
</div>
<div class="content" id="content">
</div>
</div>
<!--end the right div element-->
<!--begin the main content div - this will hold sent message-->
</BODY>
</HTML>
I have created an editable grid based on: http://www.webismymind.be/editablegrid Although I have created a few basic sites - coding is still pretty new to me, but what I want to do is make this grid editable by an admin user - and then have other users who can view it but not edit it. I am trying to create a basic staff rota & any help would be much appreciated Thanks Hey, I have a script which uses an array of numbers to represent their position in a div. its 5 by 5 like so: Code: tileMap = [ [1, 1, 1, 1, 1], [1, 1, 1, 1, 1], [1, 1, 1, 1, 1], [1, 1, 1, 1, 1], [1, 1, 1, 1, 1], ]; images = new Array(); images[1] = "no block"; images[3] = "brick.PNG"; Image[1] means you can move on the tile, 3 means you cannot (aka a collision). Now this is fine but i have issues regarding my movement of the image. I want to use WASD keyboard buttons which i can do using a CASE statement. But how do you make the image move Regarding Left/Right/Up/Down (also so that it stops moving when you stop holding down one of the keyboard buttons. I use this to detect the key button pressed: Code: function handleKeyMovement(keyValueDown)
{
switch(keyValueDown)
{
case 97: //A Move Left
//move it left
break;
case 100: //D Move Right
//move it right
break;
case 119: //W Move Up
//move it up
break;
case 115: //S Move Down
//move it down
break; }
}
p.s ideally i would like to move the said image by certain pixel amounts so it looks more smooth in movement. Is it possible? Hope you can help ! Hi, I need s JavaScript component that will allow the user to edit small amounts of data (<20 rows and Cols) in a grid format. Any suggestions on what to use? Thanks Bob Hi, This is my plan. I want to create a 3x3 grid on the page. Each square needs to be the height and width of the page. I will then use jquery scroll.to to move the grid, dispalying a different square to the user. Am I right in thinking that I wont be able use 100% width and 100% height in my CSS for the single box, since there are actually going to 8 squares that are off the page? I am guessing therefore that I should use javascript to take the window width and height, and then use this value to create each of the gridbox's. Is this the right way of doing it? Hello, I'm more looking for advice but any helpful examples would be great. So basically what I need to accomplish is a grid, that I can drop objects into, then save the coordinates. So let's say I have a 3x3 set of tiles which will represent "floor tiles", and I load from my MySql database a users "furniture", what's the best method of being able to take these dynamic items drop them on a tile which can be then saved in an xml file or something. What are the best j/s libraries for this? I know jQuery and mootools have drag and drop functions but can they accomplish what I'm looking for? Any feedback will help, I'm comfortable coding in js but I want to do it effeciently and there's got to be people who have done similar things. Hi Peers, i am trying to build a template for my work. 1- it consists of 3 rows of data pulled from a databse based on 3 parameters entered in a form. those 2 rows includes 60 cells each ( 60 columns : 60 months) 2- i will have another 2 empty rows where i have to call another data from another table or enter it manually.. 3- i ll have the last row that will hold calculation results based on the above rows.. Any idea on how to build that ? \please let me know if you need more details or mock up .. it almost like an excel web spreadsheet except that sopme data is pulled directly from a database.. thank you I've been reading a lot of tutorials on the canvas tag and seen a lot of people using JavaScript that looks something like: ctx.beginPath(); ctx.moveTo(25,25); ctx.lineTo(105,25); ctx.fill(); I understand that ctx is just the variable name and I can replace that with any variable I define, however, I'm looking for a list of all of the methods such as (moveTo, lineTo, fill etc...), as well as what they do. I hope I'm explaining this or asking this correctly. Thanks! -Mike Hi there! How should I write this - better than it's now - so that when I rotate a figure, in the next "frame" it would stay rotated? Second thing - if you run this code, and set the angle for, let's say 180 degrees the figure is being drawn in some random location. How do I fix this? Code: Code:
function GenericFigure(context) {
this.states = ["wait", "moving", "rotating", "stop"];
this.state = this.states[0];
this.ctx = context;
this.sqrW = this.sqrH = 20;
this.ctxW = 200;
this.ctxH = 350;
this.colorsO = {
red : "#ee1515",
green : "#45d137",
blue : "#17a3f3",
orange : "#ff910f",
purple : "#680077"
};
this.colorsA = ["#ee1515", "#45d137", "#17a3f3", "#ff910f", "#680077"];
this.pickColor = function() {
var num = Math.floor(Math.random() * 5);
return this.colorsA[num];
}
}
function Rectangle(context) {
this.inheritFrom = GenericFigure;
this.inheritFrom(context);
this.width = this.sqrW;
this.height = this.sqrH * 3;
this.x = this.ctxW / 2;
this.y = 0;
this.rotation = -1;
this.setRotation = function(angle) {
this.rotation = angle;
}
this.rotate = function() {
this.ctx.clearRect(0, 0, this.ctxW, this.ctxH);
this.ctx.translate(this.x + 2 * this.width, this.y - 2 * this.height + 20);
this.ctx.rotate(this.rotation * Math.PI / 180);
this.ctx.fillRect(this.ctxW / 2, 0, this.width, this.height);
this.ctx.restore();
}
this.moveDown = function() {
this.y += 20;
this.ctx.restore();
this.ctx.clearRect(0, 0, this.ctxW, this.ctxH);
this.ctx.fillRect(this.x, this.y, this.width, this.height);
this.ctx.save();
if(this.rotation > -1) {
this.rotate();
}
l("A");
}
this.draw = function() {
this.ctx.fillStyle = this.pickColor();
this.ctx.save();
this.ctx.fillRect(this.x, this.y, this.width, this.height);
}
}
//a tak można wywołać:
var ctx = document.getElementById("game").getContext("2d");
var rect = new Rectangle(ctx);
rect.draw();
var inte = setInterval(function(){if(rect.y >= rect.ctxH - rect.height){clearInterval(inte);return;}if(rect.y == 60) rect.setRotation(90);rect.moveDown();}, 500);
And the third problem: Code: this.ctx.translate(this.x, 0); I thought, that this line should set orientation point to top left corner of my figure, but it seems, that it doesn't - after rotation my figure is being drawn two heights lower. Again - how do I fix it? Any help will be much appreciated . Hey everyone, I have been practicing using canvas to make designs. My current code below will load the word the user inputs and makes it bounce around the canvas as well as a text spinner. However, whenever the user inputs a second word, the bounce below stops to start a new one and the text spinner messes up. I was wondering if anyone could help me so when the user inputs another word, that it either reloads a new textspinner or adds another one, as well as just add the word to the canvas without stopped the old one. Here's my current script. Thanks already, Joey Code:
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script>
var ctx;
var a=0.0;
var as=true;//true a is increasing, false decreasing
var x,y;
var xs = 1;
var ys = 1;
var userWord
var myDiv, t;
var test = 0;
var ds ="";//display string
var sli =0; //spinning letter index;
function init(){
ctx = document.getElementById("myCvs").getContext("2d");
userWord = document.getElementById("userWord").value;
x=Math.floor(Math.random()*801)
y=Math.floor(Math.random()*601);
drawText();
setInterval("onEnterFrame()", 50);
myDiv = document.getElementById("myDiv");
for (i =0; i<=userWord.length;i++){
ds += "*";
}
myDiv.innerHTML =ds;
textSpin();
}
function textSpin(){
myChar = randomChar();
var newString = userWord.slice(0, sli);
newString +=myChar;
newString += ds.slice(sli+1, ds.length-1);
myDiv.innerHTML = newString;
if (myChar == userWord.charAt(sli)){sli++;}
if (sli<userWord.length){
t = setTimeout("textSpin()", 80);
}
}
function randomChar(){
var rc = Math.random()*26 + 97; //random lowercase char code
return String.fromCharCode(rc);
}
function onEnterFrame(){
if(a>1){as = false;}
if(a<0){as = true;}
if(as){
a+=0.01;
}else{
a-=0.01;
}
if(x>800){xs = -1}
if(x<0){xs=1}
if(y>600){ys = -1}
if(y<0){ys=1}
x+=10 *xs;
y+=10 *ys;
drawText();
}
function drawText(){
ctx.font = "20px Times New Roman";
//ctx.fillStyle= "rgb(256,256,256)";
//ctx.fillText("Hello", x, y);
ctx.fillStyle = randomColor();
ctx.fillText(userWord, x,y);
}
function randomColor(){
var r = Math.floor(Math.random()*150)+55;
var g = Math.floor(Math.random()*256)+150;
var b = Math.floor(Math.random()*20)+50;
var a = Math.random();
return "rgba("+ r+ ","+g+","+b+","+ a+")";
}
//function randomFont(){
// var s = Math.floor(Math.random()*100) +100;
// return s; //+ "px Times New Roman";}
</script>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<style type="text/css">
body {
background-color:#000;
}
#myDiv {
color:#FFF;
}
</style>
</head>
<body onLoad=""><center>
<input type="text" id="userWord" value=""> </input><br>
<input type="button" id="enterWord" value="Enter Word" onClick="init()" ></input><br><br>
<div id="myDiv" > </div>
<canvas id="myCvs" width="800px" height="600px" /><br>
<br>
</center>
</body>
</html>
i am trying to change my background image after click on given in grid option. any body show me complete code in java script. resource: HP Laptop Repair and Solution Service Center in Delhi Anyone got any suggestions on techniques? The main one I find is to use translate to move the canvas around, which just seems odd to me. I don't even fully understand how it works. But the one I was looking at used clearRect. In examples given looked as though it had to redraw the canvas every frame. I'm just mucking around with a simple poker game, figured i'd have the table in one layer and anything that moves on a top layer? By doing that I could only clear each card as it moved around...yes? Anyone know of a better way of doing things? Code: <form>
<input id="a" size=4 name="neg" placeholder="1st Screen size in inch">
<input id="b" size=4 name="hoyr" placeholder="2nd Screen size in inch">
<input type="submit" value="GO!" onclick="getValue()">
</form>
</div>
<canvas id="MyCanvas" width="1000" height="1000"></canvas>
<script type="text/javascript">
function getValue()
{
var x = document.getElementById("a").value;
var y = document.getElementById("b").value;
var aWidth;
var aHeight;
var bWidth;
var bHeight;
var c= document.getElementById("MyCanvas");
var ctx= c.getContext("2d");
ctx.fillStyle="#4AA02C";
ctx.fillRect(0,0,x,y);
}
Here, it draws canvas then disappears immediately. So I've been making a game using html canvas. Here is a link to the game. (Move around with wasd, rotate turret with left and right arrows) http://db.tt/ei3LlR The problem is that the shadow flickers when it is rotated. This does not happen in firefox. The shadow is not an image, but another canvas element, generated dynamically from the image of the tank. So the problem seems to be with webkit drawing rotated canvas elements inside another. Could this possibly be the reason behind this, or is it more likely to be a problem on my end? Hello guys! I need your help! I want to create a rectangle with a line in the middle with the canvas object. The problem is that the line in the middle gets bigger than the rest of the rectangle. How do I solve this? I believe it has something to do with shadows. If so, how do I turn them off. My code is: <html> <head> <title></title> </head> <body> <canvas id='chart' width='400' height='200'> <script type="text/javascript"> var canvas = document.getElementById('chart'); var ctx = canvas.getContext('2d'); ctx.lineWidth = 10; ctx.strokeRect(0, 0, 400, 200); ctx.moveTo(0, 100); ctx.lineTo(400, 100); ctx.stroke(); </script> </body> </html> I just cant wrap my mind around canvas. As far as I can tell theres no logical reason as to why the code would not work. Could someone take a look at it and possibly figure out whats wrong? I'm trying to intialize and draw a canvas with a simple image. I have the functions in a custom namespace in javascript. I am also using Jquery Code: var birdr = new Image();
var birdl = new Image();
$(document).ready(function(){
if(Modernizr.canvas){
var c = document.createElement('canvas');
LK.animLoad();
document.getElementById('backg-canvas').appendChild(c);
$('canvas').attr({'width':'500','height':'500','id':'canvas'});
var context = LK.returnCanvas();
context.drawImage(birdl, 400,487,10,10);
}
});
var LK = {
birdx: 400, //unused (lets just get it to draw the image first :\)
birdy: 487, //unused
animLoad: function(){
birdl.src = "images/bird2.png";
birdr.src = "images/bird.png";
//alert(birdl);
//alert(birdr);
},
returnCanvas: function(ca){
var b_canvas = LK.getCanvas();
var b_context = b_canvas.getContext('2d');
return b_context;
},
getCanvas: function(){
var a_canvas = document.getElementById('canvas');
//alert(a_canvas);
return a_canvas;
}
}
Any help would be greatly appreciate thanks. Btw safari web inspector indicates the canvas is getting properly created and appended to the container div. So that all works fine. Hello, Codingforums. I have looked on Google for a solution, done a handful of things, and cannot get my script to draw to the page. Code: <html>
<head>
<script type="text/javascript" src="imageFuncs.js"></script>
<script type="text/javascript">
showImages = function() {
var drawingCanvas = document.getElementById("map");
// Check the element is in the DOM and the browser supports canvas
if (drawingCanvas.getContext) {
var ctx = drawingCanvas.getContext("2d");
var imageSources = new Array("map.jpg");
var images = new Array();
images = loadImages(imageSources);
for (var i = 0; i < images.length; i++) {
var img = new Image();
img.src = images[i].src;
img.onload = function(){
ctx.drawImage(img,0,0,screen.width,screen.height);
}
}
}
}
</script>
</head>
<body onload="showImages()">
<canvas id="map">Your browser does not support canvases...</canvas>
</body>
</html>
The problem appears on the ctx.drawImage(img,0,0,screen.width,screen.height); line. I read that the drawImage method will not draw the image if the images are not loaded, which is why I tried an onload event for img. When I run the code the way it is now, I get a attempt to run compile-and-go script on a cleared scope error from Firebug. When I remove the onload event, the script runs without errors. Either way, no image is drawn on the page. Any help? If it helps, this is the loadImages function that I used to get the array of loaded image objects: Code: function loadImages(sources){
var images = new Array();
var loadedImages = 0;
var numImages = 0;
for (var src in sources) {
numImages++;
}
for (var src in sources) {
images[src] = new Image();
images[src].src = sources[src];
}
return images;
}
not sure if this is the right place to ask canvas questions, but if it is, i'm trying to program a game like air hockey (with some twists). it works pretty well now but the table is viewed from overhead, and i would prefer to show the game from the player's perspective, as in the pic, without having to rewrite my existing code. anyone know of any js libraries or formulas which can accomplish this? i want to transfrom image like the picture below using canvas,it seems simple but i find no way to do , can anyone give me some ideas? ( left side is the source) I guess canvases like inline width/height instead of css width/height. This solved the issue. I'm working on a project that uses HTML5 Canvas and I'm having a strange problem with stretching. I noticed it with images and thought my math might have been wrong but then I took everything out and tried drawing a simple 100x100 square and it's completely stretched out at different proportions. The code for this (small class code)- Code: function Canvas(DOMID, F)
{
this.Frame = null;
this.width = null;
this.height = null;
this.zoom = null;
this.DOM = null;
this.ctx = null;
this.offset = null;
//Constructor
this.init = function(DOMID, F)
{
this.DOM = document.getElementById(DOMID);
this.width = $(this.DOM).width();
this.height = $(this.DOM).height();
this.ctx = this.DOM.getContext("2d");
this.zoom = 1;
this.offset = {x:0,y:0};
if(F != null)
this.setFrame(F);
this.onReady();
}
//Modifiers
this.draw = function()
{
//this.ctx.drawImage(image, 0, 0);
this.ctx.beginPath();
this.ctx.fillStyle = "#ffffff";
this.ctx.rect(0,0,100,100);
this.ctx.closePath();
this.ctx.fill();
}
this.setFrame = function(F)
{
this.Frame = F;
}
//Events
this.onReady = function(){}
this.init(DOMID, F);
}
The code calling this function is in an interval- Code: window.goToCanvas = function()
{
clearTimeout(playInterval);
playInterval = setInterval("drawCurrentCanvas()", window.playSpeed);
}
window.drawCurrentCanvas = function()
{
index = window.canvasIndex;
canvases[index].draw();
}
The page can be found here- http://micahwilliams...ewer/viewer.php I'm stumped. I hope someone can see my mistake somewhere. |
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