I want to move the image based on the coordinates from database.
I can already move the image (thing). But for example, i have x-coordinate as 293 and y-coordinate as 715, the image ends up moving to 293 and 715 BUT the image (thing) i'm moving is an arrow like
this
So i have to move the image but the upper left part of the image should be the one to locate the coordinates not the center part of it. Anyone who can help me with my problem? any help will be appreciated
here's my script so far,
<script>
function getClickPosition($valuex,$valuey) {
var theThing = document.querySelector("#thing");
var container = document.querySelector("#contentContainer");
var x1 = document.getElementById('valuex').value;
var y1 = document.getElementById('valuey').value;
var parentPosition = getPosition(x1.currentTarget);
var parentPosition = getPosition(y1.currentTarget);
var xPosition = x1 - parentPosition.x - (theThing.clientWidth / 2);
var yPosition = y1- parentPosition.y - (theThing.clientHeight / 2);
theThing.style.left = xPosition + "px";
theThing.style.top = yPosition + "px";
function getPosition(element) {
var xPosition = 0;
var yPosition = 0;
while (element) {
xPosition += (element.offsetLeft - element.scrollLeft + element.clientLeft);
yPosition += (element.offsetTop - element.scrollTop + element.clientTop);
element = element.offsetParent;
}
return { x: xPosition, y: yPosition };
}
</script>
The position is relative to the top left corner by default. You have to manually offset it to get anything else. That's what the theThing.clientWidth /2 and theThing.clientHeight / 2 is doing in your code: moving the position up and left by half of the height/width. If you want to just use the top left position, replace this:
var xPosition = x1 - parentPosition.x - (theThing.clientWidth / 2);
var yPosition = y1 - parentPosition.y - (theThing.clientHeight / 2);
With this:
var xPosition = x1 - parentPosition.x;
var yPosition = y1 - parentPosition.y;
Related
I have created the following code to make the player move towards the mouse, JSFiddle
Code
var mouseX = 0, mouseY = 0;
$(document).mousemove(function(event) {
mouseX = event.pageX;
mouseY = event.pageY;
});
$(function(){
var $map = $(".map");
var $player = $('.player');
var centerPlayerX = $player.offset().left + $player.width() / 2;
var centerPlayerY = $player.offset().top + $player.height() / 2;
var movingInterval;
$('.map').on('mousedown', function(event){
movingInterval = setInterval(function(){
var clickedPosX = mouseX,
clickedPosY = mouseY;
var currentMapPositionX = parseFloat($map.css("background-position-x"));
var currentMapPositionY = parseFloat($map.css("background-position-y"));
var moveMapX = currentMapPositionX - clickedPosX/100 + centerPlayerX/100;
var moveMapY = currentMapPositionY - clickedPosY/100 + centerPlayerY/100;
$map.css({ "background-position-x": `${moveMapX}px`, "background-position-y": `${moveMapY}px` });
var angle = getDirection(centerPlayerX, clickedPosY, clickedPosX, centerPlayerY);
$player.find('.ship').css('transform', 'rotate('+angle+'deg)');
}, 10);
}).on('mouseup', function() {
clearInterval(movingInterval);
});;
});
function getDirection(x1, y1, x2, y2){
var dx = x2 - x1;
var dy = y2 - y1;
return Math.atan2(dx, dy) / Math.PI * 180;
}
Problem
var moveMapX = currentMapPositionX - clickedPosX/100 + centerPlayerX/100;
var moveMapY = currentMapPositionY - clickedPosY/100 + centerPlayerY/100;
Problem is that I want to move the player at a set speed (px*ps). Currently the player will increase in speed when the player moves his mouse further away from the image. I currently have no idea on how I would move the player at a set speed. Therefore I would need to remove clickedPosY/X somehow and change it to a static speed but the image should still move towards were the mouse is, which is the problem.
So, let's assume you have a speed constant; what you want to do is to project the speed constant along the movement vector. The easiest way to do that is to scale the components of the offset to the click position by the ratio of the speed to the distance between the click point and the movement base:
var distanceX = clickedPosX - centerPlayerX;
var distanceY = clickedPosY - centerPlayerY;
var magnitude = Math.sqrt(distanceX * distanceX + distanceY * distanceY);
var deltaX = distanceX * speed / magnitude;
var deltaY = distanceY * speed / magnitude;
var moveMapX = currentMapPositionX - deltaX;
var moveMapY = currentMapPositionY - deltaY;
Updated fiddle
I am trying to get mouse pointer position on mousedown and mouseup event. There is a div named test and i want to get position when mousedown and mouseup happen within div area. And I am taking div as my surface so the mousedown and mouseup position should be related to div. I have a pdf inside that div so, the coordinates i get will help me to highlight the pdf.
I tried this, but its not working fine.
function getPosition(element) {
var xPosition = 0;
var yPosition = 0;
while (element) {
xPosition += (element.offsetLeft - element.scrollLeft + element.clientLeft);
yPosition += (element.offsetTop - element.scrollTop + element.clientTop);
element = element.offsetParent;
}
return { x: xPosition, y: yPosition };
}
$("#test").mousedown(function(e){
var parentPosition = getPosition(e.currentTarget);
startX = e.clientX - parentPosition.x;
startY = (e.clientY - parentPosition.y)*2.5;
});
$("#test").mouseup(function(e){
var parentPosition = getPosition(e.currentTarget);
endX = e.clientX - parentPosition.x;
endY= (e.clientY - parentPosition.y)*2.5;
});
The coordinates of the mouse relative to the div are stored in the offsetX, offsetY properties of the event object
$("#someDiv").click(function(e){
var x = e.offsetX;
var y = e.offsetY;
});
So if you have a div with a width of 100 and a height of 50, and click exactly in the center of the div then
x = 50, y = 25
JSFiddle Demo
in the jsfiddle below im trying to get the yellow and red circles to initially appear in the center, as opposed to moving to the cursor's initial assumed position - which is (0,0) as the cursor is not yet in the actual screen of the page (if I'm guessing correctly).
http://jsfiddle.net/fhmkf/220/
Is there a way I can define the initial placement of the cursor - that is when calculating (window).mousemove(function(e){... - particularly the e.pageX and e.pageY?
The js looks like so:
var Circle = function(container, follower, r){
var center = {
x: $(container).width()/2 - r,
y: $(container).height()/2 - r
};
var distanceThreshold = $(container).width()/2 - r;
var mouseX = 0, mouseY = 0;
$(window).mousemove(function(e){
var d = {
x: e.pageX - center.x,
y: e.pageY - center.y
};
var distance = Math.sqrt(d.x*d.x + d.y*d.y);
if (distance < distanceThreshold) {
mouseX = e.pageX;
mouseY = e.pageY;
} else {
mouseX = d.x / distance * distanceThreshold + center.x;
mouseY = d.y / distance * distanceThreshold + center.y;
}
});
// cache the selector
var follower = $(follower);
var xp = 0, yp = 0;
var loop = setInterval(function(){
// change 12 to alter damping higher is slower
xp += (mouseX - xp) / 2;
yp += (mouseY - yp) / 2;
follower.css({left:xp, top:yp});
}, 30);
};
var c1 = new Circle(".container", "#follower", 15);
var c2 = new Circle(".container2", "#follower2", 25);
I'm trying to get the jsfiddle sample below to make the yellow circle div follow the mouse but be constraint to a circle as opposed to a square (div).
http://jsfiddle.net/fhmkf/
The JS code looks like so:
var mouseX = 0, mouseY = 0, limitX = 150-15, limitY = 150-15;
$(window).mousemove(function(e){
mouseX = Math.min(e.pageX, limitX);
mouseY = Math.min(e.pageY, limitY);
});
// cache the selector
var follower = $("#follower");
var xp = 0, yp = 0;
var loop = setInterval(function(){
// change 12 to alter damping higher is slower
xp += (mouseX - xp) / 12;
yp += (mouseY - yp) / 12;
follower.css({left:xp, top:yp});
}, 30);
I understand the structure and methodology of the code, just not too familiar with the syntax!
Where is the best place to update the limitX/Y and throw in the extra radius, distance variables?
You can do this by computing the distance away from the center of the circle (2D distances are computed with Math.sqrt(x * x + y * y)). Then check to see if the distance is greater than the radius of the circle you'd like to constrain to. If it is, scale down the distance to match your constraining radius.
Here's the snippet:
var mouseX = 0, mouseY = 0, limitX = 150-15, limitY = 150-15;
var centerX = limitX / 2, centerY = limitY / 2;
var radius = centerX;
$(window).mousemove(function(e) {
var diffX = e.pageX - centerX;
var diffY = e.pageY - centerY;
// Get the mouse distance from the center
var r = Math.sqrt(diffX * diffX + diffY * diffY);
if (r > radius) {
// Scale the distance down to length 1
diffX /= r;
diffY /= r;
// Scale back up to the radius
diffX *= radius;
diffY *= radius;
}
mouseX = centerX + diffX;
mouseY = centerY + diffY;
});
And here's the complete code: http://jsfiddle.net/fhmkf/
So ... I created canvas element with jquery:
var canvasElement = $("<canvas id='map' width='" + CANVAS_WIDTH + "' height='" + CANVAS_HEIGHT + "'></canvas");
var canvas = canvasElement.get(0).getContext("2d");
canvasElement.appendTo('body');
And now i want to get mouse coordinates, but the next code doesn't work:
canvasElement.onmousemove = mousemove;
function mousemove(evt) {
var mouseX = evt.pageX - canvasElement.offsetLeft;
var mouseY = evt.pageY - canvasElement.offsetTop;
alert(mouseX+":"+mouseY);
}
canvasElement.offsetLeft is not work, evt.pageX too... Help !
Those properties aren't cross-browser.
I know of two solutions to get the canvas position :
the easy one : use jQuery offset
another one : use a custom and complex code :
if (!canvasElement.offsetX) {
// firefox
var obj = canvasElement;
var oX = obj.offsetLeft;var oY = obj.offsetTop;
while(obj.parentNode){
oX=oX+obj.parentNode.offsetLeft;
oY=oY+obj.parentNode.offsetTop;
if(obj==document.getElementsByTagName('body')[0]){break}
else{obj=obj.parentNode;}
}
canvas_position_x = oX;
canvas_position_y = oY;
} else {
// chrome
canvas_position_x = canvasElement.offsetX;
canvas_position_y = canvasElement.offsetY;
}
As there is a loop, you'd better store canvas_position_x and canvas_position_y and have them recomputed at each document resize instead of at each mousemove.
Demonstration
Live Demo
Its pretty easy actually without jQuery. Below is the important part from the fiddle. cX and cY are the coordinates of the clicked canvas.
function clicked(e) {
var cX = 0,
cY = 0;
if (event.pageX || event.pageY) {
cX = event.pageX;
cY = event.pageY;
}
else {
cX = event.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;
cY = event.clientY + document.body.scrollTop + document.documentElement.scrollTop;
}
cX -= canvas.offsetLeft;
cY -= canvas.offsetTop;
ctx.fillRect(cX, cY, 2, 2);
}
Demo with mouse move