Aim N Shoot Question

MinDev

Hey, i am creating game and I need some help.
I know how to make script that will return x and y coordinates of the mouse/touchpad, but I dont know how to return weapon angle around player to crosshair.

selim

I think what you are look for is Math.atan2(y,x) where x and y have (0,0) on the player center.

MinDev

Thank you but.... The script should somehow compare two positions to return angle, not one.
And angle should be returned in degrees too

selim

Let's say that the player position on screen is (x0,y0) and that the mouse click was on (x1,y1). The formula to find the angle is:

angle = Math.atan2(x1-x0, y1-y0);

You just have to keep in mind that the y-axis point toward the bottom and the origine (0,0) is on the top-left corner of the window.

MinDev

"
function RadToDeg(radians){
//converting radians to degrees
degrees = radians*(180/Math.PI);
return degrees;
}

function ReturnPlayerAimDegree(PlayerX,PlayerY,event){
//Everything's clear lets go
var PlayerCurrentMouseX = event.clientX;
var PlayerCurrentMouseY = event.clientY;
this.TransX = PlayerCurrentMouseX-PlayerX;
this.TransY = PlayerCurrentMouseY-PlayerY;
var RadDegPlayerOperation = Math.atan2(this.TransX,this.TransY);
document.getElementById("demo").innerHTML = RadToDeg(RadDegPlayerOperation);
return RadToDeg(RadDegPlayerOperation);
}

"
This script above works well
Thank you,
Everything's clear
Hope I will make aiming script correctly

MinDev

OK, I've got it EXCEPT 1 thing I have to say:
Mx = event.clientX;
My = event.clientY;
// x, y are pre-defined as player x and y s, offsets are predefined by the angle I aim and, gun size, etc.
transX = x - Mx;
transY = y - My
var GunAimRadians = math.atan2(transX - Xoffset, transY - Yoffset)
var Aim = GunAimRadians*180/Math.PI - 90. //-90 is VERY important or otherwise it will aim 90 deg up
Then.... bullets, etc.
You know, I have been experimenting with "Tululoo Game Maker"(uses pure JS, no frameworks such as JQuery) and I have found something interesting here:
http://trickkr.com/item/67/rezoners-games-from-scratch-bullets

MinDev

It also has answered me a BIG question for direction of bullets and speed relation. Again, trigonometry.