trigonometry


How can I calculate the angle


I'm creating a game where if the enemy is in a certain range and is in front of the player the player can attack the enemy. I have worked out the radius distance and made it facing forward depending in which way the player faces but how can i create the angle so it makes like a cone shape from the player. I have got an image. The thin green line is the radius which I have worked out but how can i calculate the red cone.
Here is the image for more better understanding
http://tinypic.com/view.php?pic=28v63h0&s=6
This is what I done so far
package
{
import flash.display.MovieClip;
import flash.events.Event;
import flash.events.KeyboardEvent;
import flash.events.MouseEvent;
import flash.ui.Keyboard;
public class Player extends MovieClip
{
var radius:Number = 60;
public function Player()
{
addEventListener(Event.ENTER_FRAME, Update);
}
function Update(event:Event)
{
var radiusx:Number = x+radius*Math.cos(rotation/180*Math.PI);
var radiusy:Number = y+radius*Math.sin(rotation/180*Math.PI);
// Rotate to mouse;
var dx = parent.mouseX - x;
var dy = parent.mouseY - y;
var angle = Math.atan2(dy,dx) / Math.PI * 180;
rotation = angle;
}
}
}
You can use the definition of tangent:
tan(a/2) = s/(2d)
where s is size (diamerer) of the enemy and d is the shortest distance to the enemy. Here a is the total visible angle (between two red lines).

Related Links

Calculating collisions with Radians incrementing
How do arbitrary-precision libraries like mpmath evaluate simple trigonometric functions?
How can I calculate the angle
Finding Shortest Distance Between Two Parallel Lines, With Arbitrary Point [closed]
how to convert depth in Z-cordinate
How can I simplify this expression with trigonometric in Maple?
Require trigonometry assistance with ship/wave movement
Trigonometry - Find where two curves intersect
How to calculate point 'along' unit circle radian [closed]
Issues with bullet entry points for “shoulder mounted” guns
Using the coordinates of two of a triangle's vertices to calculate the coordinates of the third
How to do the trig function Arc Cos (ACOS() in Excel) in MS-Access?
How to get the direction (angle) of rectangle after rotating it from a pivot point
How to calculate points of Chord
Is trigonometry computationally expensive?
draw lines protruding from a circle [closed]

Categories

HOME
spark-streaming
developer-tools
ng-idle
pagination
twig
google-cloud-functions
database-normalization
trac
title
pkcs#11
pattern-matching
categorical-data
parameter-passing
glyphicons
powershell-v5.0
template-engine
enterprise-miner
qliksense
shared
entity-relationship-model
datastax-enterprise-graph
twiml
memory-address
spring-security4
login-script
pop3
sql-delete
python-pptx
openerp-7
imagenet
claims
dapper-simplecrud
pom.xml
openal
builder
dotnet-httpclient
chai-as-promised
geotiff
identification
singleinstance
boo
gameplay-kit
structuremap4
autosar
builtins
latin
jboss-tools
ng-grid
synonym
clipboard.js
swizzling
shopping
phpgrid
atan2
evolus-pencil
zxspectrum
dot.js
mmwormhole
procedural-programming
unix-socket
jjaql
high-resolution
jammer
time.h
pdfviewer
tree-balancing
xcode3.2
zope.interface
correlated-subquery
garbage
appjs
database-create
kqueue
rmdir
multiplatform
creole
clrstoredprocedure
cuteeditor
undefined-index
isapi-extension
todos
localizable.strings

Resources

Mobile Apps Dev
Database Users
javascript
java
csharp
php
android
MS Developer
developer works
python
ios
c
html
jquery
RDBMS discuss
Cloud Virtualization
Database Dev&Adm
javascript
java
csharp
php
python
android
jquery
ruby
ios
html
Mobile App
Mobile App
Mobile App