Java-Gaming.org Hi !
 Featured games (84) games approved by the League of Dukes Games in Showcase (575) Games in Android Showcase (154) games submitted by our members Games in WIP (623) games currently in development
 News: Read the Java Gaming Resources, or peek at the official Java tutorials
Pages: [1]
 ignore  |  Print
 Rotating Particle (Flamethrower) Tower Spawn Acceleration  (Read 1245 times) 0 Members and 1 Guest are viewing this topic.
Slyth2727
 « Posted 2013-04-10 23:33:49 »

Right, in my Java2d TD Game I have set on making a tower that has 3 barrels which spin around and, using my particle engine, spew out fire particles at the direction the barrels are pointing. I have no trouble with the rotation, and I can set the acceleration vector by saying particle.setAcc(X, Y). If the Y value is positive, the particle will go down by that many pixels per tick. Negative, opposite. Same thing for X, just on the X axis. My only problem is if I have the rotation method going like this:

 1  2  3  4  5  6 `            if (rotateT >= rotateS) {               rotation++;               rotateT = 0;            } else {               rotateT++;            }`

and my method for spawning in particles is this:

 1 `            Screen.addOverParticle(X, Y, velocityx, velocityy, size, amount, life, image);`

how would I get it so it the spawning of the particles spins around in a circle as if a flamethrower is turning around in a continuous circle, firing. I have a few ideas, but I think it will be very CPU intensive the ways I am thinking. Thanks -cMp

Was I before Chuang Tzu who dreamt about being a butterfly, or am I now a butterfly who dreams about being Chuang Tzu?
relminator
 « Reply #1 - Posted 2013-04-11 00:46:45 »

 1  2  3 `float ang = (float)Math.toRadians(rotation);velocityx = (float)Math.cos(ang) * speed; velocityy = (float)Math.sin(ang) * speed;`

Slyth2727
 « Reply #2 - Posted 2013-04-11 01:02:08 »

I get an interesting effect with this. The particles spawn like a box and the width gets bigger than smaller while the height gets smaller than bigger in an indirect variation, if you will. Not the effect I was looking for and still am but a nice one..

Was I before Chuang Tzu who dreamt about being a butterfly, or am I now a butterfly who dreams about being Chuang Tzu?
StumpyStrust
 « Reply #3 - Posted 2013-04-11 02:02:18 »

If you get a box it is because you are using different speeds for x and y.

If you want it so it looks like someone with a water hose spinning in a circle with flames instead of water, then what relminator said is right. You might be doing something different in your particle system.

Here is how my emitters do this

 1  2  3  4  5  6  7  8  9  10  11  12  13 `float temp = angle2 - angle1;                   float newAngle = (float) (((Rnd.randomPlus(temp))+angle1) * Math.PI/180);         newAngle *= -1;         if(randomV)         {            float v = Rnd.randomPlus(vel);            x.setVel((float)(v*FastMath.cos(newAngle)),(float) (v*FastMath.sin(newAngle)));         }         else         {            x.setVel((float)(vel*FastMath.cos(newAngle)),(float) (vel*FastMath.sin(newAngle)));         }`

Note in this I have extra options like random vel and emitting particles between 2 angles but the key is the x.setVel

Slyth2727
 « Reply #4 - Posted 2013-04-11 23:33:05 »

Ok I see now! Works like a charm, thank you very much

Was I before Chuang Tzu who dreamt about being a butterfly, or am I now a butterfly who dreams about being Chuang Tzu?
Pages: [1]
 ignore  |  Print

You cannot reply to this message, because it is very, very old.

 ClaasJG (19 views) 2015-04-27 13:36:51 BurntPizza (33 views) 2015-04-23 03:42:11 theagentd (35 views) 2015-04-22 16:23:07 Riven (50 views) 2015-04-16 10:48:47 Duke0200 (59 views) 2015-04-16 01:59:01 Fairy Tailz (42 views) 2015-04-14 20:13:12 Riven (45 views) 2015-04-12 21:36:37 bus hotdog (61 views) 2015-04-10 02:39:32 CopyableCougar4 (66 views) 2015-04-10 00:51:04 BurntPizza (71 views) 2015-04-06 22:06:58
 theagentd 23x BurntPizza 17x wessles 15x kingroka123 11x alwex 11x 65K 11x kevglass 8x Rayvolution 7x Riven 7x chrislo27 7x Hanksha 7x Olo 7x Ecumene 7x ra4king 7x KevinWorkman 6x Roquen 4x
 How to: JGO Wikiby Mac702015-02-17 20:56:162D Dynamic Lighting2015-01-01 20:25:42How do I start Java Game Development?by gouessej2014-12-27 19:41:21Resources for WIP gamesby kpars2014-12-18 10:26:14Understanding relations between setOrigin, setScale and setPosition in libGdx2014-10-09 22:35:00Definite guide to supporting multiple device resolutions on Android (2014)2014-10-02 22:36:02List of Learning Resources2014-08-16 10:40:00List of Learning Resources2014-08-05 19:33:27
 java-gaming.org is not responsible for the content posted by its members, including references to external websites, and other references that may or may not have a relation with our primarily gaming and game production oriented community. inquiries and complaints can be sent via email to the info‑account of the company managing the website of java‑gaming.org