Processing Forum

Is PVector.equals implemented properly?

[1 Reply]
- 15-Jan-2013 12:10 AM
- Forum: General Discussion
Hey, I want to have a set of unique vertexes for something, and I was planning on just using some flavour of Set in the standard library. It says that it checks object.equals(otherObject) to check if an item should be added or not. I was wondering if I'll have to extend the PVector class to make this work, or if it's a default feature already.

Easy to use Quaternion class

[11 Replies]
- 09-Dec-2012 12:20 AM
- Forum: Share your Work
Hey, I remember having a lot of issues with Quaternions when I first started out, but then I foud a great C++ class after googling for a bit for one. I've decided to port it to Java so that it can be used with Processing. You can keep track of the quaternions explicitly, or if you're lazy like me, you can just use a flavor of the rotate() function that I made at the bottom there. The original class was written by Laurent Schmalen and I just ported it over to fit in with Java.

Anyways, here it is:
2. /***************************************************************************
3. * Quaternion class written by BlackAxe / Kolor aka Laurent Schmalen in 1997
4. * Translated to Java(with Processing) by RangerMauve in 2012
5. * this class is freeware. you are fully allowed to use this class in non-
6. * commercial products. Use in commercial environment is strictly prohibited
7. */
9. public class Quaternion {
10. public float W, X, Y, Z; // components of a quaternion
12. // default constructor
13. public Quaternion() {
14. W = 1.0;
15. X = 0.0;
16. Y = 0.0;
17. Z = 0.0;
18. }
20. // initialized constructor
22. public Quaternion(float w, float x, float y, float z) {
23. W = w;
24. X = x;
25. Y = y;
26. Z = z;
27. }
29. // quaternion multiplication
30. public Quaternion mult (Quaternion q) {
31. float w = W*q.W - (X*q.X + Y*q.Y + Z*q.Z);
33. float x = W*q.X + q.W*X + Y*q.Z - Z*q.Y;
34. float y = W*q.Y + q.W*Y + Z*q.X - X*q.Z;
35. float z = W*q.Z + q.W*Z + X*q.Y - Y*q.X;
37. W = w;
38. X = x;
39. Y = y;
40. Z = z;
41. return this;
42. }
44. // conjugates the quaternion
45. public Quaternion conjugate () {
46. X = -X;
47. Y = -Y;
48. Z = -Z;
49. return this;
50. }
52. // inverts the quaternion
53. public Quaternion reciprical () {
54. float norme = sqrt(W*W + X*X + Y*Y + Z*Z);
55. if (norme == 0.0)
56. norme = 1.0;
58. float recip = 1.0 / norme;
60. W = W * recip;
61. X = -X * recip;
62. Y = -Y * recip;
63. Z = -Z * recip;
65. return this;
66. }
68. // sets to unit quaternion
69. public Quaternion normalize() {
70. float norme = sqrt(W*W + X*X + Y*Y + Z*Z);
71. if (norme == 0.0)
72. {
73. W = 1.0;
74. X = Y = Z = 0.0;
75. }
76. else
77. {
78. float recip = 1.0/norme;
80. W *= recip;
81. X *= recip;
82. Y *= recip;
83. Z *= recip;
84. }
85. return this;
86. }
88. // Makes quaternion from axis
89. public Quaternion fromAxis(float Angle, float x, float y, float z) {
90. float omega, s, c;
91. int i;
93. s = sqrt(x*x + y*y + z*z);
95. if (abs(s) > Float.MIN_VALUE)
96. {
97. c = 1.0/s;
99. x *= c;
100. y *= c;
101. z *= c;
103. omega = -0.5f * Angle;
104. s = (float)sin(omega);
106. X = s*x;
107. Y = s*y;
108. Z = s*z;
109. W = (float)cos(omega);
110. }
111. else
112. {
113. X = Y = 0.0f;
114. Z = 0.0f;
115. W = 1.0f;
116. }
117. normalize();
118. return this;
119. }
121. public Quaternion fromAxis(float Angle, PVector axis) {
122. return this.fromAxis(Angle, axis.x, axis.y, axis.z);
123. }
125. // Rotates towards other quaternion
126. public void slerp(Quaternion a, Quaternion b, float t)
127. {
128. float omega, cosom, sinom, sclp, sclq;
129. int i;
132. cosom = a.X*b.X + a.Y*b.Y + a.Z*b.Z + a.W*b.W;
135. if ((1.0f+cosom) > Float.MIN_VALUE)
136. {
137. if ((1.0f-cosom) > Float.MIN_VALUE)
138. {
139. omega = acos(cosom);
140. sinom = sin(omega);
141. sclp = sin((1.0f-t)*omega) / sinom;
142. sclq = sin(t*omega) / sinom;
143. }
144. else
145. {
146. sclp = 1.0f - t;
147. sclq = t;
148. }
150. X = sclp*a.X + sclq*b.X;
151. Y = sclp*a.Y + sclq*b.Y;
152. Z = sclp*a.Z + sclq*b.Z;
153. W = sclp*a.W + sclq*b.W;
154. }
155. else
156. {
157. X =-a.Y;
158. Y = a.X;
159. Z =-a.W;
160. W = a.Z;
162. sclp = sin((1.0f-t) * PI * 0.5);
163. sclq = sin(t * PI * 0.5);
165. X = sclp*a.X + sclq*b.X;
166. Y = sclp*a.Y + sclq*b.Y;
167. Z = sclp*a.Z + sclq*b.Z;
168. }
169. }
171. public Quaternion exp()
172. {
173. float Mul;
174. float Length = sqrt(X*X + Y*Y + Z*Z);
176. if (Length > 1.0e-4)
177. Mul = sin(Length)/Length;
178. else
179. Mul = 1.0;
181. W = cos(Length);
183. X *= Mul;
184. Y *= Mul;
185. Z *= Mul;
187. return this;
188. }
190. public Quaternion log()
191. {
192. float Length;
194. Length = sqrt(X*X + Y*Y + Z*Z);
195. Length = atan(Length/W);
197. W = 0.0;
199. X *= Length;
200. Y *= Length;
201. Z *= Length;
203. return this;
204. }
205. };
Here's the rotation code:
2. //Example of rotating PVector about a directional PVector
3. PVector rotate(PVector v, PVector r, float a) {
4. Quaternion Q1 = new Quaternion(0, v.x, v.y, v.z);
5. Quaternion Q2 = new Quaternion(cos(a / 2), r.x * sin(a / 2), r.y * sin(a / 2), r.z * sin(a / 2));
6. Quaternion Q3 = Q2.mult(Q1).mult(Q2.conjugate());
7. return new PVector(Q3.X, Q3.Y, Q3.Z);
8. }

Can I use the Processing Networking library in plain Java?

[1 Reply]
- 29-Oct-2011 08:52 PM
- Forum: Core Library Questions
I like how simple the networking is in Processing, and I would really like to be able to use that in a regular Java project (say in a JFrame). I was wondering if I could do this, or if there was a similar library for regular Java.

Sending data between programs with Client and Server objects

[3 Replies]
- 05-Jul-2011 06:14 PM
- Forum: Core Library Questions
Hi, I'm trying to work on a simple multyplayer game (it's super simple.. like dots moving around) and I'm having trouble on figuring out on how to send data from to server to the clients. I've got the idea behind sending data right to a server and the server storing the clients so it can receive data from them, but I don't understand how to write data to a client one at a time, and also how the clients will read it. I know that there is the server.write function, but I don't see how the clients read it. Any help on this topic would be super useful.

Thanks in advance.

Hooking up a wiimote to processing in windows

[1 Reply]
- 16-Jun-2011 03:29 PM
- Forum: Integration and Hardware
Hi, I've seen some wiimote libraries for processing, but they all seem to be for macs. Are there any libraries that will work on a windows machine? Alternitavely, does anyone know any other programming languages that have wiimote libraries for windows.

Making an array of objects

[3 Replies]
- 18-May-2011 02:57 PM
- Forum: Programming Questions
Okie, I've made an object to hold and update these blob things that should fly all over the screen. Now, to make managing them easier, I stored them in an array.

//The class name is "enemy"
enemy[] Boop;

void setup(){
for (int i = 0;i < 10; i ++){
Boop[i] = new Enemy();
}
}

Am I initializing something wrong? I seem to be getting a null pointer exception.

Can't use PowerManager object

[2 Replies]
- 15-May-2011 07:45 PM
- Forum: Android Processing
I'm trying to turn off the whole sleep mode thing, and one of the methods I've found is ti use the PowerManager object found here. My problem is that I get an error when I try to use
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);

Actually just declaring Powermanager pm; gives me the error "cannot find symbol"

I'm not really sure if I'm using the SDK impoperly or something, because I've got the accelerometer working.
Any sort of insight into this problem or perhaps a hint as to where I can go for more info would be appreciated.

Is there a procedure that runs when an app is closed?

[2 Replies]
- 10-May-2011 03:17 PM
- Forum: Android Processing
I need to run some code every time my program closes. I saw something like "onDestroy" somewhere, but I get an error whenever I try to use it.

Turning sleep mode off in Android.

[15 Replies]
- 10-May-2011 10:55 AM
- Forum: Android Processing
I'm making a simple thing for my new android phone that uses the accelerator to move a ball around the screen. The problem is that after a few seconds, the screen goes black and I need to press my back button to turn it back on. Is there any way to disable sleep mode while my game is running?

While googling around, I found this site here. It says something like "use this flag: WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON"

Anyone know what the heck this means or how I can use it?
I've seen soemthing like this implemented on games and other apps that I've downloaded for my phone, and I've seen soem sortof methods for doing this with java. Has nobody else come across this problem but me?

Apparently someone else has asked a similer question on here. But it seems they didn't get an answer either.

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