Processing Forum

NULL POINTER EXCEPTION!!! PLEASE HELP

[3 Replies]
- 15-Feb-2012 05:15 AM
- Forum: Programming Questions
I run this without the code to communicate with arduino and it works perfectly fine, but as soon as I tried to implement the code to communicate with arduino I ran into a lot of problems. this is just the latest, and I can't seem to work my way through it. Please Please help. The highlighted area is where Processing is telling me there is a NullPointerException. Thank you!
2. //This code was inspired by Tom Carden's metropopDenim
3. //Alexander Braden Feb 2012
6. import processing.serial.*;
9. int SPRITE_SIZE = 8;
11. int NUM_PARTICLES = 10000;
12. int NUM_ATTRACTORS = 7;
13. float life = 200;
16. Particle[] particle;
17. Attractor[] attractor;
19. Serial arduinoPort;
20. String myString;
23. void setup() {
25. size(1500, 1000);
26. background(0);
27. smooth();
29. arduinoPort = new Serial(this, Serial.list()[0], 9600);
31. attractor = new Attractor[NUM_ATTRACTORS];
32. particle = new Particle[NUM_PARTICLES];
36. //scatter();
41. // attractor[0] = new Attractor(934.49005, 755.15497);
42. // attractor[1] = new Attractor(705.3572, 203.30354);
43. // attractor[2] = new Attractor(691.54987, 729.0818);
44. // attractor[3] = new Attractor(412.42975, 323.84244);
45. // attractor[4] = new Attractor(518.8423, 395.56848);
46. // attractor[5] = new Attractor(687.9407, 268.94116);
47. }
49. void draw() {
51. if (lifeOut()) {
52. // move and draw particles
54. //fill(0, 2);
55. // rect(0 , 0, width, height);
56. stroke(255, 25);
58. //stroke(random(245, 255), random(200, 215), random(0,10), 200); // use lower alpha for finer detail
60. beginShape(POINTS);
61. for (int i = 0; i < particle.length; i++) {
62. particle[i].move();
64. //vertex(particle[i].x,particle[i].y);
65. //stroke(255, 2);
66. line(particle[i].x, particle[i].y, particle[i].x+1, particle[i].y+1);
67. }
68. endShape();
69. }
71. else {
72. fill(0, 5);
73. rect(0, 0, width, height);
74. }
77. // Expand array size to the number of bytes you expect
78. byte[] inBuffer = new byte[1];
80. while (arduinoPort.available () > 0) {
81. inBuffer = arduinoPort.readBytes();
82. arduinoPort.readBytes(inBuffer);
83. if (inBuffer != null) {
84. myString = new String(inBuffer);
85. //println(myString);
86. }
87. // reset on mouse click (now button from arduino)
88. if (myString.charAt(0) == '1') {
89. scatter();
90. }
91. }
92. }
97. void scatter() {
99. life = 150;
102. // randomise attractors
103. for (int i = 0; i < attractor.length; i++) {
104. attractor[i] = new Attractor();
105. println("attractor["+i+"] = new Attractor("+attractor[i].x+","+attractor[i].y+"); "); // so you *can* get your favourite one back, if you want!
106. }
107. println();
109. // randomise particles
110. for (int i = 0; i < particle.length; i++) {
111. particle[i] = new Particle();
113. //stroke(random(0, 255), random(0, 100), random(0, 10), 200);
114. //stroke(random(0, 255), random(0, 255), random(0,10), random(0, 100));
115. }
116. }
118. boolean lifeOut() {
119. life--;
120. if (life < 0) {
121. return false;
122. }
123. else {
124. return true;
125. }
126. }
130. class Attractor {
131. float x,y;
132. Attractor(float x, float y) {
133. this.x = x;
134. this.y = y;
135. }
136. Attractor() {
137. // x = random(mouseX-300, mouseX+300);
138. // y = random(mouseY-300, mouseY+300);
139. x = random(width);
140. y = random(height);
142. }
143. }
147. float damp = 0.00002; // remember a very small amount of the last direction
148. float accel = 20000.0; // move very quickly
149. //float life = 255;
151. class Particle {
153. // location and velocity
154. float x,y,z,vx,vy;
156. Particle() {
158. // initialise with random location:
159. x = random(width);
160. y = random(height);
162. // initialise with random velocity:
163. vx = random(-accel/2,accel/2);
164. vy = random(-accel/2,accel/2);
166. }
168. void move() {
170. // move towards every attractor
171. // at a speed inversely proportional to distance squared
172. // (much slower when further away, very fast when close)
174. for (int i = 0; i < attractor.length; i++) {
176. // calculate the square of the distance
177. // from this particle to the current attractor
178. float d2 = sq(attractor[i].x-x) + sq(attractor[i].y-y);
180. if (d2 > 0.1) { // make sure we don't divide by zero
181. // accelerate towards each attractor
182. vx += accel * (attractor[i].x-x) / d2;
183. vy += accel * (attractor[i].y-y) / d2;
184. }
186. }
189. // move by the velocity
190. x += vx;
191. y += vy;
193. // scale the velocity back for the next frame
194. vx *= damp;
195. vy *= damp;
197. }
199. boolean lightOut() {
200. life--;
201. if (life < 0) {
202. return true;
203. }
204. else {
205. return false;
206. }
207. }
208. }

Trying to communicate between Arduino and Process.. A simple switch state!

[1 Reply]
- 15-Feb-2012 02:43 AM
- Forum: Integration and Hardware
I'm having serious issues setting up the communication between arduino and processing. All Im trying to do is communicate a simple switch from arduino to processing. Ive used the examples but when i try and implement them onto my code it give me an "error inside Serial<init>0" and highlight this line arduinoPort = new Serial(this, Serial.list()[0], 9600); which is the line inside setup()

Beginner dealing with computer Vision, PImages, and Alpha

[0 Replies]
- 25-Jan-2012 12:34 AM
- Forum: Core Library Questions
I am trying to create a type of xRay flashlight experience using computer vision. My code isn't broken at the moment and its very close to what I am looking for I just can't figure out how to get rid of the dark around the image, at the moment I believe I am just using brightness. I've found some code that dealt with this using PGraphics and JAVA2D I just can't seem to transfer it over to PImages. I apologize if my code is messy. Thanks for your help!
2. import processing.video.*;
3. Capture video;
5. //PImage wall;
6. PImage sky;
8. void setup() {
9. size(1500, 997);
11. sky = loadImage("sky1_HDR2.png");
12. //wall = loadImage("wall.jpg");
15. //brightness tracking
16. video = new Capture(this, width, height, 30);
17. noStroke();
18. smooth();
20. }
22. void draw() {
23. //tint(255, 0);
24. //image(sky,0,0);
25. //background (255);
27. loadPixels();
30. //tint(255, 0);
31. //image(sky, 0, 0);
35. //brightness tracking
36. if(video.available())
37. {
38. video.read();
39. //image(video, 0, 0, width, height); // Draw the webcam video onto the screen
41. int brightestX = 0; // X-coordinate of the brightest video pixel
42. int brightestY = 0; // Y-coordinate of the brightest video pixel
43. float brightestValue = 0; // Brightness of the brightest video pixel
45. // Search for the brightest pixel: For each row of pixels in the video image and
46. // for each pixel in the yth row, compute each pixel's index in the video
47. video.loadPixels();
48. int index = 0;
49. for(int y = 0; y < video.height; y++)
50. {
51. for(int x = 0; x < video.width; x++)
52. {
53. // Get the color stored in the pixel
54. int pixelValue = video.pixels[index];
55. // Determine the brightness of the pixel
56. float pixelBrightness = brightness(pixelValue);
57. // If the value is brighter than any previous, then store the
58. // brightness of that pixel, as well as its (x, y) location
59. if(pixelBrightness > brightestValue)
60. {
61. brightestValue = pixelBrightness;
62. brightestY = y;
63. brightestX = x;
64. }
65. index++;
66. }
67. }
69. // Draw a large, yellow circle at the brightest pixel
71. //creating image around brightest pixles
73. for (int x = 0; x < sky.width; x++) {
74. for (int y = 0; y < sky.height; y++) {
75. // calculate 1D pixel location
76. int loc = x + y*sky.width;
78. // get R,G,B values
79. float r = red (sky.pixels[loc]);
80. float g = green (sky.pixels[loc]);
81. float b = blue (sky.pixels[loc]);
82. float a = alpha (sky.pixels[loc]);
84. //calculate
85. float distance = dist(x,y,brightestX, brightestY);
86. float adjustAlpha = (200 - distance)/200;
87. r *= adjustAlpha;
88. g *= adjustAlpha;
89. b *= adjustAlpha;
90. a *= adjustAlpha;
92. float a_value = 100;
94. r = constrain(r, 0, 255);
95. g = constrain(g, 0, 255);
96. b = constrain(b, 0, 255);
97. a = constrain(a, 0, 255);
101. color c = color(r,g,b,255);
102. pixels[loc] = c;
106. }
107. }
110. updatePixels();
111. stroke(255, 204, 0);
112. strokeWeight(5);
113. noFill();
114. ellipse(brightestX, brightestY, 400, 400);
116. }
117. }

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