Processing Forum

Drawing a trail for a moving object

[3 Replies]
- 09-Feb-2013 06:30 AM
- Forum: Programming Questions
I'm working on an object moving around an attractor (maths mainly based on the GravitationalAttraction3D example).

However, I'd like to have it leave a trail to make it a bit more obvious. The point moves around in the expected fashion, but leaves no trail.

It's been a while since I've tried processing (never really got the hang of arrays the first time!) but this code also looks wrong. Is there anyway I can leave a trail, and make the code more readable?
2. void display() {
3. trailx[0] = location.x;
4. traily[0] = location.y;
5. for(int i = 0; i < trailx.length-1; i++){
6. trailx[i+1] = trailx[i];
7. }
8. for(int i = 0; i < traily.length-1; i++){
9. traily[i+1] = traily[i];
10. }
11. for(int i = traily.length-1; i > 1; i--){
12. line(trailx[i], traily[i], trailx[i-1], traily[i-1]);
13. }
14. line(location.x, location.y, trailx[0], traily[0]);
15. }

unexpected token: {

[2 Replies]
- 17-Dec-2011 10:15 AM
- Forum: Programming Questions
I'm having some trouble just with a new sketch. It may be something to do with my computer, as this code:
2. setup() {
3. size(310, 240);
4. }
just gives the error "unexpected token: {" when I try to run it.
Any ideas or suggestions?

Thanks!

3D vector rotation

[1 Reply]
- 25-Sep-2011 05:11 AM
- Forum: Programming Questions
Agh! I swear I'll start contributing soon. Sorry for all the questions.

Anyway, what I want to do is write a method/function for rotating a vector in 3 dimensions around an arbitrary point whilst maintaining magnitude. Kind of like spherical coordinates, but applied to PVector objects.

Anyway, I think I phrased that right. Thanks!

Look around and move camera [OPENGL]

[2 Replies]
- 18-Sep-2011 12:42 PM
- Forum: Programming Questions
Alright, I'm trying to build a first person game. Got most of it done, but am having trouble with the camera (I only need it to look around, not up and down): I've got the lookaround part, doing the direction in polar co-ordinates then converting from that to cartesian coordinates and setting the look-to distance to somwhere in the region of 30000. Now, the problem I have is how I can make this be the direction for the player to move in. So, what I need is a way to look around, then move the player in the direction they are facing. The early camera I have at the moment can look around, but only moves up and down the axes, as the movement just consists of "if 'w' pressed, playerXpos++".

Any help appreciated!

Blank window on export.

[1 Reply]
- 21-Aug-2011 10:19 AM
- Forum: Integration and Hardware
I'm having a some trouble with a unfinished game. It runs fine in the processing IDE when I hit run, but whenever I try to export it (Both to windows application (non-full screen) and web applet), it just appears as a blank white screen/window. Any help would be appreciated.

Exported windows application: http://dl.dropbox.com/u/21772177/VT74.rar

Code:
2. import controlP5.*;
3. import fisica.*;
4. PFont font;
5. FWorld world;
6. FPoly tank, gun, land;
7. pTank player;
8. ControlP5 controlP5;
9. int storystage, seed, sx, sy = 0;
10. float tankvx,tankvy,tankvr,py = 0;
11. color stro = color(255, 128, 0);
12. color fil = color(255, 128, 0);
13. boolean menu = true;
15. void setup() {
16. size(1024, 512, P2D);
17. background(0);
18. font = loadFont("VectorBattle-18.vlw");
19. Fisica.init(this);
20. world = new FWorld();
21. world.setEdges();
22. world.setEdgesFriction(20);
23. world.setGrabbable(false);
24. levelgen();
25. pTank player = new pTank();
26. player.spawn(200, 100);
27. ///////////////////////
28. // for(int i = 0; i < landscape.length; i++){
29. // landscape[i] = noise(width,i*0.08);
30. // }
31. // land = new FPoly();
32. // land.setStroke(stro);
33. // land.setFill(fil);
34. // land.setDensity(0.0f);
35. // land.vertex(0,height);
36. // land.vertex(width,height);
37. // for(int i = landscape.length; i < 0; i--){
38. // land.vertex(i, landscape[i]);
39. // }
40. // world.add(land);
41. ////////////////////////
42. controlP5 = new ControlP5(this);
43. controlP5.addSlider("health", 0, 1000, 1000, 850, 10, 100, 10);
44. }
46. void draw() {
47. background(52, 56, 56);
48. gamecheck();
49. story();
50. if ( keyPressed) {
51. if ( key == 'd' || key == 'D' ) {
52. tank.adjustAngularVelocity(0.5);
53. }
54. else if ( key == 'a' || key == 'A' ) {
55. tank.adjustAngularVelocity(-0.5);
56. }
57. if (key == 'w' || key == 'W') {
58. tank.adjustVelocity(10, 0);
59. }
60. if (key == 's' || key == 'S') {
61. tank.adjustVelocity(-10, 0);
62. }
63. if (key == 'f') {
64. delay(200);
65. storystage++;
66. }
67. }
68. if (mousePressed) {
69. stroke(255);
70. pewpew();
71. }
72. controlP5.draw();
73. world.step();
74. world.draw(this);
75. if(keyPressed){
76. if(key == 'p'){
77. delay(100);
78. saveFrame("progress-####");
79. }
80. }
81. }
82. class pTank {
83. void spawn (int xSpawn, int ySpawn) {
84. sx = xSpawn;
85. sy = ySpawn;
86. tank = new FPoly();
87. tank.setStroke(0, 180, 204);
88. tank.setFill(52, 56, 56);
89. tank.vertex(10, 10);
90. tank.vertex(30, 10);
91. tank.vertex(40, 15);
92. tank.vertex(35, 20);
93. tank.vertex(10, 20);
94. tank.vertex(5, 15);
95. tank.vertex(7, 12);
96. world.add(tank);
97. tank.setPosition(xSpawn, ySpawn);
98. }
99. }
103. void winball(int sizeOf, int Xball, int Yball) {
104. FBlob winball = new FBlob();
105. winball.setStroke(0, 180, 204);
106. winball.setFill(52, 56, 56);
107. winball.setAsCircle(Xball, Yball, 40);
108. world.add(winball);
109. }
111. void story() {
112. fill(0, 140, 158);
113. textFont(font, 18);
114. if (storystage == 0) {
115. text("Press W+S to move back and forth <'f' to advance>", 100, 30);
116. }
117. if (storystage == 1) {
118. text("Press A+D to rotate <'f' to advance>", 100, 30);
119. }
120. if (storystage == 2) {
121. text("Click on something to fire <'f' to advance>", 100, 30);
122. }
123. if (storystage == 3) {
124. text("Now, GO GO VECTOR TANK!", 100, 30);
125. }
126. }
128. void pewpew() {
129. FRaycastResult result = new FRaycastResult();
130. FBody b = world.raycastOne(tank.getX()+25, tank.getY()+2, mouseX, mouseY, result, true);
131. for (int i = 0; i<10; i++) {
132. if(result.getX() != 0){
133. line(tank.getX()+int(random(-3,3)), tank.getY()+int(random(-3,3)), result.getX()+int(random(-3,3)), result.getY()+int(random(-3,3)));
134. }
135. }
136. }
139. void levelgen() {
140. world.remove(land);
141. noiseSeed(seed);
142. land = new FPoly();
143. land.setStroke(stro);
144. land.setFill(fil);
145. land.setDensity(0.0f);
146. land.vertex(width,height);
147. land.vertex(0,height);
148. for(int i = 0; i<width; i+=10){
149. land.vertex(i,map(noise(width,i*0.005),0,1,height-100,50));
151. }
152. seed++;
153. world.add(land);
154. }
156. void turret(int spawnx, int spawny) {
157. }
159. void gamecheck(){
160. if(tank.getX() > 950){
161. py = tank.getY();
162. tankvx = tank.getVelocityX();
163. tankvy = tank.getVelocityY();
164. tankvr = tank.getAngularVelocity();
165. tank.setPosition(20,py);
166. tank.setAngularVelocity(tankvr);
167. tank.setVelocity(tankvx,tankvy);
168. levelgen();
169. }
170. }
Thanks!

Code changing

[3 Replies]
- 20-Aug-2011 08:15 AM
- Forum: Programming Questions
Is there any way to change code during the run of the sketch? My problem is that I need to get change a level for a game. Levels are stored in a class called "Level". So, to bring a new level, say level 1, I go level.level1 And that will spawn the new level. What I want to be able to do is to change the "1" at the end of level.level1 so I can switch levels. Any other code corrections would be nice too, though! Code:
2. import fisica.*;
3. import toxi.geom.*;
4. import toxi.math.*;
5. import toxi.geom.mesh2d.*;
7. FWorld world;
8. FPoly tank, gun;
9. Tank player;
10. Level level;
11. /**
12. .setStroke(173, 216, 199);
13. .setFill(22, 147, 165);
14. */
17. float tankX, tankY, tankXvelocity, tankYvelocity = 0;
19. void setup() {
20. size(1024, 512, P2D);
21. background(22, 147, 165);
22. Fisica.init(this);
23. world = new FWorld();
24. world.setEdges();
25. world.setEdgesFriction(20);
26. stroke(0);
27. noFill();
28. world.setGrabbable(false);
29. player = new Tank(100, height-40);
30. winball(40,100,100);
31. level = new Level();
33. }
35. void draw() {
36. background(22, 147, 165);
37. if ( keyPressed) {
38. if ( key == 'd' || key == 'D' ) {
39. tank.adjustVelocity(20,0);
40. } else if ( key == 'a' || key == 'A' ) {
41. tank.adjustVelocity(-20,0);
42. }
43. }
44. world.step();
45. world.draw(this);
46. }
47. class Tank{
48. int spawnX, spawnYd;
49. void Tank(int xSpawn, int ySpawn) {
50. tank = new FPoly();
51. tank.setStroke(173, 216, 199);
52. tank.setFill(22, 147, 165);
53. tank.vertex(xSpawn, ySpawn);
54. tank.vertex(xSpawn+20, ySpawn);
55. tank.vertex(xSpawn+30, ySpawn+5);
56. tank.vertex(xSpawn+25, ySpawn+10);
57. tank.vertex(xSpawn, ySpawn+10);
58. tank.vertex(xSpawn-5, ySpawn+5);
59. tank.vertex(xSpawn-3, ySpawn+2);
60. world.add(tank);
61. }
62. }
64. void winball( int sizeOf, int Xball, int Yball);
65. FBlob winball = new FBlob();
66. winball.setStroke(173, 216, 199);
67. winball.setFill(22, 147, 165);
68. winball.setAsCircle(Xball,Yball,sizeOf);
69. world.add(winball);
70. }
EDIT: Having trouble with it again. It is highlighting line 66 and giving the message "unexpected token: (" Any ideas?

unexpected char: '\' and another question.

[6 Replies]
- 16-Aug-2011 02:04 AM
- Forum: Programming Questions
Just a couple of quick questions: First, I keep getting the error "unexpected char: '\'" when I try and run this piece of code:
2. PVector position, velocity;
3. int diameter;
4. void setup(){
5. size(500,500);
6. background(0);
7. smooth();
8. position = new PVector(10,10,0);
9. velocity = new PVector(3,5,0);
10. diameter = 10;
11. }
13. void draw(){
14. background(0);
15. position.add(velocity);
16. bounceWalls();
17. noStroke();
18. fill(255);
19. ellipse(position.x,position.y,diameter,diameter);
20. }
22. void bounceWalls(){
23. float leftLimit, rightLimit, upperLimit, lowerLimit;
25. leftLimit = diameter*.5;
26. rightLimit = width–diameter*.5;
27. upperLimit = diameter*.5;
28. lowerLimit = height – diameter*.5;
29. if(position.x < leftLimit)
30. {
31. position.x = leftLimit;
32. velocity.x = velocity.x*-1;
33. }
34. if(position.x > rightLimit)
35. {
36. position.x = rightLimit;
37. velocity.x = velocity.x*-1;
38. }
39. if(position.y < upperLimit)
40. {
41. position.y = upperLimit;
42. velocity.y = velocity.y*-1;
43. }
44. if(position.y > lowerLimit)
45. {
46. position.y = lowerLimit;
47. velocity.y = velocity.y*-1;
48. }
49. }
With the IDE highlighting line 26. As you can see, there isn't a backslash on that line, so the only problem I can think of is that my IDE is a bit wrong, or there is some strange and mystical invisible backslash character somewhere in there. I've had it happen on multiple projects, but this one just annoyed me enough to post.
Second question: Is there a way to resize the processing window or applet, without changing the pixels, as it were? Like a window 600x300 px, but processing drawing lines and all in a 300x150 grid of pixels at the 600x300 px window size? I want to try and make a pixel-ly game, but don't know if I have to introduce extra code to achieve this.

Thanks in advance!

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