 |
Author |
Topic: couple small bugs in "collision.pde" demo (Read 996 times) |
|
kevinP
|
couple small bugs in "collision.pde" demo
« on: Jan 13th, 2004, 9:49pm » |
|
While playing with one of the demo scripts (collision.pde, the "pong" one) I found a couple small bugs (in the script, not processing). Perhaps they've long been fixed as I haven't read much here yet, but in case not...
No guarantees on my solutions. 
-K
// Collision (Pong)
// by REAS <http://www.groupc.net>
// Move the mouse up and down to move the paddle.
// Updated 21 August 2002
// Modified 13 Jan 2004 - K Pfeiffer
// Fixed bug that the first serve was not detected by the paddle due to ball_x incrementing by 2
// Fixed bug that paddle was constrained to edge of frame, but detection area moved half outside
// Global variables for the ball
float ball_x;
float ball_y;
float ball_dir = 1;
float ball_size = 5; // radius
float dy = 0; // direction
// Global variables for the paddle
int paddle_width = 5;
int paddle_height = 20;
int dist_wall = 15;
void setup()
{
size(200, 200);
rectMode(CENTER_RADIUS);
ellipseMode(CENTER_RADIUS);
noStroke();
ball_y = height/2;
ball_x = 1; // Was 0, but would miss 1st serve - see comment below
framerate(30);
}
void loop()
{
background(51);
ball_x += ball_dir * 2;
ball_y += dy;
if(ball_x > width+ball_size) {
ball_x = -width/2-ball_size;
ball_y = random(0, height);
dy = 0;
}
// Constrain paddle to screen
float paddle_y = constrain(mouseY, paddle_height, height-paddle_height);
// Test to see if the ball is touching the paddle
float py = width - dist_wall - paddle_width - ball_size;
if(ball_x == py // Careful, as ball_x increments by 2!
// && ball_y > mouseY - paddle_height - ball_size
// && ball_y < mouseY + paddle_height + ball_size) {
&& ball_y > paddle_y - paddle_height - ball_size
&& ball_y < paddle_y + paddle_height + ball_size) {
ball_dir *= -1;
if(mouseY != pmouseY) {
dy = (mouseY-pmouseY)/2.0;
if(dy > 5) { dy = 5; }
if(dy < -5) { dy = -5; }
}
}
// If ball hits paddle or back wall, reverse direction
if(ball_x < ball_size && ball_dir == -1) {
ball_dir *= -1;
}
// If the ball is touching top or bottom edge, reverse direction
if(ball_y > height - ball_size) {
dy = dy * -1;
}
if(ball_y < ball_size) {
dy = dy * -1;
}
// Draw ball
fill(255);
ellipse(ball_x, ball_y, ball_size, ball_size);
// Draw the paddles and constrain to the screen
// float paddle_y = constrain(mouseY, paddle_height, height-paddle_height);
// This was moved up so that paddle detection also uses same constraint on paddle position!
fill(153);
rect(width-dist_wall, paddle_y, paddle_width, paddle_height);
}
|
| « Last Edit: Jan 13th, 2004, 9:50pm by kevinP » |
|
Kevin Pfeiffer
|
|
|
REAS
|
Re: couple small bugs in "collision.pde" demo
« Reply #1 on: Jan 14th, 2004, 3:16am » |
|
thank you for taking the time to do this. i've noticed problems with this example and haven't made fixing them a priority. you've made fixing it very easy. i've corrected it now and it will be posted with the next release of the software.
+ casey
|
|
|
|
|
|
