I'm working on a game and I was wondering how I would have my character (a panda) land on a platform that I load in as an image, as opposed to going through the image as though it were just the background, and not a separate object. I was wondering if I could do this using "constrain"? I'm not sure how I should calculate when the panda is on the platform, but when it is on the platform i can just constrain its position to be stuck to it, correct? Using the y value of the platform as it's constraint. I have this as my code for the panda class:

class Panda{
 float x = 50;
 float y = 250;
 float w;
 float h;
 float velocityX = 0.0;
 float velocityY = 0.0;
 float acceleration = 0.0;
 PImage Panda;
 
 Panda (String pandain){
   panda = loadImage (pandain);
   w = panda.width / 4;
   h = panda.height / 4;
 }
 void restart(){
   x = 50;
   y = 250;
   velocityX = 0.0;
   velocityY = 0.0;
   acceleration = 0.0;
 }
 void show(){
   image (panda, x, y, w, h);
 }
 void move(){
   if ((keyPressed == true)&&(key == ' ')&&(y > 100)){
     velocityY = -3.5;
     acceleration = 1;
   }

   x = x + velocityX;
   x = constrain (x, 0, 598);
   
   y = y + velocityY;
   y = constrain (y, 0, 250);
   
   velocityY = velocityY + acceleration;
 }
}


but how do I go about constraining it while it's on a platform of some sort?

I was able to implement the collision detection for gathering the items, which has worked out just fine (thanks, by the way). But for this would I use collision detection for between the platform and the panda then use an if statement to say if it makes contact with the platform than the panda is constrained to certain y values? Like:

constrain(panda, 0, platform.y);

would something along the lines of that work? I guess I just wanted a direct example, sorry.

The code I made for the Platform is:

class Platform{
 float x;
 float y;
 float w;
 float h;
 float speed;
 PImage thisPlatform;
 boolean collect = false;
 
 Platform (float inx, float iny, float inspeed, String platform){
   x = inx;
   y = iny;
   speed = inspeed;
   thisPlatform = loadImage(platform);
   w = thisPlatform.width;
   h = thisPlatform.height;
 }
 void show(){
   image (thisPlatform, x, y);
 }
 void move(){
   x = x-speed;
   if (x < -w){
     x = width;
     speed = speed + 0.03;
   }
 }
 void restart (float inx, float iny){
   x = inx;
   y = iny;
   image(thisPlatform, x, y);
 }
 void gather(){
   if (collect == false){ //where p1 is panda and pf is platform
     if ((p1.x + p1.w) > pf.x && p1.x < (pf.x + pf.w) && (p1.y + p1.h) > pf.y && p1.y < (pf.y + pf.h)){ //land on platform
     collect = true;
     panda = constrain(panda, 0, pf.y);
     }
   }
 }
}


So this will calculate if the panda has made contact with the platform, but would it take into consideration if the panda is above the platform, or I think this would just constrain it if the panda touches it, right? I saw the post about the ball stuck to the pad; would I be able to use something similar to that except replace the rectangle dimensions with the platform's, and have the panda replace the ball? =/

Well, i've yet to test that, but i think i get the idea of how to check for the collision.. i'll just play around with that for a bit and see how it turns out.
Thanks for all the help, I appreciate it! xD;