android - LibGDX - Basic physics error? Cannot detect collision between player and ONE side of a platform (tile) -

couldn't find useful tutorials online tried freestyle algorithm collision.

basically, i've modelled player (main character) , platform (a tile player can collide with) rectangles sake of collision detection. in code, playerrect rectangle representing player , getrect() rectangle representing platform.

as stands player moves left right, can collide 3 of platform's sides (left, , bottom). have managed detect collision on top , bottom part of platform, reason can't detect collision on left side.

would highly appreciated if can have @ code , possibly find i'm going wrong.

public class platform extends gameobject { ... public void update() {     // rectangle of player     playerrect = player.getrect();     //a boolean checks whether or not player's rectangle      //and platform's rectangle overlap     isoverlapping = playerrect.overlaps(getrect());      if (isoverlapping) {          // if player hits bottom part of platform,          // have gravity pull him down         if ((playerrect.getx() > getrect().getx() &&               playerrect.getx() < getrect().getx() +                 getrect().getwidth()) &&               playerrect.gety() > getrect().gety()); {                  player.setyspeed(player.getgravity());                 // if player on platform or on ground,                  // allow him jump                 if (playeronplatform() || player.onground()) {                     player.setallow("true", "jump");                 } else {                     player.setallow("false", "jump");                 }             }          // if player on top part of platform,          // set yspeed 0 remains on platform rather          // fall due gravity         if ((playerrect.getx() > getrect().getx() &&               playerrect.getx() < getrect().getx() +               getrect().getwidth()) &&               playerrect.gety() < getrect().gety()) {              player.setyspeed(0);             // if player on platform or on ground, allow him jump             if (playeronplatform() || player.onground()) {                 player.setallow("true", "jump");             } else {                 player.setallow("false", "jump");             }             // if player hits side of platform,             // set xspeed 0 not go through platform             if(playerrect.getx() > getrect().getx() &&                (playerrect.gety() > getrect().gety() &&                 playerrect.gety() < getrect().gety() +                 getrect().getheight())) {                 player.setyspeed(20);             }         } ... } 

thanks in advance input

not if code has bug when assessing if, desired results or 0 , write set 20 player.setyspeed(20);.perhaps not understood @ time :) should not setx ... (0), no sety

// if player hits side of platform,             // set xspeed 0 not go through platform             if(playerrect.getx() > getrect().getx() &&                (playerrect.gety() > getrect().gety() &&                 playerrect.gety() < getrect().gety() +                 getrect().getheight())) {                 player.setyspeed(20);             } 

. on other hand if correct, inside, not outside have not test it, above

// if player on top part of platform,          // set yspeed 0 remains on platform rather          // fall due gravity         if ((playerrect.getx() > getrect().getx() &&               playerrect.getx() < getrect().getx() +               getrect().getwidth()) &&               playerrect.gety() < getrect().gety()) {              player.setyspeed(0);             // if player on platform or on ground, allow him jump             if (playeronplatform() || player.onground()) {                 player.setallow("true", "jump");             } else {                 player.setallow("false", "jump");             }             // if player hits side of platform,             // set xspeed 0 not go through platform             if(playerrect.getx() > getrect().getx() &&                (playerrect.gety() > getrect().gety() &&                 playerrect.gety() < getrect().gety() +                 getrect().getheight())) {                 player.setyspeed(20);             }         } 

you can use log, have if condition met sometime

   // if player hits side of platform,             // set xspeed 0 not go through platform             if(playerrect.getx() > getrect().getx() &&                (playerrect.gety() > getrect().gety() &&                 playerrect.gety() < getrect().gety() +                 getrect().getheight())) {                 player.setyspeed(20);  gdx.app.log("inside", "test");              }