java - How to change coordinate regularly using gl.glTranslatef() ? -

having following display() -

float tranx , trany , tranz ;  public void display(glautodrawable gldrawable) {     final gl gl = gldrawable.getgl();     gl.glloadidentity();     gl.glpushmatrix();     gl.gltranslatef(tranx ,trany ,tranz);     gl.glcalllist(i);     gl.glpopmatrix();     tranx += 0.05;     trany += 0.05;     tranz += 0.05; } 

as can see each display() calling matrix of object in gl.glcalllist(i) saved , coordinates change gl.gltranslatef(tranx ,trany ,tranz) .

suppose @ stage want save object @ current position (after gl.gltranslatef calling ) , start translate tranx , trany , tranz values .

how save object position considering above gl.glpushmatrix() , gl.glpopmatrix() ?

push/pop matrices there accumulate complex matrix transformations otherwise painful hand. storing , moving object positions, keeping variables have done correct. expand on and, start moving in another, add directionx/y/z. eg, tranx += directionx etc. when want change direction, set directionx/y/z different value.

the speed change depending on how fast computer though. you'll want find time since last frame (or last call display) , this: transx += velocityx * deltatime etc.

if want move object 1 point specific point, want key-framed interpolation. example position = pointa * (1.0 - x) + pointb * x , make x move 0 1 (x += speed * deltatime). when x above one, pointa becomes pointb , pointb set next position in list. subtract 1.0 x , continue.