Jumping and sidescrollers

[zeldafreak]

Hey guys, I have been working on a sidescroller system and I have the left and right movements done, but I am at a loss as to how I can have him jump and have the gravity kick in. Here is the current code.


onClipEvent (load) {
fallspeed = 8;
platforms = 1;
speed = 5;
falldec = 1.95;
}
onClipEvent (enterFrame) {
fallspeed += falldec;
this._y += fallspeed;
for (i=1; i<=platforms; i++) {
ground = _root["g"+i];
if (this.hitTest(ground)) {
this._y -= fallspeed;
}
}
if (Key.isDown(Key.SPACE) && jumping != true) {
jumping = true;
}
if (jumping == true) {
//What to put here?
}

if(Key.isDown(Key.LEFT)){
this._x -= speed;
this._xscale =-100;
this.gotoAndStop("run");
//_root._x += speed;
}
else if(Key.isDown(Key.RIGHT)){
this._x += speed;
this._xscale =100;
this.gotoAndStop("run");
//_root._x -= speed;
}
else{
this.gotoAndStop("idle");
}
}

The comments about the Root x position are simply to move the stage later on, not sure about them currently though.
I can upload the Fla later If need be, any help is appreciated. Thanks guys :D

[Nich]

Set the fall speed to something negative.

if, say, you set it to -4, for the next few frames the movement will be (approx)
y-4 (up)
y-2 (up)
y+0 (stopped, in the air)
y+2 (down)
y+4 (down)

[zeldafreak]

actually I changed the code, falldec is no longer a part of it because it made it so when you hit the ground, you fall through very quickly about 3 seconds later. The first part of the code actually looks like this.

onClipEvent (load) {
fallspeed = 8;
platforms = 1;
speed = 5;
}
onClipEvent (enterFrame) {
this._y += fallspeed;
for (i=1; i<=platforms; i++) {
ground = _root["g"+i];
if (this.hitTest(ground)) {
this._y -= fallspeed;
}
}

[Nich]

Now I don't know if it's possible to jump, You kind of need the fallDec variable for my method to work. And the jump looks better

but the reason you shot through the floor is that fallspeed still got increasingly larger as you hit the floor. Eventually, you were able to move down without triggering the hittest, causing you to shoot through the floor at high speeds. The simple solution would be to set the fallspeed to 0 when you hit, after you've corrected your position.

[zeldafreak]

Well, I used n99's tutorial and made a makeshift jumping and gravity system. But every time he runs off a platform, he does not fall unless he jumped off.

onClipEvent (enterFrame) {
if (Key.isDown(Key.SPACE) && !jumping) {
jumping = true;
}
if (jumping) {
fight = false;
walking = false;
//checks if running first (But still does not work)
if (Key.isDown(Key.LEFT) || Key.isDown(Key.RIGHT)) {
this.gotoAndStop("jump_run");
} else {
this.gotoAndStop("jump");
}
//resumes
this._y -= jump;
jump -= .9;
if (jump<0) {
falling = true;
}
if (jump<-15) {
jump = -15;
}
}
for (i=1; i<=platforms; i++) {
ground = _root["g"+i];
if (ground.hitTest(this._x, this._y, true) && jumping) {
jump = 15;
jumping = false;
falling = false;
}
//This is where the major problem is, How can I get him to fall when he runs off the platform?
if (ground.hitTest(this._x, this._y, false) && !jumping) {
trace("hit");
this._y += fallspeed;
}
}

[SacrificialLamb]

I made it so it's always falling and you have to tell it to stop every frame. I also redid a lot of the code so I could understand it more, I think it dose mostly the same things + being fixed

onClipEvent (load) {
fallspeed = 8;
platforms = 1;
speed = 5;
falldec = 1.95;
fall = 0;
}
onClipEvent (enterFrame) {
fall+=2;
if (walking) {
if (Key.isDown(Key.LEFT)) {
xspeed = -speed
this._xscale = -100;
this.gotoAndStop("run");
} else if (Key.isDown(Key.RIGHT)) {
xspeed = speed
this._xscale = 100;
this.gotoAndStop("run");
} else {

xspeed = 0
this.gotoAndStop("idle");
}
}
for (i=1; i<=platforms; i++) {
ground = _root["g"+i];
if (ground.hitTest(this._x, this._y+1, true)) {
fall = 0;
walking = true;
} else if (ground.hitTest(this._x, this._y+fall, true)) {
while (ground.hitTest(this._x, this._y+fall, true)) {
trace("tap");
fall--;
}
walking = true;
}
}
if (Key.isDown(Key.SPACE) && fall<1) {
fall = -20;
walking = false;
}
this._y += fall;
this._x += xspeed;
}

[zeldafreak]

Wow,that's great man, I wanted to have the character lock his x position when he jumped anyway. The only problem is that if you hold space he will continually jump up, and right now I cannot find a way to stop that...:stare:

[SacrificialLamb]

sorry theought i had that make "fall<1" "fall==0"

[zeldafreak]

wait, what am I supposed to change here?

[RidingDirty]

I believe he is reffering to the 6th line from the bottom....

if (Key.isDown(Key.SPACE) && fall<1) {


And that your supposed to change it to:

if (Key.isDown(Key.SPACE) && fall==1) {

But thats just what I think. Try it out, if it doesent work its easy to change it back ;)

[zeldafreak]

Hmm, that Didn't do anything different. He just jumped is beats rather than one fluid high jump.:puzzle:

[SacrificialLamb]

Really I thought that would fix it (should have tested it).
But really could you not work that out by yourself, if you move the SPACE in to the ground.hitTest so it'll only work when you are touching the ground

onClipEvent (load) {
fallspeed = 8;
platforms = 1;
speed = 5;
falldec = 1.95;
fall = 0;
}
onClipEvent (enterFrame) {
fall += 2;
if (walking) {
if (Key.isDown(Key.LEFT)) {
xspeed = -speed;
this._xscale = -100;
this.gotoAndStop("run");
} else if (Key.isDown(Key.RIGHT)) {
xspeed = speed;
this._xscale = 100;
this.gotoAndStop("run");
} else {
xspeed = 0;
this.gotoAndStop("idle");
}
}
for (i=1; i<=platforms; i++) {
ground = _root["g"+i];
if (ground.hitTest(this._x, this._y+1, true)) {
fall = 0;
walking = true;
if (Key.isDown(Key.SPACE)) {
fall = -20;
walking = false;
}
} else if (ground.hitTest(this._x, this._y+fall, true)) {
while (ground.hitTest(this._x, this._y+fall, true)) {
trace("tap");
fall--;
}
walking = true;
}
}
this._y += fall;
this._x += xspeed;
}

[zeldafreak]

Awesome man, thank you so much, I can't believe I didn't see something as basic as moving it into the hittest! :P Thanks again, I may post with more questions.