Game Maker 7 Help: Using Friction and Slopes, I'd rather not use jump to postition

Hi there MFGG! As you might know, I am making another Bony Beetle fangame, and my hopes are to make it 10* better than the last! In my opinion, it would start with a more Marioish engine. If I could get slopes and friction, my fangame could definetely have more potential for level design, which is what I will be focussing on mostly. So basically, where should I start? I have no idea. Should I start out by looking at other engines, because that could end up with me copying codes into my game...and then I would't know how to add things in later. Again: I just want a starting point, to get me on the right track, I do not want you to tell me the entire code. Thank you.
Reminder:
1. Character movement with friction
2. Character movement up and down slopes
3. Enemy movement on slopes
4. Good collision with flat blacks if slope code doesn't work for flat (testing atm)

This post has been edited by jhsoft on Jun 22 2008, 02:41 AM

1.NO friction, leads to movement errors
use the step event
if !keyboard_check(vk_left) and !keyboard_check(vk_right)
{
if hspeed<0
hspeed+=0.2
if hspeed>=
hspeed-=0.2
}

2.
if y < other.y
{y = other.y-16
vspeed = 0}

replace the 16 with anything that fits

3.same as 2

Friction usually works fine for me... :/

I never really understood friction. I just used gravity and acceleration and deacceleration variables. It's easier, IMO.

@ Latia: I keep getting this:
FATAL ERROR in
action number 1
of Step Event
for object obj_bony:

COMPILATION ERROR in code action
Error in code at line 6:
hspeed-=0.2

at position 8: Unexpected symbol in expression.

Here is what I use:

when character collides with slope:

repeat(20){
if(place_meeting(x,y+1,object_slope))break;
y+=1;
}
repeat(20){
if(!place_meeting(x,y,object_slope))break;
y-=1;
}

for object_slope step event:

solid=false

this code will only glitch when you try to jump onto the slope from underneath so keep that in mind

This post has been edited by Burnin#39;Leo on Jun 20 2008, 12:22 AM

Friction causes the player object to lose speed even if it´s supposed to not lose speed, means you can start walking a few pixels and the friction immedialystops the player. That´s at least what I get when using friction.

That's because the code should be like this:
if !keyboard_check(vk_left) and !keyboard_check(vk_right)
{
if hspeed<0
hspeed+=0.2
if hspeed>=0
hspeed-=0.2
}

There was a missing 0 in the code.

Whoops, my fault. Stupid Latia, like always. I think slopes should work with position checking, like BL explained.

@Ianprime0509 and Latia: I'll try that right away! But I do have one question before I do this, what about walking down slopes? Wouldn't I kind of float off and not be able to jump?

Visual
_____
---------\ <--->Char moving right goes here
----------\
-----------\
------------\
-------------\

This post has been edited by jhsoft on Jun 21 2008, 03:15 AM

For the going down, there is the second position check that says y+=1, which stands for going down.

Wow, Latia you are so helpful! I don't know what I would do with out your help.

Also, I forgot to mention I'm a little less than clueless with codes (can do snd_play and thats about is )
here is my fail code based off of what i've gathered

if !keyboard_check(vk_left) and !keyboard_check(vk_right)
{
if hspeed<0
hspeed+=0.2
if hspeed>=0
hspeed-=0.2
}
if not !keyboard_check(vk_left) and !keyboard_check(vk_right)
if hspeed not = 0
if hspeed<0
hspeed-=0.2
if hspeed>=0
hspeed+=0.2

btw, Im starting on a clean slate, so no gravity or collision while falling yet. just this.

This post has been edited by jhsoft on Jun 21 2008, 05:27 AM

1.Goddess :P
2.sound_play not snd_play
3.the second part with the not ! is repetitive, which results either in an error, or negating the values theirself which causes it to get positive which will cause the player to decelerate even if he´s walking.
So, cut it off.

1. Oops, typo. I wasn't referring you to as a deity (sorry ) I forgot a comma. Sorry about that. I ended up changing the whole post. Also, I guess I've developed a nasty habit. I need to stop using God as a replacement for words like wow.
2. Nevermind, I'm as clueless as it gets.

3. What do you mean by cut it off? What should I cut off?

This post has been edited by jhsoft on Jun 21 2008, 06:24 AM

No prob. Just saying.

I just wanted to notify this edit, nobody seems to notice.

The counterpart of my code, it´s useless and causes the player to decelerate when he´s running.

EDIT: This still make me slowly move to the left.

Oh ok, so just.
if !keyboard_check(vk_left) and !keyboard_check(vk_right)
{
if hspeed<0
hspeed+=0.2
if hspeed>=0
hspeed-=0.2
}

This post has been edited by jhsoft on Jun 22 2008, 02:42 AM

You can use this code for slopes

Put this code in the step event of the object
if at relative position (0,4) there is object obj_slope_steep_r
move relative to position (0,-hspeed)
if at relative position (0,2) there is object obj_slope_r
move relative to position (0,-hspeed/2)
if at relative position (0,4) there is object obj_slope_steep_l
move relative to position (0,hspeed)
if at relative position (0,2) there is object obj_slope_l
move relative to position (0,hspeed/2)

Collision Event with object obj_slope_r:
set the vertical speed to 0
move relative to position (0,-1)

Collision Event with object obj_slope_l:
set the vertical speed to 0
move relative to position (0,-1)

Collision Event with object obj_slope_steep_r:
set the vertical speed to 0
move relative to position (0,-1)

Collision Event with object obj_slope_steep_l:
set the vertical speed to 0
move relative to position (0,-1)

Should this help!

This post has been edited by Darkyoshi on Jun 22 2008, 04:20 AM

Yep.
Trying DY´s code...