#### Archived

This topic is now archived and is closed to further replies.

# why does this cause my terrain to become massivley tall?

This topic is 5986 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts



void smoothHeightMap(int iterations)
{
int i, j, x, y;
float st, sm[8];
for(i = 0; i < iterations; i++)
{
for(y = 1; y < terrain_y - 1; y++)
{
for(x = 1; x < terrain_x - 1; x++)
{
sm[0] = terrain_HeightMap[x-1][y-1];
sm[1] = terrain_HeightMap[x-1][y];
sm[2] = terrain_HeightMap[x-1][y+1];
sm[3] = terrain_HeightMap[x][y-1];
sm[4] = terrain_HeightMap[x][y];
sm[5] = terrain_HeightMap[x][y+1];
sm[6] = terrain_HeightMap[x+1][y-1];
sm[7] = terrain_HeightMap[x+1][y];
sm[8] = terrain_HeightMap[x+1][y+1];
st = 0;
for(j = 0; j < 9; j++)
{
st = st + sm[j];
}
terrain_HeightMap[x][y] = float(st / 9);
}
}
}
}

its supposed to smooth the terrain out by averaging the 9 heights around it and making that the new height. but it causes the terrain to grow miles high after only two iterations. did i make some stupid mistake i can''t seem to find for hours and hours?

##### Share on other sites
Well, for one thing you initalised sm with 8 members but i think there are meant to be nine. This could be a mistake when transfering the code to the forum, but if not then I think that is your problem, could be wrong though

[edited by - Grambo on July 28, 2002 8:34:54 PM]

##### Share on other sites
but including 0 there are 9.

##### Share on other sites
I meant the line
	float st, sm[8];

Here you initalise it with 8 memebers not 9

##### Share on other sites
When you define an [8] array, you create [0]-[7].

Thus,
sm[8] = terrain_HeightMap[x+1][y+1];
cannot be done, and
j < 9
should be < 8

just change the [8] array to [9].

------------
aud.vze.com - The Audacious Engine <-- It''s not much, yet. But it''s mine... my own... my preciousssss...
MSN: nmaster42@hotmail.com, AIM: LockePick42, ICQ: 74128155

##### Share on other sites
oh it does that automatically?!?! crap, i need to fix a lot of things. i though you initalized it with the number that you needed including 0. sorry for the thread

##### Share on other sites
Are you sure about that LockePick? I''ve always created the array with one less element (ie, if I needed 5 I would do nums[4]) and I''ve never ran into any problems. In which cases do you create the array with the higher number and when do you do it with one less? Do you always do the full number and I''ve just been lucky?

##### Share on other sites
Ivve always used the higher number, and when I haven''t it usually crashed my program, so I think you must have been lucky Ivko. Either that or something strange is going on

##### Share on other sites
quote:
Original post by Grambo
Ivve always used the higher number, and when I haven''t it usually crashed my program, so I think you must have been lucky Ivko. Either that or something strange is going on

there have been a few times when i run my program, i cause aol instant messenger''s buddy list window to freeze. i wonder if i''m overrunning my arrays?!

##### Share on other sites
quote:
Original post by Ivko
Are you sure about that LockePick? I''ve always created the array with one less element (ie, if I needed 5 I would do nums[4]) and I''ve never ran into any problems. In which cases do you create the array with the higher number and when do you do it with one less? Do you always do the full number and I''ve just been lucky?

WELLLLLLL...

You can do this as many times as you want, wherever you want and etc. BUUUUUT, when you do this your not reserving the last block of mem thath you think your reserving and so if the computer decides to use that space for some other data then your "last" entry in your array will be terminally corrupted. So you can say that if you want you can pass the array bounds at will (you can even just reserve 10 and use 10000), but you risk corrupting your data because your not reserving those blocks (worse yet, you could even pass over other data in memory and corrupt it with data that you want to put into the array).

Think of an array as a pointer to the first block in mem and then accessing [1] would be a pointer++ operation. This might help you understand why you risk writing over other data and losing array data.

I think this is a great reason *NOT* to pass the bounds in arrays.

1. 1
2. 2
Rutin
20
3. 3
khawk
17
4. 4
A4L
14
5. 5

• 12
• 16
• 26
• 10
• 44
• ### Forum Statistics

• Total Topics
633759
• Total Posts
3013720
×