Circular inheritance with C++

[Siduron]

So i'm working on a 3D engine at the moment, things are coming along really great.
However i'm stuck at this stupid problem, circular inheritance.

The idea is that i have a terrain of quads obviously, now these quads will be getting a Water object that should be derived from Quad (basically the same, but perhaps 1 or 2 different render states and HLSL vars).

The code below gives me a huge spam of

Error	1	error C2504: 'Quad' : base class undefined

Quad.h
[cpp]
#ifndef QUAD_H
#define QUAD_H
#include "Water.h"

class Quad
{
//Functions and stuff
}
[/cpp]

Water.h
[cpp]
#ifndef WATER_H
#define WATER_H
#include "Quad.h"

class Water : public Quad
{
//Function overrides
};

#endif
[/cpp]

I know this is probably not the best design for this, but it should work best with my quadtree and level of detail and all that.

[jA_cOp]

You're missing a semicolon after the declaration of Quad.

edit:

I didn't notice you were including water.h from quad.h as well, see below

[nullsquared]

Don't include water.h in quad.h, and just forward declare it with class water;

And then scrap that and rewrite the relevant portions with a better design. Why the hell does a quad (a graphics primitive) need to know about water (a graphics/physics entity)? And why is water inheriting from quad in the first place? That implies an "is-a" relationship. Water isn't a quad. Water might [b]have[/b] a quad ("has a" relationship -> composition) to represent its surface.

class water
{
    private:
        quad _surface;
};

[Siduron]

Your solution would bring me back to the original issue; I want Water to be a Quad but with a slightly edited render loop, so it [i]would[/i] be a Quad.

[PvtCupcakes]

[QUOTE=Siduron;16704949]Your solution would bring me back to the original issue; I want Water to be a Quad but with a slightly edited render loop, so it [i]would[/i] be a Quad.[/QUOTE]

You can override functions. Is that what you mean?

[Siduron]

Yes, but that's not the issue. The problem prevents me to override any functions at all.

[blankthemuffin]

[QUOTE=Siduron;16704949]Your solution would bring me back to the original issue; I want Water to be a Quad but with a slightly edited render loop, so it [i]would[/i] be a Quad.[/QUOTE]

Quad doesn't have to know anything about Water for Water to inherit from it.

[Siduron]

It includes Water.h for the water object a quad can have.

[blankthemuffin]

The Quad should not have a Water object.

[Siduron]

I'm going to add another vector to my Patch class, WITH WATER.
Hopefully it will work.

[editline]03:45AM[/editline]

Problem solved.

Instead of giving Quad a Water object, i gave the Patch object a vector with Water objects that are based on the data of another vector with Quads.

Looks awesome, will post a video tomorrow.

[jmanmc]

I am happy you fixed it. Good job.

[Siduron]

As promised, a video.
Unfortunately i had to turn off alpha blending because of a depth issue.

[media]http://www.youtube.com/watch?v=_HfWlV61Lmo[/media]