a simple grid class

[mohaps]

I was getting tired of a blank screen for my test progies .. so i took the two minutes and wrote a grid class... for drawing XZ grid

the shot is the grid class quickly hacked on top of the Tutorial 1 codebase...

Here is the code.

Code: Select all

class Grid
{
public:
	Grid():center(0,0,0),sizeHalf(1000),gridSpacing(50)
	{
		mtl.Lighting = false;
		mtl.AmbientColor = mtl.DiffuseColor = mtl.EmissiveColor = video::SColor(255,0,200,0);
	}
	virtual ~Grid()
	{
	}
	void draw(scene::ISceneManager* smgr)
	{
		core::vector3df leftMost = center;
		leftMost.X -= sizeHalf;
		leftMost.Z -= sizeHalf;

		core::vector3df rightMost = center;
		rightMost.X += sizeHalf;
		rightMost.Z += sizeHalf;

		smgr->getVideoDriver()->setMaterial(mtl);
		//cout<<"
		for(f32 x = 0; x <= 2 * sizeHalf; x+= gridSpacing)
		{
			vector3df start = leftMost;
			start.X += x ;

			vector3df end = rightMost;
			end.X = start.X;

			//cout<<"Drawing Line From : "<<start.X<<","<<start.Y<<","<<start.Z<<" to "<<end.X<<","<<end.Y<<","<<end.Z<<endl;
			smgr->getVideoDriver()->draw3DLine(start,end,mtl.AmbientColor);
		}
		//cout<<endl;
		
		for(f32 z = 0; z <= 2 * sizeHalf; z+= gridSpacing)
		{
			vector3df start = leftMost;
			start.Z += z ;

			vector3df end = rightMost;
			end.Z = start.Z;

			smgr->getVideoDriver()->draw3DLine(start,end,mtl.AmbientColor);
		}
	}

	core::vector3df center;
	f32 sizeHalf; 
	f32 gridSpacing;
	SMaterial mtl;
};

sample usage

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driver->beginScene(true, true, SColor(20,0,0,0));

		smgr->drawAll();
		grid.draw(smgr);
		guienv->drawAll();

		driver->endScene();

[/code]

[niko]

Ah, that's useful. Could need that too sometimes, until now I always created a skybox instead.

[jox]

Yea that's useful. But you might also want to set the transformation of the driver (besides the material) before drawing the grid (each time). Otherwise it might not render correctly if other nodes with transformations are present.

http://irrlicht.sourceforge.net/phpBB2/ ... line#24583

Maybe a "GridSceneNode" would be a good idea as well.

[mohaps]

yeah

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driver->setTransform(video::ETS_WORLD, AbsoluteTransformation);

should do the trick in the scene node

[etcaptor]

jox wrote
then it might not give you the expected result or even draw nothing.
driver->draw3DLine(vector3df(0,0,0), vector3df(0,10,0), SColor(0,0,0,0));

to fix this you can set the transform and material of the driver before drawing lines, for example:

True, I occur this problem in Irrlicht. Will try jox's issue about it.
About gridSceneNode - this will not difficulty to make it since we have mohap's grid class. But I think that mohap will make it instead some of us like author of grid class.

[TheRLG]

[Midnight]

I would love to see that RLG.

[dudMaN]

With the transform matrix fix, this is awesome! needed something like this for my game

-dudMan

[MasterGod]

Yeah that's pretty nice, even more then nice.
I'll use it for sure.

[humbrol]

Put the class info in a file called grid.h
then put the

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grid.draw(smgr);

into the spot the example shows, but its stating grid is undeclared?

[dudMaN]

humbrol, declare a Grid then named grid :/

-dudMan

[humbrol]

been a long week of learning alot of new stuff, the example above shows the class name as Grid but the call as grid.draw();

tried Grid.draw() with the same results,, forgive this poor noob.. im diving in deep and trying to learn.

[shogun]

"Grid" is the class, "grid" would be an instance.
Learn some OOP basics.

[Virion]

Grid* grid;
Grid* whatever;

[MasterGod]

Grid* grid;
Grid* whatever;

and..

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grid->draw();
whatever->draw();