Extern 2D-Library

[geckoman]

I thought of using an extern Library for things like rotating or scaling images (Background of Menu or Loading screens etc.) as there are no really Irrlicht solutions for that.
Do you think that's the right way, or do you know a fast, lightweight and easy library?

[mk.1]

Mixing graphics isn't a wise thing to do. You should better write it yourself in irr.

[BlindSide]

You don't have to use anything outside of Irrlicht, I think that will be inconvenient and more difficult anyway. For scaling, rotating, positioning of sprites in Irrlicht you can use this simple class I made:

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class CSprite
{
public:
	CSprite() : scale(irr::core::vector3df(1.0f, 1.0f, 0.0f))
	{
		Material.Lighting = false;
		Material.ZWriteEnable = false;

		Vertices[0] = irr::video::S3DVertex(-1.0f,-1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 
			irr::video::SColor(0xffffffff), 0.0f, 1.0f);
		Vertices[1] = irr::video::S3DVertex(-1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 
			irr::video::SColor(0xffffffff), 0.0f, 0.0f);
		Vertices[2] = irr::video::S3DVertex( 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 
			irr::video::SColor(0xffffffff), 1.0f, 0.0f);
		Vertices[3] = irr::video::S3DVertex( 1.0f,-1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 
			irr::video::SColor(0xffffffff), 1.0f, 1.0f);
		Vertices[4] = irr::video::S3DVertex(-1.0f,-1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 
			irr::video::SColor(0xffffffff), 0.0f, 1.0f);
		Vertices[5] = irr::video::S3DVertex( 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 
			irr::video::SColor(0xffffffff), 1.0f, 0.0f);
	}

	void setVertexAlpha(irr::u32 alpha)
	{
		for(irr::u32 i = 0;i < 6;++i)
			Vertices[i].Color.setAlpha(alpha);
	}

	void setVertexColor(irr::video::SColor color)
	{
		for(irr::u32 i = 0;i < 6;++i)
			Vertices[i].Color = color;
	}

	void render(irr::video::IVideoDriver* driver)
	{
		const irr::u16 indices[6] = {0, 1, 2, 3, 4, 5};

		irr::core::matrix4 mat;
		mat.setScale(scale);

		irr::core::matrix4 smat;
		smat.setRotationDegrees(rotation);
		mat *= smat;

		mat.setTranslation(position);

		driver->setMaterial(Material);
		driver->setTransform(irr::video::ETS_WORLD, mat);
		driver->setTransform(irr::video::ETS_VIEW, matrix4());
		driver->setTransform(irr::video::ETS_PROJECTION, matrix4());
		driver->drawIndexedTriangleList(&Vertices[0], 6, &indices[0], 2);
	}

	virtual irr::video::SMaterial& getMaterial()
	{
		return Material;
	}

	void setPosition(const irr::core::vector2df& positionIn)
	{
		position = irr::core::vector3df(positionIn.X * 2.0f, positionIn.Y * 2.0f, 0.0f)
			- irr::core::vector3df(1.0f, 1.0f, 0.0f);
	}

	void setRotation(const irr::f32 rotationIn)
	{
		rotation = irr::core::vector3df(0.0f, 0.0f, rotationIn);
	}

	void setScale(const irr::core::vector2df& scaleIn)
	{
		scale = irr::core::vector3df(scaleIn.X, scaleIn.Y, 0.0f);
	}

private:
	irr::video::S3DVertex Vertices[6];
	irr::video::SMaterial Material;
	irr::core::vector3df position, rotation, scale;
	
};

You can see a few vertices and a simple transformation matrix is all that's needed.

To use:

Code: Select all

CSprite mySprite;

mySprite.getMaterial().setTexture(0, driver->getTexture("TEXTURE")); // There is only one material anyway, so no parameter is taken in getMaterial().

mySprite.setPosition(vector2df(0.5, 0.5)); // Position is absolute, so 0.5 means the top-left corner of the sprite is going to be in the middle of the screen.

mySprite.setRotation(45.0f); // You can set rotation in degrees.

mySprite.setScale(vector2df(0.5f, 0.5f)); // And scale along the two axis.

### In your main loop: ###

driver->beginScene();
smgr->drawAll();
mySprite.render(driver); // You can do it after smgr->drawAll(), or before if you want background effects.
driver->endScene();

Cheers, I hope that was useful.

[geckoman]

@BlindSide: Thank you. That solution is not exactly what I searched for, as it does not return a resized image that can be used in the GUI. But if I don't need that functionality more often, I think I will use it, cause it's more easy. Anyway thanks a lot.

[Mel]

Then render the result to a texture of the desired resolution. And that's all you need!

I'm working on a sort of class to do 2D effects, like scrolling, and stuff that return the results to a RTT. All of them in hardware, though, the calculations are done in software. Maybe in a not vere far future i try to do everything in the card, but for now, all i do is programming draw2Dimage sentences one oafter another

[geckoman]

I used BlindSides Method. It works quite good, the only thing that's annoying me is that I have to call the render method in my VERY clean main loop.

Thanks all.

[sudi]

well just make CSprite a children of ISceneNode and u should be fine....

[geckoman]

Do you mean inherit CSprite from ISceneNode?

[sudi]

Yes

[tonic]

My 2D graphics/IMGUI library "Turska" supports also rendering with Irrlicht. It works in similar fashion with the method mentioned above, i.e. renders 3d polygons with custom projection.
http://jet.ro/turska/

[geckoman]

Thank you, but I really do not want to change/patch Irrlicht. I want to use it "as is" so upgrading is much more easy!

[emf2718]

I know this thread is a few days old, but I've been trying to get blindside's method to work. I can't get it to work quite right. I put it into the 2d demo that comes with Irrlicht and tried it out. Here's what I did:

I added

Code: Select all

CSprite mySprite;

mySprite.getMaterial().setTexture(0, driver->getTexture("../../media/earth.bmp")); // There is only one material anyway, so no parameter is taken in getMaterial().

mySprite.setPosition(vector2df(0.5, 0.5)); // Position is absolute, so 0.5 means the top-left corner of the sprite is going to be in the middle of the screen.

mySprite.setRotation(45.0f); // You can set rotation in degrees.

mySprite.setScale(vector2df(0.5f, 0.5f)); // And scale along the two axis.

after creating the driver; and I have "mySprite.render(driver);" in between the two imps. Unfortunately, I only see the usual dungeon scene. However, if I do this:

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      driver->setMaterial(Material);
      //driver->setTransform(irr::video::ETS_WORLD, mat);
      //driver->setTransform(irr::video::ETS_VIEW, matrix4());
      //driver->setTransform(irr::video::ETS_PROJECTION, matrix4());
      //driver->drawIndexedTriangleList(&Vertices[0], 6, &indices[0], 2);

The I see the earth map fill the window. If I do any resizing, rotating, or moving, then the first transform won't work right. Any ideas on what's going on?

[BlindSide]

Can you paste the full altered example code? I'm happy to try it out and see what's going wrong.

Cheers

[fcloud]

Can you paste the full altered example code? I'm happy to try it out and see what's going wrong.

Cheers

Hi, I tested your code. It works very nice. But I found that the picture has some deformation when the CSprite rotations. Why?

[BlindSide]

How bad is the deformation? Can I see a screenshot?