[Turbo C++ 2006] draw in a TCanvas

[Efrint]

Hello,

here is what I did: I created a new project. I added a TImage object (drawDest) to the mainform. My Form-Class looks like this:

Header:

Code: Select all

class TForm1 : public TForm
{
__published:	// Von der IDE verwaltete Komponenten
	TImage *drawDest;
private:	// Benutzer-Deklarationen
public:		// Benutzer-Deklarationen
	__fastcall TForm1(TComponent* Owner);

	irr::IrrlichtDevice *device;
	irr::video::IVideoDriver *driver;
	irr::scene::ISceneManager *smgr;
	irr::gui::IGUIEnvironment *guienv;
};

Sourcefile:

Code: Select all

__fastcall TForm1::TForm1(TComponent* Owner)
	: TForm(Owner)
{
	irr::SIrrlichtCreationParameters param;
	param.WindowId = drawDest->Canvas->Handle;
	param.DriverType = irr::video::EDT_SOFTWARE;
	device = irr::createDeviceEx(param);

	driver = device->getVideoDriver();
	smgr = device->getSceneManager();
}

When I compile and run all this I simply get the error message: EAccessViolation
The last two lines are the ones which cause the crash, but I have no idea why. Can somebody help me?

Best regards,

Efrint

[JP]

Did you consider checking if device is a valid pointer before using it? Presumably the device creation has failed and so when you do device->getVideoDriver() you've got a null pointer.

[Efrint]

No it didn't come to my mind to check if the device was created successfully. You are right. The creation fails. Any idea why?

[JP]

What does the console say? If you actually get that printed out anyway...

Presumably it fails from bad parameters passed to it or something

[Efrint]

ok. It seems to be the handle.

When I write:

Code: Select all

param.WindowId = Form1->Handle;

instead of:

Code: Select all

param.WindowId = renderDest->Canvas->Handle;

it works. (but now Irrlicht uses the whole window) Is it possible that Irrlicht can only draw into the whole window, but not in the canvas of an image?

EDIT: I replaced the canvas with a TPanel object and now it works...at least at the moment