OpenGL support

Functions
void	cv::imshow (const String &winname, const ogl::Texture2D &tex)
	Displays OpenGL 2D texture in the specified window. More...
void	cv::setOpenGlContext (const String &winname)
	Sets the specified window as current OpenGL context. More...
void	cv::setOpenGlDrawCallback (const String &winname, OpenGlDrawCallback onOpenGlDraw, void *userdata=0)
	Sets a callback function to be called to draw on top of displayed image. More...
void	cv::updateWindow (const String &winname)
	Force window to redraw its context and call draw callback ( See cv::setOpenGlDrawCallback ). More...

Detailed Description

Function Documentation

imshow()

void cv::imshow	(	const String &	winname,
		const ogl::Texture2D &	tex
	)

Displays OpenGL 2D texture in the specified window.

Parameters

winname	Name of the window.
tex	OpenGL 2D texture data.

setOpenGlContext()

void cv::setOpenGlContext

(

const String &

winname

)

Sets the specified window as current OpenGL context.

Parameters

winname

Name of the window.

setOpenGlDrawCallback()

void cv::setOpenGlDrawCallback	(	const String &	winname,
		OpenGlDrawCallback	onOpenGlDraw,
		void *	userdata = 0
	)

Sets a callback function to be called to draw on top of displayed image.

The function setOpenGlDrawCallback can be used to draw 3D data on the window. See the example of callback function below:

void on_opengl(void* param)
{
    glLoadIdentity();

    glTranslated(0.0, 0.0, -1.0);

    glRotatef( 55, 1, 0, 0 );
    glRotatef( 45, 0, 1, 0 );
    glRotatef( 0, 0, 0, 1 );

    static const int coords[6][4][3] = {
        { { +1, -1, -1 }, { -1, -1, -1 }, { -1, +1, -1 }, { +1, +1, -1 } },
        { { +1, +1, -1 }, { -1, +1, -1 }, { -1, +1, +1 }, { +1, +1, +1 } },
        { { +1, -1, +1 }, { +1, -1, -1 }, { +1, +1, -1 }, { +1, +1, +1 } },
        { { -1, -1, -1 }, { -1, -1, +1 }, { -1, +1, +1 }, { -1, +1, -1 } },
        { { +1, -1, +1 }, { -1, -1, +1 }, { -1, -1, -1 }, { +1, -1, -1 } },
        { { -1, -1, +1 }, { +1, -1, +1 }, { +1, +1, +1 }, { -1, +1, +1 } }
    };

    for (int i = 0; i < 6; ++i) {
                glColor3ub( i*20, 100+i*10, i*42 );
                glBegin(GL_QUADS);
                for (int j = 0; j < 4; ++j) {
                        glVertex3d(0.2 * coords[i][j][0], 0.2 * coords[i][j][1], 0.2 * coords[i][j][2]);
                }
                glEnd();
    }
}

Parameters

winname	Name of the window.
onOpenGlDraw	Pointer to the function to be called every frame. This function should be prototyped as void Foo(void*) .
userdata	Pointer passed to the callback function.(Optional)

updateWindow()

void cv::updateWindow

(

const String &

winname

)

Force window to redraw its context and call draw callback ( See cv::setOpenGlDrawCallback ).

Parameters

winname

Name of the window.