OpenCV  3.3.1-dev
Open Source Computer Vision
Functions
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
winnameName of the window.
texOpenGL 2D texture data.

§ setOpenGlContext()

void cv::setOpenGlContext ( const String winname)

Sets the specified window as current OpenGL context.

Parameters
winnameName 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
winnameName of the window.
onOpenGlDrawPointer to the function to be called every frame. This function should be prototyped as void Foo(void*) .
userdataPointer 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
winnameName of the window.