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Nightroad

OpenGL How to draw Transparent RubberBand ?

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Nightroad    100
Hi there,

I'm new on OpenGL , i'm using it for showing grabbed frames from video camera with texture mapping. There is no problem at all but i have to select some region of the grabbed frame then i have to zoom it, first of all i can't draw a Rubber rectangle it must be transparent when i select the some region of grabbed frame i have to see textured frame transparently could you gimme some piece of code or clue, btw i'm showing grabbed frames like that any suggestion will be good for me as i said before i'm new on OpenGL thanks for your helps ...

[code]
void GLWidget::initializeGL()
{
glShadeModel(GL_SMOOTH);
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glClearDepth(1.0f);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
glEnable(GL_TEXTURE_2D);
glGenTextures(1, &m_pTextureId);
glBindTexture(GL_TEXTURE_2D, m_pTextureId);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
}
void GLWidget::resizeGL(int w, int h)
{
glViewport(0,0,w,h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-1,1,-1,1,-1,1);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
void GLWidget::setTextureData(BYTE *data, int width, int height)
{
makeCurrent();
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
if (m_isTextured)
glTexSubImage2D(GL_TEXTURE_2D,0,0,0,width,height,GL_BGRA_EXT,GL_UNSIGNED_BYTE,data);
else
glTexImage2D(GL_TEXTURE_2D,0,3,width,height,0,GL_BGRA_EXT,GL_UNSIGNED_BYTE,0);
glBindTexture(GL_TEXTURE_2D,m_pTextureId);
glBegin(GL_QUADS);
glTexCoord2f(0.0,0.0);glVertex2f(-1.0,-1.0);
glTexCoord2f(0.0,1.0);glVertex2f(-1.0,1.0);
glTexCoord2f(1.0,1.0);glVertex2f(1.0,1.0);
glTexCoord2f(1.0,0.0);glVertex2f(1.0,-1.0);
glEnd();
swapBuffers();
}
[/code]
I'm passing captured frame data to [font="monospace"]setTextureData it's working but i dunno does it good way ...[/font]

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