bool MainWindow::Reshape( long width, long height )
{
if( height == 0 ) // Prevent A Divide By Zero By
height=1;
::glViewport( 0, 0, (GLsizei)(width), (GLsizei)(height) );
::glMatrixMode( GL_PROJECTION );
::glLoadIdentity(); // Reset The Projection Matrix
::gluPerspective( 45.0f, (GLfloat)(width)/(GLfloat)(height), // Calculate The Aspect Ratio Of The Window
0.010f, 1000.0f);
::glMatrixMode( GL_MODELVIEW ); // Select The Modelview Matrix
::glLoadIdentity();
SetPlayingAreaRect();
SetInitialPaddlePositions();
return false;
}
How do you get the dimensions of the viewport
Author
I am just looking for a way to calculatewhat will be on the screen and what will not.
I use this to resize
Same as with any other piece of state information you want from OpenGL, you use glGet*().
[edited by - Fruny on April 21, 2004 10:21:20 PM]
[edited by - Fruny on April 21, 2004 10:21:20 PM]
Author
GLdouble viewport[4];
::glGetDoublev( GL_VIEWPORT, viewport );
When I used this viewport gave me { 0, 0, 1280, 1024 }
the window size was 1280, 1024.
I want the GL coordinates of the viewport at a given value of z.
I think that that gave me the with and hight of the viewport in pixels at 0.
If I do this
glTranslatef( 10, -10, -40 )
I want to know if at that value of z x = -10 is on the screen or not without trial and error.
::glGetDoublev( GL_VIEWPORT, viewport );
When I used this viewport gave me { 0, 0, 1280, 1024 }
the window size was 1280, 1024.
I want the GL coordinates of the viewport at a given value of z.
I think that that gave me the with and hight of the viewport in pixels at 0.
If I do this
glTranslatef( 10, -10, -40 )
I want to know if at that value of z x = -10 is on the screen or not without trial and error.
Check the coordinates returned by gluUnproject against those of the viewport.
Edit - I basically did answer to the question in the topic. glGet returns the coordinates of the viewport, i.e. what you passed to glViewport. Sorry about that
[edited by - Fruny on April 21, 2004 10:55:25 PM]
Edit - I basically did answer to the question in the topic. glGet returns the coordinates of the viewport, i.e. what you passed to glViewport. Sorry about that
[edited by - Fruny on April 21, 2004 10:55:25 PM]
Author
Actually I dont think its the viewport that I am trying to get.
I am not sure what you call it.
But from what I understand the farther you draw things away from z = 0 the more room you have to draw.
That is what I am trying to calculate.
I am not sure what you call it.
But from what I understand the farther you draw things away from z = 0 the more room you have to draw.
That is what I am trying to calculate.
What you are after is a frustum check. There''s plenty of threads and resources regarding this topic - google it.
James
James
This topic is closed to new replies.
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