/*
* OpenGL implementation of glWindowPos*MESA()
*/
void glWindowPos4fMESA( GLfloat x, GLfloat y, GLfloat z, GLfloat w )
{
GLfloat fx, fy;
/* Push current matrix mode and viewport attributes */
glPushAttrib( GL_TRANSFORM_BIT | GL_VIEWPORT_BIT );
/* Setup projection parameters */
glMatrixMode( GL_PROJECTION );
glPushMatrix();
glLoadIdentity();
glMatrixMode( GL_MODELVIEW );
glPushMatrix();
glLoadIdentity();
glDepthRange( z, z );
glViewport( (int) x - 1, (int) y - 1, 2, 2 );
/* set the raster (window) position */
fx = x - (int) x;
fy = y - (int) y;
glRasterPos4f( fx, fy, 0.0, w );
/* restore matrices, viewport and matrix mode */
glPopMatrix();
glMatrixMode( GL_PROJECTION );
glPopMatrix();
glPopAttrib();
}
void CHapticViewerView::drawTextGL(int x, int y, char* text)
{
glPushAttrib(GL_TRANSFORM_BIT | GL_VIEWPORT_BIT | GL_LIGHTING);
glDisable(GL_LIGHTING);
glDisable(GL_COLOR_MATERIAL);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
y = m_windowHeight - FONT_HEIGHT - y;
glViewport(x-1, y-1, 0, 0);
glRasterPos4f(0, 0, 0, 1);
glPopMatrix();
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glColor3f(1.0, 1.0, 1.0);
glListBase(m_fontListBase);
glCallLists(strlen(text), GL_UNSIGNED_BYTE, text);
glPopAttrib();
}
void PositionText( int x, int y )
{
// If you are to use this font code for your applications,
// you must be aware that you cannot position the font in 3D,
// which means you can't rotate and scale it. That will be covered in
// the next font tutorial. BUT, though that might be a drag, this code
// is useful because when you display the text, it will always be on top
// of everything else. This is good if the camera is moving around, and you
// don't want the text to move. If the text was positioned in 3D you would have
// to come up with a tricky way of making it always render in front of the camera.
// To do this, we need to set the Raster Position. That is the position that OpenGL
// starts drawing at. Since it's in floating point, it's not very intuitive, so what
// we do is create a new view port, and then always draw the text at (0, 0, 0) in that
// view port. The weird part is that the Y is flipped, so (0, 0) is the bottom left corner.
// Below we do some simple math to flip it back to normal.
// Before we create a new view port, we need to save the current one we have.
// This saves our transform (matrix) information and our current viewport information.
// At the end of this function we POP it back.
glPushAttrib( GL_TRANSFORM_BIT | GL_VIEWPORT_BIT );
// Here we use a new projection and modelview matrix to work with.
glMatrixMode( GL_PROJECTION ); // Set our matrix to our projection matrix
glPushMatrix(); // Push on a new matrix to work with
glLoadIdentity(); // reset the matrix
glMatrixMode( GL_MODELVIEW ); // Set our matrix to our model view matrix
glPushMatrix(); // Push on a new matrix to work with
glLoadIdentity(); // Reset that matrix
// Because the Y is flipped, we want 0 to be at the top, not bottom.
// If we subtract the font height from the screen height, that should display the
// font at the top of the screen (if they passed in 0 for Y), but then we subtract
// the Y from that to get the desired position. Since the font's drawing point is
// at the base line of the font, we needed to subtract the font height to make sure
// if they passed in (0, 0) it wouldn't be off screen. If you view this in window mode,
// the top of the window will cut off part of the font, but in full screen it works fine.
// You just need to add about 25 to the Y to fix that for window mode.
y = SCREEN_HEIGHT - FONT_HEIGHT - y; // Calculate the weird screen position
// Now we create another view port (that is why we saved the old one above).
// Since glViewPort takes the lower LEFT corner, we needed to change the Y
// to make it more intuitive when using PositionText(). We minus 1 from the X and Y
// because 0 is taken into account with the position. The next 2 parameters are set
// to 0 for the width and height so it will always draw in the middle of that position.
// glRasterPos4f() takes (0, 0, 0) as the middle of the viewport, so if we give it a small
// width/height it will draw at the X and Y given. Sounds strange, to test this, try
// using glRasterPos4f(0, 0, 0, 1) instead of PositionText() and you will see, everything
// will be drawn from the middle.
glViewport( x - 1, y - 1, 0, 0 ); // Create a new viewport to draw into
// This is the most important function in here. This actually positions the text.
// The parameters are (x, y, z, w). w should always be 1 , it's a clip coordinate.
// don't worry about that though. Because we set the projection and modelview matrix
// back to the beginning (through LoadIdentity()), the view port is looking at (0, 0, 0).
// This is the middle, so if we set the drawing position to the middle, it will draw at our
// X and Y because the width/height of the viewport is 0, starting at X and Y.
// You can actually call this function (or glRasterPos2f(0, 0)) instead of PositionText(),
// but it is in floating point and doesn't work as nicely. You will see why if you try.
glRasterPos4f( 0, 0, 0, 1 ); // Set the drawing position
// Now that we positioned the raster position, any text we draw afterwards will start
// from that position. Now we just have to put everything else back to normal.
glPopMatrix(); // Pop the current modelview matrix off the stack
glMatrixMode( GL_PROJECTION ); // Go back into projection mode
glPopMatrix(); // Pop the projection matrix off the stack
glPopAttrib(); // This restores our TRANSFORM and VIEWPORT attributes
}
template< > inline void glRasterPos4< float > (float x,float y,float z, float w ) { glRasterPos4f(x,y,z,w); };
/////////////////////////////////////////////////////////
// Render
//
void GEMglRasterPos4f :: render(GemState *state) {
glRasterPos4f (x, y, z, w);
}
void glRasterPos4fv(const GLfloat *v) {
glRasterPos4f(v[0], v[1], v[2], v[3]);
}
//------------------------------------------------------------------------------
// void DrawStringAt(const wxString &str, GLfloat x, GLfloat y, GLfloat z, GLfloat k)
//------------------------------------------------------------------------------
void DrawStringAt(const wxString &str, GLfloat x, GLfloat y, GLfloat z, GLfloat k)
{
glRasterPos4f(x, y, z, k);
glCallLists(strlen(str.c_str()), GL_BYTE, (GLubyte*)str.c_str());
}
M(void, glRasterPos4f, jfloat x, jfloat y, jfloat z, jfloat w) {
glRasterPos4f(x, y, z, w);
}
