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ErikPeeters

OpenGL Switching to Ortho in list and picking, how?

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Hi all, is there a way that I can make a textured squad list which I render in 2D / ortho and the rest of the quad lists I render in my program in perspective view? When I run the following (stripped) code the 2d squad list is rendered in 2D but I cannot pick any of the objects after it. Who can I render some objects in 2D, some in 3D and still be able to pick the objects? Can someone please help me with this?
void OrthoList()
{
    m_lstOrtoList = glGenLists(1);
    glNewList(m_lstOrthoList, GL_COMPILE);

    glPushMatrix();
	
    /////////////////////////////////////////////////////////////
    // Switch to an orthographic-view (non-perspiective) matrix.
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0.0, 25.0, 25.0, 0.0, -1.0, 1.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    /////////////////////////////////////////////////////////////

    glBindTexture(GL_TEXTURE_2D, m_unTextures[7]);
    glEnable(GL_TEXTURE_2D);

    glColor3f(1.0f, 1.0f, 1.0f);
    glBegin(GL_QUADS);
        glTexCoord2f(0.0f, 1.0f); glVertex2f((GLfloat)dX1, (GLfloat)dY1);
        glTexCoord2f(1.0f, 1.0f); glVertex2f((GLfloat)dX2, (GLfloat)dY2);
        glTexCoord2f(1.0f, 0.0f); glVertex2f((GLfloat)dX3, (GLfloat)dY3);
        glTexCoord2f(0.0f, 0.0f); glVertex2f((GLfloat)dX4, (GLfloat)dY4);
    glEnd();

    glDisable(GL_TEXTURE_2D);

    /////////////////////////////////////////////////////////////
    // Switch to a perspective-view matrix.
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.0f, m_dViewAspect, 0.1f, 500.0f);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    /////////////////////////////////////////////////////////////

    glPopMatrix();

    glEndList();
}

void DrawOpenGLScene(HWND hWnd)
{
    ReleaseDC(hWnd, m_hDC);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();

    glCallList(lst1);
    glCallList(lst2);
    glCallList(lst3);

    OrthoList();
    glCallList(lstOrtoList);

}

// Picking method
#define BUFSIZE 512
GLuint	selectBuf[BUFSIZE];
static LRESULT OnLButtonDown(HWND hWnd, UINT nFlags, POINT point)
{
	//Selection Buffer
	GLuint selectBuf[BUFSIZE];
	//Number of Objects that we clicked on
	int hits;

	//create a viewport just for the selection
	int viewport[4]; //0 - x, y - 1, length - 2, width - 3

	//	//set the viewport to the size and location of the screen
	//	glGetIntegerv( GL_VIEWPORT, viewport );
	//set the viewport to the size and location of the screen
	glGetIntegerv( GL_VIEWPORT, viewport );
	//Tell OpenGL to use our array for selection
	glSelectBuffer(BUFSIZE, selectBuf);

	//put openGL in selection mode;
	glRenderMode( GL_SELECT );

	//initialize the name stack
	glInitNames();
	//push at least one entry on to the stack
	glPushName(0);

	//Now we're restricting drawing to just under the cursor.  We need the projection matrix
	//for this.  Push it to the stack then reset the new matrix with load identity
	glMatrixMode( GL_PROJECTION );
	glPushMatrix();
	glLoadIdentity();


	//Now restrict drawing using gluPickMatrix().  The first parameter is our current 
	//mouse position on the x-axis, the second is the current mouse y axis.  Then the width
	//and height of the picking region.  Finally the current viewport indicates the current boundries.
	//mouse_x and y are the center of the picking region.
	gluPickMatrix((GLdouble) point.x, (GLdouble)(viewport[3]-point.y), 1.0, 1.0, viewport );


	//gluPerspective will restrict the drawing to the area requestd by gluPickmatrix()
	//gluPerspective( 45.0f, (viewport[2] - viewport[0]) / (viewport[3] - viewport[ 1 ]), 0.1f, 100.0f );
	gluPerspective( 45.0f, m_gldAspect, 0.1f, 500.0f );

	//set the modelview to render our targets properly
	glMatrixMode( GL_MODELVIEW );
	// "render" the targets to our modelview
	DrawOpenGLScene(hWnd);
	glMatrixMode( GL_PROJECTION );
	glPopMatrix();
	glMatrixMode( GL_MODELVIEW );

	//find out how many objects we hit
	hits = glRenderMode( GL_RENDER );

	//as long as we have more than 0, we select the first object drawn to the area.
	if( hits != 0 )
	{
		int	choose = selectBuf[3];									// Make Our Selection The First Object
		int depth = selectBuf[1];									// Store How Far Away It Is 

		for (int loop = 1; loop < hits; loop++)						// Loop Through All The Detected Hits
		{
			// If This Object Is Closer To Us Than The One We Have Selected
			if (selectBuf[loop*4+1] < GLuint(depth))
			{
				choose = selectBuf[loop*4+3];						// Select The Closer Object
				depth = selectBuf[loop*4+1];						// Store How Far Away It Is
			}
		}
	}

	return TRUE;
}

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Thanks for the reply!

How will color picking work when I render a list two times? Also when I have shading the color is not comparable right?

Is there maybe an other way to display a sort of GUI in 2D in a 3D world?

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