glut_2d.cpp

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/*
 * glut_2d.cpp
 *
 * Copyright (C) 2008,2010  Thomas A. Vaughan
 * All rights reserved.
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THOMAS A. VAUGHAN ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THOMAS A. VAUGHAN BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * Implementation of various 2D glut helper methods.
 * See glut_2d.h
 */

// includes --------------------------------------------------------------------
#include "glut_2d.h"                    // always include our own header first!


namespace glut {

////////////////////////////////////////////////////////////////////////////////
//
//      static helper methods
//
////////////////////////////////////////////////////////////////////////////////



////////////////////////////////////////////////////////////////////////////////
//
//      public API
//
////////////////////////////////////////////////////////////////////////////////

void
push2D
(
IN int screenWidth,
IN int screenHeight
)
{
        ASSERT(screenWidth > 0, "Bad width: %d", screenWidth);
        ASSERT(screenHeight > 0, "Bad height: %d", screenHeight);

        // turn off expensive 3D operations
//      glDisable(GL_LIGHTING);
//      glDisable(GL_DEPTH_TEST);
//      glDisable(GL_TEXTURE_2D);

        glMatrixMode(GL_PROJECTION);
        glPushMatrix();
        glLoadIdentity();
        glOrtho(0, screenWidth, 0, screenHeight, -1, 1);

        glMatrixMode(GL_MODELVIEW);
        glPushMatrix();
        glLoadIdentity();

        // swap y-coordinate (opposite of OpenGL convention)
        glScalef(1, -1 ,1);     // positive Y is down
        glTranslatef(0, -screenHeight, 0); // y=0 is top of screen
}



void
pop2D
(
void
)
{
        glScalef(1, 1, 1);

        glMatrixMode(GL_MODELVIEW);
        glPopMatrix();

        glMatrixMode(GL_PROJECTION);
        glPopMatrix();
}



void
drawCursor
(
IN int x,
IN int y
)
{
        glColor3f(1.0, 1.0, 1.0);
        glRecti(x - 2, y - 2, x + 2, y + 2);
}



};      // glut namespace