quad.cpp

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/*
 * quad.cpp
 *
 * Copyright (C) 2007  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 a quadratic bezier.
 */

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


namespace bezier {


void
quad_bezier_t::getBoundingRect
(
OUT rect_t& r
)
const
throw()
{
        // start with first control point
        r.left = r.right = p0.x;
        r.top = r.bottom = p0.y;

        // include final control point
        r.expandToInclude(p2);

        // get extremal x-direction point
        float denom = p0.x - 2.0 * p1.x + 2.0 * p2.x;
        if (denom) {
                float t = (p0.x - p1.x) / denom;
                if (t > 0.0 && t < 1.0) {
                        r.expandToInclude(this->getPointAt(t));
                }
        }

        // extremal y-direction point
        denom = p0.y - 2.0 * p1.y + 2.0 * p2.y;
        if (denom) {
                float t = (p0.y - p1.y) / denom;
                if (t > 0.0 && t < 1.0) {
                        r.expandToInclude(this->getPointAt(t));
                }
        }
}


};      // bezier namespace