mapnik/deps/agg/src/agg_rounded_rect.cpp

//----------------------------------------------------------------------------
// Anti-Grain Geometry - Version 2.4
// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
//
// Permission to copy, use, modify, sell and distribute this software
// is granted provided this copyright notice appears in all copies.
// This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
//
//----------------------------------------------------------------------------
// Contact: mcseem@antigrain.com
//          mcseemagg@yahoo.com
//          http://www.antigrain.com
//----------------------------------------------------------------------------
//
// Rounded rectangle vertex generator
//
//----------------------------------------------------------------------------

#include <math.h>
#include "agg_rounded_rect.h"


namespace agg
{
//------------------------------------------------------------------------
rounded_rect::rounded_rect(double x1, double y1, double x2, double y2, double r) :
    m_x1(x1), m_y1(y1), m_x2(x2), m_y2(y2),
    m_rx1(r), m_ry1(r), m_rx2(r), m_ry2(r),
    m_rx3(r), m_ry3(r), m_rx4(r), m_ry4(r)
{
    if(x1 > x2) { m_x1 = x2; m_x2 = x1; }
    if(y1 > y2) { m_y1 = y2; m_y2 = y1; }
}

//--------------------------------------------------------------------
void rounded_rect::rect(double x1, double y1, double x2, double y2)
{
    m_x1 = x1;
    m_y1 = y1;
    m_x2 = x2;
    m_y2 = y2;
    if(x1 > x2) { m_x1 = x2; m_x2 = x1; }
    if(y1 > y2) { m_y1 = y2; m_y2 = y1; }
}

//--------------------------------------------------------------------
void rounded_rect::radius(double r)
{
    m_rx1 = m_ry1 = m_rx2 = m_ry2 = m_rx3 = m_ry3 = m_rx4 = m_ry4 = r;
}

//--------------------------------------------------------------------
void rounded_rect::radius(double rx, double ry)
{
    m_rx1 = m_rx2 = m_rx3 = m_rx4 = rx;
    m_ry1 = m_ry2 = m_ry3 = m_ry4 = ry;
}

//--------------------------------------------------------------------
void rounded_rect::radius(double rx_bottom, double ry_bottom,
                          double rx_top,    double ry_top)
{
    m_rx1 = m_rx2 = rx_bottom;
    m_rx3 = m_rx4 = rx_top;
    m_ry1 = m_ry2 = ry_bottom;
    m_ry3 = m_ry4 = ry_top;
}

//--------------------------------------------------------------------
void rounded_rect::radius(double rx1, double ry1, double rx2, double ry2,
                          double rx3, double ry3, double rx4, double ry4)
{
    m_rx1 = rx1; m_ry1 = ry1; m_rx2 = rx2; m_ry2 = ry2;
    m_rx3 = rx3; m_ry3 = ry3; m_rx4 = rx4; m_ry4 = ry4;
}

//--------------------------------------------------------------------
void rounded_rect::normalize_radius()
{
    double dx = std::fabs(m_x2 - m_x1);
    double dy = std::fabs(m_y2 - m_y1);

    double k = 1.0;
    double t;
    t = dx / (m_rx1 + m_rx2); if(t < k) k = t;
    t = dx / (m_rx3 + m_rx4); if(t < k) k = t;
    t = dy / (m_ry1 + m_ry2); if(t < k) k = t;
    t = dy / (m_ry3 + m_ry4); if(t < k) k = t;

    if(k < 1.0)
    {
        m_rx1 *= k; m_ry1 *= k; m_rx2 *= k; m_ry2 *= k;
        m_rx3 *= k; m_ry3 *= k; m_rx4 *= k; m_ry4 *= k;
    }
}

//--------------------------------------------------------------------
void rounded_rect::rewind(unsigned)
{
    m_status = 0;
}

//--------------------------------------------------------------------
unsigned rounded_rect::vertex(double* x, double* y)
{
    unsigned cmd = path_cmd_stop;
    switch(m_status)
    {
    case 0:
        m_arc.init(m_x1 + m_rx1, m_y1 + m_ry1, m_rx1, m_ry1,
                   pi, pi+pi*0.5);
        m_arc.rewind(0);
        m_status++;

    case 1:
        cmd = m_arc.vertex(x, y);
        if(is_stop(cmd)) m_status++;
        else return cmd;

    case 2:
        m_arc.init(m_x2 - m_rx2, m_y1 + m_ry2, m_rx2, m_ry2,
                   pi+pi*0.5, 0.0);
        m_arc.rewind(0);
        m_status++;

    case 3:
        cmd = m_arc.vertex(x, y);
        if(is_stop(cmd)) m_status++;
        else return path_cmd_line_to;

    case 4:
        m_arc.init(m_x2 - m_rx3, m_y2 - m_ry3, m_rx3, m_ry3,
                   0.0, pi*0.5);
        m_arc.rewind(0);
        m_status++;

    case 5:
        cmd = m_arc.vertex(x, y);
        if(is_stop(cmd)) m_status++;
        else return path_cmd_line_to;

    case 6:
        m_arc.init(m_x1 + m_rx4, m_y2 - m_ry4, m_rx4, m_ry4,
                   pi*0.5, pi);
        m_arc.rewind(0);
        m_status++;

    case 7:
        cmd = m_arc.vertex(x, y);
        if(is_stop(cmd)) m_status++;
        else return path_cmd_line_to;

    case 8:
        cmd = path_cmd_end_poly | path_flags_close | path_flags_ccw;
        m_status++;
        break;
    }
    return cmd;
}


}