vgfx/drawer.h

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/*
 * drawer.h
 *
 * 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.
 *
 *
 * Interface declaration for objects capable of rendering vgfx primitives.
 */

#ifndef WAVEPACKET_VGFX_DRAWER_H__
#define WAVEPACKET_VGFX_DRAWER_H__

// includes --------------------------------------------------------------------
#include "vgfx.h"

#include "bezier/quad.h"
#include "bezier/bezier.h"


namespace vgfx {


/// \ingroup vgfx
/*@{*/


enum eBrushAttribute {
        // attribute                    enum    value?
        eBrush_PenColor                 = 1,    // color as rgba
        eBrush_FillColor                = 2,    // color as rgba

        eBrush_PenThickness             = 3,    // thickness in cm

        eBrush_Font                     = 50,   // encoded font info--see
                                                //  objtree/prop_types.h
        eBrush_TextFlags                = 60,   // "center", "wrap", etc

        eBrush_Invalid                  = 0
};



/// \ingroup vgfx
///
/// Clients must implement this if they want to draw
///
/// The vgfx library is incapable of drawing!  It handles all of the logical
/// details of a vector graphics canvas, but relies on someone else for the
/// actual drawing (if any).
///
/// This interface is declared so that software layers built on top of vgfx
/// can declare and implement their own bindings to specific rendering
/// technologies. 
class Drawer {
public:
        // virtual destructor --------------------------------------------------
        virtual ~Drawer(void) throw();

        // vgfx::Drawer class interface methods --------------------------------
        virtual void pushBrush(IN dword_t key) = 0;
        virtual void popBrush(IN dword_t key) throw() = 0;
        virtual void endPath(void) = 0;
        virtual void refreshBrush(void) = 0;
        virtual void setTransform(IN const xform_2d_t& T) throw() = 0;
        virtual void setBrushAttribute(IN eBrushAttribute attribute,
                                IN const char * value) = 0;
        virtual void setClipRect(IN float left, IN float top,
                                IN float right, IN float bottom) = 0;
        virtual void drawBezier(IN const bezier::curve_t& curve) = 0;
        virtual void drawQuadBezier(IN const bezier::quad_bezier_t& qb) = 0 ;
        virtual void drawLine(IN const point_t& p0, IN const point_t& p1) = 0;
        virtual void drawRect(IN const rect_t& r) = 0;
        virtual void fillRect(IN const rect_t& r) = 0;
        virtual void drawText(IN const rect_t& r,
                                IN const char * text) = 0;
        virtual void getBoundingRect(IN const char * text,
                                OUT rect_t& r) = 0;
        virtual void getRootTransform(OUT xform_2d_t& T) throw() = 0;
        virtual bool isPrinter(void) const throw() = 0;
};



/// helper class to throw on the stack
class PushPopBrush {
public:
        PushPopBrush(IN Drawer * drawer, IN dword_t key) {
                        ASSERT(drawer, "push/pop with null drawer");
                        m_drawer = drawer;
                        m_key = key;
                        m_drawer->pushBrush(m_key);
                }

        ~PushPopBrush(void) throw() {
                        if (m_drawer)
                                m_drawer->popBrush(m_key);
                }

private:
        Drawer *        m_drawer;
        dword_t         m_key;
};



};      // vgfx namespace

#endif  // WAVEPACKET_VGFX_DRAWER_H__