Canvas.h

/* Copyright (C) 2015-2024 Marc Boris Duerner
 
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
 
  As a special exception, you may use this file as part of a free
  software library without restriction. Specifically, if other files
  instantiate templates or use macros or inline functions from this
  file, or you compile this file and link it with other files to
  produce an executable, this file does not by itself cause the
  resulting executable to be covered by the GNU General Public
  License. This exception does not however invalidate any other
  reasons why the executable file might be covered by the GNU Library
  General Public License.
 
  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.
 
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  MA 02110-1301 USA
*/
 
#ifndef PT_GFX_CANVAS_H
#define PT_GFX_CANVAS_H
 
#include <Pt/Gfx/Api.h>
#include <Pt/Gfx/Size.h>
#include <Pt/Gfx/Point.h>
#include <Pt/Gfx/Rect.h>
#include <Pt/Gfx/Scaling.h>
#include <Pt/Gfx/Pen.h>
#include <Pt/Gfx/Brush.h>
#include <Pt/Gfx/Font.h>
#include <Pt/Gfx/CompositionMode.h>
#include <Pt/Gfx/FontMetrics.h>
#include <Pt/Gfx/TextMetrics.h>
#include <Pt/Gfx/Transform.h>
#include <Pt/Gfx/Path.h>
 
#include <Pt/String.h>
#include <Pt/Types.h>
 
#include <cstddef>
 
namespace Pt {
 
namespace Gfx {
 
class Bitmap;

class PT_GFX_API Canvas
{
    friend class PaintSurface;
 
    protected:
        Canvas();
 
        enum DirtyFlags : unsigned
        {
            DirtyTransform   = 0x01,
            DirtyComposition = 0x02,
            DirtyPen         = 0x04,
            DirtyBrush       = 0x08,
            DirtyFont        = 0x10,
            DirtyClip        = 0x20,
            DirtyAll         = 0x3F
        };
 
    public:
        virtual ~Canvas();

        const PointF& origin() const;

        const RectF& region() const;

        void setRegion(const RectF& r);

        const Scaling& scaling() const;

        void setScaling(const Scaling& scaling);

        const Gfx::ImageFormat& format() const;

        const Gfx::Transform& transform() const;

        void setTransform(const Gfx::Transform& tx);

        void resetTransform();
 
    public:
        void beginPaint(const Gfx::Paint& paint);

        void finishPaint();

        bool isActive() const;
 
    public:
        void setCompositionMode(const Gfx::CompositionMode& mode);

        void setPen(const Pen& pen);

        void setBrush(const Brush& brush);

        void setFont(const Gfx::Font& font);

        void setClip(const RectF& clip);

        void resetClip();
 
    public:
        void drawLine(const PointF& from, const PointF& to);

        void drawPolyline(const Gfx::PointF* ps, const size_t n);

        void fillPolygon(const Gfx::PointF* ps, const size_t n);

        void drawRect(const Gfx::RectF& rectangle);

        void fillRect(const Gfx::RectF& rectangle);

        void drawEllipse(const Gfx::PointF& topLeft, const Gfx::SizeF& size);

        void fillEllipse(const Gfx::PointF& topLeft, const Gfx::SizeF& size);
 
    public:
        void setPath(const Path& path);

        void drawPath();

        void fillPath();

        void drawPath(const Path& path);

        void fillPath(const Path& path);
 
    public:
        const FontMetrics& fontMetrics() const;

        TextMetrics textMetrics(const Pt::String& text) const;

        void drawText(const PointF& to, const Pt::String& text, 
                      const Transform* tform = 0);
 
    public:
        void drawImage(const Gfx::PointF& to, 
                       const Gfx::Image& image, 
                       const Gfx::RectF* rect = 0);

        void drawBitmap(const Gfx::PointF& to, 
                        const Gfx::Bitmap& bitmap, 
                        const Gfx::RectF* rect = 0);
 
    protected:
        virtual void onBeginPaint(const Gfx::Paint& paint) = 0;
       
        virtual void onFinishPaint() = 0;
 
    protected:
        virtual void onSetTransform(const Gfx::Transform& tx) = 0;
 
        virtual void onApplyTransform() = 0;
 
        virtual void onSetCompositionMode(const Gfx::CompositionMode& mode) = 0;
 
        virtual void onApplyCompositionMode() = 0;
 
        virtual void onSetPen(const Pen& pen) = 0;
 
        virtual void onApplyPen() = 0;
 
        virtual void onSetBrush(const Brush& pen) = 0;
 
        virtual void onApplyBrush() = 0;
 
        virtual void onSetFont(const Gfx::Font& font) = 0;
 
        virtual void onApplyFont() = 0;
 
        virtual void onSetClip(const Gfx::RectF* clip) = 0;
 
        virtual void onApplyClip() = 0;
 
    protected:
        void invalidate(unsigned flags);
 
    protected:
        virtual void onDrawLine(const PointF& from, const PointF& to) = 0;
 
        virtual void onDrawPolyline(const Gfx::PointF* pts, const size_t n) = 0;
 
        virtual void onFillPolygon(const Gfx::PointF* ps, const size_t n) = 0;
 
        virtual void onDrawRect(const Gfx::RectF& rectangle) = 0;
 
        virtual void onFillRect(const Gfx::RectF& rectangle) = 0;
 
        virtual void onDrawEllipse(const Gfx::PointF& topLeft, const Gfx::SizeF& size) = 0;
 
        virtual void onFillEllipse(const Gfx::PointF& topLeft, const Gfx::SizeF& size) = 0;
 
    protected:
        virtual void onSetPath(const Path& path) = 0;
 
        virtual void onDrawPath() = 0;
 
        virtual void onFillPath() = 0;
 
        virtual void onDrawPath(const Path& path) = 0;
 
        virtual void onFillPath(const Path& path) = 0;
 
    protected:
        virtual const Gfx::FontMetrics& onGetFontMetrics() const = 0;
 
        virtual Gfx::TextMetrics onGetTextMetrics(const Pt::String& text) const = 0;
 
        virtual void onDrawText(const Gfx::PointF& to, 
                                const Pt::String& text, 
                                const Gfx::Transform* transform) = 0;
 
    protected:
        virtual void onDrawImage(const Gfx::PointF& to, 
                                 const Gfx::Image& image, 
                                 const Gfx::RectF* rect = 0) = 0;
 
    protected:
        void applyState();
 
    private:
        void attachSurface(PaintSurface& surface);
 
        void detachSurface(PaintSurface& surface);
 
        void updateTransform();
 
    private:
        PaintSurface*  _surface;
        PaintSurface*  _active;
        RectF          _region;
        Gfx::Scaling   _scaling;
        Transform      _viewTx;
        Transform      _userTx;
        Transform      _tx;
        unsigned       _dirty;
};
 
} // namespace
 
} // namespace
 
#endif