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//
// Draw-to-image code for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2016 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file. If this
// file is missing or damaged, see the license at:
//
// https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
// https://www.fltk.org/bugs.php
//
#ifndef Fl_Image_Surface_H
#define Fl_Image_Surface_H
#include <FL/Fl_Widget_Surface.H>
#include <FL/Fl_Image.H>
#include <FL/Fl_Shared_Image.H>
#include <FL/platform_types.h> // for Fl_Offscreen
/**
\brief Directs all graphics requests to an Fl_Image.
After creation of an Fl_Image_Surface object, make it the current drawing
surface calling Fl_Surface_Device::push_current(), and all
subsequent graphics requests will be recorded in the image. It's possible to
draw widgets (using Fl_Image_Surface::draw()) or to use any of the
\ref fl_drawings or the \ref fl_attributes. Finally, call image() on the object
to obtain a newly allocated Fl_RGB_Image object.
Fl_Gl_Window objects can be drawn in the image as well.
Usage example:
\code
// this is the widget that you want to draw into an image
Fl_Widget *g = ...;
// create an Fl_Image_Surface object
Fl_Image_Surface *image_surface = new Fl_Image_Surface(g->w(), g->h());
// direct all further graphics requests to the image
Fl_Surface_Device::push_current(image_surface);
// draw a white background
fl_color(FL_WHITE);
fl_rectf(0, 0, g->w(), g->h());
// draw the g widget in the image
image_surface->draw(g);
// get the resulting image
Fl_RGB_Image* image = image_surface->image();
// direct graphics requests back to their previous destination
Fl_Surface_Device::pop_current();
// delete the image_surface object, but not the image itself
delete image_surface;
\endcode
*/
class FL_EXPORT Fl_Image_Surface : public Fl_Widget_Surface {
friend class Fl_Graphics_Driver;
private:
class Fl_Image_Surface_Driver *platform_surface;
Fl_Offscreen get_offscreen_before_delete_();
protected:
void translate(int x, int y);
void untranslate();
public:
Fl_Image_Surface(int w, int h, int high_res = 0, Fl_Offscreen off = 0);
~Fl_Image_Surface();
void set_current();
virtual bool is_current();
Fl_RGB_Image *image();
Fl_Shared_Image *highres_image();
void origin(int *x, int *y);
void origin(int x, int y);
int printable_rect(int *w, int *h);
Fl_Offscreen offscreen();
void rescale();
};
/**
\cond DriverDev
\addtogroup DriverDeveloper
\{
*/
/** A base class describing the interface between FLTK and draw-to-image operations.
This class is only for internal use by the FLTK library.
A supported platform should implement the virtual methods of this class
in order to support drawing to an Fl_RGB_Image through class Fl_Image_Surface.
*/
class Fl_Image_Surface_Driver : public Fl_Widget_Surface {
friend class Fl_Image_Surface;
protected:
int width;
int height;
Fl_Offscreen offscreen;
int external_offscreen;
Fl_Image_Surface_Driver(int w, int h, int /*high_res*/, Fl_Offscreen off) : Fl_Widget_Surface(NULL), width(w), height(h), offscreen(off) {external_offscreen = (off != 0);}
virtual ~Fl_Image_Surface_Driver() {}
virtual void set_current() = 0;
virtual void translate(int x, int y) = 0;
virtual void untranslate() = 0;
int printable_rect(int *w, int *h);
virtual Fl_RGB_Image *image() = 0;
/** Each platform implements this function its own way.
It returns an object implementing all virtual functions
of class Fl_Image_Surface_Driver for the plaform.
*/
static Fl_Image_Surface_Driver *newImageSurfaceDriver(int w, int h, int high_res, Fl_Offscreen off);
};
/**
\}
\endcond
*/
#endif // Fl_Image_Surface_H
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