fltk/FL/Fl_Pixmap.H
Manolo Gouy f48750b0f4 Introduce HiDPI + rescaling support for the X11 platform (+ partial support for WIN32)
Corresponds to STR #3320
1) HiDPI support consists in detecting the adequate scaling factor for the screen on which
FLTK maps a window, and scaling all FLTK units by this factor. FLTK tries to detect the correct
value of this factor at startup (see more details below). Environment variable
FLTK_SCALING_FACTOR can also be used to set this value.
2) Rescaling support consists in changing the scaling factor of all FLTK windows
in reply to ctrl/+/-/0/ keystrokes.

More details for the various platforms :

- X11: Support is very advanced. Some details need still to be improved.
Automatic detection of the correct starting value of the scaling factor works well
with the gnome desktop. The present code contains no support for this on
other desktops.  FLTK_SCALING_FACTOR provides a workaround.

-WIN32: Support is incomplete at this point, although many test
applications have partial or complete HiDPI and scaling support.
The current value of the system's scaling factor is correctly detected
at application startup. Apps respond to changes of this value in real time.
Support needs to define the FLTK_HIDPI_SUPPORT preprocessor variable
at compile time. This way, standard builds produce a code with the
default WIN32 HiDPI support, that is, where all graphics goes to an internal
buffer that gets enlarged by the system and then mapped to the HiDPI
display. To experiment with (or develop) the new HiDPI support requires
a modified build procedure in which  FLTK_HIDPI_SUPPORT is defined
at compile time. When the support will be complete, the requirement for the
definition of this preprocessor variable will be removed. The present commit
contains support for a single scaling factor. Eventually, per-screen scaling
factors should be implemented, as done for X11.

- MacOS: this commit does not give new HiDPI for this platform.
Eventually, window rescaling in reply to command/+/-/0/ is desirable.
Per-screen scaling factor makes no sense on this platform because
the OS itself takes care of the difference between the resolutions of
traditional and retina displays.


git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12239 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
2017-05-17 11:54:18 +00:00

88 lines
2.7 KiB
C++

//
// "$Id$"
//
// Pixmap header file for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2017 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:
//
// http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
/* \file
Fl_Pixmap widget . */
#ifndef Fl_Pixmap_H
#define Fl_Pixmap_H
# include "Fl_Image.H"
class Fl_Widget;
struct Fl_Menu_Item;
// Older C++ compilers don't support the explicit keyword... :(
# if defined(__sgi) && !defined(_COMPILER_VERSION)
# define explicit
# endif // __sgi && !_COMPILER_VERSION
/**
The Fl_Pixmap class supports caching and drawing of colormap
(pixmap) images, including transparency.
*/
class FL_EXPORT Fl_Pixmap : public Fl_Image {
friend class Fl_Graphics_Driver;
void copy_data();
void delete_data();
void set_data(const char * const *p);
int prepare(int XP, int YP, int WP, int HP, int &cx, int &cy,
int &X, int &Y, int &W, int &H);
protected:
void measure();
public:
int alloc_data; // Non-zero if data was allocated
private:
// for internal use
fl_uintptr_t id_;
fl_uintptr_t mask_;
Fl_Color pixmap_bg_color;
float cache_scale_; // graphics scaling value when id_ was computed
public:
/** The constructors create a new pixmap from the specified XPM data. */
explicit Fl_Pixmap(char * const * D) : Fl_Image(-1,0,1), alloc_data(0), id_(0), mask_(0) {set_data((const char*const*)D); measure();}
/** The constructors create a new pixmap from the specified XPM data. */
explicit Fl_Pixmap(uchar* const * D) : Fl_Image(-1,0,1), alloc_data(0), id_(0), mask_(0) {set_data((const char*const*)D); measure();}
/** The constructors create a new pixmap from the specified XPM data. */
explicit Fl_Pixmap(const char * const * D) : Fl_Image(-1,0,1), alloc_data(0), id_(0), mask_(0) {set_data((const char*const*)D); measure();}
/** The constructors create a new pixmap from the specified XPM data. */
explicit Fl_Pixmap(const uchar* const * D) : Fl_Image(-1,0,1), alloc_data(0), id_(0), mask_(0) {set_data((const char*const*)D); measure();}
virtual ~Fl_Pixmap();
virtual Fl_Image *copy(int W, int H);
Fl_Image *copy() { return copy(w(), h()); }
virtual void color_average(Fl_Color c, float i);
virtual void desaturate();
virtual void draw(int X, int Y, int W, int H, int cx=0, int cy=0);
void draw(int X, int Y) {draw(X, Y, w(), h(), 0, 0);}
virtual void label(Fl_Widget*w);
virtual void label(Fl_Menu_Item*m);
virtual void uncache();
};
#endif
//
// End of "$Id$".
//