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
The X11 platform uses this argument to restore the correct clipping state after
drawing to an Fl_Image_Surface object.
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12226 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
See thread "fl_pop_clip: clip stack underflow! warning on X11"
started on Thu, 20 Apr 2017.
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12221 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
Ref.: https://github.com/mmuman/fltk-test-only.git,
commit 59c3cfbdf0412fb30f8312ed9ddd96f5affd2f0a by François Revol.
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12195 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
See [fltk.general] Drawing to Fl_Offscreen received signal SIGSEGV, Segmentation fault.
that is unrelated to Fl_Offscreen but caused by calling win->show(0,0).
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12179 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
With this, fl_copy_offscreen() can be used with any drawing surface (e.g., PostScript) and any Fl_Offscreen
argument (e.g., returned by Fl_image_Surface::offscreen()).
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12148 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
This ensures API compatibility with FLTK 1.3 where Fl_Surface_Device->set_current()
is used to change the current drawing surface.
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12125 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
Fl_RGB_Image's of depth-2, that is, monocolor and transparent, were not drawn using the XRender extension,
when present, as are depth-4 images. With this change they are.
A by-product of this change is that it fixes an erroneous drawing (STR#3353) that occurred when
the image expands outside the window.
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12124 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
The problem is specific to the X11 platform. The cause is that depth-2 images were not considered
in a previous change (r.10628) that introduced transparent image drawing with alpha blending.
Depth-2 images can be processed just as depth-4 images with alpha-blending.
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12120 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
