Removing all globals in file writer (#653 )
Fix some static analyser complaints
Valgrind: handle width==0 in GfxDrivers on Wayland and X11
Don't use `Fl_Input_::static_value`, it accesses previous
buffer that may be deleted
Project file write encapsulated, removing globals
Encapsulating project file reader, removing states in glbals
Project i/o increased source code readability
src/drivers/Cairo/Fl_Cairo_Graphics_Driver.cxx:
- fix font_name_process() out of bounds memory access
- unify/align font_name_process() code (see also Xlib/xft)
- fix font name string allocation
src/drivers/Xlib/Fl_Xlib_Graphics_Driver_font_xft.cxx
- unify/align font_name_process() code (see also Cairo_Graphics)
- fix font name string allocation
Todo: move common code to Fl_Graphics_Driver or another common file.
Many thanks to @wcout for providing this fix.
Xrender now draws images in the same way when tiling images
or not when FL_RGB_SCALING_BILINEAR is on.
This allows to remove static bool Fl_Tiled_Image::drawing_tiled_image()
which becomes unused.
FL_OVERRIDE is defined as `override` for C++11 and higher
FL_OVERRIDE is defined as `override` for VisualC 2015 and newer
Don't interfere with Fl_Widget::override()
The problem to fix is that the arrow drawn by draw_arrow1() in src/fl_symbols.cxx
displays a faint clear line between the stem and head of the arrow with the Cairo
graphics driver.
This occurs because draw_arrow1() draws the arrow in 2 steps (a rectangle +
a triangle) and the Cairo driver is configured to use antialiasing when filling
polygons. The antialiasing produces the faint line between stem and head.
Why does draw_arrow1() draw a rectangle + a triangle rather than a
7-vertex polygon? That's because the X11 graphics driver fails with its polygon-
drawing function when the polygon is also rotated: the polygon is drawn
empty.
We want to keep using antialiasing under Cairo for polygons because
the result is better with non horizontal/vertical polygon edges.
This implementation changes function draw_arrow1() which draws
the arrow as a 7-vertex filled polygon except when the graphics driver
returns false for its virtual member function can_fill_non_convex_polygon().
In that situation, draw_arrow1() draws, as before, a rectangle + a triangle.
The new, virtual member function can_fill_non_convex_polygon() returns
true except for the X11 graphics driver. Therefore, draw_arrow1() is effectively
unchanged under the X11 driver.
Conflicting demands arise in the implementation of class Fl_Xlib_Graphics_Driver
for drawing images with the XRender library :
1) Issue #163 leads to use a bilinear filter to draw-and-scale images.
2) This tends to blur the edges of drawn areas which is bad for tiled images
(that is because the edges get alpha values, even for an opaque source image).
This commit resolves the conflict adding a means to detect whether the library
is busy drawing a tiled image. If so, the bilinear filter is not applied, drawn areas
don't have blurred edges, resulting in a nice tiling.
With this commit, these test apps perform correctly:
- tiled_image is correct at all scaling factor values also when modified
to use a depth-3 or a depth-4 Fl_RGB_Image as tile;
- unittests - Drawing Images is correct at all scaling factor values;
- pixmap_browser scales correctly up and down JPEG and PNG images.
Modifying test/tiled_image to make it use a depth-3 image for
tiling (rather than an Fl_Pixmap) shows the filter does require
to use PictOpOver as the render op in the XRenderComposite call.
The bug would appear with test/device and when scaling up to 133% or above:
the background of the Porsche pixmap would be truncated.
The bug requires to set OPTION_XRENDERER=0 to appear.
This fixes focus box drawing on X11 for some broken graphics
drivers with line width zero as discussed on issue #156 titled
"Incorrect rendering on Alpine Linux".
This title is not entirely correct. The issue has been observed on
other Linux distros as well if the "modesetting" driver is in effect.
This does not fix rectangle drawing (missing pixels) in general which
is obviously caused by a similar or the same driver issue.
Most coordinate calculations are done with the new inline function
int Fl_Scalable_Graphics_Driver::floor(int coord)
that is used by both the Windows and X11 platforms.
Changes here concentrate the fix within static function alpha_blend() and thus
are visible only when drawing transparent images under X11 platform
without Xrender.
