FLTK - Fast Light Tool Kit - https://github.com/fltk/fltk - cross platform GUI development
00884f28e2
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. |
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| .github | ||
| cairo | ||
| CMake | ||
| documentation | ||
| examples | ||
| FL | ||
| fluid | ||
| GL | ||
| jpeg | ||
| lib | ||
| libdecor | ||
| misc | ||
| nanosvg | ||
| png | ||
| public | ||
| src | ||
| test | ||
| util | ||
| zlib | ||
| .clang-format | ||
| .gitattributes | ||
| .gitignore | ||
| .gitlab-ci.yml | ||
| ANNOUNCEMENT | ||
| autogen.sh | ||
| CHANGES_1.0.txt | ||
| CHANGES_1.1.txt | ||
| CHANGES_1.3.txt | ||
| CHANGES.txt | ||
| CMakeLists.txt | ||
| config.guess | ||
| config.sub | ||
| configh.cmake.in | ||
| configh.in | ||
| configure.ac | ||
| COPYING | ||
| CREDITS.txt | ||
| DartConfig.cmake | ||
| fl_config.cmake.in | ||
| fl_config.in | ||
| fltk_version.dat | ||
| fltk-config.in | ||
| fltk.list.in | ||
| fltk.spec.in | ||
| fltk.xpm | ||
| forms.h | ||
| install-sh | ||
| mac_endianness.h | ||
| Makefile | ||
| makeinclude.in | ||
| makesrcdist | ||
| README.abi-version.txt | ||
| README.bundled-libs.txt | ||
| README.Cairo.txt | ||
| README.CMake.txt | ||
| README.experimental.txt | ||
| README.IDE.txt | ||
| README.macOS.md | ||
| README.md | ||
| README.txt | ||
| README.Unix.txt | ||
| README.Wayland.txt | ||
| README.Windows.txt | ||
README - Fast Light Tool Kit (FLTK) Version 1.4.0
WHAT IS FLTK?
The Fast Light Tool Kit ("FLTK", pronounced "fulltick") is a
cross-platform C++ GUI toolkit for UNIX®/Linux® (X11 or
Wayland), Microsoft® Windows®, and macOS®.
FLTK provides modern GUI functionality without the bloat and
supports 3D graphics via OpenGL® and its built-in GLUT
emulation. It was originally developed by Mr. Bill Spitzak
and is currently maintained by a small group of developers
across the world with a central repository on GitHub.
For more information see README.txt:
https://github.com/fltk/fltk/blob/master/README.txt
