libsixel support #639

CMakeLists.txt

@@ -24,6 +24,7 @@ cmake_dependent_option(
   "${BUILD_TESTING}" OFF
 )
 option(USE_DOXYGEN "Build HTML cross reference with doxygen" OFF)
+option(USE_LIBSIXEL "Enable libsixel for improved Sixel graphics" OFF)
 option(USE_PANDOC "Build man pages and HTML reference with pandoc" ON)
 option(USE_POC "Build small, uninstalled proof-of-concept binaries" ON)
 option(USE_QRCODEGEN "Disable libqrcodegen QR code support" ON)
@@ -96,6 +97,10 @@ elseif(${USE_OIIO})
 pkg_check_modules(OIIO REQUIRED OpenImageIO>=2.1)
 set_property(GLOBAL APPEND PROPERTY PACKAGES_FOUND OpenImageIO)
 endif()
+if(${USE_LIBSIXEL})
+pkg_check_modules(LIBSIXEL REQUIRED libsixel>=1.8.6)
+set_property(GLOBAL APPEND PROPERTY PACKAGES_FOUND libsixel)
+endif()
 find_library(MATH_LIBRARIES m)
 if(${USE_DOCTEST})
 find_package(doctest 2.3.5)
@@ -147,8 +152,9 @@ target_include_directories(notcurses-core
     src
     "${CMAKE_REQUIRED_INCLUDES}"
     "${PROJECT_BINARY_DIR}/include"
-    "${TERMINFO_INCLUDE_DIRS}"
+    "${LIBSIXEL_INCLUDE_DIRS}"
     "${READLINE_INCLUDE_DIRS}"
+    "${TERMINFO_INCLUDE_DIRS}"
 )
 target_include_directories(notcurses-core-static
   PRIVATE
@@ -156,13 +162,15 @@ target_include_directories(notcurses-core-static
     src
     "${CMAKE_REQUIRED_INCLUDES}"
     "${PROJECT_BINARY_DIR}/include"
-    "${TERMINFO_STATIC_INCLUDE_DIRS}"
+    "${LIBSIXEL_STATIC_INCLUDE_DIRS}"
     "${READLINE_STATIC_INCLUDE_DIRS}"
+    "${TERMINFO_STATIC_INCLUDE_DIRS}"
 )
 target_link_libraries(notcurses-core
   PRIVATE
-    "${TERMINFO_LIBRARIES}"
+    "${LIBSIXEL_LIBRARIES}"
     "${READLINE_LIBRARIES}"
+    "${TERMINFO_LIBRARIES}"
     "${LIBRT}"
     unistring
   PUBLIC
@@ -170,8 +178,9 @@ target_link_libraries(notcurses-core
 )
 target_link_libraries(notcurses-core-static
   PRIVATE
-    "${TERMINFO_STATIC_LIBRARIES}"
+    "${LIBSIXEL_STATIC_LIBRARIES}"
     "${READLINE_STATIC_LIBRARIES}"
+    "${TERMINFO_STATIC_LIBRARIES}"
     "${LIBRT}"
     unistring
   PUBLIC
@@ -179,13 +188,15 @@ target_link_libraries(notcurses-core-static
 )
 target_link_directories(notcurses-core
   PRIVATE
-    "${TERMINFO_LIBRARY_DIRS}"
+    "${LIBSIXEL_LIBRARY_DIRS}"
     "${READLINE_LIBRARY_DIRS}"
+    "${TERMINFO_LIBRARY_DIRS}"
 )
 target_link_directories(notcurses-core-static
   PRIVATE
-    "${TERMINFO_STATIC_LIBRARY_DIRS}"
+    "${LIBSIXEL_STATIC_LIBRARY_DIRS}"
     "${READLINE_STATIC_LIBRARY_DIRS}"
+    "${TERMINFO_STATIC_LIBRARY_DIRS}"
 )
 # don't want these on freebsd/dragonfly/osx
 if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")

README.md

@@ -111,6 +111,7 @@ may well be possible to use still older versions. Let me know of any successes!
 * (OPTIONAL) (build+runtime) From QR-Code-generator: [libqrcodegen](https://github.com/nayuki/QR-Code-generator) 1.5.0+
 * (OPTIONAL) (build+runtime) From [FFmpeg](https://www.ffmpeg.org/): libswscale 5.0+, libavformat 57.0+, libavutil 56.0+
 * (OPTIONAL) (build+runtime) [OpenImageIO](https://github.com/OpenImageIO/oiio) 2.15.0+
+* (OPTIONAL) (build+runtime) [libsixel](https://github.com/saitoha/libsixel) 1.8.6+
 * (OPTIONAL) (testing) [Doctest](https://github.com/onqtam/doctest) 2.3.5+
 * (OPTIONAL) (documentation) [pandoc](https://pandoc.org/index.html) 1.19.2+
 * (OPTIONAL) (python bindings): Python 3.7+, [CFFI](https://pypi.org/project/cffi/) 1.13.2+, [pypandoc](https://pypi.org/project/pypandoc/) 1.5+

src/lib/internal.h

@@ -1328,9 +1328,10 @@ int sprite_kitty_cell_wipe(const notcurses* nc, sprixel* s, int y, int x);
 
 int sixel_blit(ncplane* nc, int linesize, const void* data,
                int leny, int lenx, const blitterargs* bargs);
-
 int kitty_blit(ncplane* nc, int linesize, const void* data,
                int leny, int lenx, const blitterargs* bargs);
+int libsixel_blit(ncplane* nc, int linesize, const void* data, int begy, int begx,
+                  int leny, int lenx, const blitterargs* bargs);
 
 int term_fg_rgb8(bool RGBflag, const char* setaf, int colors, FILE* out,
                  unsigned r, unsigned g, unsigned b);

src/lib/sixel.c

@@ -187,7 +187,7 @@ find_color(sixeltable* stab, unsigned char comps[static RGBSIZE]){
     }else{
       i = l;
     }
-    if(stab->colors == stab->colorregs){
+    if(stab->colors == stab->colorregs){ // used all our color registers
       return -1;
     }
     if(i < stab->colors){

tools/builddef.h.in

@@ -9,4 +9,5 @@
 #if defined(USE_FFMPEG) || defined(USE_OIIO)
 #define NOTCURSES_USE_MULTIMEDIA
 #endif
+#cmakedefine USE_LIBSIXEL
 #define NOTCURSES_SHARE "@CMAKE_INSTALL_FULL_DATADIR@/notcurses"