introduce nccapabilites struct, move utf8/ccc therein #1768

src/lib/blit.c

@@ -966,7 +966,7 @@ const struct blitset* lookup_blitset(const tinfo* tcache, ncblitter_e setid, boo
     }
   }
   // the only viable blitters in ASCII are NCBLIT_1x1 and NCBLIT_PIXEL
-  if(!tcache->utf8 && (setid != NCBLIT_1x1 && setid != NCBLIT_PIXEL)){
+  if(!tcache->caps.utf8 && (setid != NCBLIT_1x1 && setid != NCBLIT_PIXEL)){
     if(may_degrade){
       setid = NCBLIT_1x1;
     }else{

src/lib/blitset.h

@@ -25,7 +25,7 @@ encoding_x_scale(const tinfo* tcache, const struct blitset* bset) {
 // use NCBLIT_PIXEL for NCBLIT_DEFAULT, though maybe this ought change.
 static inline ncblitter_e 
 rgba_blitter_default(const tinfo* tcache, ncscale_e scale){
-  if(!tcache->utf8){
+  if(!tcache->caps.utf8){
     return NCBLIT_1x1; // only one that works in ASCII
   }
   if(scale == NCSCALE_NONE || scale == NCSCALE_SCALE){

src/lib/debug.c

@@ -15,7 +15,7 @@ tinfo_debug_caps(const tinfo* ti, FILE* debugfp, int rows, int cols,
                  unsigned images, unsigned videos){
   const char indent[] = " ";
   fprintf(debugfp, "%scolors: %u rgb: %c ccc: %c setaf: %c setab: %c\n",
-          indent, ti->colors, capbool(ti->RGBflag), capbool(ti->CCCflag),
+          indent, ti->colors, capbool(ti->RGBflag), capbool(ti->caps.can_change_colors),
           capyn(get_escape(ti, ESCAPE_SETAF)),
           capyn(get_escape(ti, ESCAPE_SETAB)));
   fprintf(debugfp, "%ssgr: %c sgr0: %c op: %c fgop: %c bgop: %c\n",
@@ -37,10 +37,10 @@ tinfo_debug_caps(const tinfo* ti, FILE* debugfp, int rows, int cols,
     fprintf(debugfp, "%srgba pixel graphics supported\n", indent);
   }
   fprintf(debugfp, "%sutf8: %c quad: %c sex: %c braille: %c images: %c videos: %c\n",
-          indent, capbool(ti->utf8), capbool(ti->quadrants),
+          indent, capbool(ti->caps.utf8), capbool(ti->quadrants),
           capbool(ti->sextants), capbool(ti->braille),
           capbool(images), capbool(videos));
-  if(ti->utf8){
+  if(ti->caps.utf8){
     fprintf(debugfp, "%s{%ls} {%ls} ⎧%.122ls⎫ ⎧%.6ls%.3ls⎫ ⎧%.6ls%.3ls⎫ ⎧█ ⎫ 🯰🯱\n", indent,
             get_blitter_egcs(NCBLIT_2x1), get_blitter_egcs(NCBLIT_2x2),
             get_blitter_egcs(NCBLIT_3x2),

src/lib/direct.c

@@ -1270,7 +1270,7 @@ bool ncdirect_canopen_images(const ncdirect* n __attribute__ ((unused))){
 
 // Is our encoding UTF-8? Requires LANG being set to a UTF8 locale.
 bool ncdirect_canutf8(const ncdirect* n){
-  return n->tcache.utf8;
+  return n->tcache.caps.utf8;
 }
 
 int ncdirect_flush(const ncdirect* nc){

src/lib/fade.c

@@ -233,7 +233,7 @@ int ncplane_fadeout_iteration(ncplane* n, ncfadectx* nctx, int iter,
 static ncfadectx* 
 ncfadectx_setup_internal(ncplane* n, const struct timespec* ts){
   if(!ncplane_notcurses(n)->tcache.RGBflag &&
-     !ncplane_notcurses(n)->tcache.CCCflag){ // terminal can't fade
+     !ncplane_notcurses(n)->tcache.caps.can_change_colors){ // terminal can't fade
     return NULL;
   }
   ncfadectx* nctx = malloc(sizeof(*nctx));
@@ -302,7 +302,7 @@ int ncplane_pulse(ncplane* n, const struct timespec* ts, fadecb fader, void* cur
   ncfadectx pp;
   int ret;
   if(!ncplane_notcurses(n)->tcache.RGBflag &&
-     !ncplane_notcurses(n)->tcache.CCCflag){ // terminal can't fade
+     !ncplane_notcurses(n)->tcache.caps.can_change_colors){ // terminal can't fade
     return -1;
   }
   if(alloc_ncplane_palette(n, &pp, ts)){

src/lib/notcurses.c

@@ -837,7 +837,7 @@ init_banner_warnings(const notcurses* nc, FILE* out){
     fprintf(out, "\n Warning! Colors subject to https://github.com/dankamongmen/notcurses/issues/4");
     fprintf(out, "\n  Specify a (correct) TrueColor TERM, or COLORTERM=24bit.\n");
   }else{
-    if(!nc->tcache.CCCflag){
+    if(!nc->tcache.caps.can_change_colors){
       fprintf(out, "\n Warning! Advertised TrueColor but no 'ccc' flag\n");
     }
   }
@@ -2126,31 +2126,31 @@ int notcurses_mouse_disable(notcurses* n){
 }
 
 bool notcurses_canutf8(const notcurses* nc){
-  return nc->tcache.utf8;
+  return nc->tcache.caps.utf8;
 }
 
 bool notcurses_canhalfblock(const notcurses* nc){
-  return nc->tcache.utf8;
+  return nc->tcache.caps.utf8;
 }
 
 bool notcurses_canquadrant(const notcurses* nc){
-  return nc->tcache.quadrants && nc->tcache.utf8;
+  return nc->tcache.quadrants && nc->tcache.caps.utf8;
 }
 
 bool notcurses_cansextant(const notcurses* nc){
-  return nc->tcache.sextants && nc->tcache.utf8;
+  return nc->tcache.sextants && nc->tcache.caps.utf8;
 }
 
 bool notcurses_canbraille(const notcurses* nc){
-  return nc->tcache.braille && nc->tcache.utf8;
+  return nc->tcache.braille && nc->tcache.caps.utf8;
 }
 
 bool notcurses_canfade(const notcurses* nc){
-  return nc->tcache.CCCflag || nc->tcache.RGBflag;
+  return nc->tcache.caps.can_change_colors || nc->tcache.RGBflag;
 }
 
 bool notcurses_canchangecolor(const notcurses* nc){
-  if(!nc->tcache.CCCflag){
+  if(!nc->tcache.caps.can_change_colors){
     return false;
   }
   ncpalette* p;

src/lib/render.c

@@ -758,7 +758,7 @@ int term_fg_rgb8(const tinfo* ti, FILE* out, unsigned r, unsigned g, unsigned b)
 
 static inline int
 update_palette(notcurses* nc, FILE* out){
-  if(nc->tcache.CCCflag){
+  if(nc->tcache.caps.can_change_colors){
     const char* initc = get_escape(&nc->tcache, ESCAPE_INITC);
     for(size_t damageidx = 0 ; damageidx < sizeof(nc->palette.chans) / sizeof(*nc->palette.chans) ; ++damageidx){
       unsigned r, g, b;

src/lib/termdesc.c

@@ -266,7 +266,7 @@ int interrogate_terminfo(tinfo* ti, int fd, const char* termname, unsigned utf8,
       return -1;
     }
   }
-  ti->utf8 = utf8;
+  ti->caps.utf8 = utf8;
   // allow the "rgb" boolean terminfo capability, a COLORTERM environment
   // variable of either "truecolor" or "24bit", or unconditionally enable it
   // for several terminals known to always support 8bpc rgb setaf/setab.
@@ -328,7 +328,7 @@ int interrogate_terminfo(tinfo* ti, int fd, const char* termname, unsigned utf8,
   if(colors){
     const char* initc = get_escape(ti, ESCAPE_INITC);
     if(initc){
-      ti->CCCflag = tigetflag("ccc") == 1;
+      ti->caps.can_change_colors = tigetflag("ccc") == 1;
     }
   }else{ // disable initc if there's no color support
     ti->escindices[ESCAPE_INITC] = 0;

src/lib/termdesc.h

@@ -86,6 +86,13 @@ typedef struct ncinputlayer {
   struct esctrie* inputescapes; // trie of input escapes -> ncspecial_keys
 } ncinputlayer;
 
+// terminal capabilities exported to the user
+typedef struct nccapabilities {
+  // assigned based off nl_langinfo() in notcurses_core_init()
+  bool utf8;              // are we using utf-8 encoding? from nl_langinfo(3)
+  bool can_change_colors; // can we change the palette? terminfo ccc capability
+} nccapabilities;
+
 // terminal interface description. most of these are acquired from terminfo(5)
 // (using a database entry specified by TERM). some are determined via
 // heuristics based off terminal interrogation or the TERM environment
@@ -94,6 +101,7 @@ typedef struct ncinputlayer {
 typedef struct tinfo {
   uint16_t escindices[ESCAPE_MAX]; // table of 1-biased indices into esctable
   char* esctable;                  // packed table of escape sequences
+  nccapabilities caps;             // exported to the user, when requested
   unsigned colors;// number of colors terminfo reported usable for this screen
   // we use the cell's size in pixels for pixel blitting. this information can
   // be acquired on all terminals with pixel support.
@@ -133,13 +141,9 @@ typedef struct tinfo {
   bool bitmap_supported;    // do we support bitmaps (post pixel_query_done)?
   bool bitmap_lowest_line;  // can we render pixels to the bottom row?
   bool RGBflag;   // "RGB" flag for 24bpc truecolor
-  bool CCCflag;   // "CCC" flag for palette set capability
   bool BCEflag;   // "BCE" flag for erases with background color
   bool AMflag;    // "AM" flag for automatic movement to next line
 
-  // assigned based off nl_langinfo() in notcurses_core_init()
-  bool utf8;      // are we using utf-8 encoding, as hoped?
-
   // these are assigned wholly through TERM-based heuristics
   bool quadrants; // do we have (good, vetted) Unicode 1 quadrant support?
   bool sextants;  // do we have (good, vetted) Unicode 13 sextant support?