turn off bitmap support if TIOCGWINSZ doesn't supply pixel info #1805

src/lib/blit.c

@@ -959,7 +959,7 @@ const struct blitset* lookup_blitset(const tinfo* tcache, ncblitter_e setid, boo
     }
   }
   // without bitmap support, NCBLIT_PIXEL decays to NCBLIT_3x2
-  if(!tcache->bitmap_supported && setid == NCBLIT_PIXEL){
+  if(!tcache->pixel_draw && setid == NCBLIT_PIXEL){
     if(may_degrade){
       setid = NCBLIT_3x2;
     }else{

src/lib/debug.c

@@ -63,7 +63,7 @@ tinfo_debug_caps(const tinfo* ti, FILE* debugfp, int rows, int cols,
                   capyn(get_escape(ti, ESCAPE_BGOP)));
   fprintf(debugfp, "%srows: %u cols: %u rpx: %u cpx: %u (%dx%d)\n",
           indent, rows, cols, ti->cellpixy, ti->cellpixx, rows * ti->cellpixy, cols * ti->cellpixx);
-  if(!ti->bitmap_supported){
+  if(!ti->pixel_init){
     fprintf(debugfp, "%sdidn't detect bitmap graphics support\n", indent);
   }else if(ti->sixel_maxy){
     fprintf(debugfp, "%smax sixel size: %dx%d colorregs: %u\n",

src/lib/direct.c

@@ -1311,7 +1311,7 @@ int ncdirect_flush(const ncdirect* nc){
 }
 
 int ncdirect_check_pixel_support(const ncdirect* n){
-  if(n->tcache.bitmap_supported){
+  if(n->tcache.pixel_draw){
     return 1;
   }
   return 0;

src/lib/notcurses.c

@@ -254,6 +254,9 @@ int update_term_dimensions(int fd, int* rows, int* cols, tinfo* tcache,
   if(tcache){
     tcache->cellpixy = ws.ws_row ? ws.ws_ypixel / ws.ws_row : 0;
     tcache->cellpixx = ws.ws_col ? ws.ws_xpixel / ws.ws_col : 0;
+    if(tcache->cellpixy == 0 || tcache->cellpixx == 0){
+      tcache->pixel_init = NULL; // disable support
+    }
   }
   if(tcache->sixel_maxy_pristine){
     tcache->sixel_maxy = tcache->sixel_maxy_pristine;
@@ -984,7 +987,7 @@ recursive_lock_init(pthread_mutex_t *lock){
 }
 
 int notcurses_check_pixel_support(const notcurses* nc){
-  if(nc->tcache.bitmap_supported){
+  if(nc->tcache.pixel_init){
     return 1;
   }
   return 0;

src/lib/termdesc.c

@@ -6,7 +6,6 @@
 // we found Sixel support -- set up the API
 static inline void
 setup_sixel_bitmaps(tinfo* ti, int fd){
-  ti->bitmap_supported = true;
   ti->pixel_init = sixel_init;
   ti->pixel_draw = sixel_draw;
   ti->pixel_remove = NULL;
@@ -20,7 +19,6 @@ setup_sixel_bitmaps(tinfo* ti, int fd){
 
 static inline void
 setup_kitty_bitmaps(tinfo* ti, int fd){
-  ti->bitmap_supported = true;
   ti->pixel_wipe = kitty_wipe;
   ti->pixel_destroy = kitty_destroy;
   ti->pixel_remove = kitty_remove;

src/lib/termdesc.h

@@ -116,7 +116,22 @@ typedef struct tinfo {
   // bg_collides_default is either 0x0000000 or (if in use) 0x1RRGGBB.
   uint32_t bg_collides_default;
 
-  // sprixel support. there are several different sprixel protocols, of
+  // bitmap support. if we support bitmaps, pixel_draw will be non-NULL
+  // wipe out a cell's worth of pixels from within a sprixel. for sixel, this
+  // means leaving out the pixels (and likely resizes the string). for kitty,
+  // this means dialing down their alpha to 0 (in equivalent space).
+  int (*pixel_wipe)(struct sprixel* s, int y, int x);
+  // perform the inverse of pixel_wipe, restoring an annihilated sprixcell.
+  int (*pixel_rebuild)(struct sprixel* s, int y, int x, uint8_t* auxvec);
+  int (*pixel_remove)(int id, FILE* out); // kitty only, issue actual delete command
+  int (*pixel_init)(const struct tinfo*, int fd); // called when support is detected
+  int (*pixel_draw)(const struct ncpile* p, struct sprixel* s, FILE* out);
+  // execute move (erase old graphic, place at new location) if non-NULL
+  int (*pixel_move)(const struct ncpile* p, struct sprixel* s, FILE* out);
+  int (*pixel_destroy)(const struct notcurses* nc, const struct ncpile* p, FILE* out, struct sprixel* s);
+  int (*pixel_shutdown)(int fd);  // called during context shutdown
+  int (*pixel_clear_all)(int fd); // called during startup, kitty only
+  // sprixel parameters. there are several different sprixel protocols, of
   // which we support sixel and kitty. the kitty protocol is used based
   // on TERM heuristics. otherwise, we attempt to detect sixel support, and
   // query the details of the implementation.
@@ -130,26 +145,11 @@ typedef struct tinfo {
   // so kitty graphics (which don't force a scroll) never deal with this.
   int sixel_maxy;          // maximum working sixel height
   int sixel_maxy_pristine; // maximum theoretical sixel height, as queried
-  int (*pixel_destroy)(const struct notcurses* nc, const struct ncpile* p, FILE* out, struct sprixel* s);
-  // wipe out a cell's worth of pixels from within a sprixel. for sixel, this
-  // means leaving out the pixels (and likely resizes the string). for kitty,
-  // this means dialing down their alpha to 0 (in equivalent space).
-  int (*pixel_wipe)(struct sprixel* s, int y, int x);
-  // perform the inverse of pixel_wipe, restoring an annihilated sprixcell.
-  int (*pixel_rebuild)(struct sprixel* s, int y, int x, uint8_t* auxvec);
-  int (*pixel_remove)(int id, FILE* out); // kitty only, issue actual delete command
-  int (*pixel_init)(const struct tinfo*, int fd); // called when support is detected
-  int (*pixel_draw)(const struct ncpile* p, struct sprixel* s, FILE* out);
-  // execute move (erase old graphic, place at new location) if non-NULL
-  int (*pixel_move)(const struct ncpile* p, struct sprixel* s, FILE* out);
-  int (*pixel_shutdown)(int fd);  // called during context shutdown
-  int (*pixel_clear_all)(int fd); // called during startup, kitty only
   int sprixel_scale_height; // sprixel must be a multiple of this many rows
   const char* termname;     // terminal name from environment variables/init
   char* termversion;        // terminal version (freeform) from query responses
   struct termios tpreserved; // terminal state upon entry
   ncinputlayer input;       // input layer
-  bool bitmap_supported;    // do we support bitmaps (post pixel_query_done)?
 
   // mlterm resets the cursor (i.e. makes it visible) any time you print
   // a sprixel. we work around this spiritedly unorthodox decision. it

src/tests/bitmap.cpp

@@ -8,8 +8,7 @@ TEST_CASE("Bitmaps") {
   auto n_ = notcurses_stdplane(nc_);
   REQUIRE(n_);
 
-  if(notcurses_check_pixel_support(nc_) <= 0){
-    CHECK(0 == nc_->tcache.bitmap_supported);
+  if(!notcurses_check_pixel_support(nc_)){
     CHECK(!notcurses_stop(nc_));
     return;
   }
@@ -17,7 +16,7 @@ TEST_CASE("Bitmaps") {
   SUBCASE("SprixelTermValues") {
     CHECK(0 < nc_->tcache.cellpixy);
     CHECK(0 < nc_->tcache.cellpixx);
-    CHECK(nc_->tcache.bitmap_supported);
+    CHECK(nc_->tcache.pixel_init);
   }
 
   SUBCASE("SprixelMinimize") {