[render] gratuitous hpa only on plane changes #2199

NEWS.md

@@ -196,7 +196,7 @@ rearrangements of Notcurses.
   * Added `ncplane_moverel()`.
   * Documented `ncplane_move_yx()` in `notcurses_plane.3`, and removed the
     false comment that "passing -1 as a coordinate will hold that axis
-    constant" from `USGAE.md` and `notcurses.h`. This has never been true.
+    constant" from `USAGE.md` and `notcurses.h`. This has never been true.
   * Added `ncdirect_putegc()` to perform Unicode segmentation. It returns
     the number of columns consumed, and makes available the number of bytes
     used by the EGC.
@@ -588,10 +588,7 @@ rearrangements of Notcurses.
     * Add new function `ncpile_render()`, which renders the pile containing the
       specified plane to the specified buffer. Add new function
       `ncpile_rasterize()` to rasterize the specified buffer to output.
-  * Added `NCSTYLE_STRUCK` for strikethrough. Note that this is not supported
-    by terminfo, and we instead just hardcode the control sequence. Use at your
-    own risk! If your terminal doesn't support this control sequence, behavior
-    is undefined.
+  * Added `NCSTYLE_STRUCK` for strikethrough.
 
 * 2.0.7 (2020-11-21)
   * The `horiz` union of `ncplane_options` has been discarded; the `int x`

src/lib/in.c

@@ -1035,6 +1035,8 @@ da2_cb(inputctx* ictx){
   if(pv == 0){
     return 2;
   }
+  // modern XTerm replies to XTVERSION, but older versions require extracting
+  // the version from secondary DA
   if(ictx->initdata->qterm == TERMINAL_XTERM){
     if(ictx->initdata->version == NULL){
       char ver[8];
@@ -1217,11 +1219,14 @@ tcap_cb(inputctx* ictx){
   // 'TN' (Terminal Name)
   if(strncasecmp(str, "544e=", 5) == 0){
     const char* tn = str + 5;
+    // FIXME clean this crap up
     if(strcasecmp(tn, "6D6C7465726D") == 0){
       ictx->initdata->qterm = TERMINAL_MLTERM;
+    }else if(strcasecmp(tn, "787465726d") == 0){
+      ictx->initdata->qterm = TERMINAL_XTERM; // "xterm"
     }else if(strcasecmp(tn, "787465726d2d6b69747479") == 0){
-      ictx->initdata->qterm = TERMINAL_KITTY;
-    }else if(strcasecmp(tn, "787465726D2D323536636F6C6F72") == 0){
+      ictx->initdata->qterm = TERMINAL_KITTY; // "xterm-kitty"
+    }else if(strcasecmp(tn, "787465726d2d323536636f6c6f72") == 0){
       ictx->initdata->qterm = TERMINAL_XTERM; // "xterm-256color"
     }else{
       logdebug("unknown terminal name %s\n", tn);

src/lib/internal.h

@@ -128,6 +128,8 @@ typedef struct rasterstate {
   // modified by: output, cursor moves, clearing the screen (during refresh).
   int y, x;
 
+  const ncplane* lastsrcp; // last source plane (we emit hpa on plane changes)
+
   unsigned lastr;   // foreground rgb, overloaded for palindexed fg
   unsigned lastg;
   unsigned lastb;
@@ -1148,22 +1150,26 @@ mouse_disable(tinfo* ti, fbuf* f){
 // sync the drawing position to the specified location with as little overhead
 // as possible (with nothing, if already at the right location). we prefer
 // absolute horizontal moves (hpa) to relative ones, in the rare event that
-// our understanding of our horizontal location is faulty.
+// our understanding of our horizontal location is faulty. if we're moving from
+// one plane to another, we emit an hpa no matter what.
 // FIXME fall back to synthesized moves in the absence of capabilities (i.e.
 // textronix lacks cup; fake it with horiz+vert moves)
 // if hardcursorpos is non-zero, we always perform a cup. this is done when we
 // don't know where the cursor currently is =].
 static inline int
-goto_location(notcurses* nc, fbuf* f, int y, int x){
+goto_location(notcurses* nc, fbuf* f, int y, int x, const ncplane* srcp){
 //fprintf(stderr, "going to %d/%d from %d/%d hard: %u\n", y, x, nc->rstate.y, nc->rstate.x, nc->rstate.hardcursorpos);
   int ret = 0;
   // if we don't have hpa, force a cup even if we're only 1 char away. the only
   // TERM i know supporting cup sans hpa is vt100, and vt100 can suck it.
   // you can't use cuf for backwards moves anyway; again, vt100 can suck it.
   const char* hpa = get_escape(&nc->tcache, ESCAPE_HPA);
   if(nc->rstate.y == y && hpa && !nc->rstate.hardcursorpos){ // only need move x
-    if(nc->rstate.x == x){ // needn't move shit
-      return 0;
+    if(nc->rstate.x == x){
+      if(nc->rstate.lastsrcp == srcp){
+        return 0; // needn't move shit
+      }
+      ++nc->stats.s.hpa_gratuitous;
     }
     if(fbuf_emit(f, tiparm(hpa, x))){
       return -1;
@@ -1182,6 +1188,7 @@ goto_location(notcurses* nc, fbuf* f, int y, int x){
   nc->rstate.x = x;
   nc->rstate.y = y;
   nc->rstate.hardcursorpos = 0;
+  nc->rstate.lastsrcp = srcp;
   return ret;
 }
 

src/lib/kitty.c

@@ -1183,7 +1183,7 @@ int kitty_move(sprixel* s, fbuf* f, unsigned noscroll, int yoff, int xoff){
   const int targx = s->n->absx;
   logdebug("moving %u to %d %d\n", s->id, targy, targx);
   int ret = 0;
-  if(goto_location(ncplane_notcurses(s->n), f, targy + yoff, targx + xoff)){
+  if(goto_location(ncplane_notcurses(s->n), f, targy + yoff, targx + xoff, s->n)){
     ret = -1;
   }else if(fbuf_printf(f, "\e_Ga=p,i=%d,p=1,q=2%s\e\\", s->id,
                        noscroll ? ",C=1" : "") < 0){

src/lib/notcurses.c

@@ -1093,7 +1093,7 @@ notcurses* notcurses_core_init(const notcurses_options* opts, FILE* outfp){
     // the u7 led the queries so that we would get a cursor position
     // unaffected by any query spill (unconsumed control sequences). move
     // us back to that location, in case there was any such spillage.
-    if(goto_location(ret, &ret->rstate.f, *cursory, *cursorx)){
+    if(goto_location(ret, &ret->rstate.f, *cursory, *cursorx, NULL)){
       goto err;
     }
   }
@@ -1227,7 +1227,7 @@ int notcurses_stop(notcurses* nc){
         fbuf_putc(&nc->rstate.f, '\n');
         --targy;
       }
-      goto_location(nc, &nc->rstate.f, targy, 0);
+      goto_location(nc, &nc->rstate.f, targy, 0, NULL);
       fbuf_finalize(&nc->rstate.f, stdout);
     }
     if(nc->stdplane){

src/lib/render.c

@@ -976,7 +976,7 @@ rasterize_scrolls(const ncpile* p, fbuf* f){
   if(p->nc->tcache.pixel_scroll){
     p->nc->tcache.pixel_scroll(p, &p->nc->tcache, scrolls);
   }
-  if(goto_location(p->nc, f, p->dimy, 0)){
+  if(goto_location(p->nc, f, p->dimy, 0, NULL)){
     return -1;
   }
   // terminals advertising 'bce' will scroll in the current background color;
@@ -1018,7 +1018,7 @@ rasterize_sprixels(notcurses* nc, ncpile* p, fbuf* f){
       if(nc->tcache.pixel_commit){
         int y, x;
         ncplane_abs_yx(s->n, &y, &x);
-        if(goto_location(nc, f, y + nc->margin_t, x + nc->margin_l)){
+        if(goto_location(nc, f, y + nc->margin_t, x + nc->margin_l, NULL)){
           return -1;
         }
         if(sprite_commit(&nc->tcache, f, s, false)){
@@ -1107,7 +1107,7 @@ rasterize_core(notcurses* nc, const ncpile* p, fbuf* f, unsigned phase){
         // was not above a sprixel (and the cell is damaged). in the second
         // phase, we draw everything that remains damaged.
         ++nc->stats.s.cellemissions;
-        if(goto_location(nc, f, y, x)){
+        if(goto_location(nc, f, y, x, rvec[damageidx].p)){
           return -1;
         }
         // set the style. this can change the color back to the default; if it
@@ -1322,7 +1322,7 @@ notcurses_rasterize(notcurses* nc, ncpile* p, fbuf* f){
   if(cursory >= 0){
     notcurses_cursor_enable(nc, cursory, cursorx);
   }else if(nc->rstate.logendy >= 0){
-    goto_location(nc, f, nc->rstate.logendy, nc->rstate.logendx);
+    goto_location(nc, f, nc->rstate.logendy, nc->rstate.logendx, NULL);
     if(fbuf_flush(f, nc->ttyfp)){
       ret = -1;
     }
@@ -1341,18 +1341,10 @@ int clear_and_home(notcurses* nc, tinfo* ti, fbuf* f){
       goto success;
     }
   }
-  const ncplane* stdn = notcurses_stdplane_const(nc);
-  // clearscr didn't fly. try scrolling everything off. first, go to the
-  // bottom of the screen, then write N newlines.
-  if(goto_location(nc, f, ncplane_dim_y(stdn) - 1, 0)){
+  if(emit_scrolls(ti, ncplane_dim_y(notcurses_stdplane_const(nc)), f)){
     return -1;
   }
-  for(int y = 0 ; y < ncplane_dim_y(stdn) ; ++y){
-    if(fbuf_putc(f, '\n') < 0){
-      return -1;
-    }
-  }
-  if(goto_location(nc, f, 0, 0)){
+  if(goto_location(nc, f, 0, 0, NULL)){
     return -1;
   }
 
@@ -1682,7 +1674,7 @@ int notcurses_cursor_enable(notcurses* nc, int y, int x){
     return -1;
   }
   // updates nc->rstate.cursor{y,x}
-  if(goto_location(nc, &f, y + nc->margin_t, x + nc->margin_l)){
+  if(goto_location(nc, &f, y + nc->margin_t, x + nc->margin_l, nc->rstate.lastsrcp)){
     fbuf_free(&f);
     return -1;
   }

src/lib/sixel.c

@@ -1010,7 +1010,7 @@ int sixel_draw(const tinfo* ti, const ncpile* p, sprixel* s, fbuf* f,
   if(p){
     const int targy = s->n->absy + yoff;
     const int targx = s->n->absx + xoff;
-    if(goto_location(p->nc, f, targy, targx)){
+    if(goto_location(p->nc, f, targy, targx, NULL)){
       return -1;
     }
     if(s->invalidated == SPRIXEL_MOVED){

src/lib/stats.c

@@ -204,10 +204,11 @@ void summarize_stats(notcurses* nc){
             1, minbuf, 1),
     bprefix(stats->renders ? stats->render_bytes / stats->renders : 0, 1, avgbuf, 1);
     bprefix(stats->render_max_bytes, 1, maxbuf, 1),
-    fprintf(stderr, "%s%sB (%sB min, %sB avg, %sB max) %"PRIu64" input%s" NL,
+    fprintf(stderr, "%s%sB (%sB min, %sB avg, %sB max) %"PRIu64" input%s Ghpa: %"PRIu64 NL,
             clreol, totalbuf, minbuf, avgbuf, maxbuf,
             stats->input_events,
-            stats->input_events == 1 ? "" : "s");
+            stats->input_events == 1 ? "" : "s",
+            stats->hpa_gratuitous);
   }
   fprintf(stderr, "%s%"PRIu64" failed render%s, %"PRIu64" failed raster%s, %"
                   PRIu64" refresh%s, %"PRIu64" input error%s" NL,
@@ -216,14 +217,13 @@ void summarize_stats(notcurses* nc){
           stats->refreshes, stats->refreshes == 1 ? "" : "es",
           stats->input_errors, stats->input_errors == 1 ? "" : "s");
   fprintf(stderr, "%sRGB emits:elides: def %"PRIu64":%"PRIu64" fg %"PRIu64":%"
-                  PRIu64" bg %"PRIu64":%"PRIu64" Ghpa: %"PRIu64 NL,
+                  PRIu64" bg %"PRIu64":%"PRIu64 NL,
           clreol, stats->defaultemissions,
           stats->defaultelisions,
           stats->fgemissions,
           stats->fgelisions,
           stats->bgemissions,
-          stats->bgelisions,
-          stats->hpa_gratuitous);
+          stats->bgelisions);
   fprintf(stderr, "%sCell emits:elides: %"PRIu64":%"PRIu64" (%.2f%%) %.2f%% %.2f%% %.2f%%" NL,
           clreol, stats->cellemissions, stats->cellelisions,
           (stats->cellemissions + stats->cellelisions) == 0 ? 0 :