raster: use terminfo indn to scroll multiple lines

src/info/main.c

@@ -400,6 +400,7 @@ tinfo_debug_styles(const notcurses* nc, struct ncplane* n, const char* indent){
   tinfo_debug_cap(n, "u7", get_escape(ti, ESCAPE_U7));
   tinfo_debug_cap(n, "ccc", ti->caps.can_change_colors);
   tinfo_debug_cap(n, "rgb", ti->caps.rgb);
+  tinfo_debug_cap(n, "csr", get_escape(ti, ESCAPE_CSR));
   finish_line(n);
   ncplane_putstr(n, indent);
   tinfo_debug_cap(n, "utf8", ti->caps.utf8);
@@ -408,6 +409,7 @@ tinfo_debug_styles(const notcurses* nc, struct ncplane* n, const char* indent){
   tinfo_debug_cap(n, "braille", ti->caps.braille);
   tinfo_debug_cap(n, "images", notcurses_canopen_images(nc));
   tinfo_debug_cap(n, "video", notcurses_canopen_videos(nc));
+  tinfo_debug_cap(n, "indn", get_escape(ti, ESCAPE_INDN));
   finish_line(n);
 }
 

src/lib/fbuf.h

@@ -282,7 +282,9 @@ static inline int
 fbuf_flush(fbuf* f, FILE* fp){
   int ret = 0;
   if(f->used){
-    if(blocking_write(fileno(fp), f->buf, f->used)){
+    if(fflush(fp) == EOF){
+      ret = -1;
+    }else if(blocking_write(fileno(fp), f->buf, f->used)){
       ret = -1;
     }
   }
@@ -296,7 +298,9 @@ static inline int
 fbuf_finalize(fbuf* f, FILE* fp){
   int ret = 0;
   if(f->used){
-    if(blocking_write(fileno(fp), f->buf, f->used)){
+    if(fflush(fp) == EOF){
+      ret = -1;
+    }else if(blocking_write(fileno(fp), f->buf, f->used)){
       ret = -1;
     }
   }

src/lib/render.c

@@ -935,8 +935,22 @@ rasterize_scrolls(ncpile* p, fbuf* f){
       return -1;
     }
   }
-  while(p->scrolls){
-    if(fbuf_putc(f, '\n') < 0){
+  if(p->scrolls > 1){
+    const char* indn = get_escape(&p->nc->tcache, ESCAPE_INDN);
+    if(indn){
+      if(fbuf_emit(f, tiparm(indn, p->scrolls)) < 0){
+        return -1;
+      }
+      p->scrolls = 0;
+      return 0;
+    }
+  }
+  const char* ind = get_escape(&p->nc->tcache, ESCAPE_IND);
+  if(ind == NULL){
+    ind = "\v";
+  }
+  while(p->scrolls > 0){
+    if(fbuf_emit(f, ind) < 0){
       return -1;
     }
     --p->scrolls;

src/lib/termdesc.c

@@ -775,7 +775,10 @@ int interrogate_terminfo(tinfo* ti, const char* termtype, FILE* out, unsigned ut
     { ESCAPE_RMUL, "rmul", },
     { ESCAPE_SC, "sc", },
     { ESCAPE_RC, "rc", },
+    { ESCAPE_IND, "ind", },
+    { ESCAPE_INDN, "indn", },
     { ESCAPE_CLEAR, "clear", },
+    { ESCAPE_CSR, "csr", },
     { ESCAPE_OC, "oc", },
     { ESCAPE_RMKX, "rmkx", },
     { ESCAPE_U7, "u7", },

src/lib/termdesc.h

@@ -60,12 +60,15 @@ typedef enum {
   ESCAPE_SMULX,   // "Smulx" deparameterized: start extended underline
   ESCAPE_SMULNOX, // "Smulx" deparameterized: kill underline
   ESCAPE_RMXX,    // "rmxx" end struckout
+  ESCAPE_IND,     // "ind" scroll 1 line up
+  ESCAPE_INDN,    // "indn" scroll n lines up
   ESCAPE_SC,      // "sc" push the cursor onto the stack
   ESCAPE_RC,      // "rc" pop the cursor off the stack
   ESCAPE_CLEAR,   // "clear" clear screen and home cursor
   ESCAPE_INITC,   // "initc" set up palette entry
   ESCAPE_GETM,    // "getm" get mouse events
   ESCAPE_U7,      // "u7" cursor position report
+  ESCAPE_CSR,     // "csr" change scroll region
   // Application synchronized updates, not present in terminfo
   // (https://gitlab.com/gnachman/iterm2/-/wikis/synchronized-updates-spec)
   ESCAPE_BSUM,     // Begin Synchronized Update Mode