Simplify display output and fix bug with bce status

terminaldisplay.cpp

@@ -49,19 +49,18 @@ std::string Display::new_frame( Framebuffer &f )
   /* iterate for every cell */
   for ( int y = 0; y < f.ds.get_height(); y++ ) {
     for ( int x = 0; x < f.ds.get_width(); /* let charwidth handle advance */ ) {
-      std::string cell_string;
       Cell *cell = f.get_cell( y, x );
-      bool different = false;
+
+      if ( initialized
+	   && ( *cell == *(last_frame.get_cell( y, x )) ) ) {
+	x += cell->width;
+	continue;
+      }
 
       char curmove[ 32 ];
       snprintf( curmove, 32, "\033[%d;%dH", y + 1, x + 1 );
-      cell_string.append( curmove );
+      screen.append( curmove );
-
+      cursor_was_moved = true;
-      /* have renditions changed? */
-      if ( (!initialized)
-	   || (cell->renditions != last_frame.get_cell( y, x )->renditions) ) {
-	different = true;
-      }
 
       std::vector<int> cell_print_renditions;
       cell_print_renditions = cell->renditions;
@@ -69,53 +68,35 @@ std::string Display::new_frame( Framebuffer &f )
 
       if ( cell_print_renditions != current_renditions ) {
 	/* print renditions */
-	cell_string.append( "\033[0" );
+	screen.append( "\033[0" );
 	char rendition[ 32 ];
 	for ( std::vector<int>::iterator i = cell->renditions.begin();
 	      i != cell->renditions.end();
 	      i++ ) {
 	  snprintf( rendition, 32, ";%d", *i );
-	  cell_string.append( rendition );
+	  screen.append( rendition );
 	}
-	cell_string.append( "m" );
+	screen.append( "m" );
+
+	current_renditions = cell_print_renditions;
       }
 
       /* clear cell */
-      cell_string.append( "\033[X" );
+      screen.append( "\033[X" );
-
-      /* did fallback status change? */
-      if ( (!initialized)
-	   || (cell->fallback != last_frame.get_cell( y, x )->fallback) ) {
-	different = true;
-      }
 
       /* cells that begin with combining character get combiner attached to no-break space */
       if ( cell->fallback ) {
 	char utf8[ 8 ];
 	snprintf( utf8, 8, "%lc", 0xA0 );
-	cell_string.append( utf8 );
+	screen.append( utf8 );
       }
 
-      /* have cell contents changed? */
-      if ( (!initialized)
-	   || (cell->contents != last_frame.get_cell( y, x )->contents) ) {
-	different = true;
-      }
-
-      /* always restrike the cell contents if anything changed */
       for ( std::vector<wchar_t>::iterator i = cell->contents.begin();
 	    i != cell->contents.end();
 	    i++ ) {
 	char utf8[ 8 ];
 	snprintf( utf8, 8, "%lc", *i );
-	cell_string.append( utf8 );
+	screen.append( utf8 );
-      }
-
-      /* if anything changed, redo cell */
-      if ( different ) {
-	screen.append( cell_string );
-	cursor_was_moved = true;
-	current_renditions = cell_print_renditions;
       }
 
       x += cell->width;

terminalframebuffer.cpp

@@ -25,6 +25,17 @@ void Cell::reset( void )
   need_back_color_erase = true;
 }
 
+bool Cell::operator==( const Cell &x )
+{
+  assert( !need_back_color_erase );
+  assert( !x.need_back_color_erase );
+
+  return ( (contents == x.contents)
+	   && (fallback == x.fallback)
+	   && (width == x.width)
+	   && (renditions == x.renditions) );
+}
+
 DrawState::DrawState( int s_width, int s_height )
   : width( s_width ), height( s_height ),
     cursor_col( 0 ), cursor_row( 0 ),
@@ -412,16 +423,14 @@ void Framebuffer::back_color_erase( void )
 {
   int bg_color = ds.get_background_rendition();
 
-  if ( bg_color < 0 ) {
-    return;
-  }
-
   for ( int row = 0; row < ds.get_height(); row++ ) {
     for ( int col = 0; col < ds.get_width(); col++ ) {
       Cell *cell = get_cell( row, col );
       if ( cell->need_back_color_erase ) {
 	assert( cell->renditions.empty() );
-	cell->renditions.push_back( bg_color );
+	if ( bg_color > 0 ) {
+	  cell->renditions.push_back( bg_color );
+	}
 	cell->need_back_color_erase = false;
       }
     }

terminalframebuffer.hpp

@@ -19,6 +19,8 @@ namespace Terminal {
     Cell();
 
     void reset( void );
+
+    bool operator==( const Cell &x );
   };
 
   class Row {