[groff] 04/05: [grotty]: Slightly refactor.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 3e9b214a881b7cb5ca339505a985ab4f3113fe4b
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Fri Oct 8 19:24:51 2021 +1100

    [grotty]: Slightly refactor.
    
    * src/devices/grotty/tty.cpp: Boolify.  Demote numerous variables (and
      one return type) from `int` to `bool`, use Boolean insted of integer
      literals with them, and give the variables names resembling logical
      predicates.
      - horizontal_tab_flag -> want_horizontal_tabs
      - form_feed_flag -> want_form_feeds
      - bold_flag_option -> want_emboldening_by_overstriking
      - bold_flag -> do_bold
      - underline_flag_option -> want_italics_by_underlining
      - underline_flag -> do_underline
      - overstrike_flag -> want_glyph_composition_by_overstriking
      - draw_flag -> allow_drawing_commands
      - italic_flag_option -> want_sgr_italics
      - italic_flag -> do_sgr_italics
      - reverse_flag_option -> want_reverse_video_for_italics
      - reverse_flag -> do_reverse_video
      - old_drawing_scheme -> use_overstriking_drawing_scheme
    
      (class tty_printer:printer): Similarly.
      - is_underline -> is_underlining
      - is_bold -> is_boldfacing
      - cu_flag -> is_continuously_underlining
    
      (tty_printer::tty_color): Demote return type as above.  Invert
      its sense; rename `unknown_color` to `is_known_color`.
    
      (tty_printer::color_to_idx): Invert sense of test at `tty_color()`
      call site.
---
 ChangeLog                  |  30 ++++++++
 src/devices/grotty/tty.cpp | 181 +++++++++++++++++++++++----------------------
 2 files changed, 121 insertions(+), 90 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 86e457a..c67290b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,33 @@
+2021-10-08  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       [grotty]: Slightly refactor.
+
+       * src/devices/grotty/tty.cpp: Boolify.  Demote numerous
+       variables (and one return type) from `int` to `bool`, use
+       Boolean insted of integer literals with them, and give the
+       variables names resembling logical predicates.
+        - horizontal_tab_flag -> want_horizontal_tabs
+        - form_feed_flag -> want_form_feeds
+        - bold_flag_option -> want_emboldening_by_overstriking
+        - bold_flag -> do_bold
+        - underline_flag_option -> want_italics_by_underlining
+        - underline_flag -> do_underline
+        - overstrike_flag -> want_glyph_composition_by_overstriking
+        - draw_flag -> allow_drawing_commands
+        - italic_flag_option -> want_sgr_italics
+        - italic_flag -> do_sgr_italics
+        - reverse_flag_option -> want_reverse_video_for_italics
+        - reverse_flag -> do_reverse_video
+        - old_drawing_scheme -> use_overstriking_drawing_scheme
+       (class tty_printer:printer): Similarly.
+        - is_underline -> is_underlining
+        - is_bold -> is_boldfacing
+        - cu_flag -> is_continuously_underlining
+       (tty_printer::tty_color): Demote return type as above.  Invert
+       its sense; rename `unknown_color` to `is_known_color`.
+       (tty_printer::color_to_idx): Invert sense of test at
+       `tty_color()` call site.
+
 2021-10-06  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        [grotty]: Slightly refactor.
diff --git a/src/devices/grotty/tty.cpp b/src/devices/grotty/tty.cpp
index a71217e..a440142 100644
--- a/src/devices/grotty/tty.cpp
+++ b/src/devices/grotty/tty.cpp
@@ -43,19 +43,19 @@ extern "C" const char *Version_string;
 // A character of the output device fits in a 32-bit word.
 typedef unsigned int output_character;
 
-static int horizontal_tab_flag = 0;
-static int form_feed_flag = 0;
-static int bold_flag_option = 1;
-static int bold_flag;
-static int underline_flag_option = 1;
-static int underline_flag;
-static int overstrike_flag = 1;
-static int draw_flag = 1;
-static int italic_flag_option = 0;
-static int italic_flag;
-static int reverse_flag_option = 0;
-static int reverse_flag;
-static int old_drawing_scheme = 0;
+static bool want_horizontal_tabs = false;
+static bool want_form_feeds = false;
+static bool want_emboldening_by_overstriking = true;
+static bool do_bold;
+static bool want_italics_by_underlining = true;
+static bool do_underline;
+static bool want_glyph_composition_by_overstriking = true;
+static bool allow_drawing_commands = true;
+static bool want_sgr_italics = false;
+static bool do_sgr_italics;
+static bool want_reverse_video_for_italics = false;
+static bool do_reverse_video;
+static bool use_overstriking_drawing_scheme = false;
 
 static void update_options();
 static void usage(FILE *stream);
@@ -127,9 +127,9 @@ tty_font *tty_font::load_tty_font(const char *s)
   long n;
   if (num != 0 && (n = strtol(num, 0, 0)) != 0)
     f->mode = (unsigned char)(n & (BOLD_MODE|UNDERLINE_MODE));
-  if (!underline_flag)
+  if (!do_underline)
     f->mode &= ~UNDERLINE_MODE;
-  if (!bold_flag)
+  if (!do_bold)
     f->mode &= ~BOLD_MODE;
   if ((f->mode & (BOLD_MODE|UNDERLINE_MODE)) == (BOLD_MODE|UNDERLINE_MODE))
     f->mode = (unsigned char)((f->mode & ~(BOLD_MODE|UNDERLINE_MODE))
@@ -178,9 +178,9 @@ class tty_printer : public printer {
   int cached_vpos;
   schar curr_fore_idx;
   schar curr_back_idx;
-  int is_underline;
-  int is_bold;
-  int cu_flag;
+  bool is_underlining;
+  bool is_boldfacing;
+  bool is_continuously_underlining;
   PTABLE(schar) tty_colors;
   void make_underline(int);
   void make_bold(output_character, int);
@@ -189,8 +189,8 @@ class tty_printer : public printer {
                unsigned char);
   void simple_add_char(const output_character, const environment *);
   char *make_rgb_string(unsigned int, unsigned int, unsigned int);
-  int tty_color(unsigned int, unsigned int, unsigned int, schar *,
-               schar = DEFAULT_COLOR_IDX);
+  bool tty_color(unsigned int, unsigned int, unsigned int, schar *,
+                schar = DEFAULT_COLOR_IDX);
   void line(int, int, int, int, color *, color *);
   void draw_line(int *, int, const environment *);
   void draw_polygon(int *, int, const environment *);
@@ -232,22 +232,22 @@ char *tty_printer::make_rgb_string(unsigned int r,
   return s;
 }
 
-int tty_printer::tty_color(unsigned int r,
-                          unsigned int g,
-                          unsigned int b, schar *idx, schar value)
+bool tty_printer::tty_color(unsigned int r,
+                           unsigned int g,
+                           unsigned int b, schar *idx, schar value)
 {
-  int unknown_color = 0;
+  bool is_known_color = true;
   char *s = make_rgb_string(r, g, b);
   schar *i = tty_colors.lookup(s);
   if (!i) {
-    unknown_color = 1;
+    is_known_color = false;
     i = new schar[1];
     *i = value;
     tty_colors.define(s, i);
   }
   *idx = *i;
   delete[] s;
-  return unknown_color;
+  return is_known_color;
 }
 
 tty_printer::tty_printer() : cached_v(0)
@@ -274,7 +274,7 @@ tty_printer::tty_printer() : cached_v(0)
   lines = new tty_glyph *[nlines];
   for (int i = 0; i < nlines; i++)
     lines[i] = 0;
-  cu_flag = 0;
+  is_continuously_underlining = false;
 }
 
 tty_printer::~tty_printer()
@@ -284,7 +284,7 @@ tty_printer::~tty_printer()
 
 void tty_printer::make_underline(int w)
 {
-  if (old_drawing_scheme) {
+  if (use_overstriking_drawing_scheme) {
     if (!w)
       warning("can't underline zero-width character");
     else {
@@ -293,21 +293,21 @@ void tty_printer::make_underline(int w)
     }
   }
   else {
-    if (!is_underline) {
-      if (italic_flag)
+    if (!is_underlining) {
+      if (do_sgr_italics)
        putstring(SGR_ITALIC);
-      else if (reverse_flag)
+      else if (do_reverse_video)
        putstring(SGR_REVERSE);
       else
        putstring(SGR_UNDERLINE);
     }
-    is_underline = 1;
+    is_underlining = true;
   }
 }
 
 void tty_printer::make_bold(output_character c, int w)
 {
-  if (old_drawing_scheme) {
+  if (use_overstriking_drawing_scheme) {
     if (!w)
       warning("can't print zero-width character in bold");
     else {
@@ -316,9 +316,9 @@ void tty_printer::make_bold(output_character c, int w)
     }
   }
   else {
-    if (!is_bold)
+    if (!is_boldfacing)
       putstring(SGR_BOLD);
-    is_bold = 1;
+    is_boldfacing = true;
   }
 }
 
@@ -329,9 +329,9 @@ schar tty_printer::color_to_idx(color *col)
   unsigned int r, g, b;
   col->get_rgb(&r, &g, &b);
   schar idx;
-  if (tty_color(r, g, b, &idx)) {
+  if (!tty_color(r, g, b, &idx)) {
     char *s = col->print_color();
-    error("Unknown color (%1) mapped to default", s);
+    error("unrecognized color '%1' mapped to default", s);
     delete[] s;
   }
   return idx;
@@ -450,9 +450,9 @@ void tty_printer::special(char *arg, const environment 
*env, char type)
       ;
     int n;
     if (*p != '\0' && sscanf(p, "%d", &n) == 1 && n == 0)
-      old_drawing_scheme = 1;
+      use_overstriking_drawing_scheme = true;
     else
-      old_drawing_scheme = 0;
+      use_overstriking_drawing_scheme = false;
     update_options();
   }
   else if (strncmp(command, "link", p - command) == 0)
@@ -468,7 +468,7 @@ void tty_printer::special(char *arg, const environment 
*env, char type)
 void tty_printer::special_link(const char *arg, const environment *env)
 {
   static bool is_link_active = false;
-  if (old_drawing_scheme)
+  if (use_overstriking_drawing_scheme)
     return;
   for (const char *s = OSC8; *s != '\0'; s++)
     simple_add_char(*s, env);
@@ -541,7 +541,7 @@ void tty_printer::change_fill_color(const environment * 
const env)
 
 void tty_printer::draw(int code, int *p, int np, const environment *env)
 {
-  if (!draw_flag)
+  if (!allow_drawing_commands)
     return;
   if (code == 'l')
     draw_line(p, np, env);
@@ -682,12 +682,12 @@ void tty_printer::put_color(schar color_index, int back)
   if (color_index == DEFAULT_COLOR_IDX) {
     putstring(SGR_DEFAULT);
     // set bold and underline again
-    if (is_bold)
+    if (is_boldfacing)
       putstring(SGR_BOLD);
-    if (is_underline) {
-      if (italic_flag)
+    if (is_underlining) {
+      if (do_sgr_italics)
        putstring(SGR_ITALIC);
-      else if (reverse_flag)
+      else if (do_reverse_video)
        putstring(SGR_REVERSE);
       else
        putstring(SGR_UNDERLINE);
@@ -757,12 +757,12 @@ void tty_printer::end_page(int page_length)
     tty_glyph *nextp;
     curr_fore_idx = DEFAULT_COLOR_IDX;
     curr_back_idx = DEFAULT_COLOR_IDX;
-    is_underline = 0;
-    is_bold = 0;
+    is_underlining = false;
+    is_boldfacing = false;
     for (p = g; p; delete p, p = nextp) {
       nextp = p->next;
       if (p->mode & CU_MODE) {
-       cu_flag = (p->code != 0);
+       is_continuously_underlining = (p->code != 0);
        continue;
       }
       if (nextp && p->hpos == nextp->hpos) {
@@ -780,7 +780,7 @@ void tty_printer::end_page(int page_length)
          nextp->code = p->code;
          continue;
        }
-       if (!overstrike_flag)
+       if (!want_glyph_composition_by_overstriking)
          continue;
       }
       if (hpos > p->hpos) {
@@ -790,44 +790,45 @@ void tty_printer::end_page(int page_length)
        } while (hpos > p->hpos);
       }
       else {
-       if (horizontal_tab_flag) {
+       if (want_horizontal_tabs) {
          for (;;) {
            int next_tab_pos = ((hpos + TAB_WIDTH) / TAB_WIDTH) * TAB_WIDTH;
            if (next_tab_pos > p->hpos)
              break;
-           if (cu_flag)
+           if (is_continuously_underlining)
              make_underline(p->w);
-           else if (!old_drawing_scheme && is_underline) {
-             if (italic_flag)
+           else if (!use_overstriking_drawing_scheme
+                    && is_underlining) {
+             if (do_sgr_italics)
                putstring(SGR_NO_ITALIC);
-             else if (reverse_flag)
+             else if (do_reverse_video)
                putstring(SGR_NO_REVERSE);
              else
                putstring(SGR_NO_UNDERLINE);
-             is_underline = 0;
+             is_underlining = false;
            }
            putchar('\t');
            hpos = next_tab_pos;
          }
        }
        for (; hpos < p->hpos; hpos++) {
-         if (cu_flag)
+         if (is_continuously_underlining)
            make_underline(p->w);
-         else if (!old_drawing_scheme && is_underline) {
-           if (italic_flag)
+         else if (!use_overstriking_drawing_scheme && is_underlining) {
+           if (do_sgr_italics)
              putstring(SGR_NO_ITALIC);
-           else if (reverse_flag)
+           else if (do_reverse_video)
              putstring(SGR_NO_REVERSE);
            else
              putstring(SGR_NO_UNDERLINE);
-           is_underline = 0;
+           is_underlining = false;
          }
          putchar(' ');
        }
       }
       assert(hpos == p->hpos);
       if (p->mode & COLOR_CHANGE) {
-       if (!old_drawing_scheme) {
+       if (!use_overstriking_drawing_scheme) {
          if (p->fore_color_idx != curr_fore_idx) {
            put_color(p->fore_color_idx, 0);
            curr_fore_idx = p->fore_color_idx;
@@ -841,22 +842,22 @@ void tty_printer::end_page(int page_length)
       }
       if (p->mode & UNDERLINE_MODE)
        make_underline(p->w);
-      else if (!old_drawing_scheme && is_underline) {
-       if (italic_flag)
+      else if (!use_overstriking_drawing_scheme && is_underlining) {
+       if (do_sgr_italics)
          putstring(SGR_NO_ITALIC);
-       else if (reverse_flag)
+       else if (do_reverse_video)
          putstring(SGR_NO_REVERSE);
        else
          putstring(SGR_NO_UNDERLINE);
-       is_underline = 0;
+       is_underlining = false;
       }
       if (p->mode & BOLD_MODE)
        make_bold(p->code, p->w);
-      else if (!old_drawing_scheme && is_bold) {
+      else if (!use_overstriking_drawing_scheme && is_boldfacing) {
        putstring(SGR_NO_BOLD);
-       is_bold = 0;
+       is_boldfacing = false;
       }
-      if (!old_drawing_scheme) {
+      if (!use_overstriking_drawing_scheme) {
        if (p->fore_color_idx != curr_fore_idx) {
          put_color(p->fore_color_idx, 0);
          curr_fore_idx = p->fore_color_idx;
@@ -869,14 +870,14 @@ void tty_printer::end_page(int page_length)
       put_char(p->code);
       hpos += p->w / font::hor;
     }
-    if (!old_drawing_scheme
-       && (is_bold || is_underline
+    if (!use_overstriking_drawing_scheme
+       && (is_boldfacing || is_underlining
            || curr_fore_idx != DEFAULT_COLOR_IDX
            || curr_back_idx != DEFAULT_COLOR_IDX))
       putstring(SGR_DEFAULT);
     putchar('\n');
   }
-  if (form_feed_flag) {
+  if (want_form_feeds) {
     if (last_line < lines_per_page)
       putchar('\f');
   }
@@ -898,19 +899,19 @@ printer *make_printer()
 
 static void update_options()
 {
-  if (old_drawing_scheme) {
-    italic_flag = 0;
-    reverse_flag = 0;
+  if (use_overstriking_drawing_scheme) {
+    do_sgr_italics = false;
+    do_reverse_video = false;
     bold_underline_mode = bold_underline_mode_option;
-    bold_flag = bold_flag_option;
-    underline_flag = underline_flag_option;
+    do_bold = want_emboldening_by_overstriking;
+    do_underline = want_italics_by_underlining;
   }
   else {
-    italic_flag = italic_flag_option;
-    reverse_flag = reverse_flag_option;
+    do_sgr_italics = want_sgr_italics;
+    do_reverse_video = want_reverse_video_for_italics;
     bold_underline_mode = BOLD_MODE|UNDERLINE_MODE;
-    bold_flag = 1;
-    underline_flag = 1;
+    do_bold = true;
+    do_underline = true;
   }
 }
 
@@ -919,7 +920,7 @@ int main(int argc, char **argv)
   program_name = argv[0];
   static char stderr_buf[BUFSIZ];
   if (getenv("GROFF_NO_SGR"))
-    old_drawing_scheme = 1;
+    use_overstriking_drawing_scheme = true;
   setbuf(stderr, stderr_buf);
   setlocale(LC_CTYPE, "");
   int c;
@@ -937,30 +938,30 @@ int main(int argc, char **argv)
       break;
     case 'i':
       // Use italic font instead of underlining.
-      italic_flag_option = 1;
+      want_sgr_italics = true;
       break;
     case 'I':
       // ignore include search path
       break;
     case 'b':
       // Do not embolden by overstriking.
-      bold_flag_option = 0;
+      want_emboldening_by_overstriking = false;
       break;
     case 'c':
       // Use old scheme for emboldening and underline.
-      old_drawing_scheme = 1;
+      use_overstriking_drawing_scheme = true;
       break;
     case 'u':
       // Do not underline.
-      underline_flag_option = 0;
+      want_italics_by_underlining = false;
       break;
     case 'o':
       // Do not overstrike (other than emboldening and underlining).
-      overstrike_flag = 0;
+      want_glyph_composition_by_overstriking = false;
       break;
     case 'r':
       // Use reverse mode instead of underlining.
-      reverse_flag_option = 1;
+      want_reverse_video_for_italics = true;
       break;
     case 'B':
       // Do bold-underlining as bold.
@@ -972,17 +973,17 @@ int main(int argc, char **argv)
       break;
     case 'h':
       // Use horizontal tabs.
-      horizontal_tab_flag = 1;
+      want_horizontal_tabs = true;
       break;
     case 'f':
-      form_feed_flag = 1;
+      want_form_feeds = true;
       break;
     case 'F':
       font::command_line_font_dir(optarg);
       break;
     case 'd':
       // Ignore \D commands.
-      draw_flag = 0;
+      allow_drawing_commands = false;
       break;
     case CHAR_MAX + 1: // --help
       usage(stdout);