support alternative fonts, using ECMA-48 SGR codes

docs/mintty.1

@@ -821,6 +821,14 @@ If a font family has no bold weight but boldness was requested, mintty
 does not adhere to this scheme but enforces bold font selection; however, 
 in this case the bold attribute may not be effective.
 .br
+\(en \fBAlternative fonts\fP (Font1= ... Font9= , Font1Weight= ... Font9Weight=):
+With these settings, up to 9 alternative fonts (and optionally weights) 
+can be configured which would then be selectable via ECMA-48 SGR character attributes 
+(see Tips wiki page \fIhttps://github.com/mintty/mintty/wiki/Tips#text-attributes-and-rendering\fP).
+\fINote:\fP The control sequence for alternative font 1 overrides the identical 
+control sequence to select the VGA character set, which would thus be disabled. 
+Configuring alternative font 1 is therefore discouraged.
+.br
 \(en \fBFont sample text\fP (FontSample=):
 This setting overrides the text for the "Sample" box in the Font chooser dialog.
 .br

src/config.c

@@ -50,6 +50,15 @@ const config default_cfg = {
   .cursor_blinks = true,
   // Text
   .font = {.name = W("Lucida Console"), .size = 9, .weight = 400, .isbold = false},
+  .fontfams[1] = {.name = W(""), .weight = 400, .isbold = false},
+  .fontfams[2] = {.name = W(""), .weight = 400, .isbold = false},
+  .fontfams[3] = {.name = W(""), .weight = 400, .isbold = false},
+  .fontfams[4] = {.name = W(""), .weight = 400, .isbold = false},
+  .fontfams[5] = {.name = W(""), .weight = 400, .isbold = false},
+  .fontfams[6] = {.name = W(""), .weight = 400, .isbold = false},
+  .fontfams[7] = {.name = W(""), .weight = 400, .isbold = false},
+  .fontfams[8] = {.name = W(""), .weight = 400, .isbold = false},
+  .fontfams[9] = {.name = W(""), .weight = 400, .isbold = false},
   .font_sample = W(""),
   .show_hidden_fonts = false,
   .font_smoothing = FS_DEFAULT,
@@ -223,6 +232,24 @@ options[] = {
   {"FontRender", OPT_FONTRENDER, offcfg(font_render)},
   {"FontMenu", OPT_INT, offcfg(fontmenu)},
   {"OldFontMenu", OPT_INT | OPT_LEGACY, offcfg(fontmenu)},
+  {"Font1", OPT_WSTRING, offcfg(fontfams[1].name)},
+  {"Font1Weight", OPT_INT, offcfg(fontfams[1].weight)},
+  {"Font2", OPT_WSTRING, offcfg(fontfams[2].name)},
+  {"Font2Weight", OPT_INT, offcfg(fontfams[2].weight)},
+  {"Font3", OPT_WSTRING, offcfg(fontfams[3].name)},
+  {"Font3Weight", OPT_INT, offcfg(fontfams[3].weight)},
+  {"Font4", OPT_WSTRING, offcfg(fontfams[4].name)},
+  {"Font4Weight", OPT_INT, offcfg(fontfams[4].weight)},
+  {"Font5", OPT_WSTRING, offcfg(fontfams[5].name)},
+  {"Font5Weight", OPT_INT, offcfg(fontfams[5].weight)},
+  {"Font6", OPT_WSTRING, offcfg(fontfams[6].name)},
+  {"Font6Weight", OPT_INT, offcfg(fontfams[6].weight)},
+  {"Font7", OPT_WSTRING, offcfg(fontfams[7].name)},
+  {"Font7Weight", OPT_INT, offcfg(fontfams[7].weight)},
+  {"Font8", OPT_WSTRING, offcfg(fontfams[8].name)},
+  {"Font8Weight", OPT_INT, offcfg(fontfams[8].weight)},
+  {"Font9", OPT_WSTRING, offcfg(fontfams[9].name)},
+  {"Font9Weight", OPT_INT, offcfg(fontfams[9].weight)},
 
   // Keys
   {"BackspaceSendsBS", OPT_BOOL, offcfg(backspace_sends_bs)},

src/config.h

@@ -56,6 +56,7 @@ typedef struct {
   bool cursor_blinks;
   // Text
   font_spec font;
+  font_spec fontfams[10];
   wstring font_sample;
   bool show_hidden_fonts;
   char font_smoothing;

src/term.h

@@ -106,6 +106,9 @@ enum {
   GRAPH_MASK      = 0x00FF00000000u,
   ATTR_GRAPH_SHIFT = 32,
 
+  FONTFAM_MASK    = 0xF0000000000000u,
+  ATTR_FONTFAM_SHIFT = 52,
+
   TATTR_RIGHTCURS = 0x010000000000u, /* cursor-on-RHS */
   TATTR_PASCURS   = 0x020000000000u, /* passive cursor (box) */
   TATTR_ACTCURS   = 0x040000000000u, /* active cursor (block) */
@@ -275,11 +278,11 @@ typedef struct {
   bool autowrap;  // switchable (xterm Wraparound Mode (DECAWM Auto Wrap))
   bool wrapnext;
   bool rev_wrap;  // switchable (xterm Reverse-wraparound Mode)
-  bool utf;
   short g0123;
   term_cset csets[4];
   term_cset cset_single;
   uchar oem_acs;
+  bool utf;
 } term_cursor;
 
 typedef struct {

src/termline.c

@@ -244,7 +244,8 @@ makeliteral_attr(struct buf *b, termchar *c)
   */
   uint colourbits;
   uint attr = c->attr.attr;
-  uint graph = c->attr.attr >> ATTR_GRAPH_SHIFT;
+  uchar graph = c->attr.attr >> ATTR_GRAPH_SHIFT;
+  uchar ff = c->attr.attr >> ATTR_FONTFAM_SHIFT;
   uint truefg = c->attr.truefg;
   uint truebg = c->attr.truebg;
 
@@ -263,7 +264,7 @@ makeliteral_attr(struct buf *b, termchar *c)
 
   attr |= (colourbits << (32 - 9));
 
-  if (attr < 0x8000) {
+  if (attr < 0x8000 && !ff && !graph) {
     add(b, (uchar) ((attr >> 8) & 0xFF));
     add(b, (uchar) (attr & 0xFF));
   }
@@ -272,8 +273,9 @@ makeliteral_attr(struct buf *b, termchar *c)
     add(b, (uchar) ((attr >> 16) & 0xFF));
     add(b, (uchar) ((attr >> 8) & 0xFF));
     add(b, (uchar) (attr & 0xFF));
+    add(b, ff);
+    add(b, graph);
   }
-  add(b, graph);
 
   add(b, (uchar) ((truefg >> 16) & 0xFF));
   add(b, (uchar) ((truefg >> 8) & 0xFF));
@@ -329,6 +331,8 @@ readliteral_attr(struct buf *b, termchar *c, termline *unused(line))
   unsigned long long val, attr;
   uint colourbits;
   uint fg, bg;
+  uchar ff = 0;
+  uchar graph = 0;
 
   val = get(b) << 8;
   val |= get(b);
@@ -337,8 +341,9 @@ readliteral_attr(struct buf *b, termchar *c, termline *unused(line))
     val <<= 16;
     val |= get(b) << 8;
     val |= get(b);
+    ff = get(b);
+    graph = get(b);
   }
-  uint graph = get(b);
 
   colourbits = (val >> (32 - 9)) & 0xFF;
   attr = (val & ((1 << (32 - 9)) - 1));
@@ -361,6 +366,7 @@ readliteral_attr(struct buf *b, termchar *c, termline *unused(line))
   bg |= get(b);
 
   attr |= (unsigned long long)graph << ATTR_GRAPH_SHIFT;
+  attr |= (unsigned long long)ff << ATTR_FONTFAM_SHIFT;
 
   c->attr.attr = attr;
   c->attr.truefg = fg;

src/termout.c

@@ -530,14 +530,29 @@ do_sgr(void)
       when 7: attr.attr |= ATTR_REVERSE;
       when 8: attr.attr |= ATTR_INVISIBLE;
       when 9: attr.attr |= ATTR_STRIKEOUT;
-      when 10 ... 11:  // ... 12 disabled
+      when 10 ... 11: {  // ... 12 disabled
         // mode 10 is the configured Character set
         // mode 11 is the VGA character set (CP437 + control range graphics)
         // mode 12 is a weird feature from the Linux console,
         // cloning the VGA character set (CP437) into the ASCII range;
-        // should we disable it? (not supported by cygwin console)
-        term.curs.oem_acs = term.csi_argv[i] - 10;
-        term_update_cs();
+        // disabled (not supported by cygwin console);
+        // modes 11 (and 12) are overridden by alternate font setting
+        // if configured
+          uchar arg_10 = term.csi_argv[i] - 10;
+          if (arg_10 && *cfg.fontfams[arg_10].name) {
+            attr.attr &= ~FONTFAM_MASK;
+            attr.attr |= (unsigned long long)arg_10 << ATTR_FONTFAM_SHIFT;
+          }
+          else {
+            if (!arg_10)
+              attr.attr &= ~FONTFAM_MASK;
+            term.curs.oem_acs = arg_10;
+            term_update_cs();
+          }
+        }
+      when 12 ... 19:
+        attr.attr &= ~FONTFAM_MASK;
+        attr.attr |= (unsigned long long)(term.csi_argv[i] - 10) << ATTR_FONTFAM_SHIFT;
       //when 21: attr.attr &= ~ATTR_BOLD;
       when 21: attr.attr |= ATTR_DOUBLYUND;
       when 22: attr.attr &= ~(ATTR_BOLD | ATTR_DIM);
@@ -1637,7 +1652,7 @@ term_write(const char *buf, uint len)
         switch (cset) {
           when CSET_LINEDRW:  // VT100 line drawing characters
             if (0x60 <= wc && wc <= 0x7E) {
-              wchar dispwc = win_linedraw_chars[wc - 0x60];
+              wchar dispwc = win_linedraw_char(wc - 0x60);
 #define draw_vt100_line_drawing_chars
 #ifdef draw_vt100_line_drawing_chars
               if ('j' <= wc && wc <= 'x') {

src/win.h

@@ -85,6 +85,6 @@ extern int cursor_blink_ticks(void);
 extern int win_char_width(xchar);
 extern wchar win_combine_chars(wchar bc, wchar cc);
 
-extern wchar win_linedraw_chars[31];
+extern wchar win_linedraw_char(int i);
 
 #endif

src/winctrls.c

@@ -812,17 +812,12 @@ winctrl_layout(winctrls *wc, ctrlpos *cp, controlset *s, int *id)
         staticbtn(&pos, "", base_id + 1, _("&Select..."), base_id + 2);
         data = new(font_spec);
 
-        num_ids++;
-        char * fontinfopat = "Leading: %d, Bold: %s, Underline: %s";
-        char * fontinfo_font = "font";
-        char * fontinfo_manual = "manual";
-        int taglen = max(strlen(fontinfo_font), strlen(fontinfo_manual));
-        char * fontinfo = newn(char, strlen(fontinfopat) + 23 + 2 * taglen);
-        sprintf(fontinfo, fontinfopat, row_spacing, 
-                bold_mode ? fontinfo_font : fontinfo_manual,
-                und_mode ? fontinfo_font : fontinfo_manual);
-        statictext(&pos, fontinfo, base_id + 3);
-        free(fontinfo);
+        char * fontinfo = fontpropinfo();
+        if (fontinfo) {
+          num_ids++;
+          statictext(&pos, fontinfo, base_id + 3);
+          free(fontinfo);
+        }
       }
       otherwise:
         assert(!"Can't happen");

src/winpriv.h

@@ -25,12 +25,7 @@ extern int cell_width, cell_height;  // includes spacing
 extern int PADDING;
 extern bool show_charinfo;
 extern void toggle_charinfo(void);
-// for display in Options – Font:
-extern int row_spacing;
-typedef enum {BOLD_SHADOW, BOLD_FONT} BOLD_MODE;
-extern BOLD_MODE bold_mode;
-typedef enum {UND_LINE, UND_FONT} UND_MODE;
-extern UND_MODE und_mode;
+extern char * fontpropinfo(void);
 
 extern bool support_wsl;