Add inverted colors mode

Also use color constants in some more places.

src/dged/buffer_view.c

@@ -313,17 +313,18 @@ static uint32_t render_line_numbers(struct buffer_view *view,
   uint32_t relline = 0;
 
   for (; relline < height && line < nlines_buf; ++line, ++relline) {
-    command_list_set_index_color_bg(commands, 8);
-    command_list_set_index_color_fg(commands, line == view->dot.line ? 15 : 7);
+    command_list_set_index_color_bg(commands, Color_BrightBlack);
+    command_list_set_index_color_fg(
+        commands, line == view->dot.line ? Color_BrightWhite : Color_White);
     uint32_t chars = snprintf(buf, 16, "%*d", longest_nchars + 1, line + 1);
     command_list_draw_text_copy(commands, 0, relline, (uint8_t *)buf, chars);
     command_list_reset_color(commands);
     command_list_draw_repeated(commands, longest_nchars + 1, relline, ' ', 1);
   }
 
   for (; relline < height; ++relline) {
-    command_list_set_index_color_bg(commands, 8);
-    command_list_set_index_color_fg(commands, 7);
+    command_list_set_index_color_bg(commands, Color_BrightBlack);
+    command_list_set_index_color_fg(commands, Color_White);
     command_list_draw_repeated(commands, 0, relline, ' ', longest_nchars + 1);
     command_list_reset_color(commands);
     command_list_draw_repeated(commands, longest_nchars + 1, relline, ' ', 1);
@@ -363,7 +364,8 @@ static void render_modeline(struct modeline *modeline, struct buffer_view *view,
     modeline->buffer[len] = '\0';
   }
 
-  command_list_set_index_color_bg(commands, 8);
+  command_list_set_index_color_bg(commands, Color_BrightBlack);
+  command_list_set_index_color_fg(commands, Color_White);
   command_list_draw_text(commands, 0, height - 1, modeline->buffer,
                          strlen((char *)modeline->buffer));
   command_list_reset_color(commands);

src/dged/display.c

@@ -351,6 +351,13 @@ void command_list_set_color_bg(struct command_list *list, uint8_t red,
   cmd->len = snprintf((char *)cmd->fmt, 64, "48;2;%d;%d;%d", red, green, blue);
 }
 
+void command_list_set_inverted_colors(struct command_list *list) {
+  struct push_fmt_cmd *cmd =
+      add_command(list, RenderCommand_PushFormat)->push_fmt;
+  cmd->fmt[0] = '7';
+  cmd->len = 1;
+}
+
 void command_list_reset_color(struct command_list *list) {
   add_command(list, RenderCommand_ClearFormat);
 }

src/dged/display.h

@@ -186,6 +186,13 @@ void command_list_set_index_color_fg(struct command_list *list,
 void command_list_set_color_fg(struct command_list *list, uint8_t red,
                                uint8_t green, uint8_t blue);
 
+/**
+ * Set colors to be inverted.
+ *
+ * Sets background as foreground and vice versa.
+ */
+void command_list_set_inverted_colors(struct command_list *list);
+
 /**
  * Reset the color and styling information.
  *