From ea6e06d689f437841e9680f8160a68ec7545eb48 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Thu, 4 Jul 2019 19:17:18 +0200
Subject: [PATCH] vt: track charsets G0-G3 and support either ASCII or
 graphical mode

---
 terminal.h |  4 ++++
 vt.c       | 23 ++++++++---------------
 2 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/terminal.h b/terminal.h
index f48158e5..71b59e4d 100644
--- a/terminal.h
+++ b/terminal.h
@@ -126,6 +126,7 @@ struct kbd {
 
 enum decckm { DECCKM_CSI, DECCKM_SS3 };
 enum keypad_mode { KEYPAD_NUMERICAL, KEYPAD_APPLICATION };
+enum charset { CHARSET_ASCII, CHARSET_GRAPHIC };
 
 struct terminal {
     pid_t slave;
@@ -138,6 +139,9 @@ struct terminal {
     bool insert_mode;
     bool bracketed_paste;
 
+    int selected_charset;
+    enum charset charset[4]; /* G0-G3 */
+
     struct vt vt;
     struct kbd kbd;
 
diff --git a/vt.c b/vt.c
index dd0f78ae..fd7ee630 100644
--- a/vt.c
+++ b/vt.c
@@ -572,15 +572,10 @@ esc_dispatch(struct terminal *term, uint8_t final)
         char param = term->vt.params.idx > 0 ? term->vt.params.v[0].value : '(';
 
         switch (param) {
-        case '(':
-            /* This is the default charset */
-            break;
-
-        case ')':
-        case '*':
-        case '+':
-            LOG_WARN("unimplemented: charset %c uses ASCII", param);
-            return false;
+        case '(': term->charset[0] = CHARSET_ASCII; break;
+        case ')': term->charset[1] = CHARSET_ASCII; break;
+        case '*': term->charset[2] = CHARSET_ASCII; break;
+        case '+': term->charset[3] = CHARSET_ASCII; break;
 
         default:
             LOG_ERR("<ESC>%cB: invalid charset identifier", param);
@@ -594,12 +589,10 @@ esc_dispatch(struct terminal *term, uint8_t final)
         char param = term->vt.params.idx > 0 ? term->vt.params.v[0].value : '(';
 
         switch (param) {
-        case '(':
-        case ')':
-        case '*':
-        case '+':
-            LOG_WARN("unimplemented: charset %c uses special characters and line drawings", param);
-            break;
+        case '(': term->charset[0] = CHARSET_GRAPHIC; break;
+        case ')': term->charset[1] = CHARSET_GRAPHIC; break;
+        case '*': term->charset[2] = CHARSET_GRAPHIC; break;
+        case '+': term->charset[3] = CHARSET_GRAPHIC; break;
 
         default:
             LOG_ERR("<ESC>%c0: invalid charset identifier", param);