From 5520a6e5eeafdd5f8bfffcd9f5a98a5b7c22b85f Mon Sep 17 00:00:00 2001
From: Lephenixnoir <sebastien.michelland@protonmail.com>
Date: Thu, 12 Aug 2021 13:12:48 +0200
Subject: [PATCH] Restore video mode after an error

When using direct-DD access, the window size would not be restored,
producing complete nonsense.
---
 README            |  4 +++-
 cgdoom/i_system.c |  2 ++
 cgdoom/i_video.c  | 26 +++++++++++++++++++-------
 cgdoom/i_video.h  |  2 ++
 cgdoom/st_stuff.c |  2 +-
 5 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/README b/README
index 0ad17a3..18a861d 100644
--- a/README
+++ b/README
@@ -14,6 +14,7 @@ sources (GPL) and nDoom (GPLv2). See LICENSE.
 UI improvements TODO:
 -> Better keyboard layout (including more keys, eg. Run)
    => Edit messages accordingly ("press y"/etc)
+-> Use MENU for the escape and EXE to validate in menus
 
 WAD support TODO:
 -> Unmodified 1.9 shareware WAD works all the way through?
@@ -29,11 +30,12 @@ Technical support TODO:
 -> Supply more VRAM memory to internal allocator
    => Merge internal heap into Z_Zone? (< 50 kB)
    => Rewrite video code to use long PRAM0 access? (138 kB)
+   => Identify arrays that can go to PRAM, eg. lumpcache
+   => Remove multiply-avoiding lookup tables?
 -> Rate-limit the game when overclocking
 -> Switches don't always show the pressed texture (?)
 -> Add more SHORT() to avoid having to copy-align lumps
    (note left by MPoupe in m_swap.h)
--> Quit Game menu sometimes crashes the add-in
 -> Load/Save game would be very cool
 -> Reenable LTO if possible
 -> Built-in overclocking?
diff --git a/cgdoom/i_system.c b/cgdoom/i_system.c
index 62040a0..9be5ebe 100644
--- a/cgdoom/i_system.c
+++ b/cgdoom/i_system.c
@@ -154,6 +154,7 @@ void I_ErrorI (const char *error, int i1,int i2,int i3,int i4)
     locate_OS( 1, 5 );CGDAppendHex32("i3:",i3,8,buf);PrintLine( buf, 21 );
     locate_OS( 1, 6 );CGDAppendHex32("i4:",i4,8,buf);PrintLine( buf, 21 );
     GetKey( &key );
+    I_ReinitAfterError();
 #else
       I_Error (error,i1,i2,i3,i4);
 #endif
@@ -181,6 +182,7 @@ void I_Error (char *error, ...)
     locate_OS( 1, 2 );
     PrintLine( error, 21 );
     GetKey( &key );
+    I_ReinitAfterError();
 #endif //#ifdef CG_EMULATOR
     //I_Quit();
 }
diff --git a/cgdoom/i_video.c b/cgdoom/i_video.c
index 7561c5f..7ab6030 100644
--- a/cgdoom/i_video.c
+++ b/cgdoom/i_video.c
@@ -130,14 +130,15 @@ static void SetWindow(int left, int top, int width, int height)
   WriteLCDReg(LCD_WINDOW_BOTTOM, top + height - 1);
 }
 
+/* Whether the black background has been rendered. We could fill the screen
+   at initialization but it would flicker. Instead, we go the extra mile and
+   render the background at the same time as the first frame. This also allows
+   redrawing it after erros.*/
+static int firstflipdone = 0;
+
 void I_Flip (void)
 {
-  /* Whether the black background has been rendered. We could fill the screen
-     at initialization but it would flicker. Instead, we go the extra mile and
-     render the background at the same time as the first frame. */
-  static int black_bg = 0;
-
-  if (!black_bg)
+  if (!firstflipdone)
   {
     SetWindow(0, 0, 396, 224);
     WriteLCDReg(LCD_GRAM_X, 0);
@@ -165,7 +166,7 @@ void I_Flip (void)
     /* Set the future window */
     SetWindow((396 - SCREENWIDTH) / 2, (224 - SCREENHEIGHT) / 2,
       SCREENWIDTH, SCREENHEIGHT);
-    black_bg = 1;
+    firstflipdone = 1;
   }
   else
   {
@@ -193,6 +194,14 @@ void I_ShutdownGraphics(void)
   SetWindow(6, 0, 384, 216);
 }
 
+void I_ReinitAfterError(void)
+{
+    firstflipdone = 0;
+    /* Redraw status bar over help message */
+    extern boolean st_firsttime;
+    st_firsttime = true;
+}
+
 #else
 
 void I_Flip (void)
@@ -223,7 +232,10 @@ void I_InitGraphics(void)
 
 void I_ShutdownGraphics(void)
 {
+}
 
+void I_SetWindowAfterError(void)
+{
 }
 
 #endif
diff --git a/cgdoom/i_video.h b/cgdoom/i_video.h
index 5bdd996..7d6abd9 100644
--- a/cgdoom/i_video.h
+++ b/cgdoom/i_video.h
@@ -51,6 +51,8 @@ void I_ReadScreen (byte* scr);
 //void I_BeginRead (void);
 //void I_EndRead (void);
 
+/* CGDOOM: Restore video after error when using direct-DD access */
+void I_ReinitAfterError (void);
 
 
 #endif
diff --git a/cgdoom/st_stuff.c b/cgdoom/st_stuff.c
index 5eab4d3..0cc2fa2 100644
--- a/cgdoom/st_stuff.c
+++ b/cgdoom/st_stuff.c
@@ -267,7 +267,7 @@
 static player_t*   plyr; 
 
 // ST_Start() has just been called
-static boolean    st_firsttime;
+boolean    st_firsttime;
 
 // used to execute ST_Init() only once
 static int     veryfirsttime = 1;