From d2b08e8601362bd9f1ade63c9bca892aab0e410e Mon Sep 17 00:00:00 2001
From: Holger Schemel <info@artsoft.org>
Date: Sun, 17 May 2015 13:25:58 +0200
Subject: [PATCH] changed redraw system to prevent unneeded screen updates

---
 src/game.c          | 11 ++++++++++-
 src/game.h          |  1 +
 src/game_em/input.c |  1 -
 src/game_sp/main.c  |  2 +-
 src/tools.c         | 36 +++++++++++++++++-------------------
 src/tools.h         |  1 +
 6 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/src/game.c b/src/game.c
index 59f98fdb..49908daa 100644
--- a/src/game.c
+++ b/src/game.c
@@ -11191,8 +11191,10 @@ void GameActions()
   }
   else
   {
-    GameActions_RND();
+    GameActions_RND_Main();
   }
+
+  redraw_mask |= REDRAW_FIELD;
 }
 
 void GameActions_EM_Main()
@@ -11227,6 +11229,13 @@ void GameActions_SP_Main()
   AdvanceFrameAndPlayerCounters(-1);	/* advance counters for all players */
 }
 
+void GameActions_RND_Main()
+{
+  GameActions_RND();
+
+  BlitScreenToBitmap_RND(backbuffer);
+}
+
 void GameActions_RND()
 {
   int magic_wall_x = 0, magic_wall_y = 0;
diff --git a/src/game.h b/src/game.h
index 3e62cf4d..a962abd7 100644
--- a/src/game.h
+++ b/src/game.h
@@ -354,6 +354,7 @@ void StartGameActions(boolean, boolean, int);
 void GameActions(void);
 void GameActions_EM_Main();
 void GameActions_SP_Main();
+void GameActions_RND_Main();
 void GameActions_RND();
 
 void ScrollLevel(int, int);
diff --git a/src/game_em/input.c b/src/game_em/input.c
index 47097518..e314272f 100644
--- a/src/game_em/input.c
+++ b/src/game_em/input.c
@@ -112,7 +112,6 @@ void GameActions_EM(byte action[MAX_PLAYERS], boolean warp_mode)
   RedrawPlayfield_EM(FALSE);
 
   BlitScreenToBitmap_EM(backbuffer);
-  BackToFront_EM();
 }
 
 /* read input device for players */
diff --git a/src/game_sp/main.c b/src/game_sp/main.c
index f0b7603e..51d799e7 100644
--- a/src/game_sp/main.c
+++ b/src/game_sp/main.c
@@ -59,7 +59,7 @@ void RedrawPlayfield_SP(boolean force_redraw)
 
   UpdatePlayfield(force_redraw);
 
-  BlitScreenToBitmap_SP(window);
+  BlitScreenToBitmap_SP(backbuffer);
 }
 
 void UpdateGameDoorValues_SP()
diff --git a/src/tools.c b/src/tools.c
index 1676bc89..1dc4f4bc 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -354,7 +354,7 @@ void DrawMaskedBorder(int redraw_mask)
   }
 }
 
-static void BlitScreenToBitmap_RND(Bitmap *target_bitmap)
+void BlitScreenToBitmap_RND(Bitmap *target_bitmap)
 {
   DrawBuffer *buffer = (drawto_field == window ? backbuffer : drawto_field);
   int fx = FX, fy = FY;
@@ -410,23 +410,7 @@ static void BlitScreenToBitmap_RND(Bitmap *target_bitmap)
       fy = 2 * TILEY_VAR - (EVEN(lev_fieldy) ? TILEY_VAR / 2 : 0);
   }
 
-  if (border.draw_masked[GAME_MODE_PLAYING])
-  {
-    if (buffer != backbuffer)
-    {
-      /* copy playfield buffer to backbuffer to add masked border */
-      BlitBitmap(buffer, backbuffer, fx, fy, SXSIZE, SYSIZE, SX, SY);
-      DrawMaskedBorder(REDRAW_FIELD);
-    }
-
-    BlitBitmap(backbuffer, target_bitmap,
-	       REAL_SX, REAL_SY, FULL_SXSIZE, FULL_SYSIZE,
-	       REAL_SX, REAL_SY);
-  }
-  else
-  {
-    BlitBitmap(buffer, target_bitmap, fx, fy, SXSIZE, SYSIZE, SX, SY);
-  }
+  BlitBitmap(buffer, target_bitmap, fx, fy, SXSIZE, SYSIZE, SX, SY);
 }
 
 void BlitScreenToBitmap(Bitmap *target_bitmap)
@@ -439,7 +423,7 @@ void BlitScreenToBitmap(Bitmap *target_bitmap)
     BlitScreenToBitmap_RND(target_bitmap);
 }
 
-void BackToFront()
+void BackToFront_OLD()
 {
   DrawBuffer *buffer = (drawto_field == window ? backbuffer : drawto_field);
 
@@ -575,6 +559,20 @@ void BackToFront()
   redraw_mask = REDRAW_NONE;
 }
 
+void BackToFront()
+{
+  if (redraw_mask == REDRAW_NONE)
+    return;
+
+  // draw masked border to all viewports, if defined
+  DrawMaskedBorder(redraw_mask);
+
+  // blit backbuffer to visible screen
+  BlitBitmap(backbuffer, window, 0, 0, WIN_XSIZE, WIN_YSIZE, 0, 0);
+
+  redraw_mask = REDRAW_NONE;
+}
+
 static void FadeCrossSaveBackbuffer()
 {
   BlitBitmap(backbuffer, bitmap_db_cross, 0, 0, WIN_XSIZE, WIN_YSIZE, 0, 0);
diff --git a/src/tools.h b/src/tools.h
index 9ebaed30..af450a90 100644
--- a/src/tools.h
+++ b/src/tools.h
@@ -79,6 +79,7 @@ void DrawMaskedBorder(int);
 
 void SetDrawtoField(int);
 void RedrawPlayfield();
+void BlitScreenToBitmap_RND(Bitmap *);
 void BlitScreenToBitmap(Bitmap *);
 void BackToFront();
 
-- 
2.34.1