--- hatari/src/convert/vdi4.c	2019/04/01 07:10:27	1.1.1.2
+++ hatari/src/convert/vdi4.c	2019/04/09 08:49:46	1.1.1.7
@@ -1,65 +1,70 @@
-/* Screen Conversion, VDI Res to 4Colour */
+/*
+  Hatari - vdi4.c
 
+  This file is distributed under the GNU Public License, version 2 or at your
+  option any later version. Read the file gpl.txt for details.
 
-void ConvertVDIRes_4Colour(void)
+  Screen Conversion, VDI resolution with 4 colors
+*/
+
+
+static void ConvertVDIRes_4Colour(void)
 {
-  Uint32 *edi, *ebp;
-  Uint32 *esi;
-  register Uint32 eax, ebx, ecx;
+	Uint32 *edi, *ebp;
+	Uint32 *esi;
+	Uint32 eax, ebx, ecx;
+	int y, x, update;
 
-  ScrY = 0;                           /* Starting line in ST screen */
+	/* Get screen addresses, 'edi'-ST screen, 'ebp'-Previous ST screen, 'esi'-PC screen */
+	edi = (Uint32 *)pSTScreen;          /* ST format screen 2-plane 4 colors */
+	ebp = (Uint32 *)pSTScreenCopy;      /* Previous ST format screen */
+	update = ScrUpdateFlag & PALETTEMASK_UPDATEMASK;
 
-  /* Get screen addresses, 'edi'-ST screen, 'ebp'-Previous ST screen, 'esi'-PC screen */
-  edi = (Uint32 *)pSTScreen;          /* ST format screen 2-plane 4 colors */
-  ebp = (Uint32 *)pSTScreenCopy;      /* Previous ST format screen */
+	for (y = 0; y < VDIHeight; y++)
+	{
 
-  do       /* y-loop */
-  {
-    esi = (Uint32 *)pPCScreenDest;    /* PC format screen, byte per pixel 256 colors */
+		esi = (Uint32 *)pPCScreenDest;  /* PC format screen, byte per pixel 256 colors */
 
-    ScrX = VDIWidth >> 4;             /* Amount to draw across - in 16-pixels (4 bytes) */
+		x = VDIWidth >> 4;              /* Amount to draw across - in 16-pixels (4 bytes) */
 
-    do          /* x-loop */
-    {
-      /* Do 16 pixels at one time */
-      ebx = *edi;
+		do  /* x-loop */
+		{
+			/* Do 16 pixels at one time */
+			ebx = *edi;
 
-      if( (ScrUpdateFlag&0xe0000000) || ebx!=*ebp )  /* Update? */
-	  {
-	    bScreenContentsChanged = TRUE;
+			if (update || ebx != *ebp)  /* Update? */
+			{
+				bScreenContentsChanged = true;
 
-        /* Plot pixels */
+				/* Plot pixels */
 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
-        MED_BUILD_PIXELS_0 ;          /* Generate 'ecx' as pixels [4,5,6,7] */
-        PLOT_MED_640_8BIT(3) ;
-        MED_BUILD_PIXELS_1 ;          /* Generate 'ecx' as pixels [12,13,14,15] */
-        PLOT_MED_640_8BIT(1) ;
-        MED_BUILD_PIXELS_2 ;          /* Generate 'ecx' as pixels [0,1,2,3] */
-        PLOT_MED_640_8BIT(2) ;
-        MED_BUILD_PIXELS_3 ;          /* Generate 'ecx' as pixels [8,9,10,11] */
-        PLOT_MED_640_8BIT(0) ;
+				MED_BUILD_PIXELS_0 ;    /* Generate 'ecx' as pixels [12,13,14,15] */
+				PLOT_MED_640_8BIT(3) ;
+				MED_BUILD_PIXELS_1 ;    /* Generate 'ecx' as pixels [4,5,6,7] */
+				PLOT_MED_640_8BIT(1) ;
+				MED_BUILD_PIXELS_2 ;    /* Generate 'ecx' as pixels [8,9,10,11] */
+				PLOT_MED_640_8BIT(2) ;
+				MED_BUILD_PIXELS_3 ;    /* Generate 'ecx' as pixels [0,1,2,3] */
+				PLOT_MED_640_8BIT(0) ;
 #else
-        MED_BUILD_PIXELS_0 ;          /* Generate 'ecx' as pixels [4,5,6,7] */
-        PLOT_MED_640_8BIT(1) ;
-        MED_BUILD_PIXELS_1 ;          /* Generate 'ecx' as pixels [12,13,14,15] */
-        PLOT_MED_640_8BIT(3) ;
-        MED_BUILD_PIXELS_2 ;          /* Generate 'ecx' as pixels [0,1,2,3] */
-        PLOT_MED_640_8BIT(0) ;
-        MED_BUILD_PIXELS_3 ;          /* Generate 'ecx' as pixels [8,9,10,11] */
-        PLOT_MED_640_8BIT(2) ;
+				MED_BUILD_PIXELS_0 ;    /* Generate 'ecx' as pixels [4,5,6,7] */
+				PLOT_MED_640_8BIT(1) ;
+				MED_BUILD_PIXELS_1 ;    /* Generate 'ecx' as pixels [12,13,14,15] */
+				PLOT_MED_640_8BIT(3) ;
+				MED_BUILD_PIXELS_2 ;    /* Generate 'ecx' as pixels [0,1,2,3] */
+				PLOT_MED_640_8BIT(0) ;
+				MED_BUILD_PIXELS_3 ;    /* Generate 'ecx' as pixels [8,9,10,11] */
+				PLOT_MED_640_8BIT(2) ;
 #endif
-      }
-
-      esi += 4;                       /* Next PC pixels */
-      edi += 1;                       /* Next ST pixels */
-      ebp += 1;                       /* Next ST copy pixels */
-    }
-    while( --ScrX );                  /* Loop on X */
-
-    pPCScreenDest = (void *)(((Uint8 *)pPCScreenDest)+PCScreenBytesPerLine);  /* Offset to next line */
-
-    ScrY += 1;
-  }
-  while( ScrY < VDIHeight );          /* Loop on Y */
+			}
 
+			esi += 4;                   /* Next PC pixels */
+			edi += 1;                   /* Next ST pixels */
+			ebp += 1;                   /* Next ST copy pixels */
+		}
+		while (--x);                    /* Loop on X */
+
+		/* Offset to next line */
+		pPCScreenDest = (((Uint8 *)pPCScreenDest) + PCScreenBytesPerLine);
+	}
 }