[aandrejevic] 72489: [NTVDM:SVGA] Fix the refresh rate calculation, again.

Author: aandrejevic
Date: Sun Aug 28 16:17:14 2016
New Revision: 72489

URL: http://svn.reactos.org/svn/reactos?rev=72489&view=rev
Log:
[NTVDM:SVGA]
Fix the refresh rate calculation, again.


Modified:
    trunk/reactos/subsystems/mvdm/ntvdm/hardware/video/svga.c

Modified: trunk/reactos/subsystems/mvdm/ntvdm/hardware/video/svga.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/mvdm/ntvdm/hard…
==============================================================================
--- trunk/reactos/subsystems/mvdm/ntvdm/hardware/video/svga.c	[iso-8859-1] (original)
+++ trunk/reactos/subsystems/mvdm/ntvdm/hardware/video/svga.c	[iso-8859-1] Sun Aug 28
16:17:14 2016
@@ -1118,6 +1118,22 @@
 
             VerticalRetraceEnd = VerticalRetraceStart +
(VgaCrtcRegisters[VGA_CRTC_END_VERT_RETRACE_REG] & 0x0F);
 
+            if (VgaGcRegisters[VGA_GC_MISC_REG] & VGA_GC_MISC_NOALPHA)
+            {
+                BYTE MaximumScanLine = 1 + (VgaCrtcRegisters[VGA_CRTC_MAX_SCAN_LINE_REG]
& 0x1F);
+
+                if (VgaCrtcRegisters[VGA_CRTC_MAX_SCAN_LINE_REG] &
VGA_CRTC_MAXSCANLINE_DOUBLE)
+                {
+                    VerticalRetraceStart <<= 1;
+                    VerticalRetraceEnd <<= 1;
+                }
+                else
+                {
+                    VerticalRetraceStart *= MaximumScanLine;
+                    VerticalRetraceEnd *= MaximumScanLine;
+                }
+            }
+
             /* Calculate the horizontal blanking duration in cycles */
             HblankStart = VgaCrtcRegisters[VGA_CRTC_START_HORZ_BLANKING_REG] & 0x1F;
             HblankEnd = VgaCrtcRegisters[VGA_CRTC_END_HORZ_BLANKING_REG] & 0x1F;
@@ -1644,15 +1660,18 @@
     VerticalRetraceStart |= (VgaCrtcRegisters[VGA_CRTC_OVERFLOW_REG] &
VGA_CRTC_OVERFLOW_VRS8) << 6;
     VerticalRetraceStart |= (VgaCrtcRegisters[VGA_CRTC_OVERFLOW_REG] &
VGA_CRTC_OVERFLOW_VRS9) << 2;
 
-    if (VgaCrtcRegisters[VGA_CRTC_MAX_SCAN_LINE_REG] & VGA_CRTC_MAXSCANLINE_DOUBLE)
-    {
-        VerticalRetraceStart <<= 1;
-        VerticalTotal <<= 1;
-    }
-    else
-    {
-        VerticalRetraceStart *= MaximumScanLine;
-        VerticalTotal *= MaximumScanLine;
+    if (VgaGcRegisters[VGA_GC_MISC_REG] & VGA_GC_MISC_NOALPHA)
+    {
+        if (VgaCrtcRegisters[VGA_CRTC_MAX_SCAN_LINE_REG] &
VGA_CRTC_MAXSCANLINE_DOUBLE)
+        {
+            VerticalRetraceStart <<= 1;
+            VerticalTotal <<= 1;
+        }
+        else
+        {
+            VerticalRetraceStart *= MaximumScanLine;
+            VerticalTotal *= MaximumScanLine;
+        }
     }
 
     /* Set the cycle */