gdi32: Use NtGdiArcInternal for Arc implementation.

dlls/gdi32/gdidc.c

@@ -42,3 +42,15 @@ BOOL WINAPI MoveToEx( HDC hdc, INT x, INT y, POINT *pt )
     TRACE( "%p, (%d, %d), %p\n", hdc, x, y, pt );
     return NtGdiMoveTo( hdc, x, y, pt );
 }
+
+/***********************************************************************
+ *           Arc    (GDI32.@)
+ */
+BOOL WINAPI Arc( HDC hdc, INT left, INT top, INT right, INT bottom,
+                 INT xstart, INT ystart, INT xend, INT yend )
+{
+    TRACE( "%p, (%d, %d)-(%d, %d), (%d, %d), (%d, %d)\n", hdc, left, top,
+           right, bottom, xstart, ystart, xend, yend );
+    return NtGdiArcInternal( NtGdiArc, hdc, left, top, right, bottom,
+                             xstart, ystart, xend, yend );
+}

dlls/gdi32/painting.c

@@ -275,22 +275,29 @@ BOOL WINAPI NtGdiMoveTo( HDC hdc, INT x, INT y, POINT *pt )
 
 
 /***********************************************************************
- *           Arc    (GDI32.@)
+ *           NtGdiArcInternal    (win32u.@)
  */
-BOOL WINAPI Arc( HDC hdc, INT left, INT top, INT right,
-                     INT bottom, INT xstart, INT ystart,
-                     INT xend, INT yend )
+BOOL WINAPI NtGdiArcInternal( UINT type, HDC hdc, INT left, INT top, INT right,
+                              INT bottom, INT xstart, INT ystart, INT xend, INT yend )
 {
     PHYSDEV physdev;
     BOOL ret;
-    DC * dc = get_dc_ptr( hdc );
-
-    TRACE( "%p, (%d, %d)-(%d, %d), (%d, %d), (%d, %d)\n", hdc, left, top, right, bottom, xstart, ystart, xend, yend );
+    DC *dc;
 
-    if (!dc) return FALSE;
+    if (!(dc = get_dc_ptr( hdc ))) return FALSE;
     update_dc( dc );
+
+    switch (type)
+    {
+    case NtGdiArc:
         physdev = GET_DC_PHYSDEV( dc, pArc );
         ret = physdev->funcs->pArc( physdev, left, top, right, bottom, xstart, ystart, xend, yend );
+        break;
+    default:
+        WARN( "invalid arc type %u\n", type );
+        ret = FALSE;
+    }
+
     release_dc_ptr( dc );
     return ret;
 }

include/ntgdi.h

@@ -72,6 +72,14 @@ typedef struct _GDI_SHARED_MEMORY
     GDI_HANDLE_ENTRY Handles[GDI_MAX_HANDLE_COUNT];
 } GDI_SHARED_MEMORY, *PGDI_SHARED_MEMORY;
 
+enum
+{
+    NtGdiArc,
+    NtGdiArcTo,
+    NtGdiChord,
+    NtGdiPie,
+};
+
 INT      WINAPI NtGdiAbortDoc( HDC hdc );
 BOOL     WINAPI NtGdiAbortPath( HDC hdc );
 BOOL     WINAPI NtGdiAngleArc( HDC hdc, INT x, INT y, DWORD radius, FLOAT start_angle,