Revert "mi: Remove unused overlay support"

This reverts commit 9120e58556.

 Whoops, please revert this patch -- overlay is in use in nvidia drivers,
 and it's too late in release cycle to remove it.

 I feel really sorry that I kept this patch in my tree. I will submit
another one, removing only XAA overlay hooks which are not used at all.

hw/xfree86/loader/sdksyms.sh

@@ -231,6 +231,7 @@ cat > sdksyms.c << EOF
 #include "miwideline.h"
 #include "mistruct.h"
 #include "mifpoly.h"
+#include "mioverlay.h"
 
 
 /* randr/Makefile.am */

hw/xfree86/xaa/xaaOverlay.c

@@ -16,6 +16,7 @@
 #include "xaawrap.h"
 #include "gcstruct.h"
 #include "pixmapstr.h"
+#include "mioverlay.h"
 
 #ifdef PANORAMIX
 #include "panoramiX.h"
@@ -36,6 +37,7 @@ XAACopyWindow8_32(
     ScreenPtr pScreen = pWin->drawable.pScreen;
     XAAInfoRecPtr infoRec = 
 	GET_XAAINFORECPTR_FROM_DRAWABLE((&pWin->drawable));
+    Bool doUnderlay = miOverlayCopyUnderlay(pScreen);
     RegionPtr borderClip = &pWin->borderClip;
     Bool freeReg = FALSE;
 
@@ -54,6 +56,9 @@ XAACopyWindow8_32(
 
     pwinRoot = pScreen->root;
 
+    if(doUnderlay)
+	freeReg = miOverlayCollectUnderlayRegions(pWin, &borderClip);
+
     RegionNull(&rgnDst);
 
     dx = ptOldOrg.x - pWin->drawable.x;
@@ -76,7 +81,7 @@ XAACopyWindow8_32(
 	ppt++; pbox++;
     }
     
-    infoRec->ScratchGC.planemask = 0xff000000;
+    infoRec->ScratchGC.planemask = doUnderlay ? 0x00ffffff : 0xff000000;
     infoRec->ScratchGC.alu = GXcopy;
 
     XAADoBitBlt((DrawablePtr)pwinRoot, (DrawablePtr)pwinRoot,
@@ -88,6 +93,25 @@ XAACopyWindow8_32(
 	RegionDestroy(borderClip);
 }
 
+static void
+XAASetColorKey8_32(
+    ScreenPtr pScreen,
+    int nbox,
+    BoxPtr pbox
+){
+    XAAInfoRecPtr infoRec = GET_XAAINFORECPTR_FROM_SCREEN(pScreen);
+    ScrnInfoPtr pScrn = infoRec->pScrn;
+
+    /* I'm counting on writes being clipped away while switched away.
+       If this isn't going to be true then I need to be wrapping instead. */
+    if(!infoRec->pScrn->vtSema) return;
+
+    (*infoRec->FillSolidRects)(pScrn, pScrn->colorKey << 24, GXcopy, 
+					0xff000000, nbox, pbox);
+  
+    SET_SYNC_FLAG(infoRec);
+}
+
 void
 XAASetupOverlay8_32Planar(ScreenPtr pScreen)
 {
@@ -96,6 +120,9 @@ XAASetupOverlay8_32Planar(ScreenPtr pScreen)
 
     pScreen->CopyWindow = XAACopyWindow8_32;
 
+    if(!(infoRec->FillSolidRectsFlags & NO_PLANEMASK))
+	miOverlaySetTransFunction(pScreen, XAASetColorKey8_32);
+
     infoRec->FullPlanemask = ~0;
     for(i = 0; i < 32; i++) /* haven't thought about this much */
 	infoRec->FullPlanemasks[i] = ~0;

mi/Makefile.am

@@ -3,7 +3,7 @@ noinst_LTLIBRARIES = libmi.la
 if XORG
 sdk_HEADERS = micmap.h miline.h mipointer.h mi.h mibstore.h \
               migc.h mipointrst.h mizerarc.h micoord.h mifillarc.h \
-              mispans.h miwideline.h mistruct.h mifpoly.h
+              mispans.h miwideline.h mistruct.h mifpoly.h mioverlay.h
 endif
 
 AM_CFLAGS = $(DIX_CFLAGS)
@@ -33,6 +33,8 @@ libmi_la_SOURCES = 	\
 	migc.h		\
 	miglblt.c	\
 	miline.h	\
+	mioverlay.c	\
+	mioverlay.h	\
 	mipointer.c	\
 	mipointer.h	\
 	mipointrst.h	\

mi/mioverlay.h

@@ -0,0 +1,32 @@
+
+#ifdef HAVE_DIX_CONFIG_H
+#include <dix-config.h>
+#endif
+
+#ifndef __MIOVERLAY_H
+#define __MIOVERLAY_H
+
+typedef void (*miOverlayTransFunc)(ScreenPtr, int, BoxPtr);
+typedef Bool (*miOverlayInOverlayFunc)(WindowPtr);
+
+extern _X_EXPORT Bool
+miInitOverlay(
+   ScreenPtr pScreen, 
+   miOverlayInOverlayFunc inOverlay,
+   miOverlayTransFunc trans
+);
+
+extern _X_EXPORT Bool
+miOverlayGetPrivateClips(
+    WindowPtr pWin,
+    RegionPtr *borderClip,
+    RegionPtr *clipList
+);
+
+extern _X_EXPORT Bool miOverlayCollectUnderlayRegions(WindowPtr, RegionPtr*);
+extern _X_EXPORT void miOverlayComputeCompositeClip(GCPtr, WindowPtr);
+extern _X_EXPORT Bool miOverlayCopyUnderlay(ScreenPtr);
+extern _X_EXPORT void miOverlaySetTransFunction(ScreenPtr, miOverlayTransFunc);
+extern _X_EXPORT void miOverlaySetRootClip(ScreenPtr, Bool);
+
+#endif /* __MIOVERLAY_H */