[PATCH 3/3] exa: Use damage to optimise away useless copies.

[Maarten Maathuis]

- This is most useful for cases where the first operation is a hardware rendered one.
---
 exa/exa_migration_mixed.c |   50 ++++++++++++++++++++++++++++++++++++++------
 exa/exa_mixed.c           |   27 +++++++++++++++++++++++-
 2 files changed, 69 insertions(+), 8 deletions(-)

diff --git a/exa/exa_migration_mixed.c b/exa/exa_migration_mixed.c
index bed7141..88077a3 100644
--- a/exa/exa_migration_mixed.c
+++ b/exa/exa_migration_mixed.c
@@ -35,12 +35,28 @@ static void
 exaUploadFallback(PixmapPtr pPixmap, CARD8 *src, int src_pitch,
 	      CARD8 *dst, int dst_pitch)
  {
-    int i;
+    ExaPixmapPriv(pPixmap);
+    RegionPtr damage = DamageRegion (pExaPixmap->pDamage);
+    int i, cpp = pPixmap->drawable.bitsPerPixel / 8;
+    int bytes, nbox;
+    BoxPtr pbox;
+
+    pbox = REGION_RECTS(damage);
+    nbox = REGION_NUM_RECTS(damage);
+
+    while (nbox--) {
+	bytes = (pbox->x2 - pbox->x1) * cpp;
+
+	src += pbox->y1 * src_pitch + pbox->x1 * cpp;
+	dst += pbox->y1 * dst_pitch + pbox->x1 * cpp;
+
+	for (i = pbox->y2 - pbox->y1; i; i--) {
+	    memcpy (dst, src, bytes);
+	    src += src_pitch;
+	    dst += dst_pitch;
+	}
 
-    for (i = pPixmap->drawable.height; i; i--) {
-	memcpy (dst, src, min(src_pitch, dst_pitch));
-	src += src_pitch;
-	dst += dst_pitch;
+	pbox++;
     }
 }
 
@@ -50,12 +66,15 @@ exaCreateDriverPixmap_mixed(PixmapPtr pPixmap)
     ScreenPtr pScreen = pPixmap->drawable.pScreen;
     ExaScreenPriv(pScreen);
     ExaPixmapPriv(pPixmap);
+    RegionPtr damage = DamageRegion (pExaPixmap->pDamage);
     void *sys_buffer = pExaPixmap->sys_ptr;
     int w = pPixmap->drawable.width, h = pPixmap->drawable.height;
     int depth = pPixmap->drawable.depth, bpp = pPixmap->drawable.bitsPerPixel;
     int usage_hint = pPixmap->usage_hint;
     int sys_pitch = pExaPixmap->sys_pitch;
     int paddedWidth = sys_pitch;
+    int nbox;
+    BoxPtr pbox;
 
     /* Already done. */
     if (pExaPixmap->driverPriv)
@@ -91,8 +110,18 @@ exaCreateDriverPixmap_mixed(PixmapPtr pPixmap)
     if (!pExaScr->info->UploadToScreen)
 	goto fallback;
 
-    if (pExaScr->info->UploadToScreen(pPixmap, 0, 0, w, h, sys_buffer, sys_pitch))
-	goto finish;
+    pbox = REGION_RECTS(damage);
+    nbox = REGION_NUM_RECTS(damage);
+
+    while (nbox--) {
+	if (!pExaScr->info->UploadToScreen(pPixmap, pbox->x1, pbox->y1, pbox->x2 - pbox->x1,
+		pbox->y2 - pbox->y1, (char *) (sys_buffer) + pbox->y1 * sys_pitch + pbox->x1 * (bpp / 8), sys_pitch))
+	    goto fallback;
+
+	pbox++;
+    }
+
+    goto finish;
 
 fallback:
     ExaDoPrepareAccess(&pPixmap->drawable, EXA_PREPARE_DEST);
@@ -105,6 +134,13 @@ finish:
     pExaPixmap->score = EXA_PIXMAP_SCORE_PINNED;
 
     exaSetAccelBlock(pExaScr, pExaPixmap, w, h, bpp);
+
+    /* We no longer need this. */
+    if (pExaPixmap->pDamage) {
+	DamageUnregister(&pPixmap->drawable, pExaPixmap->pDamage);
+	DamageDestroy(pExaPixmap->pDamage);
+	pExaPixmap->pDamage = NULL;
+    }
 }
 
 void
diff --git a/exa/exa_mixed.c b/exa/exa_mixed.c
index 80af521..9090078 100644
--- a/exa/exa_mixed.c
+++ b/exa/exa_mixed.c
@@ -108,6 +108,23 @@ exaCreatePixmap_mixed(ScreenPtr pScreen, int w, int h, int depth,
 
 	/* We want to be able to copy the pixmap to driver memory later on. */
 	pExaPixmap->score = EXA_PIXMAP_SCORE_INIT;
+
+	/* Set up damage tracking */
+	pExaPixmap->pDamage = DamageCreate (NULL, NULL,
+					    DamageReportNone, TRUE,
+					    pScreen, pPixmap);
+
+	if (pExaPixmap->pDamage == NULL) {
+	    swap(pExaScr, pScreen, DestroyPixmap);
+	    pScreen->DestroyPixmap (pPixmap);
+	    swap(pExaScr, pScreen, DestroyPixmap);
+	    return NULL;
+	}
+
+	DamageRegister (&pPixmap->drawable, pExaPixmap->pDamage);
+	/* This ensures that pending damage reflects the current operation. */
+	/* This is used by exa to optimize migration. */
+	DamageSetReportAfterOp (pExaPixmap->pDamage, TRUE);
     }
 
     return pPixmap;
@@ -130,8 +147,16 @@ exaModifyPixmapHeader_mixed(PixmapPtr pPixmap, int width, int height, int depth,
 
     if (pExaPixmap) {
         if (pPixData) {
-	    if (pExaPixmap->sys_ptr && !exaPixmapIsPinned(pPixmap))
+	    if (pExaPixmap->sys_ptr && !exaPixmapIsPinned(pPixmap)) {
 		free(pExaPixmap->sys_ptr);
+
+		/* We no longer need this. */
+		if (pExaPixmap->pDamage) {
+		    DamageUnregister(&pPixmap->drawable, pExaPixmap->pDamage);
+		    DamageDestroy(pExaPixmap->pDamage);
+		    pExaPixmap->pDamage = NULL;
+		}
+	    }
             pExaPixmap->sys_ptr = pPixData;
 	}
 
-- 
1.6.4