From: Bertram Felgenhauer <int-e@gmx.de>
Date: Tue, 22 Jan 2008 07:00:05 +0000 (+0100)
Subject: eliminate a special case in fbRasterizeEdges{4,8}.
X-Git-Tag: pixman-0.10.0~36^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=054be107365cac5dc6cff2b6f705978f1899c79e;p=platform%2Fupstream%2Fpixman.git

eliminate a special case in fbRasterizeEdges{4,8}.
---

diff --git a/pixman/pixman-edge-imp.h b/pixman/pixman-edge-imp.h
index 9c33f94..0982a46 100644
--- a/pixman/pixman-edge-imp.h
+++ b/pixman/pixman-edge-imp.h
@@ -59,7 +59,15 @@ rasterizeEdges (pixman_image_t  *image,
 	if (lx < 0)
 	    lx = 0;
 	if (pixman_fixed_to_int (rx) >= width)
+#if N_BITS == 1
 	    rx = pixman_int_to_fixed (width);
+#else
+	    /* Use the last pixel of the scanline, covered 100%.
+	     * We can't use the first pixel following the scanline,
+	     * because accessing it could result in a buffer overrun.
+	     */
+	    rx = pixman_int_to_fixed (width) - 1;
+#endif
 
 	/* Skip empty (or backwards) sections */
 	if (rx > lx)
@@ -117,12 +125,7 @@ rasterizeEdges (pixman_image_t  *image,
 			AddAlpha (N_X_FRAC(N_BITS));
 			StepAlpha;
 		    }
-		    /* Do not add in a 0 alpha here. This check is necessary
-		     * to avoid a buffer overrun when rx is exactly on a pixel
-		     * boundary.
-		     */
-		    if (rxs != 0)
-			AddAlpha (rxs);
+		    AddAlpha (rxs);
 		}
 	    }
 #endif
diff --git a/pixman/pixman-edge.c b/pixman/pixman-edge.c
index 1ed6f10..4a9df9a 100644
--- a/pixman/pixman-edge.c
+++ b/pixman/pixman-edge.c
@@ -147,7 +147,11 @@ fbRasterizeEdges8 (pixman_image_t       *image,
 	    lx = 0;
 	rx = r->x;
 	if (pixman_fixed_to_int (rx) >= width)
-	    rx = pixman_int_to_fixed (width);
+	    /* Use the last pixel of the scanline, covered 100%.
+	     * We can't use the first pixel following the scanline,
+	     * because accessing it could result in a buffer overrun.
+	     */
+	    rx = pixman_int_to_fixed (width) - 1;
 
 	/* Skip empty (or backwards) sections */
 	if (rx > lx)
@@ -235,11 +239,7 @@ fbRasterizeEdges8 (pixman_image_t       *image,
 		    add_saturate_8 (ap + lxi, N_X_FRAC(8), rxi - lxi);
 		}
 
-		/* Do not add in a 0 alpha here. This check is
-		 * necessary to avoid a buffer overrun, (when rx
-		 * is exactly on a pixel boundary). */
-		if (rxs)
-		    WRITE(image, ap + rxi, clip255 (READ(image, ap + rxi) + rxs));
+		WRITE(image, ap + rxi, clip255 (READ(image, ap + rxi) + rxs));
 	    }
 	}