1 files changed, 134 insertions, 0 deletions
diff --git a/fb/fbedgeimp.h b/fb/fbedgeimp.h
new file mode 100644
index 000000000..4a91adc19
--- /dev/null
+++ b/fb/fbedgeimp.h
@@ -0,0 +1,134 @@
+/*
+ * $Id$
+ *
+ * Copyright © 2004 Keith Packard
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of Keith Packard not be used in
+ * advertising or publicity pertaining to distribution of the software without
+ * specific, written prior permission.  Keith Packard makes no
+ * representations about the suitability of this software for any purpose.  It
+ * is provided "as is" without express or implied warranty.
+ *
+ * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef rasterizeSpan
+#endif
+
+static void
+rasterizeEdges (FbBits		*buf,
+		int		width,
+		int		stride,
+		RenderEdge	*l,
+		RenderEdge	*r,
+		xFixed		t,
+		xFixed		b)
+{
+    xFixed  y = t;
+    FbBits  *line;
+    
+    line = buf + xFixedToInt (y) * stride;
+    
+    for (;;)
+    {
+	xFixed	lx, rx;
+	int	lxi, rxi;
+	
+	/* clip X */
+	lx = l->x;
+	if (lx < 0)
+	    lx = 0;
+	rx = r->x;
+	if (xFixedToInt (rx) >= width)
+	    rx = IntToxFixed (width);
+	
+	/* Skip empty (or backwards) sections */
+	if (rx > lx)
+	{
+
+	    /* Find pixel bounds for span */
+	    lxi = xFixedToInt (lx);
+	    rxi = xFixedToInt (rx);
+
+#if N_BITS == 1
+	    {
+		FbBits  *a = line;
+		FbBits  startmask, endmask;
+		int	    nmiddle;
+		int	    width = rxi - lxi;
+		int	    x = lxi;
+
+		a += x >> FB_SHIFT;
+		x &= FB_MASK;
+
+		FbMaskBits (x, width, startmask, nmiddle, endmask);
+		if (startmask)
+		    *a++ |= startmask;
+		while (nmiddle--)
+		    *a++ = FB_ALLONES;
+		if (endmask)
+		    *a |= endmask;
+	    }
+#else
+	    {
+		DefineAlpha(line,lxi);
+		int	    lxs, rxs;
+
+		/* Sample coverage for edge pixels */
+		lxs = RenderSamplesX (lx, N_BITS);
+		rxs = RenderSamplesX (rx, N_BITS);
+
+		/* Add coverage across row */
+		if (lxi == rxi)
+		{
+		    AddAlpha (rxs - lxs);
+		}
+		else
+		{
+		    int	xi;
+
+		    AddAlpha (N_X_FRAC(N_BITS) - lxs);
+		    StepAlpha;
+		    for (xi = lxi + 1; xi < rxi; xi++)
+		    {
+			AddAlpha (N_X_FRAC(N_BITS));
+			StepAlpha;
+		    }
+		    AddAlpha (rxs);
+		}
+	    }
+#endif
+	}
+
+	if (y == b)
+	    break;
+
+#if N_BITS > 1
+	if (xFixedFrac (y) != Y_FRAC_LAST(N_BITS))
+	{
+	    RenderEdgeStepSmall (l);
+	    RenderEdgeStepSmall (r);
+	    y += STEP_Y_SMALL(N_BITS);
+	}
+	else
+#endif
+	{
+	    RenderEdgeStepBig (l);
+	    RenderEdgeStepBig (r);
+	    y += STEP_Y_BIG(N_BITS);
+	    line += stride;
+	}
+    }
+}
+
+#undef rasterizeSpan