gl/msaa: Introduce an MSAA compositor for OpenGL

The MSAA compositor will composite OpenGL primitives directly and
anti-alias via the GPU.

src/Makefile.sources

@@ -366,6 +366,7 @@ cairo_gl_sources = cairo-gl-composite.c \
 		   cairo-gl-info.c \
 		   cairo-gl-operand.c \
 		   cairo-gl-shaders.c \
+		   cairo-gl-msaa-compositor.c \
 		   cairo-gl-spans-compositor.c \
 		   cairo-gl-traps-compositor.c \
 		   cairo-gl-surface.c

src/cairo-gl-msaa-compositor.c

@@ -0,0 +1,110 @@
+/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
+/* cairo - a vector graphics library with display and print output
+ *
+ * Copyright © 2002 University of Southern California
+ * Copyright © 2005 Red Hat, Inc.
+ * Copyright © 2011 Intel Corporation
+ * Copyright © 2011 Samsung Electronics
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ *
+ * The Original Code is the cairo graphics library.
+ *
+ * The Initial Developer of the Original Code is University of Southern
+ * California.
+ *
+ * Contributor(s):
+ *	Henry Song <hsong@sisa.samsung.com>
+ *	Martin Robinson <mrobinson@igalia.com>
+ */
+
+#include "cairoint.h"
+
+#include "cairo-clip-private.h"
+#include "cairo-composite-rectangles-private.h"
+#include "cairo-compositor-private.h"
+#include "cairo-gl-private.h"
+#include "cairo-traps-private.h"
+
+static cairo_int_status_t
+_cairo_gl_msaa_compositor_paint (const cairo_compositor_t	*compositor,
+				 cairo_composite_rectangles_t	*composite)
+{
+    return CAIRO_INT_STATUS_UNSUPPORTED;
+}
+
+static cairo_int_status_t
+_cairo_gl_msaa_compositor_mask (const cairo_compositor_t	*compositor,
+				cairo_composite_rectangles_t	*composite)
+{
+    return CAIRO_INT_STATUS_UNSUPPORTED;
+}
+
+static cairo_int_status_t
+_cairo_gl_msaa_compositor_stroke (const cairo_compositor_t	*compositor,
+				  cairo_composite_rectangles_t	*composite,
+				  const cairo_path_fixed_t	*path,
+				  const cairo_stroke_style_t	*style,
+				  const cairo_matrix_t		*ctm,
+				  const cairo_matrix_t		*ctm_inverse,
+				  double			 tolerance,
+				  cairo_antialias_t		 antialias)
+{
+    return CAIRO_INT_STATUS_UNSUPPORTED;
+}
+
+static cairo_int_status_t
+_cairo_gl_msaa_compositor_fill (const cairo_compositor_t	*compositor,
+				cairo_composite_rectangles_t	*composite,
+				const cairo_path_fixed_t	*path,
+				cairo_fill_rule_t		 fill_rule,
+				double				 tolerance,
+				cairo_antialias_t		 antialias)
+{
+    return CAIRO_INT_STATUS_UNSUPPORTED;
+}
+
+static void
+_cairo_gl_msaa_compositor_init (cairo_compositor_t	 *compositor,
+				const cairo_compositor_t *delegate)
+{
+    compositor->delegate = delegate;
+
+    compositor->paint = _cairo_gl_msaa_compositor_paint;
+    compositor->mask = _cairo_gl_msaa_compositor_mask;
+    compositor->fill = _cairo_gl_msaa_compositor_fill;
+    compositor->stroke = _cairo_gl_msaa_compositor_stroke;
+    /* always fallback to common glyph cache implmentation */
+}
+
+const cairo_compositor_t *
+_cairo_gl_msaa_compositor_get (void)
+{
+    static cairo_compositor_t compositor;
+    if (compositor.delegate == NULL)
+	_cairo_gl_msaa_compositor_init (&compositor,
+					_cairo_gl_span_compositor_get ());
+
+    return &compositor;
+}

src/cairo-gl-private.h

@@ -645,6 +645,9 @@ _cairo_gl_operand_copy (cairo_gl_operand_t *dst,
 cairo_private void
 _cairo_gl_operand_destroy (cairo_gl_operand_t *operand);
 
+cairo_private const cairo_compositor_t *
+_cairo_gl_msaa_compositor_get (void);
+
 cairo_private const cairo_compositor_t *
 _cairo_gl_span_compositor_get (void);