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authorMatthew Barnes <mbarnes@redhat.com>2010-06-14 06:37:27 +0800
committerMatthew Barnes <mbarnes@redhat.com>2010-06-14 09:31:58 +0800
commite6972011f01eab9f8d0a4584f32ee1e2a00f3231 (patch)
tree69e2a5e846965c3b369724b825f5b35c6d88056a /libart_lgpl/art_gray_svp.c
parent7f3377c78a560aa762e04d596b79f847c4acd870 (diff)
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Embed libart_lgpl and libgnomecanvas.
Both of these modules are deprecated and going away in GNOME 3 but we still rely heavily on them for GnomeCalendar and ETable. So, welcome to the island of unwanted libraries...
Diffstat (limited to 'libart_lgpl/art_gray_svp.c')
-rw-r--r--libart_lgpl/art_gray_svp.c123
1 files changed, 123 insertions, 0 deletions
diff --git a/libart_lgpl/art_gray_svp.c b/libart_lgpl/art_gray_svp.c
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+++ b/libart_lgpl/art_gray_svp.c
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+/* Libart_LGPL - library of basic graphic primitives
+ * Copyright (C) 1998 Raph Levien
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/* Render a sorted vector path into a graymap. */
+
+#include "config.h"
+#include "art_gray_svp.h"
+
+#include <string.h> /* for memset */
+#include "art_misc.h"
+
+#include "art_svp.h"
+#include "art_svp_render_aa.h"
+
+typedef struct _ArtGraySVPData ArtGraySVPData;
+
+struct _ArtGraySVPData {
+ art_u8 *buf;
+ int rowstride;
+ int x0, x1;
+};
+
+static void
+art_gray_svp_callback (void *callback_data, int y,
+ int start, ArtSVPRenderAAStep *steps, int n_steps)
+{
+ ArtGraySVPData *data = (ArtGraySVPData *)callback_data;
+ art_u8 *linebuf;
+ int run_x0, run_x1;
+ int running_sum = start;
+ int x0, x1;
+ int k;
+
+#if 0
+ printf ("start = %d", start);
+ running_sum = start;
+ for (k = 0; k < n_steps; k++)
+ {
+ running_sum += steps[k].delta;
+ printf (" %d:%d", steps[k].x, running_sum >> 16);
+ }
+ printf ("\n");
+#endif
+
+ linebuf = data->buf;
+ x0 = data->x0;
+ x1 = data->x1;
+
+ if (n_steps > 0)
+ {
+ run_x1 = steps[0].x;
+ if (run_x1 > x0)
+ memset (linebuf, running_sum >> 16, run_x1 - x0);
+
+ for (k = 0; k < n_steps - 1; k++)
+ {
+ running_sum += steps[k].delta;
+ run_x0 = run_x1;
+ run_x1 = steps[k + 1].x;
+ if (run_x1 > run_x0)
+ memset (linebuf + run_x0 - x0, running_sum >> 16, run_x1 - run_x0);
+ }
+ running_sum += steps[k].delta;
+ if (x1 > run_x1)
+ memset (linebuf + run_x1 - x0, running_sum >> 16, x1 - run_x1);
+ }
+ else
+ {
+ memset (linebuf, running_sum >> 16, x1 - x0);
+ }
+
+ data->buf += data->rowstride;
+}
+
+/**
+ * art_gray_svp_aa: Render the vector path into the bytemap.
+ * @svp: The SVP to render.
+ * @x0: The view window's left coord.
+ * @y0: The view window's top coord.
+ * @x1: The view window's right coord.
+ * @y1: The view window's bottom coord.
+ * @buf: The buffer where the bytemap is stored.
+ * @rowstride: the rowstride for @buf.
+ *
+ * Each pixel gets a value proportional to the area within the pixel
+ * overlapping the (filled) SVP. Pixel (x, y) is stored at:
+ *
+ * @buf[(y - * @y0) * @rowstride + (x - @x0)]
+ *
+ * All pixels @x0 <= x < @x1, @y0 <= y < @y1 are generated. A
+ * stored value of zero is no coverage, and a value of 255 is full
+ * coverage. The area within the pixel (x, y) is the region covered
+ * by [x..x+1] and [y..y+1].
+ **/
+void
+art_gray_svp_aa (const ArtSVP *svp,
+ int x0, int y0, int x1, int y1,
+ art_u8 *buf, int rowstride)
+{
+ ArtGraySVPData data;
+
+ data.buf = buf;
+ data.rowstride = rowstride;
+ data.x0 = x0;
+ data.x1 = x1;
+ art_svp_render_aa (svp, x0, y0, x1, y1, art_gray_svp_callback, &data);
+}