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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
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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...
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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.
+ */
+
+#include "config.h"
+#include "art_rgb_affine_private.h"
+
+#include <math.h>
+#include "art_misc.h"
+#include "art_point.h"
+#include "art_affine.h"
+
+/* Private functions for the rgb affine image compositors - primarily,
+ the determination of runs, eliminating the need for source image
+ bbox calculation in the inner loop. */
+
+/* Determine a "run", such that the inverse affine of all pixels from
+ (x0, y) inclusive to (x1, y) exclusive fit within the bounds
+ of the source image.
+
+ Initial values of x0, x1, and result values stored in first two
+ pointer arguments.
+*/
+
+#define EPSILON 1e-6
+
+void
+art_rgb_affine_run (int *p_x0, int *p_x1, int y,
+ int src_width, int src_height,
+ const double affine[6])
+{
+ int x0, x1;
+ double z;
+ double x_intercept;
+ int xi;
+
+ x0 = *p_x0;
+ x1 = *p_x1;
+
+ /* do left and right edges */
+ if (affine[0] > EPSILON)
+ {
+ z = affine[2] * (y + 0.5) + affine[4];
+ x_intercept = -z / affine[0];
+ xi = ceil (x_intercept + EPSILON - 0.5);
+ if (xi > x0)
+ x0 = xi;
+ x_intercept = (-z + src_width) / affine[0];
+ xi = ceil (x_intercept - EPSILON - 0.5);
+ if (xi < x1)
+ x1 = xi;
+ }
+ else if (affine[0] < -EPSILON)
+ {
+ z = affine[2] * (y + 0.5) + affine[4];
+ x_intercept = (-z + src_width) / affine[0];
+ xi = ceil (x_intercept + EPSILON - 0.5);
+ if (xi > x0)
+ x0 = xi;
+ x_intercept = -z / affine[0];
+ xi = ceil (x_intercept - EPSILON - 0.5);
+ if (xi < x1)
+ x1 = xi;
+ }
+ else
+ {
+ z = affine[2] * (y + 0.5) + affine[4];
+ if (z < 0 || z >= src_width)
+ {
+ *p_x1 = *p_x0;
+ return;
+ }
+ }
+
+ /* do top and bottom edges */
+ if (affine[1] > EPSILON)
+ {
+ z = affine[3] * (y + 0.5) + affine[5];
+ x_intercept = -z / affine[1];
+ xi = ceil (x_intercept + EPSILON - 0.5);
+ if (xi > x0)
+ x0 = xi;
+ x_intercept = (-z + src_height) / affine[1];
+ xi = ceil (x_intercept - EPSILON - 0.5);
+ if (xi < x1)
+ x1 = xi;
+ }
+ else if (affine[1] < -EPSILON)
+ {
+ z = affine[3] * (y + 0.5) + affine[5];
+ x_intercept = (-z + src_height) / affine[1];
+ xi = ceil (x_intercept + EPSILON - 0.5);
+ if (xi > x0)
+ x0 = xi;
+ x_intercept = -z / affine[1];
+ xi = ceil (x_intercept - EPSILON - 0.5);
+ if (xi < x1)
+ x1 = xi;
+ }
+ else
+ {
+ z = affine[3] * (y + 0.5) + affine[5];
+ if (z < 0 || z >= src_height)
+ {
+ *p_x1 = *p_x0;
+ return;
+ }
+ }
+
+ *p_x0 = x0;
+ *p_x1 = x1;
+}