[gimp] app: add a polygon canvas item class (filled polygons unimplemented)

[Michael Natterer <mitch src gnome org>]

commit 4bedffd2cff73e3fa481fa01eac20086533b4266
Author: Michael Natterer <mitch gimp org>
Date:   Wed Sep 22 23:59:10 2010 +0200

    app: add a polygon canvas item class (filled polygons unimplemented)

 app/display/Makefile.am         |    2 +
 app/display/gimpcanvaspolygon.c |  284 +++++++++++++++++++++++++++++++++++++++
 app/display/gimpcanvaspolygon.h |   57 ++++++++
 3 files changed, 343 insertions(+), 0 deletions(-)
---
diff --git a/app/display/Makefile.am b/app/display/Makefile.am
index a494836..6135453 100644
--- a/app/display/Makefile.am
+++ b/app/display/Makefile.am
@@ -25,6 +25,8 @@ libappdisplay_a_sources = \
 	gimpcanvasitem.h			\
 	gimpcanvasline.c			\
 	gimpcanvasline.h			\
+	gimpcanvaspolygon.c			\
+	gimpcanvaspolygon.h			\
 	gimpcanvasrectangle.c			\
 	gimpcanvasrectangle.h			\
 	gimpcursorview.c			\
diff --git a/app/display/gimpcanvaspolygon.c b/app/display/gimpcanvaspolygon.c
new file mode 100644
index 0000000..0075b49
--- /dev/null
+++ b/app/display/gimpcanvaspolygon.c
@@ -0,0 +1,284 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaspolygon.c
+ * Copyright (C) 2010 Michael Natterer <mitch gimp org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "core/gimpparamspecs.h"
+
+#include "gimpcanvaspolygon.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-transform.h"
+
+
+enum
+{
+  PROP_0,
+  PROP_POINTS,
+  PROP_FILLED
+};
+
+
+typedef struct _GimpCanvasPolygonPrivate GimpCanvasPolygonPrivate;
+
+struct _GimpCanvasPolygonPrivate
+{
+  GimpVector2 *points;
+  gint         n_points;
+  gboolean     filled;
+};
+
+#define GET_PRIVATE(polygon) \
+        G_TYPE_INSTANCE_GET_PRIVATE (polygon, \
+                                     GIMP_TYPE_CANVAS_POLYGON, \
+                                     GimpCanvasPolygonPrivate)
+
+
+/*  local function prototypes  */
+
+static void        gimp_canvas_polygon_finalize     (GObject          *object);
+static void        gimp_canvas_polygon_set_property (GObject          *object,
+                                                     guint             property_id,
+                                                     const GValue     *value,
+                                                     GParamSpec       *pspec);
+static void        gimp_canvas_polygon_get_property (GObject          *object,
+                                                     guint             property_id,
+                                                     GValue           *value,
+                                                     GParamSpec       *pspec);
+static void        gimp_canvas_polygon_draw         (GimpCanvasItem   *item,
+                                                     GimpDisplayShell *shell,
+                                                     cairo_t          *cr);
+static GdkRegion * gimp_canvas_polygon_get_extents  (GimpCanvasItem   *item,
+                                                     GimpDisplayShell *shell);
+
+
+G_DEFINE_TYPE (GimpCanvasPolygon, gimp_canvas_polygon,
+               GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_polygon_parent_class
+
+
+static void
+gimp_canvas_polygon_class_init (GimpCanvasPolygonClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->finalize     = gimp_canvas_polygon_finalize;
+  object_class->set_property = gimp_canvas_polygon_set_property;
+  object_class->get_property = gimp_canvas_polygon_get_property;
+
+  item_class->draw           = gimp_canvas_polygon_draw;
+  item_class->get_extents    = gimp_canvas_polygon_get_extents;
+
+  g_object_class_install_property (object_class, PROP_POINTS,
+                                   gimp_param_spec_array ("points", NULL, NULL,
+                                                          GIMP_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_FILLED,
+                                   g_param_spec_boolean ("filled", NULL, NULL,
+                                                         FALSE,
+                                                         GIMP_PARAM_READWRITE));
+
+  g_type_class_add_private (klass, sizeof (GimpCanvasPolygonPrivate));
+}
+
+static void
+gimp_canvas_polygon_init (GimpCanvasPolygon *polygon)
+{
+}
+
+static void
+gimp_canvas_polygon_finalize (GObject *object)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (object);
+
+  if (private->points)
+    {
+      g_free (private->points);
+      private->points = NULL;
+      private->n_points = 0;
+    }
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gimp_canvas_polygon_set_property (GObject      *object,
+                                  guint         property_id,
+                                  const GValue *value,
+                                  GParamSpec   *pspec)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_POINTS:
+      break;
+    case PROP_FILLED:
+      private->filled = g_value_get_boolean (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_polygon_get_property (GObject    *object,
+                                    guint       property_id,
+                                    GValue     *value,
+                                    GParamSpec *pspec)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_POINTS:
+      break;
+    case PROP_FILLED:
+      g_value_set_boolean (value, private->filled);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_polygon_transform (GimpCanvasItem   *item,
+                               GimpDisplayShell *shell,
+                               GimpVector2      *points)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (item);
+  gint                      i;
+
+  for (i = 0; i < private->n_points; i++)
+    {
+      gimp_display_shell_transform_xy_f (shell,
+                                         private->points[i].x,
+                                         private->points[i].y,
+                                         &points[i].x,
+                                         &points[i].y,
+                                         FALSE);
+
+      points[i].x = PROJ_ROUND (points[i].x) + 0.5;
+      points[i].y = PROJ_ROUND (points[i].y) + 0.5;
+    }
+}
+
+static void
+gimp_canvas_polygon_draw (GimpCanvasItem   *item,
+                          GimpDisplayShell *shell,
+                          cairo_t          *cr)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (item);
+  GimpVector2              *points;
+  gint                      i;
+
+  points = g_new0 (GimpVector2, private->n_points);
+
+  gimp_canvas_polygon_transform (item, shell, points);
+
+  cairo_move_to (cr, points[0].x, points[0].y);
+
+  for (i = 1; i < private->n_points; i++)
+    {
+      cairo_line_to (cr, points[i].x, points[i].y);
+    }
+
+  if (private->filled)
+    _gimp_canvas_item_fill (item, shell, cr);
+  else
+    _gimp_canvas_item_stroke (item, shell, cr);
+
+  g_free (points);
+}
+
+static GdkRegion *
+gimp_canvas_polygon_get_extents (GimpCanvasItem   *item,
+                                 GimpDisplayShell *shell)
+{
+  GimpCanvasPolygonPrivate *private = GET_PRIVATE (item);
+  GdkRectangle              rectangle;
+  GimpVector2              *points;
+  gint                      x1, y1, x2, y2;
+  gint                      i;
+
+  points = g_new0 (GimpVector2, private->n_points);
+
+  gimp_canvas_polygon_transform (item, shell, points);
+
+  x1 = floor (points[0].x - 1.5);
+  y1 = floor (points[0].y - 1.5);
+  x2 = x1 + 3;
+  y2 = y1 + 3;
+
+  for (i = 1; i < private->n_points; i++)
+    {
+      gint x3 = floor (points[i].x - 1.5);
+      gint y3 = floor (points[i].y - 1.5);
+      gint x4 = x3 + 3;
+      gint y4 = y3 + 3;
+
+      x1 = MIN (x1, x3);
+      y1 = MIN (y1, y3);
+      x2 = MAX (x2, x4);
+      y2 = MAX (y2, y4);
+    }
+
+  g_free (points);
+
+  rectangle.x      = x1;
+  rectangle.y      = y1;
+  rectangle.width  = x2 - x1;
+  rectangle.height = y2 - y1;
+
+  return gdk_region_rectangle (&rectangle);
+}
+
+GimpCanvasItem *
+gimp_canvas_polygon_new (const GimpVector2 *points,
+                         gint               n_points,
+                         gboolean           filled)
+{
+  GimpCanvasItem           *item;
+  GimpCanvasPolygonPrivate *private;
+
+  item = g_object_new (GIMP_TYPE_CANVAS_POLYGON,
+                       "filled", filled,
+                       NULL);
+  private = GET_PRIVATE (item);
+
+  /* puke */
+  private->points   = g_memdup (points, n_points * sizeof (GimpVector2));
+  private->n_points = n_points;
+
+  return item;
+}
diff --git a/app/display/gimpcanvaspolygon.h b/app/display/gimpcanvaspolygon.h
new file mode 100644
index 0000000..54dadcd
--- /dev/null
+++ b/app/display/gimpcanvaspolygon.h
@@ -0,0 +1,57 @@
+/* GIMP - The GNU Image Manipulation Program Copyright (C) 1995
+ * Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvaspolygon.h
+ * Copyright (C) 2010 Michael Natterer <mitch gimp org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_POLYGON_H__
+#define __GIMP_CANVAS_POLYGON_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_POLYGON            (gimp_canvas_polygon_get_type ())
+#define GIMP_CANVAS_POLYGON(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_POLYGON, GimpCanvasPolygon))
+#define GIMP_CANVAS_POLYGON_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_POLYGON, GimpCanvasPolygonClass))
+#define GIMP_IS_CANVAS_POLYGON(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_POLYGON))
+#define GIMP_IS_CANVAS_POLYGON_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_POLYGON))
+#define GIMP_CANVAS_POLYGON_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_POLYGON, GimpCanvasPolygonClass))
+
+
+typedef struct _GimpCanvasPolygon      GimpCanvasPolygon;
+typedef struct _GimpCanvasPolygonClass GimpCanvasPolygonClass;
+
+struct _GimpCanvasPolygon
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasPolygonClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_polygon_get_type (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_polygon_new      (const GimpVector2 *points,
+                                               gint               n_points,
+                                               gboolean           filled);
+
+
+#endif /* __GIMP_CANVAS_POLYGON_H__ */