Slight restructure the SVG grid output.

In particular:
* Make the svg_project_point() a function in an anonymous namespace
  in the .cc file, rather than a static member function of the class.
* Make those of its arguments that represent directions into tensors,
  rather than Points.
* Move a couple of variable declarations next to their initialization.

As far as functionality is concerned, represent cells by
'level.index' rather than 'level,index', since the former is what you
get when you pass a cell to a std::ostream. Also just use 'level'
in the SVG caption, rather than 'level_number'.

diff --git a/include/deal.II/grid/grid_out.h b/include/deal.II/grid/grid_out.h
index c8ef27c336c966745b409a24799d7940ec2ac500..5be78f2e3a291709015f95aafdfd7571f7a0745b 100644 (file)
--- a/include/deal.II/grid/grid_out.h
+++ b/include/deal.II/grid/grid_out.h
@@ -1723,22 +1723,6 @@ private:
                   std::ostream &             out) const;
 
 
-  /**
-   * This function projects a three-dimensional point (Point<3> point) onto a
-   * two-dimensional image plane, specified by the position of the camera
-   * viewing system (Point<3> camera_position), camera direction (Point<3>
-   * camera_position), camera horizontal (Point<3> camera_horizontal,
-   * necessary for the correct alignment of the later images), and the focus
-   * of the camera (float camera_focus).
-   *
-   * For SVG output of grids.
-   */
-  static Point<2> svg_project_point(Point<3> point,
-                                    Point<3> camera_position,
-                                    Point<3> camera_direction,
-                                    Point<3> camera_horizontal,
-                                    float    camera_focus);
-
   /**
    * Return the number of faces in the triangulation which have a boundary
    * indicator not equal to zero. Only these faces are explicitly printed in

diff --git a/source/grid/grid_out.cc b/source/grid/grid_out.cc
index c7c1205c3dc16feb25d4afba2e4fbad4621f94df..62cdcf9ac4bb83ce35188e5cbfc20e77ed15518c 100644 (file)
--- a/source/grid/grid_out.cc
+++ b/source/grid/grid_out.cc
@@ -1517,6 +1517,71 @@ GridOut::write_xfig(const Triangulation<2> &tria,
 
 
 
+namespace
+{
+  /**
+   * This function projects a three-dimensional point (Point<3> point) onto a
+   * two-dimensional image plane, specified by the position of the camera
+   * viewing system (Point<3> camera_position), camera direction (Point<3>
+   * camera_position), camera horizontal (Point<3> camera_horizontal,
+   * necessary for the correct alignment of the later images), and the focus
+   * of the camera (float camera_focus).
+   *
+   * For SVG output of grids.
+   */
+  Point<2> svg_project_point(Point<3>     point,
+                             Point<3>     camera_position,
+                             Tensor<1, 3> camera_direction,
+                             Tensor<1, 3> camera_horizontal,
+                             float        camera_focus)
+  {
+    // ...
+    Point<3> camera_vertical;
+    camera_vertical[0] = camera_horizontal[1] * camera_direction[2] -
+                         camera_horizontal[2] * camera_direction[1];
+    camera_vertical[1] = camera_horizontal[2] * camera_direction[0] -
+                         camera_horizontal[0] * camera_direction[2];
+    camera_vertical[2] = camera_horizontal[0] * camera_direction[1] -
+                         camera_horizontal[1] * camera_direction[0];
+
+    float phi;
+    phi = camera_focus;
+    phi /= (point[0] - camera_position[0]) * camera_direction[0] +
+           (point[1] - camera_position[1]) * camera_direction[1] +
+           (point[2] - camera_position[2]) * camera_direction[2];
+
+    Point<3> projection;
+    projection[0] = camera_position[0] + phi * (point[0] - camera_position[0]);
+    projection[1] = camera_position[1] + phi * (point[1] - camera_position[1]);
+    projection[2] = camera_position[2] + phi * (point[2] - camera_position[2]);
+
+    Point<2> projection_decomposition;
+    projection_decomposition[0] = (projection[0] - camera_position[0] -
+                                   camera_focus * camera_direction[0]) *
+                                  camera_horizontal[0];
+    projection_decomposition[0] += (projection[1] - camera_position[1] -
+                                    camera_focus * camera_direction[1]) *
+                                   camera_horizontal[1];
+    projection_decomposition[0] += (projection[2] - camera_position[2] -
+                                    camera_focus * camera_direction[2]) *
+                                   camera_horizontal[2];
+
+    projection_decomposition[1] = (projection[0] - camera_position[0] -
+                                   camera_focus * camera_direction[0]) *
+                                  camera_vertical[0];
+    projection_decomposition[1] += (projection[1] - camera_position[1] -
+                                    camera_focus * camera_direction[1]) *
+                                   camera_vertical[1];
+    projection_decomposition[1] += (projection[2] - camera_position[2] -
+                                    camera_focus * camera_direction[2]) *
+                                   camera_vertical[2];
+
+    return projection_decomposition;
+  }
+} // namespace
+
+
+
 template <int dim, int spacedim>
 void
 GridOut::write_svg(const Triangulation<dim, spacedim> &,
@@ -1555,11 +1620,7 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
   // time_stamp = time(0);
   // now = localtime(&time_stamp);
 
-  // vectors and variables for the perspective view
-  Point<3> camera_position;
-  Point<3> camera_direction;
-  Point<3> camera_horizontal;
-  float    camera_focus;
+  float camera_focus;
 
   Point<3> point;
   Point<2> projection_decomposition;
@@ -1657,14 +1718,18 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
     }
 
   // set the camera position to top view, targeting at the origin
+  // vectors and variables for the perspective view
+  Point<3> camera_position;
   camera_position[0] = 0;
   camera_position[1] = 0;
   camera_position[2] = 2. * std::max(x_dimension, y_dimension);
 
+  Tensor<1, 3> camera_direction;
   camera_direction[0] = 0;
   camera_direction[1] = 0;
   camera_direction[2] = -1;
 
+  Tensor<1, 3> camera_horizontal;
   camera_horizontal[0] = 1;
   camera_horizontal[1] = 0;
   camera_horizontal[2] = 0;
@@ -1767,7 +1832,7 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
                  std::max(x_dimension, y_dimension);
     }
 
-  projection_decomposition = GridOut::svg_project_point(
+  projection_decomposition = svg_project_point(
     point, camera_position, camera_direction, camera_horizontal, camera_focus);
 
   x_max_perspective = projection_decomposition[0];
@@ -1792,11 +1857,11 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
             std::max(x_dimension, y_dimension);
         }
 
-      projection_decomposition = GridOut::svg_project_point(point,
-                                                            camera_position,
-                                                            camera_direction,
-                                                            camera_horizontal,
-                                                            camera_focus);
+      projection_decomposition = svg_project_point(point,
+                                                   camera_position,
+                                                   camera_direction,
+                                                   camera_horizontal,
+                                                   camera_focus);
 
       if (x_max_perspective < projection_decomposition[0])
         x_max_perspective = projection_decomposition[0];
@@ -1811,11 +1876,11 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
       point[0] = cell->vertex(1)[0];
       point[1] = cell->vertex(1)[1];
 
-      projection_decomposition = GridOut::svg_project_point(point,
-                                                            camera_position,
-                                                            camera_direction,
-                                                            camera_horizontal,
-                                                            camera_focus);
+      projection_decomposition = svg_project_point(point,
+                                                   camera_position,
+                                                   camera_direction,
+                                                   camera_horizontal,
+                                                   camera_focus);
 
       if (x_max_perspective < projection_decomposition[0])
         x_max_perspective = projection_decomposition[0];
@@ -1830,11 +1895,11 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
       point[0] = cell->vertex(2)[0];
       point[1] = cell->vertex(2)[1];
 
-      projection_decomposition = GridOut::svg_project_point(point,
-                                                            camera_position,
-                                                            camera_direction,
-                                                            camera_horizontal,
-                                                            camera_focus);
+      projection_decomposition = svg_project_point(point,
+                                                   camera_position,
+                                                   camera_direction,
+                                                   camera_horizontal,
+                                                   camera_focus);
 
       if (x_max_perspective < projection_decomposition[0])
         x_max_perspective = projection_decomposition[0];
@@ -1849,11 +1914,11 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
       point[0] = cell->vertex(3)[0];
       point[1] = cell->vertex(3)[1];
 
-      projection_decomposition = GridOut::svg_project_point(point,
-                                                            camera_position,
-                                                            camera_direction,
-                                                            camera_horizontal,
-                                                            camera_focus);
+      projection_decomposition = svg_project_point(point,
+                                                   camera_position,
+                                                   camera_direction,
+                                                   camera_horizontal,
+                                                   camera_focus);
 
       if (x_max_perspective < projection_decomposition[0])
         x_max_perspective = projection_decomposition[0];
@@ -2143,12 +2208,11 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
                          std::max(x_dimension, y_dimension);
             }
 
-          projection_decomposition =
-            GridOut::svg_project_point(point,
-                                       camera_position,
-                                       camera_direction,
-                                       camera_horizontal,
-                                       camera_focus);
+          projection_decomposition = svg_project_point(point,
+                                                       camera_position,
+                                                       camera_direction,
+                                                       camera_horizontal,
+                                                       camera_focus);
 
           out << static_cast<unsigned int>(
                    .5 +
@@ -2168,12 +2232,11 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
           point[0] = cell->vertex(1)[0];
           point[1] = cell->vertex(1)[1];
 
-          projection_decomposition =
-            GridOut::svg_project_point(point,
-                                       camera_position,
-                                       camera_direction,
-                                       camera_horizontal,
-                                       camera_focus);
+          projection_decomposition = svg_project_point(point,
+                                                       camera_position,
+                                                       camera_direction,
+                                                       camera_horizontal,
+                                                       camera_focus);
 
           out << static_cast<unsigned int>(
                    .5 +
@@ -2193,12 +2256,11 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
           point[0] = cell->vertex(3)[0];
           point[1] = cell->vertex(3)[1];
 
-          projection_decomposition =
-            GridOut::svg_project_point(point,
-                                       camera_position,
-                                       camera_direction,
-                                       camera_horizontal,
-                                       camera_focus);
+          projection_decomposition = svg_project_point(point,
+                                                       camera_position,
+                                                       camera_direction,
+                                                       camera_horizontal,
+                                                       camera_focus);
 
           out << static_cast<unsigned int>(
                    .5 +
@@ -2218,12 +2280,11 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
           point[0] = cell->vertex(2)[0];
           point[1] = cell->vertex(2)[1];
 
-          projection_decomposition =
-            GridOut::svg_project_point(point,
-                                       camera_position,
-                                       camera_direction,
-                                       camera_horizontal,
-                                       camera_focus);
+          projection_decomposition = svg_project_point(point,
+                                                       camera_position,
+                                                       camera_direction,
+                                                       camera_horizontal,
+                                                       camera_focus);
 
           out << static_cast<unsigned int>(
                    .5 +
@@ -2243,12 +2304,11 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
           point[0] = cell->vertex(0)[0];
           point[1] = cell->vertex(0)[1];
 
-          projection_decomposition =
-            GridOut::svg_project_point(point,
-                                       camera_position,
-                                       camera_direction,
-                                       camera_horizontal,
-                                       camera_focus);
+          projection_decomposition = svg_project_point(point,
+                                                       camera_position,
+                                                       camera_direction,
+                                                       camera_horizontal,
+                                                       camera_focus);
 
           out << static_cast<unsigned int>(
                    .5 +
@@ -2289,12 +2349,11 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
               float distance_factor =
                 distance_to_camera / (2. * std::max(x_dimension, y_dimension));
 
-              projection_decomposition =
-                GridOut::svg_project_point(point,
-                                           camera_position,
-                                           camera_direction,
-                                           camera_horizontal,
-                                           camera_focus);
+              projection_decomposition = svg_project_point(point,
+                                                           camera_position,
+                                                           camera_direction,
+                                                           camera_horizontal,
+                                                           camera_focus);
 
               const auto font_size_this_cell = static_cast<unsigned int>(
                 .5 +
@@ -2326,7 +2385,7 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
               if (svg_flags.label_cell_index)
                 {
                   if (svg_flags.label_level_number)
-                    out << ',';
+                    out << '.';
                   out << cell->index();
                 }
 
@@ -2389,11 +2448,11 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
                         }
 
                       projection_decomposition =
-                        GridOut::svg_project_point(point,
-                                                   camera_position,
-                                                   camera_direction,
-                                                   camera_horizontal,
-                                                   camera_focus);
+                        svg_project_point(point,
+                                          camera_position,
+                                          camera_direction,
+                                          camera_horizontal,
+                                          camera_focus);
 
                       out << "  <line x1=\""
                           << static_cast<unsigned int>(
@@ -2427,11 +2486,11 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
                         }
 
                       projection_decomposition =
-                        GridOut::svg_project_point(point,
-                                                   camera_position,
-                                                   camera_direction,
-                                                   camera_horizontal,
-                                                   camera_focus);
+                        svg_project_point(point,
+                                          camera_position,
+                                          camera_direction,
+                                          camera_horizontal,
+                                          camera_focus);
 
                       out << "\" x2=\""
                           << static_cast<unsigned int>(
@@ -2505,12 +2564,12 @@ GridOut::write_svg(const Triangulation<2, 2> &tria, std::ostream &out) const
                                            (++line_offset) * 1.5 * font_size)
               << "\" style=\"text-anchor:start; font-style:oblique; font-size:"
               << font_size << "px\">"
-              << "level_number";
+              << "cell_level";
 
           if (svg_flags.label_cell_index || svg_flags.label_material_id ||
               svg_flags.label_subdomain_id ||
               svg_flags.label_level_subdomain_id)
-            out << ',';
+            out << '.';
 
           out << "</text>" << '\n';
         }
@@ -3745,57 +3804,6 @@ GridOut::write_ucd_lines(const Triangulation<dim, spacedim> &tria,
 }
 
 
-Point<2> GridOut::svg_project_point(Point<3> point,
-                                    Point<3> camera_position,
-                                    Point<3> camera_direction,
-                                    Point<3> camera_horizontal,
-                                    float    camera_focus)
-{
-  // ...
-  Point<3> camera_vertical;
-  camera_vertical[0] = camera_horizontal[1] * camera_direction[2] -
-                       camera_horizontal[2] * camera_direction[1];
-  camera_vertical[1] = camera_horizontal[2] * camera_direction[0] -
-                       camera_horizontal[0] * camera_direction[2];
-  camera_vertical[2] = camera_horizontal[0] * camera_direction[1] -
-                       camera_horizontal[1] * camera_direction[0];
-
-  float phi;
-  phi = camera_focus;
-  phi /= (point[0] - camera_position[0]) * camera_direction[0] +
-         (point[1] - camera_position[1]) * camera_direction[1] +
-         (point[2] - camera_position[2]) * camera_direction[2];
-
-  Point<3> projection;
-  projection[0] = camera_position[0] + phi * (point[0] - camera_position[0]);
-  projection[1] = camera_position[1] + phi * (point[1] - camera_position[1]);
-  projection[2] = camera_position[2] + phi * (point[2] - camera_position[2]);
-
-  Point<2> projection_decomposition;
-  projection_decomposition[0] =
-    (projection[0] - camera_position[0] - camera_focus * camera_direction[0]) *
-    camera_horizontal[0];
-  projection_decomposition[0] +=
-    (projection[1] - camera_position[1] - camera_focus * camera_direction[1]) *
-    camera_horizontal[1];
-  projection_decomposition[0] +=
-    (projection[2] - camera_position[2] - camera_focus * camera_direction[2]) *
-    camera_horizontal[2];
-
-  projection_decomposition[1] =
-    (projection[0] - camera_position[0] - camera_focus * camera_direction[0]) *
-    camera_vertical[0];
-  projection_decomposition[1] +=
-    (projection[1] - camera_position[1] - camera_focus * camera_direction[1]) *
-    camera_vertical[1];
-  projection_decomposition[1] +=
-    (projection[2] - camera_position[2] - camera_focus * camera_direction[2]) *
-    camera_vertical[2];
-
-  return projection_decomposition;
-}
-
-
 
 namespace internal
 {