Move 3D axis manipulation functions to separate file

(bzr r3226)

1 files changed, 129 insertions, 0 deletions

diff --git a/src/axis-manip.h b/src/axis-manip.h
new file mode 100644
index 000000000..7ad716046
--- /dev/null
+++ b/src/axis-manip.h
@@ -0,0 +1,129 @@
+/*
+ * Generic auxiliary routines for 3D axes
+ *
+ * Authors:
+ *   Maximilian Albert <Anhalter42@gmx.de>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#ifndef SEEN_AXIS_MANIP_H
+#define SEEN_AXIS_MANIP_H
+
+#include <gtk/gtk.h>
+#include "libnr/nr-point.h"
+
+namespace Box3D {
+
+// The X-/Y-/Z-axis corresponds to the first/second/third digit
+// in binary representation, respectively.
+enum Axis {
+    X = 1,
+    Y = 2,
+    Z = 4,
+    XY = 3,
+    XZ = 5,
+    YZ = 6,
+    XYZ = 7,
+    NONE = 0
+};
+
+// We use the fourth bit in binary representation
+// to indicate whether a face is front or rear.
+enum FrontOrRear { // find a better name
+    FRONT = 0,
+    REAR = 8
+};
+
+extern Axis axes[3];
+extern Axis planes[3];
+extern FrontOrRear face_positions [2];
+
+// Given a bit sequence that unambiguously specifies the face of a 3D box,
+// return a number between 0 and 5 corresponding to that particular face
+// (which is normally used to index an array). Return -1 if the bit sequence
+// does not specify a face. A face can either be given by its plane (e.g, XY)
+// or by the axis that is orthogonal to it (e.g., Z).
+inline gint face_to_int (guint face_id) {
+    switch (face_id) {
+      case 1:  return 0;
+      case 2:  return 2;
+      case 4:  return 4;
+      case 3:  return 4;
+      case 5:  return 2;
+      case 6:  return 0;
+
+      case 9:  return 1;
+      case 10: return 3;
+      case 12: return 5;
+      case 11: return 5;
+      case 13: return 3;
+      case 14: return 1;
+
+    default: return -1;
+    }
+}
+
+inline bool is_single_axis_direction (Box3D::Axis dir) {
+    // tests whether dir is nonzero and a power of 2
+    return (!(dir & (dir - 1)) && dir);
+}
+
+/**
+ * Given two axis directions out of {X, Y, Z} or the corresponding plane, return the remaining one
+ * We don't check if 'plane' really specifies a plane (i.e., if it consists of precisely two directions).
+ */
+inline Box3D::Axis third_axis_direction (Box3D::Axis dir1, Box3D::Axis dir2) {
+    return (Box3D::Axis) ((dir1 + dir2) ^ 0x7);
+}
+inline Box3D::Axis third_axis_direction (Box3D::Axis plane) {
+    return (Box3D::Axis) (plane ^ 0x7);
+}
+
+/* returns the first/second axis direction occuring in the (possibly compound) expression 'dirs' */
+inline Box3D::Axis extract_first_axis_direction (Box3D::Axis dirs) {
+    if (dirs & Box3D::X) return Box3D::X;
+    if (dirs & Box3D::Y) return Box3D::Y;
+    if (dirs & Box3D::Z) return Box3D::Z;
+    return Box3D::NONE;
+}
+inline Box3D::Axis extract_second_axis_direction (Box3D::Axis dirs) {
+    return extract_first_axis_direction ((Box3D::Axis) (dirs ^ extract_first_axis_direction(dirs)));
+}
+
+inline Box3D::Axis orth_plane (Box3D::Axis axis) {
+    return (Box3D::Axis) (Box3D::XYZ ^ axis);
+}
+
+/* returns an axis direction perpendicular to the ones occuring in the (possibly compound) expression 'dirs' */
+inline Box3D::Axis get_perpendicular_axis_direction (Box3D::Axis dirs) {
+    if (!(dirs & Box3D::X)) return Box3D::X;
+    if (!(dirs & Box3D::Y)) return Box3D::Y;
+    if (!(dirs & Box3D::Z)) return Box3D::Z;
+    return Box3D::NONE;
+}
+
+inline gchar * string_from_axes (Box3D::Axis axes) {
+    GString *pstring = g_string_new("");
+    if (axes & Box3D::X) g_string_append_printf (pstring, "X");
+    if (axes & Box3D::Y) g_string_append_printf (pstring, "Y");
+    if (axes & Box3D::Z) g_string_append_printf (pstring, "Z");
+    return pstring->str;
+}
+
+} // namespace Box3D
+
+#endif /* !SEEN_AXIS_MANIP_H */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :