forward declaration to include functions elsewhere

src/typed-geometry/detail/constructors-fun.hh

@@ -9,12 +9,14 @@
 
 #include <typed-geometry/types/objects/box.hh>
 #include <typed-geometry/types/objects/ellipse.hh>
+#include <typed-geometry/types/objects/frustum.hh>
 #include <typed-geometry/types/objects/halfspace.hh>
 #include <typed-geometry/types/objects/line.hh>
 #include <typed-geometry/types/objects/plane.hh>
 
 #include <typed-geometry/detail/operators/ops_pos.hh>
 #include <typed-geometry/functions/vector/dot.hh>
+#include <typed-geometry/functions/vector/length.hh>
 
 // Header for all constructors that depend on functions
 
@@ -63,4 +65,22 @@ constexpr line<D, ScalarT> line<D, ScalarT>::from_points(pos_t a, pos_t b)
 {
     return line(a, normalize(b - a));
 }
+
+template <class ScalarT>
+constexpr frustum<ScalarT>::frustum(mat<4, 4, ScalarT> const& m)
+{
+    // computing planes in order: left, right, bottom, top, near, far
+    for (auto i = 0u; i < 3; ++i)
+        for (auto j = 0u; j < 2; ++j)
+        {
+            // plane parameters from matrix (see http://www8.cs.umu.se/kurser/5DV051/HT12/lab/plane_extraction.pdf)
+            vec4 abcd;
+            for (auto k = 0; k < 4; ++k)
+                abcd[k] = j == 0 ? m[k][3] + m[k][i] : m[k][3] - m[k][i];
+
+            auto n = vec3(abcd);
+            auto l = length(n);
+            planes[2 * i + j] = plane3(dir3(n / l), -abcd.w / l);
+        }
+}
 }

src/typed-geometry/types/objects/frustum.hh

@@ -2,10 +2,6 @@
 
 #include <typed-geometry/feature/assert.hh>
 
-#include <typed-geometry/functions/swizzling/swizzling-basic.hh>
-#include <typed-geometry/functions/vector/dot.hh>
-#include <typed-geometry/functions/vector/length.hh>
-#include <typed-geometry/functions/vector/normalize.hh>
 #include <typed-geometry/types/scalars/default.hh>
 #include "../pos.hh"
 #include "../vec.hh"
@@ -36,22 +32,7 @@ struct frustum
     }
 
     // extract frustum from a view-projection-matrix (proj * view)
-    explicit constexpr frustum(mat<4, 4, ScalarT> const& m)
-    {
-        // computing planes in order: left, right, bottom, top, near, far
-        for (auto i = 0u; i < 3; ++i)
-            for (auto j = 0u; j < 2; ++j)
-            {
-                // plane parameters from matrix (see http://www8.cs.umu.se/kurser/5DV051/HT12/lab/plane_extraction.pdf)
-                vec4 abcd;
-                for (auto k = 0; k < 4; ++k)
-                    abcd[k] = j == 0 ? m[k][3] + m[k][i] : m[k][3] - m[k][i];
-
-                auto n = vec3(abcd);
-                auto l = length(n);
-                planes[2 * i + j] = plane3(dir3(n / l), -abcd.w / l);
-            }
-    }
+    constexpr frustum(mat<4, 4, ScalarT> const& m); // requires tg.hh
 
     [[nodiscard]] bool operator==(frustum const& rhs) const
     {