rewrote entirely the triangle clipping algorithm

There is still a lot of work needed to refactor it properly.

- use the Sutherland–Hodgman algorithm, with some minor changes
- made clipping more general, allowing clipping of any coordinate,
  before and after division by w
- compute the z coordinate only at the fragment stage instead of each
  time clipping creates / moves a vertex, in addition to the fragment
  stage
- added VectorCoords to choose at compile-time different coordinates
  based on a template argument
- added transpose struct to allow shuffling of vectors coordinates
- added math::utils::lerp which interpolate linearly a float
- added Vector{2,3,4}::map() which maps a vector from one range to
  another
- added template parameter to DerivedVertex (and therefore
  TriangleDerived) to allow choosing which dimension to use

1 files changed, 2 insertions, 2 deletions

diff --git a/src/o3d/tri.hpp b/src/o3d/tri.hpp
index 712c135..56ff1dd 100644
--- a/src/o3d/tri.hpp
+++ b/src/o3d/tri.hpp
@@ -12,8 +12,8 @@ struct Triangle {
     Vertex vertex2;
     Vertex vertex3;
 
-    constexpr TriangleDerived to_derived() const & {
-        return {{vertex1.vertex, 1.f, 0.f}, {vertex2.vertex, 0.f, 1.f}, {vertex3.vertex, 0.f, 0.f}};
+    constexpr TriangleDerived<engine::math::Vector4> to_derived() const & {
+        return { { vertex1.vertex, 1.f, 0.f }, { vertex2.vertex, 0.f, 1.f }, { vertex3.vertex, 0.f, 0.f } };
     }
 };