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, 4 insertions, 11 deletions

diff --git a/src/o3d/tri_deriv.hpp b/src/o3d/tri_deriv.hpp
index 65713ed..64369fc 100644
--- a/src/o3d/tri_deriv.hpp
+++ b/src/o3d/tri_deriv.hpp
@@ -1,23 +1,16 @@
 #ifndef O3D_TRI_VERTEX_HPP
 #define O3D_TRI_VERTEX_HPP
 
-#include <vector>
 #include "o3d/vertex.hpp"
 #include "o3d/deriv_vertex.hpp"
 
 namespace engine::o3d {
 
+template<engine::math::VectorTypeConcept VectorType>
 struct TriangleDerived {
-    DerivedVertex derived_vertex1;
-    DerivedVertex derived_vertex2;
-    DerivedVertex derived_vertex3;
-
-    std::vector<TriangleDerived> perspective_crop_xy_out(float x1, float x2, float y1, float y2) const;
-    std::vector<TriangleDerived> crop_z_out(float z1, float z2) const;
-
-    constexpr TriangleDerived div_by_w() const & {
-        return {derived_vertex1.div_by_w(), derived_vertex2.div_by_w(), derived_vertex3.div_by_w()};
-    }
+    DerivedVertex<VectorType> derived_vertex1;
+    DerivedVertex<VectorType> derived_vertex2;
+    DerivedVertex<VectorType> derived_vertex3;
 };
 
 }