diff options
Diffstat (limited to 'src/critter.cpp')
| -rw-r--r-- | src/critter.cpp | 39 |
1 files changed, 27 insertions, 12 deletions
diff --git a/src/critter.cpp b/src/critter.cpp index 637324ec..c0e17d44 100644 --- a/src/critter.cpp +++ b/src/critter.cpp @@ -47,8 +47,8 @@ constexpr auto arrows_to_dir(bool left, bool right, bool up, bool down) case D: return SE; case R: return NE; case U: return NW; + default: std::unreachable(); } - std::unreachable(); } constexpr Vector2i rotation_to_vec(rotation r) @@ -65,8 +65,8 @@ constexpr Vector2i rotation_to_vec(rotation r) case SW: return { -1, 1 }; case W: return { -1, 0 }; case NW: return { -1, -1 }; + default: std::unreachable(); } - std::unreachable(); } constexpr std::array<rotation, 3> rotation_to_similar(rotation r) @@ -83,8 +83,8 @@ constexpr std::array<rotation, 3> rotation_to_similar(rotation r) case SW: return { SW, S, W }; case W: return { W, SW, NW }; case NW: return { NW, W, N }; + default: std::unreachable(); } - std::unreachable(); } } // namespace @@ -121,11 +121,13 @@ int critter::allocate_frame_time(float dt) return ret; } -Vector2 critter::move_vec(Vector2i vec) +constexpr Vector2 move_vec(Vector2i vec) { const int left_right = vec[0], top_bottom = vec[1]; constexpr auto c = move_speed * frame_time; - return c * Vector2((float)sgn(left_right), (float)sgn(top_bottom)).normalized(); + auto dir = Vector2((float)sgn(left_right), (float)sgn(top_bottom)); + auto inv_norm = 1.f/math::sqrt(Math::dot(dir, dir)); + return c * dir * inv_norm; } void critter::set_keys(bool L, bool R, bool U, bool D) @@ -147,6 +149,24 @@ Vector2 critter::ordinal_offset(Vector2b offset) const return Vector2(offset); } +constexpr auto make_move_vec(rotation r) +{ + auto [_0, _1, _2] = rotation_to_similar(r); + return std::array<Vector2, 3>{{ + move_vec(rotation_to_vec(_0)), + move_vec(rotation_to_vec(_1)), + move_vec(rotation_to_vec(_2)), + }}; +} + +template<size_t... Index> +constexpr auto make_move_vecs(std::index_sequence<Index...>) +{ + return std::array<std::array<Vector2, 3>, (size_t)rotation_COUNT>{{ + make_move_vec((rotation)Index)..., + }}; +} + void critter::update(size_t i, float dt) { const auto new_r = arrows_to_dir(b_L, b_R, b_U, b_D); @@ -158,16 +178,11 @@ void critter::update(size_t i, float dt) } int nframes = allocate_frame_time(dt); - if (nframes == 0) return; - auto [_0, _1, _2] = rotation_to_similar(r); - const Vector2 move_vecs[] = { - move_vec(rotation_to_vec(_0)), - move_vec(rotation_to_vec(_1)), - move_vec(rotation_to_vec(_2)), - }; + constexpr auto move_vecs_ = make_move_vecs(std::make_index_sequence<(size_t)rotation_COUNT>{}); + const auto& move_vecs = move_vecs_[(size_t)r]; if (r != new_r) if (is_dynamic()) |