editor: move duplicated code to pixel_to_point()

2 files changed, 19 insertions, 3 deletions

diff --git a/main/main-impl.hpp b/main/main-impl.hpp
index 39e07d4c..66f143d1 100644
--- a/main/main-impl.hpp
+++ b/main/main-impl.hpp
@@ -65,8 +65,9 @@ struct main_impl final : Platform::Sdl2Application, floormat_main
     fm_settings& settings() noexcept override;
     const fm_settings& settings() const noexcept override;
 
-    global_coords pixel_to_tile(Vector2d position) const noexcept override;
+    global_coords pixel_to_tile(Vector2d position, int8_t z_level = 0) const noexcept override;
     Vector2d pixel_to_tile_(Vector2d position) const noexcept override;
+    point pixel_to_point(Vector2d position, int8_t z_level = 0) const noexcept override;
 
     ArrayView<const clickable> clickable_scenery() const noexcept override;
     ArrayView<clickable> clickable_scenery() noexcept override;
diff --git a/main/projection.cpp b/main/projection.cpp
index 8b32777e..b7ee01da 100644
--- a/main/projection.cpp
+++ b/main/projection.cpp
@@ -1,15 +1,16 @@
 #include "main-impl.hpp"
 #include "src/tile-constants.hpp"
+#include "src/point.hpp"
 #include <algorithm>
 #include <limits>
 
 namespace floormat {
 
-global_coords main_impl::pixel_to_tile(Vector2d position) const noexcept
+global_coords main_impl::pixel_to_tile(Vector2d position, int8_t z_level) const noexcept
 {
     auto vec = pixel_to_tile_(position);
     auto vec_ = Math::floor(vec);
-    return { (int32_t)vec_.x(), (int32_t)vec_.y(), 0 };
+    return { (int32_t)vec_.x(), (int32_t)vec_.y(), z_level };
 }
 
 Vector2d main_impl::pixel_to_tile_(Vector2d position) const noexcept
@@ -20,6 +21,20 @@ Vector2d main_impl::pixel_to_tile_(Vector2d position) const noexcept
     return tile_shader::unproject(px*.5) / pixel_size + half;
 }
 
+point main_impl::pixel_to_point(Vector2d pixel, int8_t z_level) const noexcept
+{
+    const auto tileʹ = pixel_to_tile_(pixel);
+    const auto tileʹʹ = Math::floor(tileʹ);
+    const auto tile = global_coords{(int)tileʹʹ.x(), (int)tileʹʹ.y(), z_level};
+    const auto subpixelʹ = Math::fmod(Vector2(tileʹ), 1.f);
+    const auto subpixelʹ_neg = Vector2{Vector2i(tile.chunk()) < Vector2i{}};
+    auto subpixel = TILE_SIZE2 * (subpixelʹ + subpixelʹ_neg);
+    constexpr auto half_tile = Vector2(iTILE_SIZE2/2);
+    subpixel -= half_tile;
+    subpixel = Math::clamp(Math::round(subpixel), -half_tile, half_tile-Vector2{1.f});
+    return point{ tile, Vector2b{subpixel} };
+}
+
 auto main_impl::get_draw_bounds() const noexcept -> draw_bounds
 {
     using limits = std::numeric_limits<int16_t>;