w

2 files changed, 78 insertions, 0 deletions

diff --git a/src/hole.cpp b/src/hole.cpp
index f9e6f05c..cdd409d7 100644
--- a/src/hole.cpp
+++ b/src/hole.cpp
@@ -1,7 +1,52 @@
 #include "hole.hpp"
+//#include <mg/Functions.h>
 
 namespace floormat {
 
+using bbox = cut_rectangle_result::bbox;
+
+namespace {
+
+
+} // namespace
+
+cut_rectangle_result cut_rectangle(cut_rectangle_result::bbox input, cut_rectangle_result::bbox hole)
+{
+    const auto ihalf  = Vector2i{input.bbox_size/2};
+    const auto istart = input.position - ihalf;
+    const auto iend   = input.position + Vector2i{input.bbox_size} - ihalf;
+    const auto hhalf  = Vector2i{hole.bbox_size/2};
+    const auto hstart = hole.position - hhalf;
+    const auto hend   = hole.position + Vector2i{hole.bbox_size} - hhalf;
+
+    //std::atomic_signal_fence(std::memory_order::relaxed); // compiler-only barrier
+
+    {
+        bool iempty = Vector2ui{input.bbox_size}.product() == 0;
+        bool hempty = Vector2ui{hole.bbox_size}.product() == 0;
+        bool empty_before_x  = hend.x() <= istart.x();
+        bool empty_before_y  = hend.y() <= istart.y();
+        bool empty_after_x   = hstart.x() >= iend.x();
+        bool empty_after_y   = hstart.y() >= iend.y();
+        if (iempty | hempty | empty_before_x | empty_before_y | empty_after_x | empty_after_y)
+            return {};
+    }
+
+    const bool sx = hstart.x() <= istart.x();
+    const bool ex = hend.x()   >= iend.x();
+    const bool sy = hstart.y() <= istart.y();
+    const bool ey = hend.y()   >= iend.y();
+
+    enum : uint8_t { SX, EX, SY, EY };
+    enum : uint8_t { startx = 1 << SX, endx = 1 << EX, starty = 1 << SY, endy = 1 << EY };
+
+    constexpr auto mask = uint8_t(startx | endx | starty | endy);
+    auto val = uint8_t(sx << SX | ex << EX | sy << SY | ey << EY);
+    CORRADE_ASSUME((val & mask) == val);
+    (void)val;
+
+    return {};
+}
 
 
 } // namespace floormat
diff --git a/src/hole.hpp b/src/hole.hpp
index d97c72f9..bf01ccd2 100644
--- a/src/hole.hpp
+++ b/src/hole.hpp
@@ -1,7 +1,40 @@
 #pragma once
+#include "object.hpp"
+#include <array>
 
 namespace floormat {
 
+struct hole_proto final : object_proto
+{
+    bool affects_render  : 1 = true;
+    bool affects_physics : 1 = false;
+};
 
+struct hole : object
+{
+    bool affects_render  : 1 = true;
+    bool affects_physics : 1 = false;
+
+    hole(object_id id, class chunk& c, const hole_proto& proto);
+};
+
+struct cut_rectangle_result
+{
+    struct bbox
+    {
+        Vector2i position;
+        Vector2ub bbox_size;
+    };
+
+    struct rect { Vector2i min, max; };
+
+    uint8_t code = 0;
+    uint8_t size = 0;
+    std::array<rect, 8> ret;
+
+    operator ArrayView<const bbox>() const;
+};
+
+cut_rectangle_result cut_rectangle(cut_rectangle_result::bbox input, cut_rectangle_result::bbox hole);
 
 } // namespace floormat