w broken

src/hole.cpp

@@ -1,7 +1,37 @@
 #include "hole.hpp"
+//#include <mg/Functions.h>
 
 namespace floormat {
 
+using bbox = cut_rectangle_result::bbox;
 
+cut_rectangle_result cut_rectangle(bbox input, bbox hole)
+{
+    auto ihalf  = Vector2i{input.bbox_size/2};
+    auto istart = input.position - ihalf;
+    auto iend   = input.position + Vector2i{input.bbox_size} - ihalf;
+
+    auto hhalf  = Vector2i{hole.bbox_size/2};
+    auto hstart = hole.position - hhalf;
+    auto hend   = hole.position + Vector2i{hole.bbox_size} - hhalf;
+
+    bool iempty = Vector2ui{input.bbox_size}.product() == 0;
+    bool hempty = Vector2ui{hole.bbox_size}.product() == 0;
+
+    bool outside_before_x = hend.x() >= istart.x();
+    bool outside_after_x  = hstart.x() <= iend.x();
+    bool affects_start_x  = hstart.x() <= istart.x();
+    bool affects_end_x    = hend.x() >= iend.x();
+
+    //std::atomic_signal_fence(std::memory_order::relaxed); // compiler-only barrier
+
+#if 1
+    auto foo = uint8_t(outside_before_x << 0 | outside_after_x << 1 | affects_start_x << 2 | affects_end_x << 3 | iempty << 4 | hempty << 5);
+    volatile auto bar = foo;
+    (void)bar;
+#endif
+
+    return {};
+}
 
 } // namespace floormat

src/hole.hpp

@@ -1,7 +1,37 @@
 #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;
+    };
+
+    std::array<bbox, 8> ret;
+    uint8_t size = 0;
+
+    operator ArrayView<const bbox>() const;
+};
+
+cut_rectangle_result cut_rectangle(cut_rectangle_result::bbox input, cut_rectangle_result::bbox hole);
 
 } // namespace floormat

test/app.cpp

@@ -61,6 +61,7 @@ int App::exec()
         FM_TEST(test_math),
         FM_TEST(test_astar_pool),
         FM_TEST(test_coords),
+        FM_TEST(test_hole),
         FM_TEST(test_bptr),
         FM_TEST(test_iptr),
         FM_TEST(test_entity),

test/app.hpp

@@ -24,6 +24,7 @@ void test_critter();
 void test_dijkstra();
 void test_entity();
 void test_hash();
+void test_hole();
 void test_iptr();
 void test_json();
 void test_json2();

test/hole.cpp

@@ -0,0 +1,19 @@
+#include "app.hpp"
+
+namespace floormat {
+
+namespace {
+
+// tests go here
+void test1()
+{
+}
+
+} // namespace
+
+void Test::test_hole()
+{
+    test1();
+}
+
+} // namespace floormat