src: add collision iterator adapter

1 files changed, 89 insertions, 0 deletions

diff --git a/src/collision.cpp b/src/collision.cpp
new file mode 100644
index 00000000..1a9c0b3f
--- /dev/null
+++ b/src/collision.cpp
@@ -0,0 +1,89 @@
+#include "collision.hpp"
+#include "compat/assert.hpp"
+#include "src/chunk.hpp"
+#include "compat/LooseQuadtree-impl.h"
+#include <utility>
+
+namespace floormat {
+
+void collision_bb_extractor::ExtractBoundingBox(const collision_bbox* x, BB* bbox)
+{
+    *bbox = { x->left, x->top, std::int16_t(x->width), std::int16_t(x->height) };
+}
+
+collision_iterator::collision_iterator() noexcept : q{nullptr} {}
+collision_iterator::collision_iterator(Query* q) noexcept : q{q} {}
+
+collision_iterator::~collision_iterator() noexcept
+{
+    if (q)
+        while (!q->EndOfQuery())
+            q->Next();
+}
+
+collision_iterator& collision_iterator::operator++() noexcept
+{
+    fm_debug_assert(q != nullptr && !q->EndOfQuery());
+    q->Next();
+    return *this;
+}
+
+auto collision_iterator::operator++(int) noexcept -> const collision_bbox*
+{
+    fm_debug_assert(q != nullptr && !q->EndOfQuery());
+    auto* bbox = q->GetCurrent();
+    fm_debug_assert(bbox != nullptr);
+    operator++();
+    return bbox;
+}
+
+auto collision_iterator::operator*() const noexcept -> const collision_bbox&
+{
+    return *operator->();
+}
+
+auto collision_iterator::operator->() const noexcept -> const collision_bbox*
+{
+    fm_debug_assert(q != nullptr && !q->EndOfQuery());
+    auto* ptr = q->GetCurrent();
+    fm_debug_assert(ptr != nullptr);
+    return ptr;
+}
+
+bool collision_iterator::operator==(const collision_iterator& other) const noexcept
+{
+    if (q && !other.q) [[likely]]
+        return q->EndOfQuery();
+    else if (!q && !other.q)
+        return true;
+    else if (!q)
+        return other.q->EndOfQuery();
+    else
+        return q == other.q;
+}
+
+collision_iterator::operator bool() const noexcept
+{
+    return q && !q->EndOfQuery();
+}
+
+collision_query::collision_query(collision_query::Query&& q) noexcept : q{std::move(q)} {}
+collision_iterator collision_query::begin() noexcept { return collision_iterator{&q}; }
+collision_iterator collision_query::end() noexcept { return collision_iterator{nullptr}; }
+
+collision_bbox::operator BB() const noexcept
+{
+    return BB{left, top, (Short)width, (Short)height};
+}
+
+bool collision_bbox::intersects(BB bb) const noexcept
+{
+    return BB(*this).Intersects(bb);
+}
+
+bool collision_bbox::intersects(collision_bbox bb) const noexcept
+{
+    return BB(*this).Intersects(bb);
+}
+
+} // namespace floormat