wayland/screencopy: add screencopy

src/core/stacklist.hpp

@@ -0,0 +1,159 @@
+#pragma once
+
+#include <algorithm>
+#include <array>
+#include <cstddef>
+#include <cstdint>
+#include <iterator>
+#include <vector>
+
+#include <qtypes.h>
+
+template <class T, size_t N>
+class StackList {
+public:
+	T& operator[](size_t i) {
+		if (i < N) {
+			return this->array[i];
+		} else {
+			return this->vec[i - N];
+		}
+	}
+
+	const T& operator[](size_t i) const {
+		return const_cast<StackList<T, N>*>(this)->operator[](i); // NOLINT
+	}
+
+	void push(const T& value) {
+		if (this->size < N) {
+			this->array[this->size] = value;
+		} else {
+			this->vec.push_back(value);
+		}
+
+		++this->size;
+	}
+
+	[[nodiscard]] size_t length() const { return this->size; }
+	[[nodiscard]] bool isEmpty() const { return this->size == 0; }
+
+	[[nodiscard]] bool operator==(const StackList<T, N>& other) const {
+		if (other.size != this->size) return false;
+
+		for (size_t i = 0; i < this->size; ++i) {
+			if (this->operator[](i) != other[i]) return false;
+		}
+
+		return true;
+	}
+
+	template <typename Self, typename ListPtr, typename IT>
+	struct BaseIterator {
+		using iterator_category = std::bidirectional_iterator_tag;
+		using difference_type = int64_t;
+		using value_type = IT;
+		using pointer = IT*;
+		using reference = IT&;
+
+		BaseIterator() = default;
+		explicit BaseIterator(ListPtr list, size_t i): list(list), i(i) {}
+
+		reference operator*() const { return this->list->operator[](this->i); }
+		pointer operator->() const { return &**this; }
+
+		Self& operator++() {
+			++this->i;
+			return *static_cast<Self*>(this);
+		}
+		Self& operator--() {
+			--this->i;
+			return *static_cast<Self*>(this);
+		}
+
+		Self operator++(int) {
+			auto v = *this;
+			this->operator++();
+			return v;
+		}
+		Self operator--(int) {
+			auto v = *this;
+			this->operator--();
+			return v;
+		}
+
+		difference_type operator-(const Self& other) {
+			return static_cast<int64_t>(this->i) - static_cast<int64_t>(other.i);
+		}
+
+		Self& operator+(difference_type offset) {
+			return Self(this->list, static_cast<int64_t>(this->i) + offset);
+		}
+
+		[[nodiscard]] bool operator==(const Self& other) const {
+			return this->list == other.list && this->i == other.i;
+		}
+
+		[[nodiscard]] bool operator!=(const Self& other) const { return !(*this == other); }
+
+	private:
+		ListPtr list = nullptr;
+		size_t i = 0;
+	};
+
+	struct Iterator: public BaseIterator<Iterator, StackList<T, N>*, T> {
+		Iterator() = default;
+		Iterator(StackList<T, N>* list, size_t i)
+		    : BaseIterator<Iterator, StackList<T, N>*, T>(list, i) {}
+	};
+
+	struct ConstIterator: public BaseIterator<ConstIterator, const StackList<T, N>*, const T> {
+		ConstIterator() = default;
+		ConstIterator(const StackList<T, N>* list, size_t i)
+		    : BaseIterator<ConstIterator, const StackList<T, N>*, const T>(list, i) {}
+	};
+
+	[[nodiscard]] Iterator begin() { return Iterator(this, 0); }
+	[[nodiscard]] Iterator end() { return Iterator(this, this->size); }
+
+	[[nodiscard]] ConstIterator begin() const { return ConstIterator(this, 0); }
+	[[nodiscard]] ConstIterator end() const { return ConstIterator(this, this->size); }
+
+	[[nodiscard]] bool isContiguous() const { return this->vec.empty(); }
+	[[nodiscard]] const T* pArray() const { return this->array.data(); }
+	[[nodiscard]] size_t dataLength() const { return this->size * sizeof(T); }
+
+	const T* populateAlloc(void* alloc) const {
+		auto arraylen = std::min(this->size, N) * sizeof(T);
+		memcpy(alloc, this->array.data(), arraylen);
+
+		if (!this->vec.empty()) {
+			memcpy(
+			    static_cast<char*>(alloc) + arraylen, // NOLINT
+			    this->vec.data(),
+			    this->vec.size() * sizeof(T)
+			);
+		}
+
+		return static_cast<T*>(alloc);
+	}
+
+private:
+	std::array<T, N> array {};
+	std::vector<T> vec;
+	size_t size = 0;
+};
+
+// might be incorrectly aligned depending on type
+// #define STACKLIST_ALLOCA_VIEW(list) ((list).isContiguous() ? (list).pArray() : (list).populateAlloc(alloca((list).dataLength())))
+
+// NOLINTBEGIN
+#define STACKLIST_VLA_VIEW(type, list, var)                                                        \
+	const type* var;                                                                                 \
+	type var##Data[(list).length()];                                                                 \
+	if ((list).isContiguous()) {                                                                     \
+		(var) = (list).pArray();                                                                       \
+	} else {                                                                                         \
+		(list).populateAlloc(var##Data);                                                               \
+		(var) = var##Data;                                                                             \
+	}
+// NOLINTEND