From 4409f3cc68edbe728b6e699e5868b781348108f4 Mon Sep 17 00:00:00 2001 From: Marcel Admiraal Date: Fri, 1 May 2020 17:06:36 +0100 Subject: Fix array slicing. --- core/array.cpp | 72 +++++++++++++++++++++++++--------------------------------- core/array.h | 3 +-- 2 files changed, 32 insertions(+), 43 deletions(-) diff --git a/core/array.cpp b/core/array.cpp index cd4e0fb4c8..7c0129ffde 100644 --- a/core/array.cpp +++ b/core/array.cpp @@ -285,59 +285,49 @@ Array Array::duplicate(bool p_deep) const { return new_arr; } -int Array::_fix_slice_index(int p_index, int p_arr_len, int p_top_mod) { - p_index = CLAMP(p_index, -p_arr_len, p_arr_len + p_top_mod); - if (p_index < 0) { - p_index = (p_index % p_arr_len + p_arr_len) % p_arr_len; // positive modulo - } - return p_index; -} +int Array::_clamp_slice_index(int p_index) const { -int Array::_clamp_index(int p_index) const { - return CLAMP(p_index, -size() + 1, size() - 1); + int arr_size = size(); + int fixed_index = CLAMP(p_index, -arr_size, arr_size - 1); + if (fixed_index < 0) { + fixed_index = arr_size + fixed_index; + } + return fixed_index; } -#define ARRAY_GET_DEEP(idx, is_deep) is_deep ? get(idx).duplicate(is_deep) : get(idx) - Array Array::slice(int p_begin, int p_end, int p_step, bool p_deep) const { // like python, but inclusive on upper bound - Array new_arr; - - if (empty()) // Don't try to slice empty arrays. - return new_arr; - p_begin = Array::_fix_slice_index(p_begin, size(), -1); // can't start out of range - p_end = Array::_fix_slice_index(p_end, size(), 0); + Array new_arr; - int x = p_begin; - int new_arr_i = 0; + ERR_FAIL_COND_V_MSG(p_step == 0, new_arr, "Array slice step size cannot be zero."); - ERR_FAIL_COND_V(p_step == 0, new_arr); - if (Array::_clamp_index(p_begin) == Array::_clamp_index(p_end)) { // don't include element twice - new_arr.resize(1); - // new_arr[0] = 1; - new_arr[0] = ARRAY_GET_DEEP(Array::_clamp_index(p_begin), p_deep); + if (empty()) // Don't try to slice empty arrays. return new_arr; - } else { - int element_count = ceil((int)MAX(0, (p_end - p_begin) / p_step)) + 1; - if (element_count == 1) { // delta going in wrong direction to reach end - new_arr.resize(0); + if (p_step > 0) { + if (p_begin >= size() || p_end < -size()) + return new_arr; + } else { // p_step < 0 + if (p_begin < -size() || p_end >= size()) return new_arr; - } - new_arr.resize(element_count); } - // if going backwards, have to have a different terminating condition - if (p_step < 0) { - while (x >= p_end) { - new_arr[new_arr_i] = ARRAY_GET_DEEP(Array::_clamp_index(x), p_deep); - x += p_step; - new_arr_i += 1; + int begin = _clamp_slice_index(p_begin); + int end = _clamp_slice_index(p_end); + + int new_arr_size = MAX(((end - begin + p_step) / p_step), 0); + new_arr.resize(new_arr_size); + + if (p_step > 0) { + int dest_idx = 0; + for (int idx = begin; idx <= end; idx += p_step) { + ERR_FAIL_COND_V_MSG(dest_idx < 0 || dest_idx >= new_arr_size, Array(), "Bug in Array slice()"); + new_arr[dest_idx++] = p_deep ? get(idx).duplicate(p_deep) : get(idx); } - } else if (p_step > 0) { - while (x <= p_end) { - new_arr[new_arr_i] = ARRAY_GET_DEEP(Array::_clamp_index(x), p_deep); - x += p_step; - new_arr_i += 1; + } else { // p_step < 0 + int dest_idx = 0; + for (int idx = begin; idx >= end; idx += p_step) { + ERR_FAIL_COND_V_MSG(dest_idx < 0 || dest_idx >= new_arr_size, Array(), "Bug in Array slice()"); + new_arr[dest_idx++] = p_deep ? get(idx).duplicate(p_deep) : get(idx); } } diff --git a/core/array.h b/core/array.h index 2840ce199c..14db57f15f 100644 --- a/core/array.h +++ b/core/array.h @@ -44,8 +44,7 @@ class Array { void _ref(const Array &p_from) const; void _unref() const; - int _clamp_index(int p_index) const; - static int _fix_slice_index(int p_index, int p_arr_len, int p_top_mod); + inline int _clamp_slice_index(int p_index) const; protected: Array(const Array &p_base, uint32_t p_type, const StringName &p_class_name, const Variant &p_script); -- cgit v1.2.3