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Diffstat (limited to 'source/blender/compositor/intern/COM_BufferArea.h')
| -rw-r--r-- | source/blender/compositor/intern/COM_BufferArea.h | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/source/blender/compositor/intern/COM_BufferArea.h b/source/blender/compositor/intern/COM_BufferArea.h new file mode 100644 index 00000000000..6f7756ecbfc --- /dev/null +++ b/source/blender/compositor/intern/COM_BufferArea.h @@ -0,0 +1,215 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * Copyright 2021, Blender Foundation. + */ + +#pragma once + +#include "BLI_assert.h" +#include "BLI_rect.h" +#include <iterator> + +namespace blender::compositor { + +/* Forward declarations. */ +template<typename T> class BufferAreaIterator; + +/** + * A rectangle area of buffer elements. + */ +template<typename T> class BufferArea : rcti { + public: + using Iterator = BufferAreaIterator<T>; + using ConstIterator = BufferAreaIterator<const T>; + + private: + T *buffer_; + /* Number of elements in a buffer row. */ + int buffer_width_; + /* Buffer element stride. */ + int elem_stride_; + + public: + constexpr BufferArea() = default; + + /** + * Create a buffer area containing given rectangle area. + */ + constexpr BufferArea(T *buffer, int buffer_width, const rcti &area, int elem_stride = 1) + : rcti(area), buffer_(buffer), buffer_width_(buffer_width), elem_stride_(elem_stride) + { + } + + /** + * Create a buffer area containing whole buffer with no offsets. + */ + constexpr BufferArea(T *buffer, int buffer_width, int buffer_height, int elem_stride = 1) + : buffer_(buffer), buffer_width_(buffer_width), elem_stride_(elem_stride) + { + BLI_rcti_init(this, 0, buffer_width, 0, buffer_height); + } + + constexpr friend bool operator==(const BufferArea &a, const BufferArea &b) + { + return a.buffer_ == b.buffer_ && BLI_rcti_compare(&a, &b) && a.elem_stride_ == b.elem_stride_; + } + + constexpr const rcti &get_rect() const + { + return *this; + } + + /** + * Number of elements in a row. + */ + constexpr int width() const + { + return BLI_rcti_size_x(this); + } + + /** + * Number of elements in a column. + */ + constexpr int height() const + { + return BLI_rcti_size_y(this); + } + + constexpr Iterator begin() + { + return begin_iterator<Iterator>(); + } + + constexpr Iterator end() + { + return end_iterator<Iterator>(); + } + + constexpr ConstIterator begin() const + { + return begin_iterator<ConstIterator>(); + } + + constexpr ConstIterator end() const + { + return end_iterator<ConstIterator>(); + } + + private: + template<typename TIterator> constexpr TIterator begin_iterator() const + { + T *end_ptr = get_end_ptr(); + if (elem_stride_ == 0) { + /* Iterate a single element. */ + return TIterator(buffer_, end_ptr, 1, 1, 1); + } + + T *begin_ptr = buffer_ + (intptr_t)this->ymin * buffer_width_ * elem_stride_ + + (intptr_t)this->xmin * elem_stride_; + return TIterator(begin_ptr, end_ptr, buffer_width_, BLI_rcti_size_x(this), elem_stride_); + } + + template<typename TIterator> constexpr TIterator end_iterator() const + { + T *end_ptr = get_end_ptr(); + if (elem_stride_ == 0) { + /* Iterate a single element. */ + return TIterator(end_ptr, end_ptr, 1, 1, 1); + } + + return TIterator(end_ptr, end_ptr, buffer_width_, BLI_rcti_size_x(this), elem_stride_); + } + + T *get_end_ptr() const + { + if (elem_stride_ == 0) { + return buffer_ + 1; + } + return buffer_ + (intptr_t)(this->ymax - 1) * buffer_width_ * elem_stride_ + + (intptr_t)this->xmax * elem_stride_; + } +}; + +template<typename T> class BufferAreaIterator { + public: + using iterator_category = std::input_iterator_tag; + using value_type = T *; + using pointer = T *const *; + using reference = T *const &; + using difference_type = std::ptrdiff_t; + + private: + int elem_stride_; + int row_stride_; + /* Stride between a row end and the next row start. */ + int rows_gap_; + T *current_; + const T *row_end_; + const T *end_; + + public: + constexpr BufferAreaIterator() = default; + + constexpr BufferAreaIterator( + T *current, const T *end, int buffer_width, int area_width, int elem_stride = 1) + : elem_stride_(elem_stride), + row_stride_(buffer_width * elem_stride), + rows_gap_(row_stride_ - area_width * elem_stride), + current_(current), + row_end_(current + area_width * elem_stride), + end_(end) + { + } + + constexpr BufferAreaIterator &operator++() + { + current_ += elem_stride_; + BLI_assert(current_ <= row_end_); + if (current_ == row_end_) { + BLI_assert(current_ <= end_); + if (current_ == end_) { + return *this; + } + current_ += rows_gap_; + row_end_ += row_stride_; + } + return *this; + } + + constexpr BufferAreaIterator operator++(int) const + { + BufferAreaIterator copied_iterator = *this; + ++copied_iterator; + return copied_iterator; + } + + constexpr friend bool operator!=(const BufferAreaIterator &a, const BufferAreaIterator &b) + { + return a.current_ != b.current_; + } + + constexpr friend bool operator==(const BufferAreaIterator &a, const BufferAreaIterator &b) + { + return a.current_ == b.current_; + } + + constexpr T *operator*() const + { + return current_; + } +}; + +} // namespace blender::compositor |