Merge branch 'master' into temp-geometry-nodes-curve-sampletemp-geometry-nodes-curve-sample

1 files changed, 164 insertions, 0 deletions

diff --git a/source/blender/compositor/intern/COM_BuffersIterator.h b/source/blender/compositor/intern/COM_BuffersIterator.h
new file mode 100644
index 00000000000..58dbd9c6f59
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+++ b/source/blender/compositor/intern/COM_BuffersIterator.h
@@ -0,0 +1,164 @@
+/*
+ * 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_rect.h"
+#include "BLI_vector.hh"
+
+namespace blender::compositor {
+
+/**
+ * Builds an iterator for simultaneously iterating an area of elements in an output buffer and any
+ * number of input buffers. It's not a standard C++ iterator and it does not support neither
+ * deference, equality or postfix increment operators.
+ */
+template<typename T> class BuffersIteratorBuilder {
+ public:
+  class Iterator {
+    const T *out_end_;
+    const T *out_row_end_;
+    int out_elem_stride_;
+    int out_row_stride_;
+    /* Stride between an output row end and the next row start. */
+    int out_rows_gap_;
+
+    struct In {
+      int elem_stride;
+      int rows_gap;
+      const T *in;
+    };
+    Vector<In, 6> ins_;
+
+    friend class BuffersIteratorBuilder;
+
+   public:
+    /**
+     * Current output element.
+     */
+    T *out;
+
+   public:
+    /**
+     * Get current element from an input.
+     */
+    const T *in(int input_index) const
+    {
+      BLI_assert(input_index < ins_.size());
+      return ins_[input_index].in;
+    }
+
+    int get_num_inputs() const
+    {
+      return ins_.size();
+    }
+
+    /**
+     * Has the end of the area been reached.
+     */
+    bool is_end() const
+    {
+      return out >= out_end_;
+    }
+
+    /**
+     * Go to the next element in the area.
+     */
+    void next()
+    {
+      out += out_elem_stride_;
+      for (In &in : ins_) {
+        in.in += in.elem_stride;
+      }
+      if (out == out_row_end_) {
+        out += out_rows_gap_;
+        out_row_end_ += out_row_stride_;
+        for (In &in : ins_) {
+          in.in += in.rows_gap;
+        }
+      }
+    }
+
+    Iterator &operator++()
+    {
+      this->next();
+      return *this;
+    }
+  };
+
+ private:
+  Iterator iterator_;
+  rcti area_;
+  bool is_built_;
+
+ public:
+  /**
+   * Create a buffers iterator builder to iterate given output buffer area.
+   * \param output: Output buffer.
+   * \param buffer_width: Number of elements in an output buffer row.
+   * \param area: Rectangle area to be iterated in all buffers.
+   * \param elem_stride: Output buffer element stride.
+   */
+  BuffersIteratorBuilder(T *output, int buffer_width, const rcti &area, int elem_stride = 1)
+      : area_(area), is_built_(false)
+  {
+    iterator_.out_elem_stride_ = elem_stride;
+    iterator_.out_row_stride_ = buffer_width * elem_stride;
+    iterator_.out_rows_gap_ = iterator_.out_row_stride_ - BLI_rcti_size_x(&area) * elem_stride;
+    iterator_.out = output + (intptr_t)area.ymin * iterator_.out_row_stride_ +
+                    (intptr_t)area.xmin * elem_stride;
+    iterator_.out_row_end_ = iterator_.out + (intptr_t)BLI_rcti_size_x(&area) * elem_stride;
+    iterator_.out_end_ = iterator_.out_row_end_ +
+                         (intptr_t)iterator_.out_row_stride_ * (BLI_rcti_size_y(&area) - 1);
+  }
+
+  /**
+   * Create a buffers iterator builder to iterate given output buffer with no offsets.
+   */
+  BuffersIteratorBuilder(T *output, int buffer_width, int buffer_height, int elem_stride = 1)
+      : BuffersIteratorBuilder(
+            output, buffer_width, {0, buffer_width, 0, buffer_height}, elem_stride)
+  {
+  }
+
+  /**
+   * Add an input buffer to be iterated. Its coordinates must be correlated with the output.
+   */
+  void add_input(const T *input, int buffer_width, int elem_stride = 1)
+  {
+    BLI_assert(!is_built_);
+    typename Iterator::In in;
+    in.elem_stride = elem_stride;
+    in.rows_gap = buffer_width * elem_stride - BLI_rcti_size_x(&area_) * elem_stride;
+    in.in = input + area_.ymin * buffer_width * elem_stride + area_.xmin * elem_stride;
+    iterator_.ins_.append(std::move(in));
+  }
+
+  /**
+   * Build the iterator.
+   */
+  BuffersIteratorBuilder::Iterator build()
+  {
+    is_built_ = true;
+    return iterator_;
+  }
+};
+
+template<typename T> using BuffersIterator = typename BuffersIteratorBuilder<T>::Iterator;
+
+}  // namespace blender::compositor