1 files changed, 58 insertions, 0 deletions
diff --git a/source/blender/compositor/realtime_compositor/algorithms/COM_algorithm_parallel_reduction.hh b/source/blender/compositor/realtime_compositor/algorithms/COM_algorithm_parallel_reduction.hh
new file mode 100644
index 00000000000..9d0851eff84
--- /dev/null
+++ b/source/blender/compositor/realtime_compositor/algorithms/COM_algorithm_parallel_reduction.hh
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+
+#include "BLI_math_vec_types.hh"
+
+#include "GPU_texture.h"
+
+#include "COM_context.hh"
+
+namespace blender::realtime_compositor {
+
+/* --------------------------------------------------------------------
+ * Sum Reductions.
+ */
+
+/* Computes the sum of the red channel of all pixels in the given texture. */
+float sum_red(Context &context, GPUTexture *texture);
+
+/* Computes the sum of the green channel of all pixels in the given texture. */
+float sum_green(Context &context, GPUTexture *texture);
+
+/* Computes the sum of the blue channel of all pixels in the given texture. */
+float sum_blue(Context &context, GPUTexture *texture);
+
+/* Computes the sum of the luminance of all pixels in the given texture, using the given luminance
+ * coefficients to compute the luminance. */
+float sum_luminance(Context &context, GPUTexture *texture, float3 luminance_coefficients);
+
+/* --------------------------------------------------------------------
+ * Sum Of Squared Difference Reductions.
+ */
+
+/* Computes the sum of the squared difference between the red channel of all pixels in the given
+ * texture and the given subtrahend. This can be used to compute the standard deviation if the
+ * given subtrahend is the mean. */
+float sum_red_squared_difference(Context &context, GPUTexture *texture, float subtrahend);
+
+/* Computes the sum of the squared difference between the green channel of all pixels in the given
+ * texture and the given subtrahend. This can be used to compute the standard deviation if the
+ * given subtrahend is the mean. */
+float sum_green_squared_difference(Context &context, GPUTexture *texture, float subtrahend);
+
+/* Computes the sum of the squared difference between the blue channel of all pixels in the given
+ * texture and the given subtrahend. This can be used to compute the standard deviation if the
+ * given subtrahend is the mean. */
+float sum_blue_squared_difference(Context &context, GPUTexture *texture, float subtrahend);
+
+/* Computes the sum of the squared difference between the luminance of all pixels in the given
+ * texture and the given subtrahend, using the given luminance coefficients to compute the
+ * luminance. This can be used to compute the standard deviation if the given subtrahend is the
+ * mean. */
+float sum_luminance_squared_difference(Context &context,
+                                       GPUTexture *texture,
+                                       float3 luminance_coefficients,
+                                       float subtrahend);
+
+}  // namespace blender::realtime_compositor