[PATCH] ipa: libipa: vector: Add element-wise division operator

[Laurent Pinchart]

Add an operator to divide a scaler by a vector element-wise. Use it in
the rkisp1 AWB algorithm to replace manual operation on individual RGB
components.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 src/ipa/libipa/vector.cpp         | 10 ++++++++++
 src/ipa/libipa/vector.h           | 11 +++++++++++
 src/ipa/rkisp1/algorithms/awb.cpp |  6 +-----
 3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/src/ipa/libipa/vector.cpp b/src/ipa/libipa/vector.cpp
index 8019f8cfdc85..f665813c24d6 100644
--- a/src/ipa/libipa/vector.cpp
+++ b/src/ipa/libipa/vector.cpp
@@ -312,6 +312,16 @@ namespace ipa {
  * \return Product of matrix \a m and vector \a v
  */

+/**
+ * \fn Vector<T, Rows> operator/(T scalar, const Vector<T, Rows> &vector)
+ * \brief Divide a scalar by a vector element-wise
+ * \tparam T Numerical type of the contents of the vector
+ * \tparam Rows The number of rows in the vector
+ * \param scalar The scalar
+ * \param vector The vector
+ * \return The element-wise division of \a scaler by the \a vector
+ */
+
 /**
  * \typedef RGB
  * \brief A Vector of 3 elements representing an RGB pixel value
diff --git a/src/ipa/libipa/vector.h b/src/ipa/libipa/vector.h
index fe33c9d6fbd1..25882616ba8a 100644
--- a/src/ipa/libipa/vector.h
+++ b/src/ipa/libipa/vector.h
@@ -308,6 +308,17 @@ Vector<T, Rows> operator*(const Matrix<T, Rows, Cols> &m, const Vector<T, Cols>
 	return result;
 }

+template<typename T, unsigned int Rows>
+Vector<T, Rows> operator/(T scalar, const Vector<T, Rows> &vector)
+{
+	Vector<T, Rows> result;
+
+	for (unsigned int i = 0; i < Rows; i++)
+		result[i] = scalar / vector[i];
+
+	return result;
+}
+
 template<typename T, unsigned int Rows>
 bool operator==(const Vector<T, Rows> &lhs, const Vector<T, Rows> &rhs)
 {
diff --git a/src/ipa/rkisp1/algorithms/awb.cpp b/src/ipa/rkisp1/algorithms/awb.cpp
index cffaa06a22c1..319f7e0b5ef2 100644
--- a/src/ipa/rkisp1/algorithms/awb.cpp
+++ b/src/ipa/rkisp1/algorithms/awb.cpp
@@ -316,11 +316,7 @@ void Awb::process(IPAContext &context,
 	 * gain is hardcoded to 1.0. Avoid divisions by zero by clamping the
 	 * divisor to a minimum value of 1.0.
 	 */
-	RGB<double> gains({
-		rgbMeans.g() / std::max(rgbMeans.r(), 1.0),
-		1.0,
-		rgbMeans.g() / std::max(rgbMeans.b(), 1.0)
-	});
+	RGB<double> gains = rgbMeans.g() / rgbMeans.max(1.0);

 	/*
 	 * Clamp the gain values to the hardware, which expresses gains as Q2.8

base-commit: 9bc8b6a573a63b8c9f5588cdea6da5ae71abd138
--
Regards,

Laurent Pinchart