[{"id":33795,"web_url":"https://patchwork.libcamera.org/comment/33795/","msgid":"<174344098620.3394313.1620116981433662506@ping.linuxembedded.co.uk>","date":"2025-03-31T17:09:46","subject":"Re: [PATCH v2 08/17] libcamera: vector: Extend matrix multiplication\n\toperator to heterogenous types","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Stefan Klug (2025-03-19 16:11:13)\n> From: Laurent Pinchart \n> \n> It is useful to multiply matrices and vectors of heterogeneous types, for\n> instance float and double. Extend the multiplication operator to support\n> this, avoiding the need to convert one of the operations. The type of the\n> returned vector is selected automatically to avoid loosing precision.\n> \n> Signed-off-by: Laurent Pinchart \n> Signed-off-by: Stefan Klug \n> \n> Changes in v2:\n> - Added this patch\n\nI hope there's some tests added for these ;-)\n\n\nAcked-by: Kieran Bingham \n\n> ---\n> include/libcamera/internal/vector.h | 9 +++++----\n> src/libcamera/vector.cpp | 5 +++--\n> 2 files changed, 8 insertions(+), 6 deletions(-)\n> \n> diff --git a/include/libcamera/internal/vector.h b/include/libcamera/internal/vector.h\n> index 66cc5ac988c2..d518de9689a3 100644\n> --- a/include/libcamera/internal/vector.h\n> +++ b/include/libcamera/internal/vector.h\n> @@ -13,6 +13,7 @@\n> #include \n> #include \n> #include \n> +#include \n> \n> #include \n> #include \n> @@ -295,13 +296,13 @@ private:\n> template\n> using RGB = Vector;\n> \n> -template\n> -Vector operator*(const Matrix &m, const Vector &v)\n> +template\n> +Vector, Rows> operator*(const Matrix &m, const Vector &v)\n> {\n> - Vector result;\n> + Vector, Rows> result;\n> \n> for (unsigned int i = 0; i < Rows; i++) {\n> - T sum = 0;\n> + std::common_type_t sum = 0;\n> for (unsigned int j = 0; j < Cols; j++)\n> sum += m[i][j] * v[j];\n> result[i] = sum;\n> diff --git a/src/libcamera/vector.cpp b/src/libcamera/vector.cpp\n> index 435f2fc62f8b..c9419da8c663 100644\n> --- a/src/libcamera/vector.cpp\n> +++ b/src/libcamera/vector.cpp\n> @@ -308,9 +308,10 @@ LOG_DEFINE_CATEGORY(Vector)\n> */\n> \n> /**\n> - * \\fn Vector operator*(const Matrix &m, const Vector &v)\n> + * \\fn operator*(const Matrix &m, const Vector &v)\n> * \\brief Multiply a matrix by a vector\n> - * \\tparam T Numerical type of the contents of the matrix and vector\n> + * \\tparam T Numerical type of the contents of the matrix\n> + * \\tparam U Numerical type of the contents of the vector\n> * \\tparam Rows The number of rows in the matrix\n> * \\tparam Cols The number of columns in the matrix (= rows in the vector)\n> * \\param m The matrix\n> -- \n> 2.43.0\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 4AD05C323E\n\tfor ;\n\tMon, 31 Mar 2025 17:09:50 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 0150468985;\n\tMon, 31 Mar 2025 19:09:50 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id D231A6897A\n\tfor ;\n\tMon, 31 Mar 2025 19:09:48 +0200 (CEST)","from pendragon.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust6594.18-1.cable.virginm.net [86.31.185.195])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 519F0703;\n\tMon, 31 Mar 2025 19:07:57 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"mbrKJoEi\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1743440877;\n\tbh=gaNTTX+yhPle5niJ9AELwO5aXAG6U8Rwl451rM9w3nU=;\n\th=In-Reply-To:References:Subject:From:Cc:To:Date:From;\n\tb=mbrKJoEiuCYNUg+sR8mMXe8y7+XMocVHdiRqXT1e5vgFyfbAqRykHVwOXDoI1/8v1\n\tUHvBMP9QEmb7uTkuMFhyyJYc0bWPt9TIRnStdobhy7R0gvm+oRxSZp7XsA0Ih7rlAd\n\txBzS9rVlxXU/7V6krMBgfeaXfMvqfXQ/ngXZo1zE=","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20250319161152.63625-9-stefan.klug@ideasonboard.com>","References":"<20250319161152.63625-1-stefan.klug@ideasonboard.com>\n\t<20250319161152.63625-9-stefan.klug@ideasonboard.com>","Subject":"Re: [PATCH v2 08/17] libcamera: vector: Extend matrix multiplication\n\toperator to heterogenous types","From":"Kieran Bingham ","Cc":"Stefan Klug ,\n\tLaurent Pinchart ","To":"Stefan Klug ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Mon, 31 Mar 2025 18:09:46 +0100","Message-ID":"<174344098620.3394313.1620116981433662506@ping.linuxembedded.co.uk>","User-Agent":"alot/0.10","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]