From patchwork Thu Apr 3 15:49:07 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Klug X-Patchwork-Id: 23118 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id E0CB0C327D for ; Thu, 3 Apr 2025 15:49:42 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 97C9B689A8; Thu, 3 Apr 2025 17:49:42 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="UjaJQHE2"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id EB826689A4 for ; Thu, 3 Apr 2025 17:49:40 +0200 (CEST) Received: from ideasonboard.com (unknown [IPv6:2a00:6020:448c:6c00:6d9d:9854:3fc1:4bb2]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 458AB8FA; Thu, 3 Apr 2025 17:47:47 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1743695267; bh=/lShqxVKPC83P8c7ZF16LUmZo5jxREkUBIJoqFx7/k0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UjaJQHE2eskJNvLGNEU0NJZCJdv+SG4T6z9XdcV6/hEIkE+/MHGnPfAJaB9hM696u NF+sQmGnD7ZTlb4zt3tJZO5v1qvqzCu8jLwE+lyfEGOmnYFzj9slydyMEi+1H8KQN3 Cq9gOEtQhGsKSZGEO63tJf+zPgY38KneMV2N7RfA= From: Stefan Klug To: libcamera-devel@lists.libcamera.org Cc: Stefan Klug , Laurent Pinchart Subject: [PATCH v3 02/16] libcamera: matrix: Make most functions constexpr Date: Thu, 3 Apr 2025 17:49:07 +0200 Message-ID: <20250403154925.382973-3-stefan.klug@ideasonboard.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250403154925.382973-1-stefan.klug@ideasonboard.com> References: <20250403154925.382973-1-stefan.klug@ideasonboard.com> MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" By zero-initializing the data_ member we can make most functions constexpr which will come in handy in upcoming patches. Note that this is due to C++17. In C++20 we will be able to leave data_ uninitialized for constexpr. The Matrix(std::array) version of the constructor can not be constexpr because std::copy only became constexpr in C++20. Signed-off-by: Stefan Klug Reviewed-by: Laurent Pinchart --- Changes in v2: - Added this patch Changes in v3: - Added comment on data_ initializer --- include/libcamera/internal/matrix.h | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/include/libcamera/internal/matrix.h b/include/libcamera/internal/matrix.h index b9c3d41ef855..512c1162c3bc 100644 --- a/include/libcamera/internal/matrix.h +++ b/include/libcamera/internal/matrix.h @@ -25,9 +25,8 @@ class Matrix static_assert(std::is_arithmetic_v, "Matrix type must be arithmetic"); public: - Matrix() + constexpr Matrix() { - data_.fill(static_cast(0)); } Matrix(const std::array &data) @@ -35,7 +34,7 @@ public: std::copy(data.begin(), data.end(), data_.begin()); } - static Matrix identity() + static constexpr Matrix identity() { Matrix ret; for (size_t i = 0; i < std::min(Rows, Cols); i++) @@ -63,14 +62,14 @@ public: return out.str(); } - Span data() const { return data_; } + constexpr Span data() const { return data_; } - Span operator[](size_t i) const + constexpr Span operator[](size_t i) const { return Span{ &data_.data()[i * Cols], Cols }; } - Span operator[](size_t i) + constexpr Span operator[](size_t i) { return Span{ &data_.data()[i * Cols], Cols }; } @@ -88,7 +87,12 @@ public: } private: - std::array data_; + /* + * \todo The initializer is only necessary for the constructor to be + * constexpr in C++17. Remove the initializer as soon as we are on + * C++20. + */ + std::array data_ = {}; }; #ifndef __DOXYGEN__ @@ -141,7 +145,7 @@ constexpr Matrix operator*(const Matrix &m1, const Matrix< } template -Matrix operator+(const Matrix &m1, const Matrix &m2) +constexpr Matrix operator+(const Matrix &m1, const Matrix &m2) { Matrix result;