From patchwork Tue Jun 11 13:24:28 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Elder X-Patchwork-Id: 20257 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 C1418C31E9 for ; Tue, 11 Jun 2024 13:24:53 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 53FDE6546C; Tue, 11 Jun 2024 15:24:53 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="ZhSfnlmb"; 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 29D4B65446 for ; Tue, 11 Jun 2024 15:24:52 +0200 (CEST) Received: from neptunite.hamster-moth.ts.net (h175-177-049-156.catv02.itscom.jp [175.177.49.156]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 5FFFA29A; Tue, 11 Jun 2024 15:24:35 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1718112279; bh=rq6nC96L6BZseNkTETpAyP1Hvuwio3Zqd5fmq8Bpv7E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZhSfnlmbTOq8B0DY10D0rgeDv5i1w3oe+TciKmg7LONFiZe/zJWHGc9GufsYdGidk o5hkRTW8N+tHvCvynPQGAo5sGCwc0ufDctNpL6cTypR3G1ic3Rzl0xezo1jFz6wfth 7Geo0daztWvsKYP18Kl2mErdvAoKON1nuypNsI6U= From: Paul Elder To: libcamera-devel@lists.libcamera.org Cc: Paul Elder , Stefan Klug , David Plowman , Kieran Bingham Subject: [PATCH v8 2/4] ipa: libipa: Copy pwl from rpi Date: Tue, 11 Jun 2024 22:24:28 +0900 Message-Id: <20240611132430.404814-3-paul.elder@ideasonboard.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240611132430.404814-1-paul.elder@ideasonboard.com> References: <20240611132430.404814-1-paul.elder@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" Copy the piecewise linear function code from Raspberry Pi. Signed-off-by: Paul Elder Reviewed-by: Stefan Klug Acked-by: David Plowman Reviewed-by: Kieran Bingham Reviewed-by: Laurent Pinchart --- No change in v8 No change in v7 No change in v6 Changes in v5: - remove meson.build to prevent compilation this early in the merge Changes in v4: - update the copy No change in v3 No change in v2 --- src/ipa/libipa/pwl.cpp | 269 +++++++++++++++++++++++++++++++++++++++++ src/ipa/libipa/pwl.h | 127 +++++++++++++++++++ 2 files changed, 396 insertions(+) create mode 100644 src/ipa/libipa/pwl.cpp create mode 100644 src/ipa/libipa/pwl.h diff --git a/src/ipa/libipa/pwl.cpp b/src/ipa/libipa/pwl.cpp new file mode 100644 index 000000000000..e39123767aa6 --- /dev/null +++ b/src/ipa/libipa/pwl.cpp @@ -0,0 +1,269 @@ +/* SPDX-License-Identifier: BSD-2-Clause */ +/* + * Copyright (C) 2019, Raspberry Pi Ltd + * + * piecewise linear functions + */ + +#include +#include +#include + +#include "pwl.h" + +using namespace RPiController; + +int Pwl::read(const libcamera::YamlObject ¶ms) +{ + if (!params.size() || params.size() % 2) + return -EINVAL; + + const auto &list = params.asList(); + + for (auto it = list.begin(); it != list.end(); it++) { + auto x = it->get(); + if (!x) + return -EINVAL; + if (it != list.begin() && *x <= points_.back().x) + return -EINVAL; + + auto y = (++it)->get(); + if (!y) + return -EINVAL; + + points_.push_back(Point(*x, *y)); + } + + return 0; +} + +void Pwl::append(double x, double y, const double eps) +{ + if (points_.empty() || points_.back().x + eps < x) + points_.push_back(Point(x, y)); +} + +void Pwl::prepend(double x, double y, const double eps) +{ + if (points_.empty() || points_.front().x - eps > x) + points_.insert(points_.begin(), Point(x, y)); +} + +Pwl::Interval Pwl::domain() const +{ + return Interval(points_[0].x, points_[points_.size() - 1].x); +} + +Pwl::Interval Pwl::range() const +{ + double lo = points_[0].y, hi = lo; + for (auto &p : points_) + lo = std::min(lo, p.y), hi = std::max(hi, p.y); + return Interval(lo, hi); +} + +bool Pwl::empty() const +{ + return points_.empty(); +} + +double Pwl::eval(double x, int *spanPtr, bool updateSpan) const +{ + int span = findSpan(x, spanPtr && *spanPtr != -1 ? *spanPtr : points_.size() / 2 - 1); + if (spanPtr && updateSpan) + *spanPtr = span; + return points_[span].y + + (x - points_[span].x) * (points_[span + 1].y - points_[span].y) / + (points_[span + 1].x - points_[span].x); +} + +int Pwl::findSpan(double x, int span) const +{ + /* + * Pwls are generally small, so linear search may well be faster than + * binary, though could review this if large PWls start turning up. + */ + int lastSpan = points_.size() - 2; + /* + * some algorithms may call us with span pointing directly at the last + * control point + */ + span = std::max(0, std::min(lastSpan, span)); + while (span < lastSpan && x >= points_[span + 1].x) + span++; + while (span && x < points_[span].x) + span--; + return span; +} + +Pwl::PerpType Pwl::invert(Point const &xy, Point &perp, int &span, + const double eps) const +{ + assert(span >= -1); + bool prevOffEnd = false; + for (span = span + 1; span < (int)points_.size() - 1; span++) { + Point spanVec = points_[span + 1] - points_[span]; + double t = ((xy - points_[span]) % spanVec) / spanVec.len2(); + if (t < -eps) /* off the start of this span */ + { + if (span == 0) { + perp = points_[span]; + return PerpType::Start; + } else if (prevOffEnd) { + perp = points_[span]; + return PerpType::Vertex; + } + } else if (t > 1 + eps) /* off the end of this span */ + { + if (span == (int)points_.size() - 2) { + perp = points_[span + 1]; + return PerpType::End; + } + prevOffEnd = true; + } else /* a true perpendicular */ + { + perp = points_[span] + spanVec * t; + return PerpType::Perpendicular; + } + } + return PerpType::None; +} + +Pwl Pwl::inverse(bool *trueInverse, const double eps) const +{ + bool appended = false, prepended = false, neither = false; + Pwl inverse; + + for (Point const &p : points_) { + if (inverse.empty()) + inverse.append(p.y, p.x, eps); + else if (std::abs(inverse.points_.back().x - p.y) <= eps || + std::abs(inverse.points_.front().x - p.y) <= eps) + /* do nothing */; + else if (p.y > inverse.points_.back().x) { + inverse.append(p.y, p.x, eps); + appended = true; + } else if (p.y < inverse.points_.front().x) { + inverse.prepend(p.y, p.x, eps); + prepended = true; + } else + neither = true; + } + + /* + * This is not a proper inverse if we found ourselves putting points + * onto both ends of the inverse, or if there were points that couldn't + * go on either. + */ + if (trueInverse) + *trueInverse = !(neither || (appended && prepended)); + + return inverse; +} + +Pwl Pwl::compose(Pwl const &other, const double eps) const +{ + double thisX = points_[0].x, thisY = points_[0].y; + int thisSpan = 0, otherSpan = other.findSpan(thisY, 0); + Pwl result({ { thisX, other.eval(thisY, &otherSpan, false) } }); + while (thisSpan != (int)points_.size() - 1) { + double dx = points_[thisSpan + 1].x - points_[thisSpan].x, + dy = points_[thisSpan + 1].y - points_[thisSpan].y; + if (std::abs(dy) > eps && + otherSpan + 1 < (int)other.points_.size() && + points_[thisSpan + 1].y >= + other.points_[otherSpan + 1].x + eps) { + /* + * next control point in result will be where this + * function's y reaches the next span in other + */ + thisX = points_[thisSpan].x + + (other.points_[otherSpan + 1].x - + points_[thisSpan].y) * + dx / dy; + thisY = other.points_[++otherSpan].x; + } else if (std::abs(dy) > eps && otherSpan > 0 && + points_[thisSpan + 1].y <= + other.points_[otherSpan - 1].x - eps) { + /* + * next control point in result will be where this + * function's y reaches the previous span in other + */ + thisX = points_[thisSpan].x + + (other.points_[otherSpan + 1].x - + points_[thisSpan].y) * + dx / dy; + thisY = other.points_[--otherSpan].x; + } else { + /* we stay in the same span in other */ + thisSpan++; + thisX = points_[thisSpan].x, + thisY = points_[thisSpan].y; + } + result.append(thisX, other.eval(thisY, &otherSpan, false), + eps); + } + return result; +} + +void Pwl::map(std::function f) const +{ + for (auto &pt : points_) + f(pt.x, pt.y); +} + +void Pwl::map2(Pwl const &pwl0, Pwl const &pwl1, + std::function f) +{ + int span0 = 0, span1 = 0; + double x = std::min(pwl0.points_[0].x, pwl1.points_[0].x); + f(x, pwl0.eval(x, &span0, false), pwl1.eval(x, &span1, false)); + while (span0 < (int)pwl0.points_.size() - 1 || + span1 < (int)pwl1.points_.size() - 1) { + if (span0 == (int)pwl0.points_.size() - 1) + x = pwl1.points_[++span1].x; + else if (span1 == (int)pwl1.points_.size() - 1) + x = pwl0.points_[++span0].x; + else if (pwl0.points_[span0 + 1].x > pwl1.points_[span1 + 1].x) + x = pwl1.points_[++span1].x; + else + x = pwl0.points_[++span0].x; + f(x, pwl0.eval(x, &span0, false), pwl1.eval(x, &span1, false)); + } +} + +Pwl Pwl::combine(Pwl const &pwl0, Pwl const &pwl1, + std::function f, + const double eps) +{ + Pwl result; + map2(pwl0, pwl1, [&](double x, double y0, double y1) { + result.append(x, f(x, y0, y1), eps); + }); + return result; +} + +void Pwl::matchDomain(Interval const &domain, bool clip, const double eps) +{ + int span = 0; + prepend(domain.start, eval(clip ? points_[0].x : domain.start, &span), + eps); + span = points_.size() - 2; + append(domain.end, eval(clip ? points_.back().x : domain.end, &span), + eps); +} + +Pwl &Pwl::operator*=(double d) +{ + for (auto &pt : points_) + pt.y *= d; + return *this; +} + +void Pwl::debug(FILE *fp) const +{ + fprintf(fp, "Pwl {\n"); + for (auto &p : points_) + fprintf(fp, "\t(%g, %g)\n", p.x, p.y); + fprintf(fp, "}\n"); +} diff --git a/src/ipa/libipa/pwl.h b/src/ipa/libipa/pwl.h new file mode 100644 index 000000000000..7d5e7e4d3fda --- /dev/null +++ b/src/ipa/libipa/pwl.h @@ -0,0 +1,127 @@ +/* SPDX-License-Identifier: BSD-2-Clause */ +/* + * Copyright (C) 2019, Raspberry Pi Ltd + * + * piecewise linear functions interface + */ +#pragma once + +#include +#include +#include + +#include "libcamera/internal/yaml_parser.h" + +namespace RPiController { + +class Pwl +{ +public: + struct Interval { + Interval(double _start, double _end) + : start(_start), end(_end) + { + } + double start, end; + bool contains(double value) + { + return value >= start && value <= end; + } + double clip(double value) + { + return value < start ? start + : (value > end ? end : value); + } + double len() const { return end - start; } + }; + struct Point { + Point() : x(0), y(0) {} + Point(double _x, double _y) + : x(_x), y(_y) {} + double x, y; + Point operator-(Point const &p) const + { + return Point(x - p.x, y - p.y); + } + Point operator+(Point const &p) const + { + return Point(x + p.x, y + p.y); + } + double operator%(Point const &p) const + { + return x * p.x + y * p.y; + } + Point operator*(double f) const { return Point(x * f, y * f); } + Point operator/(double f) const { return Point(x / f, y / f); } + double len2() const { return x * x + y * y; } + double len() const { return sqrt(len2()); } + }; + Pwl() {} + Pwl(std::vector const &points) : points_(points) {} + int read(const libcamera::YamlObject ¶ms); + void append(double x, double y, const double eps = 1e-6); + void prepend(double x, double y, const double eps = 1e-6); + Interval domain() const; + Interval range() const; + bool empty() const; + /* + * Evaluate Pwl, optionally supplying an initial guess for the + * "span". The "span" may be optionally be updated. If you want to know + * the "span" value but don't have an initial guess you can set it to + * -1. + */ + double eval(double x, int *spanPtr = nullptr, + bool updateSpan = true) const; + /* + * Find perpendicular closest to xy, starting from span+1 so you can + * call it repeatedly to check for multiple closest points (set span to + * -1 on the first call). Also returns "pseudo" perpendiculars; see + * PerpType enum. + */ + enum class PerpType { + None, /* no perpendicular found */ + Start, /* start of Pwl is closest point */ + End, /* end of Pwl is closest point */ + Vertex, /* vertex of Pwl is closest point */ + Perpendicular /* true perpendicular found */ + }; + PerpType invert(Point const &xy, Point &perp, int &span, + const double eps = 1e-6) const; + /* + * Compute the inverse function. Indicate if it is a proper (true) + * inverse, or only a best effort (e.g. input was non-monotonic). + */ + Pwl inverse(bool *trueInverse = nullptr, const double eps = 1e-6) const; + /* Compose two Pwls together, doing "this" first and "other" after. */ + Pwl compose(Pwl const &other, const double eps = 1e-6) const; + /* Apply function to (x,y) values at every control point. */ + void map(std::function f) const; + /* + * Apply function to (x, y0, y1) values wherever either Pwl has a + * control point. + */ + static void map2(Pwl const &pwl0, Pwl const &pwl1, + std::function f); + /* + * Combine two Pwls, meaning we create a new Pwl where the y values are + * given by running f wherever either has a knot. + */ + static Pwl + combine(Pwl const &pwl0, Pwl const &pwl1, + std::function f, + const double eps = 1e-6); + /* + * Make "this" match (at least) the given domain. Any extension my be + * clipped or linear. + */ + void matchDomain(Interval const &domain, bool clip = true, + const double eps = 1e-6); + Pwl &operator*=(double d); + void debug(FILE *fp = stdout) const; + +private: + int findSpan(double x, int span) const; + std::vector points_; +}; + +} /* namespace RPiController */