libcamera/vivid.git - libcamera pipeline handler for VIVID

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Diffstat (limited to 'test/v4l2_subdevice')

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/* SPDX-License-Identifier: BSD-2-Clause */ /* * Copyright (C) 2019, Raspberry Pi (Trading) Limited * * pwl.cpp - piecewise linear functions */ #include <cassert> #include <stdexcept> #include "pwl.hpp" using namespace RPiController; void Pwl::Read(boost::property_tree::ptree const &params) { for (auto it = params.begin(); it != params.end(); it++) { double x = it->second.get_value<double>(); assert(it == params.begin() || x > points_.back().x); it++; double y = it->second.get_value<double>(); points_.push_back(Point(x, y)); } assert(points_.size() >= 2); } 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 *span_ptr, bool update_span) const { int span = findSpan(x, span_ptr && *span_ptr != -1 ? *span_ptr : points_.size() / 2 - 1); if (span_ptr && update_span) *span_ptr = 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 last_span = points_.size() - 2; // some algorithms may call us with span pointing directly at the last // control point span = std::max(0, std::min(last_span, span)); while (span < last_span && 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 prev_off_end = false; for (span = span + 1; span < (int)points_.size() - 1; span++) { Point span_vec = points_[span + 1] - points_[span]; double t = ((xy - points_[span]) % span_vec) / span_vec.Len2(); if (t < -eps) // off the start of this span { if (span == 0) { perp = points_[span]; return PerpType::Start; } else if (prev_off_end) { 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; } prev_off_end = true; } else // a true perpendicular { perp = points_[span] + span_vec * t; return PerpType::Perpendicular; } } return PerpType::None; } Pwl Pwl::Compose(Pwl const &other, const double eps) const { double this_x = points_[0].x, this_y = points_[0].y; int this_span = 0, other_span = other.findSpan(this_y, 0); Pwl result({ { this_x, other.Eval(this_y, &other_span, false) } }); while (this_span != (int)points_.size() - 1) { double dx = points_[this_span + 1].x - points_[this_span].x, dy = points_[this_span + 1].y - points_[this_span].y; if (abs(dy) > eps && other_span + 1 < (int)other.points_.size() && points_[this_span + 1].y >= other.points_[other_span + 1].x + eps) { // next control point in result will be where this // function's y reaches the next span in other this_x = points_[this_span].x + (other.points_[other_span + 1].x - points_[this_span].y) * dx / dy; this_y = other.points_[++other_span].x; } else if (abs(dy) > eps && other_span > 0 && points_[this_span + 1].y <= other.points_[other_span - 1].x - eps) { // next control point in result will be where this // function's y reaches the previous span in other this_x = points_[this_span].x + (other.points_[other_span + 1].x - points_[this_span].y) * dx / dy; this_y = other.points_[--other_span].x; } else { // we stay in the same span in other this_span++; this_x = points_[this_span].x, this_y = points_[this_span].y; } result.Append(this_x, other.Eval(this_y, &other_span, false), eps); } return result; }


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