From 1928a1812bb296bb3fd09b9a0084e30048332fa6 Mon Sep 17 00:00:00 2001
From: "Joachim Wuttke (h)" <j.wuttke@fz-juelich.de>
Date: Thu, 23 Nov 2023 09:15:38 +0100
Subject: [PATCH] Ellipse: check at 7*7 points
---
Base/Axis/Bin.cpp | 5 +++++
Base/Axis/Bin.h | 1 +
Device/Mask/Ellipse.cpp | 15 ++++++++++-----
3 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/Base/Axis/Bin.cpp b/Base/Axis/Bin.cpp
index c6461fcbf14..d731b4a9000 100644
--- a/Base/Axis/Bin.cpp
+++ b/Base/Axis/Bin.cpp
@@ -43,6 +43,11 @@ Bin1D::Bin1D(double lower, double upper)
}
}
+double Bin1D::atFraction(double fraction) const
+{
+ return m_lower * (1 - fraction) + m_upper * fraction;
+}
+
std::optional<Bin1D> Bin1D::clipped_or_nil(double lower, double upper) const
{
ASSERT(lower <= upper);
diff --git a/Base/Axis/Bin.h b/Base/Axis/Bin.h
index 0efd1201f01..6651b02fffb 100644
--- a/Base/Axis/Bin.h
+++ b/Base/Axis/Bin.h
@@ -33,6 +33,7 @@ public:
double upperBound() const { return m_upper; }
double center() const { return (m_lower + m_upper) / 2; }
double binSize() const { return m_upper - m_lower; }
+ double atFraction(double fraction) const;
std::optional<Bin1D> clipped_or_nil(double lower, double upper) const;
diff --git a/Device/Mask/Ellipse.cpp b/Device/Mask/Ellipse.cpp
index 13ea40d4392..c9d38dac4b8 100644
--- a/Device/Mask/Ellipse.cpp
+++ b/Device/Mask/Ellipse.cpp
@@ -37,17 +37,22 @@ Ellipse::Ellipse(double xcenter, double ycenter, double xradius, double yradius,
bool Ellipse::contains(double x, double y) const
{
- double u = std::cos(m_theta) * (x - m_xc) + std::sin(m_theta) * (y - m_yc);
- double v = -std::sin(m_theta) * (x - m_xc) + std::cos(m_theta) * (y - m_yc);
+ double u = std::cos(m_theta) * (x - m_xc) - std::sin(m_theta) * (y - m_yc);
+ double v = std::sin(m_theta) * (x - m_xc) + std::cos(m_theta) * (y - m_yc);
double d = (u / m_xr) * (u / m_xr) + (v / m_yr) * (v / m_yr);
return d <= 1;
}
-//! Returns true if area defined by two bins is inside or on border of ellipse;
-//! more precisely, if mid point of two bins satisfy this condition.
bool Ellipse::contains(const Bin1D& binx, const Bin1D& biny) const
{
- return contains(binx.center(), biny.center());
+ // The overlap of an ellipse and a rectangle, in full generality, requires quite
+ // a complicated algorithm. We therefore content ourselves with a check for n*n points.
+ const int n = 7;
+ for (int ix = 0; ix < n; ++ix)
+ for (int iy = 0; iy < n; ++iy)
+ if (contains(binx.atFraction(ix / (n - 1.)), biny.atFraction(iy / (n - 1.))))
+ return true;
+ return false;
}
void Ellipse::print(std::ostream& ostr) const
--
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