chart2/source/view/charttypes/PieChart.cxx | 92 ++++++++++++++++-------------
chart2/source/view/charttypes/PieChart.hxx | 9 ++
2 files changed, 62 insertions(+), 39 deletions(-)
New commits:
commit 86dcdfd097b0fdd91d69ecb8be0e72a84112a514
Author: Kurt Nordback <kurt.nordb...@protonmail.com>
AuthorDate: Wed May 15 17:27:22 2024 -0600
Commit: Noel Grandin <noel.gran...@collabora.co.uk>
CommitDate: Thu May 16 10:56:21 2024 +0200
tdf#159547 of-pie connector lines aren't quite geometrically correct
Fixed code computing the left endpoints of of-pie connector lines, so
that they're tangent to the circle when the composite slice is large enough
(and they terminate at the tangent point).
Change-Id: I4ff4d8e31f47259f0f48721b532dc245ede83003
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/167712
Reviewed-by: Noel Grandin <noel.gran...@collabora.co.uk>
Tested-by: Jenkins
diff --git a/chart2/source/view/charttypes/PieChart.cxx
b/chart2/source/view/charttypes/PieChart.cxx
index d99e3d944af3..fcb79ef1907a 100644
--- a/chart2/source/view/charttypes/PieChart.cxx
+++ b/chart2/source/view/charttypes/PieChart.cxx
@@ -807,6 +807,47 @@ bool PieChart::isSeparateStackingForDifferentSigns(
sal_Int32 /* nDimensionIndex
return false;
}
+// Determine left endpoints of connecting lines. These will terminate either
+// at the corners of the composite wedge (if the wedge is small enough), or
+// tangent to the left pie circle (if the wedge is larger). The endpoints
+// are at the returned values (xl0, +/-yl0).
+// static
+void PieChart::leftConnEndpoints(double* xl0_p, double* yl0_p,
+ const PieDataSrcBase *pDataSrc,
+ const VDataSeries *pSeries,
+ const ShapeParam &aParam)
+{
+ const sal_Int32 nEnd = pDataSrc->getNPoints(pSeries, SubPieType::LEFT);
+ const double compFrac = pDataSrc->getData(pSeries, nEnd - 1,
+ SubPieType::LEFT) / aParam.mfLogicYSum;
+
+ // Assuming temporarily that the left circle is at the origin,
+ // the tangent point (xp0, yp0) on the left circle satisfies
+ // (1) xp0 = (1-r) / t
+ // (2) xp0^2 + yp0^2 = 1
+ // where the left-hand circle has radius 1, the right-hand circle
+ // has radius r, and the right-hand circle is centered at (t, 0).
+ const double r0 = aParam.mfUnitCircleOuterRadius * m_fLeftScale;
+ const double rho = m_fRightScale / m_fLeftScale;
+ const double xp0 = (1 - rho) / (m_fRightShift - m_fLeftShift);
+ // Determine if the composite wedge is large enough that the
+ // connecting lines hit the tangent point, instead of the corners of
+ // the wedge
+ assert(abs(xp0) <= 1.0);
+ const double theta = acos(xp0);
+
+ double xl0, yl0;
+ if (compFrac < theta / M_PI) {
+ xl0 = r0 * cos(compFrac * M_PI);
+ yl0 = r0 * sin(compFrac * M_PI);
+ } else {
+ xl0 = r0 * xp0;
+ yl0 = sqrt(r0 * r0 - xl0 * xl0);
+ }
+ *xl0_p = xl0;
+ *yl0_p = yl0;
+}
+
void PieChart::createShapes()
{
///a ZSlot is a vector< vector< VDataSeriesGroup > >. There is only one
@@ -941,19 +982,9 @@ void PieChart::createShapes()
//
double xl0, xl1, yl0, yl1, x0, y0, x1, y1, y2, y3;
- // Get coordinates of "corners" of left composite wedge
- sal_Int32 nEnd = pDataSrc->getNPoints(pSeries, SubPieType::LEFT);
- double compFrac = pDataSrc->getData(pSeries, nEnd - 1,
- SubPieType::LEFT) / aParam.mfLogicYSum;
- if (compFrac < 0.5) {
- xl0 = aParam.mfUnitCircleOuterRadius * m_fLeftScale *
- cos(compFrac * M_PI) + m_fLeftShift;
- yl0 = aParam.mfUnitCircleOuterRadius * m_fLeftScale *
- sin(compFrac * M_PI);
- } else {
- xl0 = m_fLeftShift;
- yl0 = aParam.mfUnitCircleOuterRadius * m_fLeftScale;
- }
+ leftConnEndpoints(&xl0, &yl0, pDataSrc, pSeries, aParam);
+
+ xl0 += m_fLeftShift;
// Coordinates of bar top left corner
xl1 = m_fBarLeft;
@@ -1000,39 +1031,22 @@ void PieChart::createShapes()
//
double xl0, xl1, yl0, yl1, x0, y0, x1, y1, y2, y3;
- // Get coordinates of "corners" of left composite wedge
- sal_Int32 nEnd = pDataSrc->getNPoints(pSeries, SubPieType::LEFT);
- double compFrac = pDataSrc->getData(pSeries, nEnd - 1,
- SubPieType::LEFT) / aParam.mfLogicYSum;
- // The following isn't quite right. The tangent points on the left
- // pie are only at pi/2 and -pi/2 for composite wedges over 1/2 the
- // total if left and right pies are the same diameter. And the
- // threshold of 1/2 isn't quite right either. So there
- // really should be a more sophisticated approach here. TODO
- if (compFrac < 0.5) {
- // Translated, per below
- xl0 = aParam.mfUnitCircleOuterRadius * m_fLeftScale *
- cos(compFrac * M_PI) + m_fLeftShift - m_fRightShift;
- yl0 = aParam.mfUnitCircleOuterRadius * m_fLeftScale *
- sin(compFrac * M_PI);
- } else {
- // Translated, per below
- xl0 = m_fLeftShift - m_fRightShift;
- yl0 = aParam.mfUnitCircleOuterRadius * m_fLeftScale;
- }
+ leftConnEndpoints(&xl0, &yl0, pDataSrc, pSeries, aParam);
+
+ // Translated, per below
+ xl0 += m_fLeftShift - m_fRightShift;
// Compute tangent point on the right-hand circle of the line
// through (xl0, yl0). If we translate things so the right-hand
// circle is centered on the origin, then this point (x,y)
- // satisfies these two equations, where r is the radius of the
+ // satisfies these two equations, where r1 is the radius of the
// right-hand circle:
- // (1) x^2 + y^2 = r^2
+ // (1) x^2 + y^2 = r1^2
// (2) (y - yl0) / (x - xl0) = -x / y
- const double r = aParam.mfUnitCircleOuterRadius * m_fRightScale;
-
- xl1 = (r*r * xl0 + yl0 * r * sqrt(xl0*xl0 + yl0*yl0 - r*r)) /
+ const double r1 = aParam.mfUnitCircleOuterRadius * m_fRightScale;
+ xl1 = (r1*r1 * xl0 + yl0 * r1 * sqrt(xl0*xl0 + yl0*yl0 - r1*r1)) /
(xl0*xl0 + yl0*yl0);
- yl1 = sqrt(r*r - xl1*xl1);
+ yl1 = sqrt(r1*r1 - xl1*xl1);
// Now translate back to the coordinates we use
xl0 += m_fRightShift;
diff --git a/chart2/source/view/charttypes/PieChart.hxx
b/chart2/source/view/charttypes/PieChart.hxx
index ccbe9cb94d94..a7b158435d17 100644
--- a/chart2/source/view/charttypes/PieChart.hxx
+++ b/chart2/source/view/charttypes/PieChart.hxx
@@ -225,6 +225,15 @@ struct PieLabelInfo;
const PieDataSrcBase *pDataSrc,
sal_Int32 n3DRelativeHeight);
+ // Determine left endpoints of connecting lines. These will terminate
either
+ // at the corners of the composite wedge (if the wedge is small enough), or
+ // tangent to the left pie circle (if the wedge is larger). The endpoints
+ // are at the returned values (xl0, +/-yl0).
+ static void leftConnEndpoints(double* xl0_p, double* yl0_p,
+ const PieDataSrcBase *pDataSrc,
+ const VDataSeries *pSeries,
+ const ShapeParam &aParam);
+
private: //member
// Constants for of-pie charts. Some of these will want to become
// user-selectable values. TODO
