lazarus/docs/xml/lazutils/graphmath.xml

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XML

<?xml version="1.0" encoding="UTF-8"?>
<!--
Documentation for LCL (Lazarus Component Library) and LazUtils (Lazarus
Utilities) are published under the Creative Commons Attribution-ShareAlike 4.0
International public license.
https://creativecommons.org/licenses/by-sa/4.0/legalcode.txt
file://../../cc-by-sa-4-0.txt
Copyright (c) 1997-2024, by the Lazarus Development Team.
-->
<fpdoc-descriptions>
<package name="lazutils">
<!--
====================================================================
GraphMath
====================================================================
-->
<module name="GraphMath">
<short>
A set of mathematical helper routines to simply cross-platform canvas
drawing.
</short>
<descr>
<p>
<file>graphmath.pp</file> contains math helper routines for use for
graphics drawing. It is used to simply cross-platform canvas drawing
operations. <file>graphmath.pp</file> is part of the <file>LazUtils</file>
package.
</p>
</descr>
<!-- unresolved references -->
<element name="Types"/>
<element name="Classes"/>
<element name="SysUtils"/>
<element name="Math"/>
<element name="GraphType"/>
<element name="LazUtilities"/>
<element name="TFloatPoint">
<short>
<var>TFloatPoint</var> is an extended precision record specifying the X and
Y coordinates of a point in a graphic environment.
</short>
<descr/>
<seealso/>
</element>
<element name="TFloatPoint.X">
<short>
Horizontal position for the coordinate.
</short>
</element>
<element name="TFloatPoint.Y">
<short>
Vertical position for the coordinate.
</short>
</element>
<element name="TBezier">
<short>
Array type used to store the coordinates for Bezier control points as
floating point values.
</short>
<descr>
<p>
<var>TBezier</var> allows up to 4 coordinates to be specified which represent
the control points for the parametric curve. Each coordinate is implemented
using the TFloatPoint type, and stored as elements in the array.
</p>
<p>
TBezier is the type returned by the Bezier function. The type is passed as an
argument to routines like: Arc2Bezier, Bezier2Polyline, BezierMidPoint, and
SplitBezier.
</p>
</descr>
<seealso>
<link id="Bezier"/>
<link id="Arc2Bezier"/>
<link id="Bezier2Polyline"/>
<link id="BezierMidPoint"/>
<link id="SplitBezier"/>
</seealso>
</element>
<element name="PPoint">
<short>
Pointer to the TPoint type.
</short>
<descr/>
<seealso>
<link id="#rtl.classes.TPoint">TPoint</link>
</seealso>
</element>
<element name="Angles2Coords">
<short>
Converts an Eccentric Angle and an Angle-Length, into the coordinates for
the Start and End radial Points.
</short>
<descr>
<p>
Use <var>Angles2Coords</var> to convert an Eccentric (Radial) angle and an
angle-length, such as are used in X-Windows and GTK, into the coordinates
for the Start and End radial Points. Like those used in the Arc, Pie, and
Chord routines from the Windows API.
</p>
<p>
The angles are specified in 1/16th of a degree. For example, a full circle
equals 5760 (16*360).
</p>
<p>
Positive values in Angle and AngleLength mean counter-clockwise, while
negative values mean clockwise direction. Zero degrees is at the 3
o&apos;clock position.
</p>
</descr>
<seealso/>
</element>
<element name="Angles2Coords.X">
<short/>
</element>
<element name="Angles2Coords.Y">
<short/>
</element>
<element name="Angles2Coords.Width">
<short/>
</element>
<element name="Angles2Coords.Height">
<short/>
</element>
<element name="Angles2Coords.Angle1">
<short/>
</element>
<element name="Angles2Coords.Angle2">
<short/>
</element>
<element name="Angles2Coords.SX">
<short/>
</element>
<element name="Angles2Coords.SY">
<short/>
</element>
<element name="Angles2Coords.EX">
<short/>
</element>
<element name="Angles2Coords.EY">
<short/>
</element>
<element name="Arc2Bezier">
<short>
Converts an Arc and ArcLength into a Bezier Approximation of the Arc.
</short>
<descr>
<p>
Use <var>Arc2Bezier</var> to convert an Arc and ArcLength into a Bezier
approximation of the Arc. The Rotation parameter accepts a Rotation-Angle
for a rotated Ellipse. For a non-rotated ellipse this value would be 0, or
360. If the AngleLength is greater than 90 degrees, or is equal to 0, it
automatically exits, as Bezier cannot accurately approximate any angle
greater then 90 degrees, and in fact for best result no angle greater than
45 should be converted, instead an array of Bezier's should be created,
each Bezier describing a portion of the total arc no greater than 45
degrees.
</p>
<p>
The angles are specified in 1/16th of a degree. For example, a full circle
equals 5760 (16*360).
</p>
<p>
Positive values in Angle and AngleLength mean counter-clockwise while
negative values mean clockwise direction. Zero degrees is at the 3
o&apos;clock position.
</p>
</descr>
<seealso/>
</element>
<element name="Arc2Bezier.X">
<short/>
</element>
<element name="Arc2Bezier.Y">
<short/>
</element>
<element name="Arc2Bezier.Width">
<short/>
</element>
<element name="Arc2Bezier.Height">
<short/>
</element>
<element name="Arc2Bezier.Angle1">
<short/>
</element>
<element name="Arc2Bezier.Angle2">
<short/>
</element>
<element name="Arc2Bezier.Rotation">
<short/>
</element>
<element name="Arc2Bezier.Points">
<short/>
</element>
<element name="Bezier">
<short>
Gets a TBezier instance representing the specified Bezier control points.
</short>
<descr/>
<seealso/>
</element>
<element name="Bezier.Result">
<short>
TBezier instance with the values in C1, C2, C3, and C4.
</short>
</element>
<element name="Bezier.C1">
<short>
Control point on the parametric curve. C1 is an endpoint.
</short>
</element>
<element name="Bezier.C2">
<short>
Control point on the parametric curve. C2 is a directional control point for
a Quadratic or Cubic Bezier.
</short>
</element>
<element name="Bezier.C3">
<short>
Control point on the parametric curve. C3 is a directional control point for
a Cubic Bezier.
</short>
</element>
<element name="Bezier.C4">
<short>
Control point on the parametric curve. C4 is an endpoint.
</short>
</element>
<element name="Bezier2Polyline">
<short>
<var>Bezier2Polyline</var> - convert a 4-Point Bezier into a Pointer Array
of TPoint and a Count variable.
</short>
<descr>
<p>
Use BezierToPolyline to convert a 4-Point Bezier into a Pointer Array of
TPoint and a Count variable which can then be used within either a
Polyline, or Polygon routine. It is primarily for use within
PolyBezier2Polyline.
</p>
<p>
If Points is not initialized or Count is less then 0, it is set to nil and
the array starts at 0, otherwise it tries to append points to the array
starting at Count. Points should ALWAYS be Freed when done by calling to
ReallocMem(Points, 0) or FreeMem.
</p>
</descr>
<seealso/>
</element>
<element name="Bezier2Polyline.Bezier">
<short/>
</element>
<element name="Bezier2Polyline.Points">
<short/>
</element>
<element name="Bezier2Polyline.Count">
<short/>
</element>
<element name="BezierArcPoints">
<short>
<var>BezierArcPoints</var> - convert an Arc and ArcLength into a Pointer
Array of TPoints for use with Polyline or Polygon.
</short>
<descr>
<p>
Use BezierArcPoints to convert an Arc and ArcLength into a Pointer Array of
TPoints for use with Polyline or Polygon. The Rotation parameter accepts a
Rotation-Angle for a rotated Ellipse. For a non-rotated ellipse this value
would be 0, or 360. The result is an Approximation based on 1 or more
Beziers.
</p>
<p>
If the AngleLength is greater than 90 degrees, it calls
PolyBezierArcPoints, otherwise it Converts the angles into a Bezier by
calling to Arc2Bezier, and then converts the Bezier into an array of Points
by calling to Bezier2Polyline.
</p>
<p>
The angles are specified in 1/16th of a degree. For example, a full circle
equals 5760 (16*360).
</p>
<p>
Positive values in Angle and AngleLength mean counter-clockwise while
negative values mean clockwise direction. Zero degrees is at the 3
o&apos;clock position.
</p>
<p>
If Points is not initialized or Count is less then 0, it is set to nil and
the array starts at 0, otherwise it tries to append points to the array
starting at Count. Points should ALWAYS be Freed when done by calling
ReallocMem(Points, 0) or FreeMem.
</p>
</descr>
<seealso/>
</element>
<element name="BezierArcPoints.X">
<short/>
</element>
<element name="BezierArcPoints.Y">
<short/>
</element>
<element name="BezierArcPoints.Width">
<short/>
</element>
<element name="BezierArcPoints.Height">
<short/>
</element>
<element name="BezierArcPoints.Angle1">
<short/>
</element>
<element name="BezierArcPoints.Angle2">
<short/>
</element>
<element name="BezierArcPoints.Rotation">
<short/>
</element>
<element name="BezierArcPoints.Points">
<short/>
</element>
<element name="BezierArcPoints.Count">
<short/>
</element>
<element name="BezierMidPoint">
<short>
<var>BezierMidPoint</var> - get the Mid-Point of any 4-Point Bezier. It is
primarily for use in SplitBezier.
</short>
<descr/>
<seealso/>
</element>
<element name="BezierMidPoint.Result">
<short/>
</element>
<element name="BezierMidPoint.Bezier">
<short/>
</element>
<element name="CenterPoint">
<short>
<var>CenterPoint</var> - get the Center-Point of any rectangle. It is
primarily for use with, and in, other routines such as Quadrant, and
RadialPoint.
</short>
<descr/>
<seealso/>
</element>
<element name="CenterPoint.Result">
<short/>
</element>
<element name="CenterPoint.Rect">
<short/>
</element>
<element name="CalculateLeftTopWidthHeight">
<short>
Calculates the values for the output variables in Left, Top, Width, and Height.
</short>
<descr>
<p>
<var>CalculateLeftTopWidthHeight</var> checks values in the X1, X2, Y1, and Y2
arguments and sets the values for the Left, Top, Width, and Height output
parameters accordingly.
</p>
<dl>
<dt>Left</dt>
<dd>
Set to the smaller of the two values in X1 and X2.
</dd>
<dt>Width</dt>
<dd>
Set to the difference between the X1 and X2 values. The value will be a
positive integer value or zero (0).
</dd>
<dt>Top</dt>
<dd>
Set to the smaller of the two values in Y1 and Y2.
</dd>
<dt>Height</dt>
<dd>
Set to the difference between Y1 and Y2. The value will be a positive integer
value or zero (0).
</dd>
</dl>
<p>
Used in the implementation of the Rectangle and Ellipse routines for the GTK
widgetset.
</p>
</descr>
<version>
Added in LazUtils version 3.0.
</version>
<seealso/>
</element>
<element name="CalculateLeftTopWidthHeight.X1">
<short>
Horizontal coordinate examined in the routine.
</short>
</element>
<element name="CalculateLeftTopWidthHeight.Y1">
<short>
Vertical coordinate examined in the routine.
</short>
</element>
<element name="CalculateLeftTopWidthHeight.X2">
<short>
Horizontal coordinate examined in the routine.
</short>
</element>
<element name="CalculateLeftTopWidthHeight.Y2">
<short>
Vertical coordinate examined in the routine.
</short>
</element>
<element name="CalculateLeftTopWidthHeight.Left">
<short>
Returns the left coordinate for the specified values.
</short>
</element>
<element name="CalculateLeftTopWidthHeight.Top">
<short>
Returns the top coordinate for the specified values.
</short>
</element>
<element name="CalculateLeftTopWidthHeight.Width">
<short>
Returns the width for the specified horizontal coordinates.
</short>
</element>
<element name="CalculateLeftTopWidthHeight.Height">
<short>
Returns the height for the specified vertical coordinates.
</short>
</element>
<element name="Coords2Angles">
<short>
<var>Coords2Angles</var> - convert the coords for Start and End Radial-
Points into an Eccentric counter clockwise Angle and an Angle-Length.
</short>
<descr>
<p>
Use Coords2Angles to convert the coords for Start and End Radial-Points,
such as are used in the Windows API Arc Pie and Chord routines, into an
Eccentric (aka Radial) counter clockwise Angle and an Angle-Length, such as
are used in X-Windows and GTK.
</p>
<p>
The angles angle1 and angle2 are returned in 1/16th of a degree. For
example, a full circle equals 5760 (16*360).
</p>
<p>
Zero degrees is at the 3 o&apos;clock position.
</p>
</descr>
<seealso/>
</element>
<element name="Coords2Angles.X">
<short/>
</element>
<element name="Coords2Angles.Y">
<short/>
</element>
<element name="Coords2Angles.Width">
<short/>
</element>
<element name="Coords2Angles.Height">
<short/>
</element>
<element name="Coords2Angles.SX">
<short/>
</element>
<element name="Coords2Angles.SY">
<short/>
</element>
<element name="Coords2Angles.EX">
<short/>
</element>
<element name="Coords2Angles.EY">
<short/>
</element>
<element name="Coords2Angles.Angle1">
<short/>
</element>
<element name="Coords2Angles.Angle2">
<short/>
</element>
<element name="Distance">
<short>
Gets the distance between two points, or the distance of a point from a
specified line.
</short>
<descr>
<p>
<var>Distance</var> is an overloaded function with variants that operate on
either two point coordinates, or on a point and a line defined by two
additional points values. The Distance() function is used primarily for
internal purposes (such as in Bezier2PolyLine and EccentricAngle)
but can be used for any purpose.
</p>
<p>
The return value is an Extended type with the calculated distance between the
argument values. The return value is always a positive value.
</p>
<p>
The variants using two point arguments (TPoint or TFloatPoint) calculates the
length of a straight line between the coordinates in PT1 and PT2 using the
Pythagorean theorem. The distance between identical points is always zero (0).
</p>
<p>
The variant with three TFloatPoint arguments calculates the distance between
the point Pt and the line represented by the points in SP and EP using
Euclidean geometry. The distance is derived by finding the length of an
imaginary line between Pt and the closest point that intersects the slope of
the line in SP and EP. The distance for a point which lies on the defined line
is always zero (0).
</p>
</descr>
<seealso/>
</element>
<element name="Distance.Result">
<short>
Straight-line distance between the specified coordinates or objects.
</short>
</element>
<element name="Distance.PT1">
<short>
Starting point for the calculated distance.
</short>
</element>
<element name="Distance.PT2">
<short>
Ending point for the calculated distance.
</short>
</element>
<element name="Distance.Pt">
<short>
Fixed point for the calculated distance.
</short>
</element>
<element name="Distance.SP">
<short>
Starting point for the line used in the distance calculation.
</short>
</element>
<element name="Distance.WP">
<short>
Ending point for the line used in the distance calculation.
</short>
</element>
<element name="EccentricAngle">
<short>
<var>EccentricAngle</var> - get the Eccentric Angle of a given point on any
non-rotated ellipse.
</short>
<descr>
<p>
Use EccentricAngle to get the Eccentric( aka Radial ) Angle of a given
point on any non-rotated ellipse. It is primarily for use in Coords2Angles.
The result is in 1/16th of a degree. For example, a full circle equals 5760
(16*360). Zero degrees is at the 3 o&apos;clock position.
</p>
</descr>
<seealso/>
</element>
<element name="EccentricAngle.Result">
<short/>
</element>
<element name="EccentricAngle.PT">
<short/>
</element>
<element name="EccentricAngle.Rect">
<short/>
</element>
<element name="EllipseRadialLength">
<short>
<var>EllipseRadialLength</var> - Radial-Length of non-rotated ellipse at
any given Eccentric Angle.
</short>
<descr>
<p>
Use EllipseRadialLength to get the Radial-Length of non-rotated ellipse at
any given Eccentric( aka Radial ) Angle. It is primarily for use in other
routines such as RadialPoint. The Eccentric angle is in 1/16th of a degree.
For example, a full circle equals 5760 (16*360). Zero degrees is at the 3
o&apos;clock position.
</p>
</descr>
<seealso/>
</element>
<element name="EllipseRadialLength.Result">
<short/>
</element>
<element name="EllipseRadialLength.Rect">
<short/>
</element>
<element name="EllipseRadialLength.EccentricAngle">
<short/>
</element>
<element name="EllipsePolygon">
<short>
Gets an array of points for a polygon which approximates an ellipse in the
specified rectangle.
</short>
<descr>
<p>
<var>EllipsePolygon</var> is a <var>TPointArray</var> function used to
calculate the array of points which approximate an ellipse bounded by the
rectangle specified in the ARect argument. In EllipsePolygon, the ellipse is
aligned to X and Y axes in the rectangle. It calculates the center point,
radii, and diameter for the ellipse using ARect as well as the minimum number
of points needed such that the distance between the edges of the rectangle and
the mathematical circle is less than the rounding error (0.5) and a smoother
stepping value of 0.4. The points for the polygon are calculated and stored in
the return value.
</p>
</descr>
<version>
Added in LCL version 4.0.
</version>
<seealso/>
</element>
<element name="EllipsePolygon.Result">
<short>
Array with the points for the polygon.
</short>
</element>
<element name="EllipsePolygon.ARect">
<short>
Rectangle instance with the bounds for an X- and Y-aligned ellipse.
</short>
</element>
<element name="FloatPoint">
<short>
<var>FloatPoint</var> - it is essentially like Classes.Point in use, except
that it accepts Extended Parameters. It is Primarily for use with and in
Bezier routines.
</short>
<descr/>
<seealso/>
</element>
<element name="FloatPoint.Result">
<short/>
</element>
<element name="FloatPoint.AX">
<short/>
</element>
<element name="FloatPoint.AY">
<short/>
</element>
<element name="LineEndPoint">
<short>
<var>LineEndPoint</var> - get the End-Point of a line of any given Length
at any given angle with any given Start-Point.
</short>
<descr>
<p>
Use LineEndPoint to get the End-Point of a line of any given Length at any
given angle with any given Start-Point. It is primarily for use in other
routines such as RadialPoint. The angle is in 1/16th of a degree. For
example, a full circle equals 5760 (16*360). Zero degrees is at the 3
o&apos;clock position.
</p>
</descr>
<seealso/>
</element>
<element name="LineEndPoint.Result">
<short/>
</element>
<element name="LineEndPoint.StartPoint">
<short/>
</element>
<element name="LineEndPoint.Angle">
<short/>
</element>
<element name="LineEndPoint.Length">
<short/>
</element>
<element name="MakeMinMax">
<short>
Ensures that the i1 argument is the smaller of the two Integer values.
</short>
<descr>
<p>
<var>MakeMinMax</var> swaps the values in i1 and i2 variable parameters when
i1 is larger than i2. No actions are performed in the routine if i1 is smaller
than i2, or the arguments have the same value.
</p>
</descr>
<version>
Added in LazUtils version 3.0.
</version>
<seealso/>
</element>
<element name="MakeMinMax.i1">
<short>
Integer value compared (and potentially updated) in the routine.
</short>
</element>
<element name="MakeMinMax.i2">
<short>
Integer value compared (and potentially updated) in the routine.
</short></element>
<element name="MoveRect">
<short>
Moves the specified rectangle to the origin in the x and y arguments.
</short>
<descr>
<p>
<var>MoveRect</var> sets the Left and Top members in ARect to the values
specified in x and y (respectively). The Right and Bottom members in ARect are
updated to reflect the relative distance from the original Top and Left on
entry.
</p>
</descr>
<version>
Added in LazUtils version 3.0.
</version>
<seealso/>
</element>
<element name="MoveRect.ARect">
<short>
TRect instance updated in the routine.
</short>
</element>
<element name="MoveRect.x">
<short>
New position for the Top coordinate in the rectangle.
</short>
</element>
<element name="MoveRect.y">
<short>
New position for the Left coordinate in the rectangle.
</short>
</element>
<element name="MoveRectToFit">
<short>
Moves and potentially resizes a rectangle to fit within the specified target
rectangle.
</short>
<descr>
<p>
<var>ARect</var> is the TRect instance repositioned in the routine. Values in
the Left, Right, Top, and Bottom members may be updated in the routine if the
rectangle is not located within the bounds for the target rectangle.
</p>
<p>
<var>MaxRect</var> is the TRectangle instance where ARect is repositioned. It
also establishes the maximum size for ARect after it has been repositioned. If
aRect is larger than MaxRect, ARect is resized to fit with in the constraints
in MaxRect.
</p>
<p>
MoveRectToFit is used in the implementation for the DoDock method in TControl.
</p>
</descr>
<version>
Added in LazUtils version 3.0.
</version>
<seealso/>
</element>
<element name="MoveRectToFit.ARect">
<short>
TRect instance moved and optionally resized in the routine.
</short>
</element>
<element name="MoveRectToFit.MaxRect">
<short>
TRect instance where the rectangle is relocated. It also specifies the maximum
size for the relocated rectangle.
</short>
</element>
<element name="SameRect">
<short>
Indicates whether member in the specified rectangles have the same values.
</short>
<descr>
<p>
<var>SameRect</var> is <var>Boolean</var> function used to determine whether
the <var>TRect</var> instances R1 and R2 represent the same rectangular areas.
It compares the values for the Left, Right, Top, and Bottom members in the
TRect instances. The return value is <b>True</b> when members in R1 have the
same values as the corresponding members in R2.
</p>
<p>
SameRect replaces the deprecated CompareRect routine in the
<file>lclproc.pas</file> unit in the LCL.
</p>
</descr>
<version>
Added in LazUtils version 3.99.
</version>
<seealso>
<link id="#lcl.lclproc.CompareRect">CompareRect</link>
<link id="#rtl.types.PRect">PRect</link>
<link id="#rtl.types.TRect">TRect</link>
</seealso>
</element>
<element name="SameRect.Result">
<short>
True when the specified rectangles have the same values in the members.
</short>
</element>
<element name="SameRect.R1">
<short>
Pointer to a TRect instance examined in the routine.
</short>
</element>
<element name="SameRect.R2">
<short>
Pointer to a TRect instance examined in the routine.
</short>
</element>
<element name="PolyBezier2Polyline">
<short>
<var>PolyBezier2Polyline</var> - convert an array of 4-Point Bezier into a
Pointer Array of TPoint and a Count variable.
</short>
<descr>
<p>
Use BezierToPolyline to convert an array of 4-Point Bezier into a Pointer
Array of TPoint and a Count variable which can then be used within either a
Polyline, or Polygon routine. Points is automatically initialized, so any
existing information is lost, and the array starts at 0. Points should
ALWAYS be Freed when done by calling to ReallocMem(Points, 0).
</p>
</descr>
<seealso/>
</element>
<element name="PolyBezier2Polyline.Beziers">
<short/>
</element>
<element name="PolyBezier2Polyline.Points">
<short/>
</element>
<element name="PolyBezier2Polyline.Count">
<short/>
</element>
<element name="PolyBezierArcPoints">
<short>
<var>PolyBezierArcPoints</var> - convert an Arc and ArcLength into a
Pointer Array of TPoints for use with Polyline or Polygon.
</short>
<descr>
<p>
Use PolyBezierArcPoints to convert an Arc and ArcLength into a Pointer
Array of TPoints for use with Polyline or Polygon. The Rotation parameter
accepts a Rotation-Angle for a rotated Ellipse - for a non-rotated ellipse
this value would be 0, or 360. The result is an Approximation based on 1 or
more Beziers. If the AngleLength is greater than 45 degrees, it recursively
breaks the Arc into Arcs of 45 degrees or less, and converts them into
Beziers with BezierArcPoints.
</p>
<p>
The angles are specified in 1/16th of a degree. For example, a full circle
equals 5760 (16*360).
</p>
<p>
Positive values in Angle and AngleLength mean counter-clockwise while
negative values mean clockwise direction. Zero degrees is at the 3
o&apos;clock position.
</p>
<p>
Points is automatically initialized, so any existing information is lost,
and the array starts at 0. Points should ALWAYS be Freed when done by
calling to ReallocMem(Points, 0).
</p>
</descr>
<seealso/>
</element>
<element name="PolyBezierArcPoints.X">
<short/>
</element>
<element name="PolyBezierArcPoints.Y">
<short/>
</element>
<element name="PolyBezierArcPoints.Width">
<short/>
</element>
<element name="PolyBezierArcPoints.Height">
<short/>
</element>
<element name="PolyBezierArcPoints.Angle1">
<short/>
</element>
<element name="PolyBezierArcPoints.Angle2">
<short/>
</element>
<element name="PolyBezierArcPoints.Rotation">
<short/>
</element>
<element name="PolyBezierArcPoints.Points">
<short/>
</element>
<element name="PolyBezierArcPoints.Count">
<short/>
</element>
<element name="Quadrant">
<short>
Determine the <var>Quadrant</var> of any point, given the Center.
</short>
<descr>
<p>
Use Quadrant to determine the Quadrant of any point, given the Center. It
is primarily for use in other routines such as EccentricAngle. A result of
1-4 represents the primary 4 quadrants. A result of 5-8 means the point
lies on one of the Axis, 5 = -Y Axis, 6 = +X Axis, 7 = +Y Axis, and 8 = -X
Axis. A result of -1 means that it does not fall in any quadrant, that is,
it is the Center.
</p>
</descr>
<seealso/>
</element>
<element name="Quadrant.Result">
<short/>
</element>
<element name="Quadrant.PT">
<short/>
</element>
<element name="Quadrant.Center">
<short/>
</element>
<element name="RadialPoint">
<short>
Get the <var>RadialPoint</var> at any given Eccentric angle on any non-
rotated ellipse.
</short>
<descr>
<p>
Use RadialPoint to get the Radial-Point at any given Eccentric(aka Radial)
angle on any non-rotated ellipse. It is primarily for use in Angles2Coords.
The EccentricAngle is in 1/16th of a degree. For example, a full circle
equals 5760 (16*360). Zero degrees is at the 3 o&apos;clock position.
</p>
</descr>
<seealso/>
</element>
<element name="RadialPoint.Result">
<short/>
</element>
<element name="RadialPoint.EccentricAngle">
<short/>
</element>
<element name="RadialPoint.Rect">
<short/>
</element>
<element name="RotatePoint">
<short>
Rotates a point around the origin by the specified angle (in radians).
</short>
<descr>
<p>
Rotates a point around the origin (0,0) by the angle in AAngle. The angle is
in radians and positive for counter-clockwise rotation.
Note that y points downwards.
</p>
</descr>
<seealso/>
</element>
<element name="RotatePoint.Result">
<short>TPoint with the coordinates after rotation.</short>
</element>
<element name="RotatePoint.APoint">
<short>TPoint with coordinates rotated in the routine.</short>
</element>
<element name="RotatePoint.AAngle">
<short>Rotation angle in radians.</short>
</element>
<element name="RotateRect">
<short>
Rotates a rectangle with the specified dimensions by the specified angle
(in radians).
</short>
<descr>
<p>
Rotates the rectangle (0, 0, AWidth, AHeight) around its top-left corner
(0,0) by the angle in AAngle (in radians).
Note that y points downwards.
</p>
</descr>
<seealso/>
</element>
<element name="RotateRect.Result">
<short>The smallest TRect which contains the rotated rectangle.</short>
</element>
<element name="RotateRect.AWidth">
<short>Width for the rectangle.</short>
</element>
<element name="RotateRect.AHeight">
<short>Height for the rectangle.</short>
</element>
<element name="RotateRect.AAngle">
<short>Rotation angle in radians.</short>
</element>
<element name="SplitBezier">
<short>
<var>SplitBezier</var> - split any 4-Point Bezier into two 4-Point Beziers:
a 'Left' and a 'Right'
</short>
<descr>
<p>
Use SplitBezier to split any 4-Point Bezier into two 4-Point Beziers: a
'Left' and a 'Right'. It is primarily for use in Bezier2Polyline.
</p>
</descr>
<seealso/>
</element>
<element name="SplitBezier.Bezier">
<short/>
</element>
<element name="SplitBezier.Left">
<short/>
</element>
<element name="SplitBezier.Right">
<short/>
</element>
<element name="operator +(TFloatPoint,TFloatPoint):TFloatPoint">
<short>
Implements the Add operator (+) for values using the TFloatPoint type.
</short>
<descr>
<p>
Values for the X and Y members in the addends are summed and stored in the
corresponding members in the TFloatPoint result.
</p>
</descr>
</element>
<element name="operator +(TFloatPoint,Extended):TFloatPoint">
<short>
Implements the Add operator (+) for values using the TFloatPoint and Extended
types.
</short>
<descr>
<p>
The Extended value is added to both the X and Y members in the TFloatPoint
type and used in the result for the operator.
</p>
</descr>
<seealso/>
</element>
<element name="operator +(Extended,TFloatPoint):TFloatPoint">
<short>
Implements the Add operator (+) for values using the Extended and TFloatPoint
types.
</short>
<descr>
<p>
The Extended value is added to both the X and Y members in the TFloatPoint
type and used in the result for the operator.
</p>
</descr>
<seealso/>
</element>
<element name="operator +(TFloatPoint,TPoint):TFloatPoint">
<short>
Implements the Add operator (+) for values using the TFloatPoint and TPoint
types.
</short>
<descr/>
<seealso/>
</element>
<element name="operator +(TPoint,TFloatPoint):TFloatPoint">
<short>
Implements the Add operator (+) for values using the TPoint and TFloatPoint
types.
</short>
<descr/>
<seealso/>
</element>
<element name="operator -(TFloatPoint,Extended):TFloatPoint">
<short>
Implements the Subtract operator (-) for values using the TFloatPoint and
Extended types.
</short>
<descr>
<p>
The value in the Extended type is subtracted from both the X and Y members in
the TFloatPoint type and used in the result for the operator.
</p>
</descr>
</element>
<element name="operator -(TFloatPoint,TFloatPoint):TFloatPoint">
<short>
Implements the Subtract operator (-) for values using the TFloatPoint type.
</short>
<descr/>
</element>
<element name="operator -(TFloatPoint,TPoint):TFloatPoint">
<short>
Implements the Subtract operator (-) for values using the TFloatPoint and
TPoint types.
</short>
<descr/>
</element>
<element name="operator -(TPoint,TFloatPoint):TFloatPoint">
<short>
Implements the Subtract operator (-) for values using the TPoint and
TFloatPoint types.
</short>
<descr/>
</element>
<element name="operator *(TFloatPoint,TFloatPoint):TFloatPoint">
<short>
Implements the Multiply operator (*) for values using the TFloatPoint type.
</short>
<descr/>
</element>
<element name="operator *(TFloatPoint,Extended):TFloatPoint">
<short>
Implements the Multiply operator (*) for values using the TFloatPoint and
Extended types.
</short>
<descr>
<p>
The value in the Extended type is applied to both the X and Y members in the TFloatPoint type and used in the result for the operator.
</p>
</descr>
</element>
<element name="operator *(Extended,TFloatPoint):TFloatPoint">
<short>
Implements the Multiply operator (*) for values using the Extended and
TFloatPoint types.
</short>
<descr>
<p>
The value in the Extended type is applied to both the X and Y members in the TFloatPoint type and used in the result for the operator.
</p>
</descr>
</element>
<element name="operator *(TFloatPoint,TPoint):TFloatPoint">
<short>
Implements the Multiply operator (*) for values using the TFloatPoint and
TPoint types.
</short>
<descr/>
</element>
<element name="operator *(TPoint,TFloatPoint):TFloatPoint">
<short>
Implements the Multiply operator (*) for values using the TPoint and
TFloatPoint types.
</short>
<descr/>
</element>
<element name="operator /(TFloatPoint,TFloatPoint):TFloatPoint">
<short>
Implements the Divide operator (/) for values using the TFloatPoint type.
</short>
<descr/>
</element>
<element name="operator /(TFloatPoint,Extended):TFloatPoint">
<short>
Implements the Divide operator (/) for values using the TFloatPoint and
Extended types.
</short>
<descr>
<p>
The value in the Extended type is applied to both the X and Y members in the
TFloatPoint type and used in the result for the operator. No validation is
performed for the divisor in the operator.
</p>
</descr>
</element>
<element name="operator /(TFloatPoint,TPoint):TFloatPoint">
<short>
Implements the Divide operator (/) for values using the TFloatPoint and
TPoint types.
</short>
<descr/>
</element>
<element name="operator /(TPoint,TFloatPoint):TFloatPoint">
<short>
Implements the Divide operator (/) for values using the TPoint and
TFloatPoint types.
</short>
<descr/>
</element>
<element name="operator =(TPoint,TPoint):Boolean">
<short>
Implements the Equal operator (=) to compare values using the TPoint type.
</short>
<descr>
<p>
The result is <b>True</b> when the X and Y members in the compared values are
the same.
</p>
</descr>
</element>
<element name="operator =(TFloatPoint,TFloatPoint):Boolean">
<short>
Implements the Equal operator (=) to compare values using the TFloatPoint type.
</short>
<descr>
<p>
The result is <b>True</b> when the X and Y members in the compared values are
the same.
</p>
</descr>
</element>
<element name="operator =(TRect,TRect):Boolean">
<short>
Implements the Equal operator (=) to compare values using the TRect type.
</short>
<descr>
<p>
The result is <b>True</b> when the Left, Top, Right, and Bottom members in the
compared values are the same.
</p>
</descr>
</element>
<element name="operator :=(TFloatPoint):TPoint">
<short>
Implements the Assign operator (=) to store a value using the TFloatPoint type
to a TPoint instance.
</short>
<descr>
<p>
<var>SimpleRoundTo</var> in the RTL <file>math.pp</file> unit is called to
round both the X and Y members to a Double value with 0 decimals in the
precision. The Double values are truncated and stored to the Longint types
used for the X and Y members in the result for the operator.
</p>
</descr>
</element>
<element name="operator :=(TPoint):TFloatPoint">
<short>
Implements the Assign operator (=) to store a value using the TPoint type to a
TFloatPoint instance.
</short>
<descr/>
</element>
<topic name="GraphMathOperators">
<short>
<b>GraphMath Operators</b>.
</short>
<descr>
<p>
This Unit contains a number of routines for calculating and converting
series of graphic points from one coordinate system to another.
</p>
<p>
A fundamental type is introduced, called TFloatPoint. It is an extended
precision record containing an X and a Y coordinate for a graphic point.
Its structure is as follows:
</p>
<code>
type
TFloatPoint = record
X, Y: Extended;
end;
</code>
<p>
The Unit contains definitions for mathematical operators which extend the
normal definitions of addition, subtraction, multiplication, division and
comparison to cover manipulations with TFloatPoints, allowing, for example,
addition or multiplication of two TFloatPoints, a TFloatPoint and a TPoint,
or a TFloatPoint and an Extended precision number.
</p>
</descr>
</topic>
</module>
<!-- GraphMath -->
</package>
</fpdoc-descriptions>