TRect / TPoint

Fonte: source/classes/rect.prg

Standalone classes (no inheritance)

TRect and TPoint are utility classes for 2D geometry operations. TRect represents a rectangle defined by its top, left, bottom, and right edges. TPoint represents a single point with row and column (or Y and X) coordinates. Both classes support arithmetic operators and geometric transformations commonly needed in UI layout and drawing code.

TRect

Key DATA Members

DATA	Type	Description
`aRect`	Array	Core data: `{ nTop, nLeft, nBottom, nRight }`
`nTop`	Numeric	Top edge (accessor for aRect[1])
`nLeft`	Numeric	Left edge (accessor for aRect[2])
`nBottom`	Numeric	Bottom edge (accessor for aRect[3])
`nRight`	Numeric	Right edge (accessor for aRect[4])
`nWidth`	Numeric	Computed width
`nHeight`	Numeric	Computed height
`cRect`	Character	Binary RECT structure (8 bytes) for Win32 API calls
`CenterPt`	Array	Center point as `{ nTop, nLeft }`
`lWinRect`	Logical	Windows-style rect (exclusive right/bottom). Default .T.

TRect Methods

Method	Description
`New( nTop, nLeft, nBottom, nRight [, nWidth, nHeight] )`	Create a new rectangle. Accepts array, binary string, or four coordinates. nWidth/nHeight override nRight/nBottom.
`MoveBy( nRows, nCols )`	Offset the entire rectangle by the given deltas
`MoveTo( nNewTop, nNewLeft )`	Move rectangle so its top-left corner is at the given position
`Contains( aPoint )`	Check if a point { row, col } or another rectangle is inside this one
`Resize( nRatio [, aPoint] )`	Resize by a ratio relative to center (or specified anchor point)
`FitInside( oRect, nType, cAlign )`	Fit this rectangle inside another, optionally enlarging. nType: 1=exact, 2=fill outer, 3=fit inside.
`AsSquare( lOuter, cAlign )`	Adjust to make a square by expanding or contracting the larger dimension
`Modify( ... )`	Return a new TRect with modified edges; supports absolute, fractional, and relative changes

TRect Operators

Operator	Description
`==`	Equality comparison (all four edges match)
`+, -, *, /, %`	Arithmetic on all four edges by a value or array
`+=, -=, *=, /=, %=`	In-place arithmetic operators
`[]`	Indexed access: `oRect[1]` = nTop, `oRect[2]` = nLeft, etc.

TPoint

TPoint Key DATA Members

DATA	Type	Description
`nRow`	Numeric	Row (Y) coordinate
`nCol`	Numeric	Column (X) coordinate
`X`	Numeric	Alias for nCol
`Y`	Numeric	Alias for nRow
`aPt`	Array	`{ nRow, nCol }`
`aXY`	Array	`{ X, Y }` = `{ nCol, nRow }`

TPoint Methods

Method	Description
`New( nRow, nCol )`	Create from row/col; also accepts an array {row,col}
`NewXY( x, y )`	Create from X/Y coordinates (stored as nCol/nRow)
`Rect( nRadius [, yRadius] )`	Return a TRect centered at this point with the given radius
`Distance( oPt )`	Euclidean distance to another point
`Plus( r, c [, lNew] )`	Add deltas and return a new point (or modify Self if lNew is .F.)

TPoint Operators

Operator	Description
`+`	Create a new point offset by the given delta
`+=`	In-place offset
`-`	Return the distance between two points

Example

#include "FiveWin.ch"

function Main()

   local oRect, oPt, oInner

   // Create a 200x100 rectangle at position (10,10)
   oRect := TRect():New( 10, 10, 110, 210 )

   // Test if a point is inside
   oPt := TPoint():New( 50, 100 )
   if oRect:Contains( oPt:aPt )
      MsgInfo( "Point is inside the rectangle" )
   endif

   // Create a square and fit it inside the rectangle
   oInner := TRect():New( 0, 0, 100, 100 )
   oInner:FitInside( oRect, 3, "C" )  // Fit inside, centered

   // Move the rectangle by 10 pixels in each direction
   oRect:MoveBy( 10, 10 )

return nil

Notes

TRect can be constructed from an array, from a binary RECT structure, or from four numeric coordinates.
The lWinRect flag controls whether width/height calculations use Windows convention (exclusive bottom/right edges, default .T.) or inclusive convention (.F.).
TPoint's - operator returns the Euclidean distance (a numeric value), not a new point.
Both classes provide OPERATOR overloading for natural arithmetic and indexing syntax.
Helper Funções PointXY( x, y ) and PointRowCol( r, c ) create TPoint objects inline.