lazarus/components/tachart/tachartutils.pas
2009-04-24 11:32:33 +00:00

359 lines
9.0 KiB
ObjectPascal

{
/***************************************************************************
TAChartUtils.pas
----------------
Component Library Standard Graph Utiliity Functions
***************************************************************************/
*****************************************************************************
* *
* See the file COPYING.modifiedLGPL.txt, included in this distribution, *
* for details about the copyright. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. *
* *
*****************************************************************************
Authors: Luнs Rodrigues, Philippe Martinole, Alexander Klenin
}
unit TAChartUtils;
{$H+}
interface
uses
Graphics, Types, SysUtils;
const
MaxColor = 15;
Colors: array [1..MaxColor] of TColor = (
clRed, clGreen, clYellow, clBlue, clWhite, clGray, clFuchsia,
clTeal, clNavy, clMaroon, clLime, clOlive, clPurple, clSilver, clAqua);
type
EChartError = class(Exception);
TChartCoord = record
x, y: Double;
Color: TColor;
Text: String;
end;
PChartCoord = ^TChartCoord;
TDoublePoint = record
X, Y: Double;
end;
TDoubleRect = record
case Integer of
0: (
a, b: TDoublePoint;
);
1: (
coords: array [1..4] of Double;
);
end;
TPointDistFunc = function (const A, B: TPoint): Integer;
TAxisScale = (asIncreasing, asDecreasing, asLogIncreasing, asLogDecreasing);
TPenBrushFont = set of (pbfPen, pbfBrush, pbfFont);
TSeriesMarksStyle = (
smsCustom, { user-defined }
smsNone, { no labels }
smsValue, { 1234 }
smsPercent, { 12 % }
smsLabel, { Cars }
smsLabelPercent, { Cars 12 % }
smsLabelValue, { Cars 1234 }
smsLegend, { ? }
smsPercentTotal, { 12 % of 1234 }
smsLabelPercentTotal, { Cars 12 % of 1234 }
smsXValue); { 21/6/1996 }
TSeriesPointerStyle = (
psNone, psRectangle, psCircle, psCross, psDiagCross, psStar,
psLowBracket, psHighBracket, psLeftBracket, psRightBracket, psDiamond);
{ TPenBrushFontRecall }
TPenBrushFontRecall = class
private
FBrush: TBrush;
FCanvas: TCanvas;
FFont: TFont;
FPen: TPen;
public
constructor Create(ACanvas: TCanvas; AParams: TPenBrushFont);
destructor Destroy; override;
procedure Recall;
end;
const
// 0-value, 1-percent, 2-label, 3-total, 4-xvalue
SERIES_MARK_FORMATS: array [TSeriesMarksStyle] of String = (
'', '',
'%0:g', // smsValue
'%1:.2f%%', // smsPercent
'%2:s', // smsLabel
'%2:s %1:.2f%%', // smsLabelPercent
'%2:s %0:g', // smsLabelValue
'%2:s', // smsLegend: not sure what it means, left for Delphi compatibility
'%1:.2f%% of %3:g', // smsPercentTotal
'%1:.2f%% of %3:g', // smsLabelPercentTotal
'%4:g' // smsXValue
);
EmptyDoubleRect: TDoubleRect = (coords: (0, 0, 0, 0));
procedure CalculateIntervals(
AMin, AMax: Double; AxisScale: TAxisScale; out AStart, AStep: Double);
function DoublePoint(const ACoord: TChartCoord): TDoublePoint; inline;
function DoubleRect(AX1, AY1, AX2, AY2: Double): TDoubleRect; inline;
procedure Exchange(var A, B: Integer); overload;
procedure Exchange(var A, B: Double); overload;
procedure Exchange(var A, B: TDoublePoint); overload;
// True if float ranges [A, B] and [C, D] have at least one common point.
function FloatRangesOverlap(A, B, C, D: Double): Boolean; inline;
function PointDist(const A, B: TPoint): Integer; inline;
function PointDistX(const A, B: TPoint): Integer; inline;
function PointDistY(const A, B: TPoint): Integer; inline;
procedure RotateLabel(
Canvas: TCanvas; x, y: Integer; const St: String; RotDegree: Integer);
// Call this to silence 'parameter is unused' hint
procedure Unused(const A1);
procedure Unused(const A1, A2);
operator +(const A: TPoint; B: TSize): TPoint;
implementation
uses
Math, LCLIntf, LCLType;
procedure CalculateIntervals(
AMin, AMax: Double; AxisScale: TAxisScale; out AStart, AStep: Double);
var
extent, extentTmp, stepCount, scale, maxStepCount, m: Double;
i: Integer;
const
GOOD_STEPS: array [1..3] of Double = (0.2, 0.5, 1.0);
begin
extent := AMax - AMin;
AStep := 1;
AStart := AMin;
if extent <= 0 then exit;
maxStepCount := 0;
scale := 1.0;
for i := Low(GOOD_STEPS) to High(GOOD_STEPS) do begin
extentTmp := extent / GOOD_STEPS[i];
m := power(10, Round(log10(extentTmp)));
while extentTmp * m > 10 do
m *= 0.1;
while extentTmp * m <= 1 do
m *= 10;
stepCount := extentTmp * m;
if stepCount > maxStepCount then begin
maxStepCount := stepCount;
scale := m;
AStep := GOOD_STEPS[i] / m;
end;
end;
case AxisScale of
asIncreasing: begin
// If 0 is in the interval, set it as a mark.
if InRange(0, AMin, AMax) then
AStart := 0
else
AStart := Round((AMin - AStep) * scale) / scale;
while AStart > AMin do AStart -= AStep;
end;
asDecreasing: begin
// If 0 is in the interval, set it as a mark.
if InRange(0, AMin, AMax) then
AStart := 0
else
AStart := Round((AMax + AStep) * scale) / scale;
while AStart < AMax do AStart += AStep;
end;
asLogIncreasing: begin
// FIXME: asLogIncreasing is still not implemented.
// The following is the same code for asIncreasing;
// If 0 is in the interval, set it as a mark.
if InRange(0, AMin, AMax) then
AStart := 0
else
AStart := Round((AMin - AStep) * scale) / scale;
while AStart > AMin do AStart -= AStep;
end;
asLogDecreasing: begin
// FIXME: asLogDecreasing is still not implemented.
// The following is the same code for asIncreasing;
// If 0 is in the interval, set it as a mark.
if InRange(0, AMin, AMax) then
AStart := 0
else
AStart := Round((AMax + AStep) * scale) / scale;
while AStart < AMax do AStart += AStep;
end;
end; {case AxisScale}
end;
function DoublePoint(const ACoord: TChartCoord): TDoublePoint;
begin
Result.X := ACoord.x;
Result.Y := ACoord.y;
end;
function DoubleRect(AX1, AY1, AX2, AY2: Double): TDoubleRect; inline;
begin
Result.a.X := AX1;
Result.a.Y := AY1;
Result.b.X := AX2;
Result.b.Y := AY2;
end;
procedure Exchange(var A, B: Integer); overload;
var
t: Integer;
begin
t := A;
A := B;
B := t;
end;
procedure Exchange(var A, B: Double); overload;
var
t: Double;
begin
t := A;
A := B;
B := t;
end;
procedure Exchange(var A, B: TDoublePoint);
var
t: TDoublePoint;
begin
t := A;
A := B;
B := t;
end;
function FloatRangesOverlap(A, B, C, D: Double): Boolean; inline;
begin
Result := (A <= D) and (C <= B);
end;
function PointDist(const A, B: TPoint): Integer;
begin
Result := Sqr(A.X - B.X) + Sqr(A.Y - B.Y);
end;
function PointDistX(const A, B: TPoint): Integer;
begin
Result := Abs(A.X - B.X);
end;
function PointDistY(const A, B: TPoint): Integer; inline;
begin
Result := Abs(A.Y - B.Y);
end;
procedure RotateLabel(
Canvas: TCanvas; x, y: Integer; const St: String; RotDegree: Integer);
var
OldFont, NewFont: HFONT;
LogRec: TLOGFONT;
DC: HDC;
begin
with Canvas do begin
Brush.Style := bsClear;
GetObject(Font.Handle, SizeOf(LogRec), @LogRec);
LogRec.lfEscapement := RotDegree * 10;
LogRec.lfOrientation := 0;
LogRec.lfOutPrecision := OUT_TT_ONLY_PRECIS;
NewFont := CreateFontIndirect(LogRec);
DC := Handle;
end;
OldFont := SelectObject(DC, NewFont);
TextOut(DC, X, Y, @St[1], Length(St));
DeleteObject(SelectObject(DC, OldFont));
end;
{$HINTS OFF}
procedure Unused(const A1);
begin
end;
procedure Unused(const A1, A2);
begin
end;
{$HINTS ON}
operator + (const A: TPoint; B: TSize): TPoint;
begin
Result.X := A.X + B.cx;
Result.Y := A.Y + B.cy;
end;
{ TPenBrushFontRecall }
constructor TPenBrushFontRecall.Create(ACanvas: TCanvas; AParams: TPenBrushFont);
begin
inherited Create;
FCanvas := ACanvas;
if pbfPen in AParams then begin
FPen := TPen.Create;
FPen.Assign(FCanvas.Pen);
end;
if pbfBrush in AParams then begin
FBrush := TBrush.Create;
FBrush.Assign(FCanvas.Brush);
end;
if pbfFont in AParams then begin
FFont := TFont.Create;
FFont.Assign(FCanvas.Font);
end;
end;
destructor TPenBrushFontRecall.Destroy;
begin
Recall;
inherited;
end;
procedure TPenBrushFontRecall.Recall;
begin
if FPen <> nil then begin
FCanvas.Pen.Assign(FPen);
FreeAndNil(FPen);
end;
if FBrush <> nil then begin
FCanvas.Brush.Assign(FBrush);
FreeAndNil(FBrush);
end;
if FFont <> nil then begin
FCanvas.Font.Assign(FFont);
FreeAndNil(FFont);
end;
end;
end.