A wave plotter component that is able to draw sin, poly and squared lines, I used this in a osciloscope xD
I didn't liked this code, but the draw part (TWaveShape.paint) is looking cool, I used the same "X" coord to draw the 3 kinds of lines :)
I mean:
loop(x){
case waveType of
wtSin: y := lala;
wtPoly: y := lele;
wtSqr: y := lili;
end;
}
unit WavePlotter;
interface
uses
forms, dialogs, SysUtils, Classes, Controls, Graphics;
const
PI2 = PI * 2;
type
TWaveType = ( wtSqr, wtPoly, wtSin );
TWave = class( TPersistent )
public
waveType: TWaveType;
color: TColor;
offset: integer;
frequency, amplitude, volts, interval, gain: extended;
procedure AssignTo(Dest: TPersistent); override;
end;
TWaveShape = class( TGraphicControl )
protected
fWaves: TList;
fBoxSize: integer;
fLineColor: TColor;
function getWave(const index: integer): TWave;
procedure setBoxSize(const Value: integer);
function getBackgroundColor: TColor;
procedure setBackgroundColor(const Value: TColor);
procedure setLineColor(const Value: TColor);
public
constructor create( AOwner: TComponent ); override;
destructor destroy; override;
procedure clear;
procedure delete( const index: integer );
function add: integer;
property waves[ const index: integer]: TWave read GetWave;
published
procedure paint; override;
property boxSize: integer read fBoxSize write setBoxSize;
property backgroundColor: TColor read getBackgroundColor write setBackgroundColor;
property lineColor: TColor read fLineColor write setLineColor;
//inherited
//property Canvas;
property Align;
property Anchors;
property Constraints;
property DragCursor;
property DragKind;
property DragMode;
property Enabled;
//property Font;
property ParentColor;
//property ParentFont;
property ParentShowHint;
property PopupMenu;
property ShowHint;
property Visible;
property OnClick;
property OnContextPopup;
property OnDblClick;
property OnDragDrop;
property OnDragOver;
property OnEndDock;
property OnEndDrag;
property OnMouseDown;
property OnMouseMove;
property OnMouseUp;
property OnStartDock;
property OnStartDrag;
end;
implementation
function max( const a, b: integer ): integer;
begin
if a > b then
result := a
else
result := b;
end;
{ TWaveShape }
function TWaveShape.add: integer;
begin
result := fWaves.add( TWave.Create );
end;
procedure TWaveShape.clear;
begin
while fWaves.count > 0 do begin
TWave( fWaves[0] ).free;
fWaves.delete( 0 );
end;
end;
constructor TWaveShape.create(AOwner: TComponent);
begin
inherited;
fWaves := TList.create;
fLineColor := clGray;
color := clBtnFace;
fBoxSize := 50;
end;
procedure TWaveShape.delete(const index: integer);
begin
if ( index > -1 ) and ( index < fWaves.count ) then begin
TWave( fWaves[index] ).free;
fWaves.delete( index );
end;
end;
destructor TWaveShape.destroy;
begin
fWaves.free;
inherited;
end;
function TWaveShape.getBackgroundColor: TColor;
begin
result := color;
end;
function TWaveShape.getWave(const index: integer): TWave;
begin
result := nil;
if ( index > -1 ) and ( index < fWaves.count ) then
result := TWave( fWaves[ index ] );
end;
procedure TWaveShape.paint;
var
k, x: integer;
lastX, lastY: array of integer;
y: extended;
begin
if not enabled then
exit;
canvas.brush.color := color;
canvas.fillRect( clientRect );
setLength( lastY, fWaves.count );
setLength( lastX, fWaves.count );
for k := 0 to high( lastY ) do begin
lastY[k] := clientHeight div 2 + waves[k].offset;
lastX[k] := 0;
end;
for x := 0 to max( clientWidth, clientHeight ) do begin
with canvas do begin
pen.color := fLineColor;
pen.width := 1;
pen.style := psDot;
if x mod fBoxSize = 0 then begin
moveTo( 0, x + trunc( frac( clientHeight / 2 / fBoxSize ) * fBoxSize ) );
lineTo( clientWidth, x + trunc( frac( clientHeight / 2 / fBoxSize ) * fBoxSize ) );
moveTo( x, 0 );
lineTo( x, clientHeight );
end;
for k := 0 to fWaves.count - 1 do begin
with waves[k] do begin
pen.color := color;
pen.width := 1;
pen.style := psSolid;
y := pi*k + PI2 * x * interval / fBoxSize * frequency;
case waveType of
wtSin:
y := sin( y );
wtPoly: begin
y := frac( y / PI2 );
if y <= 0.25 then
y := y / 0.25
else if y <= 0.75 then
y := ( -y + 0.5 ) / 0.25
else
y := ( y - 1 ) / 0.25;
end;
wtSqr: begin
if frac( y / PI2 ) <= 0.5 then
y := 1
else
y := -1;
end;
end;
y := ( y * ( fBoxSize / volts ) * amplitude * gain ) + clientHeight / 2 + offset;
moveTo( lastX[k], lastY[k] );
lastX[k] := x;
lastY[k] := trunc( y );
lineTo( x, lastY[k] );
end;
end;
end;
end;
end;
procedure TWaveShape.setBackgroundColor(const Value: TColor);
begin
color := Value;
Invalidate;
end;
procedure TWaveShape.setBoxSize(const Value: integer);
begin
fBoxSize := Value;
invalidate;
end;
procedure TWaveShape.setLineColor(const Value: TColor);
begin
fLineColor := Value;
Invalidate;
end;
{ TWave }
procedure TWave.AssignTo(Dest: TPersistent);
begin
if Dest.ClassType <> TWave then
inherited;
with TWave( Dest ) do begin
waveType := self.waveType;
color := self.color;
offset := self.offset;
frequency := self.frequency;
amplitude := self.amplitude;
volts := self.volts;
interval := self.interval;
gain := self.gain;
end;
end;
end.
