RN_ValueHistory.pas

unit RN_ValueHistory;
interface

type
  TValueHistory = class
  private
    const MAX_HISTORY = 256;
    var
    m_samples: array [0..MAX_HISTORY-1] of Single;
    m_hsamples: Integer;
  public
    constructor Create();
    destructor Destroy; override;

    procedure addSample(const val: Single);
    function getSampleCount(): Integer;
    function getSample(const i: Integer): Single;

    function getSampleMin(): Single;
    function getSampleMax(): Single;
    function getAverage(): Single;
  end;

  PGraphParams = ^TGraphParams;
  TGraphParams = record
    procedure setRect(ix, iy, iw, ih, ipad: Integer);
    procedure setValueRange(ivmin, ivmax: Single; indiv: Integer; const iunits: PShortInt);
  public
    x, y, w, h, pad: Integer;
    vmin, vmax: Single;
    ndiv: Integer;
    units: array [0..15] of ShortInt;
  end;

  procedure drawGraphBackground(const p: PGraphParams);

  procedure drawGraph(const p: PGraphParams; const graph: TValueHistory;
           idx: Integer; const &label: PShortInt; const col: Cardinal);


implementation


constructor TValueHistory.Create();
var i: Integer;
begin
  inherited;

	for i := 0 to MAX_HISTORY - 1 do
		m_samples[i] := 0;
end;

destructor TValueHistory.Destroy;
begin
  inherited;
end;

procedure TValueHistory.addSample(const val: Single);
begin
  m_hsamples := (m_hsamples+MAX_HISTORY-1) mod MAX_HISTORY;
  m_samples[m_hsamples] := val;
end;

function TValueHistory.getSampleCount(): Integer;
begin
  Result := MAX_HISTORY;
end;

function TValueHistory.getSample(const i: Integer): Single;
begin
  Result := m_samples[(m_hsamples+i) mod MAX_HISTORY];
end;

function TValueHistory.getSampleMin(): Single;
var val: Single; i: Integer;
begin
	val := m_samples[0];
	for i := 1 to MAX_HISTORY - 1 do
		if (m_samples[i] < val) then
			val := m_samples[i];
	Result := val;
end;

function TValueHistory.getSampleMax(): Single;
var val: Single; i: Integer;
begin
	val := m_samples[0];
	for i := 1 to MAX_HISTORY - 1 do
		if (m_samples[i] > val) then
			val := m_samples[i];
	Result := val;
end;

function TValueHistory.getAverage(): Single;
var val: Single; i: Integer;
begin
	val := 0;
	for i := 1 to MAX_HISTORY - 1 do
		val := val + m_samples[i];
	Result := val/MAX_HISTORY;
end;

procedure TGraphParams.setRect(ix, iy, iw, ih, ipad: Integer);
begin
	x := ix;
	y := iy;
	w := iw;
	h := ih;
	pad := ipad;
end;

procedure TGraphParams.setValueRange(ivmin, ivmax: Single; indiv: Integer; const iunits: PShortInt);
begin
	vmin := ivmin;
	vmax := ivmax;
	ndiv := indiv;
	//todo: Delphi: strcpy(units, iunits);
end;

procedure drawGraphBackground(const p: PGraphParams);
begin
{	// BG
	imguiDrawRoundedRect((float)p.x, (float)p.y, (float)p.w, (float)p.h, (float)p.pad, imguiRGBA(64,64,64,128));

	const float sy := (p.h-p.pad*2) / (p.vmax-p.vmin);
	const float oy := p.y+p.pad-p.vmin*sy;

	char text[64];

	// Divider Lines
	for (int i := 0; i <= p.ndiv; ++i)
	begin
		const float u := (float)i/(float)p.ndiv;
		const float v := p.vmin + (p.vmax-p.vmin)*u;
		snprintf(text, 64, "%.2f %s", v, p.units);
		const float fy := oy + v*sy;
		imguiDrawText(p.x + p.w - p.pad, (int)fy-4, IMGUI_ALIGN_RIGHT, text, imguiRGBA(0,0,0,255));
		imguiDrawLine((float)p.x + (float)p.pad, fy, (float)p.x + (float)p.w - (float)p.pad - 50, fy, 1.0f, imguiRGBA(0,0,0,64));
	end;}
end;

procedure drawGraph(const p: PGraphParams; const graph: TValueHistory;
           idx: Integer; const &label: PShortInt; const col: Cardinal);
begin
{	const float sx := (p.w - p.pad*2) / (float)graph.getSampleCount();
	const float sy := (p.h - p.pad*2) / (p.vmax - p.vmin);
	const float ox := (float)p.x + (float)p.pad;
	const float oy := (float)p.y + (float)p.pad - p.vmin*sy;

	// Values
	float px=0, py=0;
	for (int i := 0; i < graph.getSampleCount()-1; ++i)
	begin
		const float x := ox + i*sx;
		const float y := oy + graph.getSample(i)*sy;
		if (i > 0)
			imguiDrawLine(px,py, x,y, 2.0f, col);
		px := x;
		py := y;
	end;

	// Label
	const int size := 15;
	const int spacing := 10;
	int ix := p.x + p.w + 5;
	int iy := p.y + p.h - (idx+1)*(size+spacing);

	imguiDrawRoundedRect((float)ix, (float)iy, (float)size, (float)size, 2.0f, col);

	char text[64];
	snprintf(text, 64, "%.2f %s", graph.getAverage(), p.units);
	imguiDrawText(ix+size+5, iy+3, IMGUI_ALIGN_LEFT, label, imguiRGBA(255,255,255,192));
	imguiDrawText(ix+size+150, iy+3, IMGUI_ALIGN_RIGHT, text, imguiRGBA(255,255,255,128));}
end;

end.