TTeeCanvasCalcPoints parameters ?
Posted: Wed Nov 23, 2005 2:46 pm
Can anybody explain to me the meaning of parameters in TTeeCanvasCalcPoints function (part of TGLCanvas.Surface3D method)?
Teodor
Teodor
Below you have FastCalcPoints code. Basically, what this method does is calculating a point position in a quicker way considering the previous point position so that the point can be drawn quicker. If this is possible it returns true, otherwise it returns false.
Code: Select all
Function TSurfaceSeries.FastCalcPoints( x,z:Integer;
Var P0,P1:TPoint3D;
Var Color0,Color1:TColor):Boolean;
var tmp0 : TChartValue;
tmp1 : TChartValue;
begin
result:=False;
ValueIndex0:=GridIndex[x-1,z];
if ValueIndex0<>-1 then
begin
ValueIndex1:=GridIndex[x,z];
if ValueIndex1<>-1 then
begin
With GetHorizAxis do
begin
P0.x:=CalcXPosValue(XValues.Value[ValueIndex0]);
P1.x:=CalcXPosValue(XValues.Value[ValueIndex1]);
end;
P0.z:=CalcZPos(ValueIndex0);
P1.z:=CalcZPos(ValueIndex1);
tmp0:=YValues.Value[ValueIndex0];
tmp1:=YValues.Value[ValueIndex1];
With GetVertAxis do
begin
P0.y:=CalcYPosValue(tmp0);
P1.y:=CalcYPosValue(tmp1);
end;
if not FSameBrush then
begin
Color0:=ValueColor[ValueIndex0];
Color1:=ValueColor[ValueIndex1];
end;
result:=True;
end;
end;
end;