Mouse Position in cs Orthogonal CameraStyle

[Damjan Mikuž]

Hello to all!

Here is the function that I use to determine the mouse position in csPerspective CameraStyle:

function Tmain.MouseWorldPos(const X, Y: Integer; isy: boolean = false): TVector;
var
v: TVector;
InvertedY: Integer;
begin

InvertedY := Viewer.Height - Y;

SetVector(v, X, InvertedY, 0);
if not isy then
Viewer.Buffer.ScreenVectorIntersectWithPlaneXZ
(v,TargetCamera.AbsolutePosition.y, Result)
else
Viewer.Buffer.ScreenVectorIntersectWithPlaneXY
(v,TargetCamera.AbsolutePosition.z, Result)
end;

I am also to able determine the intersection on FreeForm with procedure like this on csOrthogonal CameraStyle:

procedure TForm1.GLSceneViewer1MouseDown(Sender: TObject;
Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
var
rayStart, rayVector, iPoint, iNormal : TVector;
begin
// retrieve raycasting data:
// rayStart is obtained for camera and screen position
// rayVector is the camera direction (i.e direction to target since our camera is targeted)
// (note that (0, 0) is lower left for the Screen function, whereas Delphi
// uses top-left as origin, hence the Y inversion)
SetVector(rayStart, GLSceneViewer1.Buffer.OrthoScreenToWorld(x, GLSceneViewer1.Height-y));
SetVector(rayVector, GLCamera1.AbsoluteVectorToTarget);
NormalizeVector(rayVector);
// Here we require RayCast intersection
if FreeForm1.RayCastIntersect(rayStart, rayVector, @iPoint, @iNormal) then begin
// got one, move the sphere there and orient it appropriately
Sphere1.Position.AsVector:=iPoint;
Sphere1.Direction.AsVector:=VectorNormalize(iNormal);
// make it visible
Sphere1.Visible:=True;
end else begin
// hide it if we did not hit
Sphere1.Visible:=False;
end;
end;

Now here is my problem: how to determine intersection WithPlaneXY or WithPlaneX in csOrthogonal CameraStyle like in case 1:
Here is some example how i try, but with no sucsess!
Procedure TForm1.ViewerMouseMove(Sender: TObject; Shift: TShiftState; X,
Y: Integer);
var
raystart,rayvector,ipoint,inormal:TVector;
raytarget,v:TAffineVector ;

cp : TPoint;

begin

v := viewer.Buffer.OrthoScreenToWorld(x, y);

     //glcube2.AbsoluteToLocal(v);
 setVector(raystart, viewer.Buffer.OrthoScreenToWorld(x, viewer.Height-y),0);
// edit4.Text:=MouseWorldPos(x,Y).X.ToString();

   setVector(rayvector, glcamera1.AbsoluteVectorToTarget);

Viewer.Buffer.ScreenVectorIntersectWithPlaneyz(raystart,rayvector.y,ipoint);

// GLGetCursorPos(cp);
glcube1.Position.AsVector:=(ipoint);
// glcube1.Position.Y:=(rayvector.z);
// glcube1.Position.Z:=(raystart.y);
edit1.Text:=(ipoint.x).ToString();
edit2.Text:=(ipoint.Y).ToString();
edit3.Text:=(ipoint.z).ToString;

 end;

[Jerome.D (BeanzMaster)]

Hi can you provide a full sample, If i'm remember well your problem come from ScreenVectorIntersectWithPlaneyz. I don't rember with csOrthogonal CameraStyle what the right planes to test. I must do some research in some old codes

[Damjan Mikuž]

Hello,
here is my code(be aware that is quite a mess).
I partly solved with adding a TGLPlane to Glscene and using Viewer.Buffer.OrthoScreenToWorld(x, viewer.Height-y)) +TGLPlane.RayCastIntersect(rayStart, rayVector, @iPoint, @iNormal) . But if I remember correctly in csPerspective CameraStyle adding GLPlane it is not necessary. The code bellow absolutely needs a fix!
I will dig a little deeper!
Ps. tray press radio button rbYZ, Whay is TGLCube does not intersect corectly!