Differences

This shows you the differences between two versions of the page.

--- interaction [2020/05/26 11:44] – [Keyboard Interaction] admin
+++ interaction [2020/11/06 09:23] – [Input-Controller] admin
@@ Line 1: / Line 1: @@
 ====== Interaction ======
-In the following the implementation of mouse and keyboard interaction with default FMX methods will be described.
+In the following the implementation of mouse, keyboard and gesture interaction with default FMX methods will be described.
 In case you'll need extended features, have a look at the InputController implementation: [[inputpolling|Input Polling]]
@@ Line 166: / Line 166: @@
 ===== Keyboard Interaction =====
+In case you'll need keyboard interaction, best performance will be reached when key events are declared in the form itself.
+In the following example we setup a physics demo with a sphere. When cursor keys are down, an impulse will be applied to the sphere rigid body, which moves the object in space.
-Next step: [[android|Android]]
+<file pascal>
+uses
+  [...],
+  Gorilla.Sphere, Gorilla.Physics;
+type
+TForm1 = class(TForm)
+  GorillaSphere1: TGorillaSphere;
+  GorillaPhysicsSystem1: TGorillaPhysicsSystem;
+  procedure FormKeyDown(Sender: TObject; var Key: Word; var KeyChar: Char;
+    Shift: TShiftState);
+  [...]
+end;
+[...]
+procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word; var KeyChar: Char;
+  Shift: TShiftState);
+var LImpulse : TPoint3D;
+    LBody : TQ3Body;
+begin
+  if (Key = vkLEFT) then
+    LImpulse := TPoint3D.Create(-1, 0, 0)
+  else if (Key = vkRIGHT) then
+    LImpulse := TPoint3D.Create(1, 0, 0)
+  else if (Key = vkUP) then
+    LImpulse := TPoint3D.Create(0, 0, 1)
+  else if (Key = vkDOWN) then
+    LImpulse := TPoint3D.Create(0, 0, -1);
+  // apply impulse on sphere
+  GorillaPhysicsSystem1.RemoteBodyImpulse(GorillaSphere1, LImpulse);
+end;
+</file>
+The usage of form key events is very rudimentary and may reach its limits very fast.
+===== Gesture Interaction =====
+Gesture handling is supported for Gorilla3D viewport. To allow gesture management you will need a TGestureManager component on your form and you have to link it to the TGorillaViewport component.
+In the example below it is described, how to rotate and zoom a model. Therefor we use the interactive gestures: ZOOM and PAN.
+In the //OnGesture// event of our GorillaViewport1 we setup a callback procedure to handle gesture input. Simple check for the supplied interactive gesture event: //igiZoom// or //igiPan// and execute the very simple //DoZoom// and //DoRotate// sub-routines.
+<file pascal>
+type
+  TForm1 = class(TForm)
+    GorillaViewport1: TGorillaViewport;
+    GestureManager1: TGestureManager;
+    GorillaModel1: TGorillaModel;
+    procedure GorillaViewport1Gesture(Sender: TObject;
+      const EventInfo: TGestureEventInfo; var Handled: Boolean);
+    protected
+      FLastPos : TPointF;
+    [...]
+  end;
+procedure TForm1.FormCreate(Sender : TObject);
+begin
+  GorillaViewport1.Touch.GestureManager := GestureManager1;
+  GorillaViewport1.Touch.InteractiveGestures := [Zoom, Pan];
+  GorillaViewport1.OnGesture := GorillaViewport1Gesture;
+  [...]
+end;
+procedure TForm1.GorillaViewport1Gesture(Sender: TObject;
+  const EventInfo: TGestureEventInfo; var Handled: Boolean);
+  procedure DoZoom();
+  var LScale : Single;
+  begin
+    if not (TInteractiveGestureFlag.gfBegin in EventInfo.Flags)
+    and not (TInteractiveGestureFlag.gfEnd in EventInfo.Flags) then
+    begin
+      LScale := EventInfo.Distance / 100;
+      GorillaModel1.Scale.Point := Point3D(LScale, LScale, LScale);
+    end;
+  end;
+  procedure DoRotate();
+  var LDist : Single;
+      LDiff,
+      LNew,
+      LPos  : TPointF;
+  begin
+    LNew := EventInfo.Location;
+    if not Assigned(GorillaModel1) then
+    begin
+      FLastPos := LNew;
+      Exit;
+    end;
+    if not (TInteractiveGestureFlag.gfBegin in EventInfo.Flags)
+    and not (TInteractiveGestureFlag.gfEnd in EventInfo.Flags) then
+    begin
+      LPos := EventInfo.Location;
+      LDiff := FLastPos - LPos;
+      LDist := LDiff.X / 5;
+      GorillaModel1.RotationAngle.Y := GorillaModel1.RotationAngle.Y + LDist;
+    end;
+    FLastPos := LNew;
+  end;
+begin
+  // just a dirty and quick solution for gesture handling
+  case EventInfo.GestureID of
+    igiZoom :
+      begin
+        // zoom
+        DoZoom();
+        Handled := true;
+      end;
+    igiPan :
+      begin
+        // rotate model
+        DoRotate();
+        Handled := true;
+      end;
+    else
+      begin
+        Handled := false;
+      end;
+  end;
+end;
+</file>
+===== GamePad Interaction =====
+Interacting with gamepads in Firemonkey is not possible out of the box. But of course you can build your own component.
+But before bothering, have a look at the TGorillaInputController of Gorilla3D, which already provides support for gamepads. It is very easy to use and allows combinations of mouse and keyboard input.
+Read more: [[inputpolling|Input Polling]]
+===== Input-Controller =====
+Because most games and applications use mouse and keyboard in combination, it can be become complex very fast. It's also a bad idea to handle inputs in mainthread an reduce rendering performance by that.
+Besides that, it's very often a hassle to manage lots of hotkeys or input-sequences. Take a further read on the TGorillaInputController to learn how you could handle those things much easier.
+Read more: [[inputpolling|Input Polling]]
+Next step: [[charactercontrolling|CharacterControlling]]