From 215b0ca147f58dd82b48007e139a84e74b048721 Mon Sep 17 00:00:00 2001
From: David North <hobnob@users.noreply.github.com>
Date: Mon, 28 Oct 2024 20:55:09 +0000
Subject: [PATCH] Starts to add Pointer helper events

---
 .../scala/indigo/shared/FrameContext.scala    |  1 +
 .../scala/indigo/shared/input/Pointers.scala  | 68 ++++++++++++++++---
 2 files changed, 59 insertions(+), 10 deletions(-)

diff --git a/indigo/indigo/src/main/scala/indigo/shared/FrameContext.scala b/indigo/indigo/src/main/scala/indigo/shared/FrameContext.scala
index e76dd1d9b..e436aef56 100644
--- a/indigo/indigo/src/main/scala/indigo/shared/FrameContext.scala
+++ b/indigo/indigo/src/main/scala/indigo/shared/FrameContext.scala
@@ -39,5 +39,6 @@ final class FrameContext[StartUpData](
   export inputState.mouse
   export inputState.keyboard
   export inputState.gamepad
+  export inputState.pointers
   export boundaryLocator.findBounds
   export boundaryLocator.bounds
diff --git a/indigo/indigo/src/main/scala/indigo/shared/input/Pointers.scala b/indigo/indigo/src/main/scala/indigo/shared/input/Pointers.scala
index 929005d46..d660539d0 100644
--- a/indigo/indigo/src/main/scala/indigo/shared/input/Pointers.scala
+++ b/indigo/indigo/src/main/scala/indigo/shared/input/Pointers.scala
@@ -4,21 +4,69 @@ import indigo.shared.collections.Batch
 import indigo.shared.datatypes.Point
 import indigo.shared.datatypes.Rectangle
 import indigo.shared.events.PointerEvent
+import indigo.shared.events.PointerEvent.PointerId
+import indigo.shared.collections.Batch.toBatch
+import indigo.MouseButton
 
 final class Pointers(
-    val pointerEvents: Batch[PointerEvent],
-    val position: Point
-)
+    private val pointerBatch: Batch[Pointer],
+    private val pointerEvents: Batch[PointerEvent]
+) {
+  def isButtonDown(button: MouseButton): Boolean = pointerBatch.map(_.buttonsDown).contains(button)
+
+  lazy val isLeftDown: Boolean   = isButtonDown(MouseButton.LeftMouseButton)
+  lazy val isRightDown: Boolean  = isButtonDown(MouseButton.RightMouseButton)
+  lazy val isMiddleDown: Boolean = isButtonDown(MouseButton.MiddleMouseButton)
+
+  lazy val pointerPressed: Boolean  = pressed(MouseButton.LeftMouseButton)
+  lazy val pointerReleased: Boolean = released(MouseButton.LeftMouseButton)
+
+  def pressed(button: MouseButton): Boolean =
+    pointerEvents.exists {
+      case md: PointerEvent.PointerDown if md.button == Some(button) => true
+      case _                                                         => false
+    }
+
+  def released(button: MouseButton): Boolean =
+    pointerEvents.exists {
+      case mu: PointerEvent.PointerUp if mu.button == Some(button) => true
+      case _                                                       => false
+    }
+}
 
 object Pointers:
   val default: Pointers =
-    Pointers(Batch.empty, Point.zero)
+    Pointers(Batch.empty, Batch.empty)
 
   def calculateNext(previous: Pointers, events: Batch[PointerEvent]): Pointers =
-    Pointers(
-      pointerEvents = events,
-      position = lastPointerPosition(previous.position, events)
-    )
+    Pointers(updatePointers(events, previous), events)
+
+  private def updatePointers(events: Batch[PointerEvent], previous: Pointers): Batch[Pointer] =
+    events
+      .map(_ match {
+        case e: PointerEvent.PointerCancel => None
+        case e                             => Some(e)
+      })
+      .collect { case Some(e) => e }
+      .map(e => updatePointer(e, previous.pointerBatch.find(_.id == e.pointerId)))
+
+  private def updatePointer(event: PointerEvent, previous: Option[Pointer]): Pointer =
+    previous match
+      case None =>
+        Pointer(
+          event.pointerId,
+          event match {
+            case e: PointerEvent.PointerDown => e.buttons
+            case _                           => Batch.empty
+          },
+          event.position
+        )
+
+      case Some(p) =>
+        Pointer(
+          p.id,
+          event.buttons,
+          event.position
+        )
 
-  private def lastPointerPosition(previous: Point, events: Batch[PointerEvent]): Point =
-    events.collect { case mp: PointerEvent.PointerMove => mp.position }.lastOption.fold(previous)(identity)
+final case class Pointer(id: PointerId, buttonsDown: Batch[MouseButton], position: Point)