From 9a65e40be19b6c0611d219f3a968645dfcd7c142 Mon Sep 17 00:00:00 2001
From: Koitharu <nvasya95@gmail.com>
Date: Wed, 5 Jan 2022 15:37:13 +0200
Subject: [PATCH] Update page flip animation

---
 .../reversed/ReversedPageAnimTransformer.kt   | 45 +++++++++----------
 .../ui/pager/standard/PageAnimTransformer.kt  | 45 +++++++++----------
 .../org/koitharu/kotatsu/utils/ext/ViewExt.kt |  2 +
 3 files changed, 42 insertions(+), 50 deletions(-)

diff --git a/app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/reversed/ReversedPageAnimTransformer.kt b/app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/reversed/ReversedPageAnimTransformer.kt
index 1da4a9d39..87ea32b7f 100644
--- a/app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/reversed/ReversedPageAnimTransformer.kt
+++ b/app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/reversed/ReversedPageAnimTransformer.kt
@@ -5,32 +5,27 @@ import androidx.viewpager2.widget.ViewPager2
 
 class ReversedPageAnimTransformer : ViewPager2.PageTransformer {
 
-	override fun transformPage(page: View, position: Float) {
-		with(page) {
-			val pageWidth = width
-			when {
-				position > 1 -> alpha = 0f
-				position >= 0 -> {
-					alpha = 1f
-					translationX = 0f
-					translationZ = 0f
-					scaleX = 1 + FACTOR * position
-					scaleY = 1f
-				}
-				position >= -1 -> {
-					alpha = 1f
-					translationX = pageWidth * -position
-					translationZ = -1f
-					scaleX = 1f
-					scaleY = 1f
-				}
-				else -> alpha = 0f
+	override fun transformPage(page: View, position: Float) = with(page) {
+		translationX = -position * width
+		pivotX = width.toFloat()
+		pivotY = height / 2f
+		cameraDistance = 20000f
+		when {
+			position < -1f || position > 1f -> {
+				alpha = 0f
+				rotationY = 0f
+				translationZ = -1f
+			}
+			position <= 0f -> {
+				alpha = 1f
+				rotationY = 0f
+				translationZ = 0f
+			}
+			position > 0f -> {
+				alpha = 1f
+				rotationY = 120 * position
+				translationZ = 2f
 			}
 		}
 	}
-
-	private companion object {
-
-		const val FACTOR = 0.1f
-	}
 }
\ No newline at end of file
diff --git a/app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/standard/PageAnimTransformer.kt b/app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/standard/PageAnimTransformer.kt
index cd03ce8eb..1aad3c8b0 100644
--- a/app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/standard/PageAnimTransformer.kt
+++ b/app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/standard/PageAnimTransformer.kt
@@ -5,32 +5,27 @@ import androidx.viewpager2.widget.ViewPager2
 
 class PageAnimTransformer : ViewPager2.PageTransformer {
 
-	override fun transformPage(page: View, position: Float) {
-		page.apply {
-			val pageWidth = width
-			when {
-				position < -1 -> alpha = 0f
-				position <= 0 -> { // [-1,0]
-					alpha = 1f
-					translationX = 0f
-					translationZ = 0f
-					scaleX = 1 + FACTOR * position
-					scaleY = 1f
-				}
-				position <= 1 -> { // (0,1]
-					alpha = 1f
-					translationX = pageWidth * -position
-					translationZ = -1f
-					scaleX = 1f
-					scaleY = 1f
-				}
-				else -> alpha = 0f
+	override fun transformPage(page: View, position: Float) = with(page) {
+		translationX = -position * width
+		pivotX = 0f
+		pivotY = height / 2f
+		cameraDistance = 20000f
+		when {
+			position < -1f || position > 1f -> {
+				alpha = 0f
+				rotationY = 0f
+				translationZ = -1f
+			}
+			position > 0f -> {
+				alpha = 1f
+				rotationY = 0f
+				translationZ = 0f
+			}
+			position <= 0f -> {
+				alpha = 1f
+				rotationY = 120 * position
+				translationZ = 2f
 			}
 		}
 	}
-
-	private companion object {
-
-		const val FACTOR = 0.1f
-	}
 }
\ No newline at end of file
diff --git a/app/src/main/java/org/koitharu/kotatsu/utils/ext/ViewExt.kt b/app/src/main/java/org/koitharu/kotatsu/utils/ext/ViewExt.kt
index 87e21bf2d..2bd9d2e49 100644
--- a/app/src/main/java/org/koitharu/kotatsu/utils/ext/ViewExt.kt
+++ b/app/src/main/java/org/koitharu/kotatsu/utils/ext/ViewExt.kt
@@ -133,6 +133,8 @@ fun View.resetTransformations() {
 	translationZ = 0f
 	scaleX = 1f
 	scaleY = 1f
+	rotationX = 0f
+	rotationY = 0f
 }
 
 inline fun RecyclerView.doOnCurrentItemChanged(crossinline callback: (Int) -> Unit) {