templates: add motion template system for dynamic SDUI generation

modules/3d-filament-renderer/src/main/java/com/tejpratapsingh/motionlib/filamentrenderer/Filament3dView.kt

@@ -1,6 +1,6 @@
 package com.tejpratapsingh.motionlib.filamentrenderer
 
 import android.content.Context
 import android.graphics.Bitmap
 import android.graphics.Matrix
 import android.graphics.SurfaceTexture
@@ -31,7 +31,7 @@
     private val modelAssetPath: String,
     override val startFrame: Int,
     override val endFrame: Int,
-    override val loop: Pair<Int, Int> = Pair(0, 0),
+    override var loop: Pair<Int, Int> = Pair(0, 0),
     effects: List<MotionEffect> = emptyList(),
 ) : FrameLayout(context),
     MotionView {

modules/3d-opengl-renderer/src/main/java/com/tejpratapsingh/motionlib/openglrenderer/MotionOpenGlView.kt

@@ -13,7 +13,7 @@ class MotionOpenGlView(
     modelAssetPath: String,
     override val startFrame: Int,
     override val endFrame: Int,
-    override val loop: Pair<Int, Int> = Pair(0, 0),
+    override var loop: Pair<Int, Int> = Pair(0, 0),
     effects: List<MotionEffect> = emptyList(),
 ) : FrameLayout(context),
     MotionView {

modules/app/src/main/java/com/tejpratapsingh/animator/presentation/SampleMotionVideo.kt

@@ -12,6 +12,7 @@
 import com.tejpratapsingh.motionlib.core.extensions.downloadFile
 import com.tejpratapsingh.motionlib.core.motion.BaseContourMotionView
 import com.tejpratapsingh.motionlib.core.motion.MotionVideoProducer
+import com.tejpratapsingh.motionlib.core.motion.transitions.CrossFadeTransition
 import com.tejpratapsingh.motionlib.core.setCurrentConfig
 import com.tejpratapsingh.motionlib.ui.custom.background.GradientView
 import com.tejpratapsingh.motionlib.ui.custom.background.Orientation
@@ -107,7 +108,7 @@
 //        motionConfig = motionConfig
 //    )
 
-    val motionView2: MotionView =
+    val motionView2 =
         GradientView(
             context = applicationContext,
             startFrame = motionView.endFrame + 1,
@@ -126,5 +127,8 @@
         .with(
             context = applicationContext,
             motionAudio = motionAudio,
-        ).addMotionViewToSequence(motionView = motionView)
+        )
+        .addMotionViewToSequence(motionView = motionView)
+        .addTransition(CrossFadeTransition(), duration = 30)
+        .addMotionViewToSequence(motionView = motionView2)
 }

modules/core/src/main/java/com/tejpratapsingh/motionlib/core/MotionTextSizeProvider.kt

@@ -5,7 +5,7 @@ import kotlin.math.min
 /**
  * Text size variants for video overlays.
  */
-internal enum class MotionTextVariant {
+enum class MotionTextVariant {
     H1,
     H2,
     H3,
@@ -33,6 +33,11 @@ internal data class MotionTextSizes(
  * Provides scaled font sizes in pixels relative to the video dimensions.
  */
 object MotionTextSizeProvider {
+    /**
+     * Base scale for all font sizes. Can be updated to scale all text sizes at once.
+     */
+    var baseTextScale: Float = 1.5f
+
     /**
      * Returns the [MotionTextSizes] for the given [aspectRatio].
      *
@@ -44,26 +49,26 @@ object MotionTextSizeProvider {
         }
 
         return MotionTextSizes(
-            h1 = aspectRatio.scale(96f),
-            h2 = aspectRatio.scale(72f),
-            h3 = aspectRatio.scale(48f),
-            h4 = aspectRatio.scale(36f),
-            h5 = aspectRatio.scale(24f),
-            h6 = aspectRatio.scale(20f),
-            p = aspectRatio.scale(32f),
+            h1 = aspectRatio.scale(160f * baseTextScale),
+            h2 = aspectRatio.scale(120f * baseTextScale),
+            h3 = aspectRatio.scale(80f * baseTextScale),
+            h4 = aspectRatio.scale(60f * baseTextScale),
+            h5 = aspectRatio.scale(40f * baseTextScale),
+            h6 = aspectRatio.scale(32f * baseTextScale),
+            p = aspectRatio.scale(48f * baseTextScale),
         )
     }
 
     /**
      * Returns the font size in pixels for the given [variant] and [aspectRatio].
      *
-     * For [VideoAspectRatio.Custom], it returns a fallback size of 32.0f.
+     * For [VideoAspectRatio.Custom], it returns a fallback size of (32.0f * baseTextScale).
      */
-    internal fun getFontSize(
+    fun getFontSize(
         aspectRatio: VideoAspectRatio,
         variant: MotionTextVariant,
     ): Float {
-        val sizes = getTextSizes(aspectRatio) ?: return 32f
+        val sizes = getTextSizes(aspectRatio) ?: return aspectRatio.scale(32f * baseTextScale)
 
         return when (variant) {
             MotionTextVariant.H1 -> sizes.h1

modules/core/src/main/java/com/tejpratapsingh/motionlib/core/MotionTransition.kt

@@ -0,0 +1,18 @@
+package com.tejpratapsingh.motionlib.core
+
+import android.view.ViewGroup
+
+/**
+ * Interface for defining a transition between two [MotionView]s.
+ * A transition usually overlaps the end of the first view and the start of the second view.
+ */
+interface MotionTransition {
+    /**
+     * Applies the transition between [from] and [to].
+     *
+     * @param from The outgoing view.
+     * @param to The incoming view.
+     * @param duration The duration of the transition in frames.
+     */
+    fun apply(from: MotionView, to: MotionView, duration: Int)
+}

modules/core/src/test/java/com/tejpratapsingh/motionlib/core/MotionTextSizeProviderTest.kt

@@ -0,0 +1,48 @@
+package com.tejpratapsingh.motionlib.core
+
+import org.junit.Assert.assertEquals
+import org.junit.Before
+import org.junit.Test
+
+class MotionTextSizeProviderTest {
+
+    @Before
+    fun setup() {
+        // Reset baseTextScale before each test
+        MotionTextSizeProvider.baseTextScale = 1.0f
+    }
+
+    @Test
+    fun testDefaultFontSizes() {
+        val aspectRatio = VideoAspectRatio.Ratio16x9_1080 // 1920x1080, min is 1080, scale is 1.0
+
+        // H1 should be 160f * 1.0 = 160f
+        assertEquals(160f, MotionTextSizeProvider.getFontSize(aspectRatio, MotionTextVariant.H1), 0.01f)
+
+        // P should be 48f * 1.0 = 48f
+        assertEquals(48f, MotionTextSizeProvider.getFontSize(aspectRatio, MotionTextVariant.P), 0.01f)
+    }
+
+    @Test
+    fun testBaseTextScale() {
+        val aspectRatio = VideoAspectRatio.Ratio16x9_1080 // 1920x1080, min is 1080, scale is 1.0
+
+        MotionTextSizeProvider.baseTextScale = 2.0f
+
+        // H1 should be 160f * 2.0 = 320f
+        assertEquals(320f, MotionTextSizeProvider.getFontSize(aspectRatio, MotionTextVariant.H1), 0.01f)
+
+        // P should be 48f * 2.0 = 96f
+        assertEquals(96f, MotionTextSizeProvider.getFontSize(aspectRatio, MotionTextVariant.P), 0.01f)
+    }
+
+    @Test
+    fun testScalingWithAspectRatio() {
+        // 480p 16:9 is 854x480, min is 480. 
+        // Scale = 480 / 1080 = 0.4444...
+        val aspectRatio = VideoAspectRatio.Ratio16x9_480
+
+        val expectedH1 = 160f * (480f / 1080f)
+        assertEquals(expectedH1, MotionTextSizeProvider.getFontSize(aspectRatio, MotionTextVariant.H1), 0.01f)
+    }
+}

modules/ffmpeg-motion-ext/src/main/java/com/tejpratapsingh/motionlib/ffmpeg/video/FFMpegVideoFrameView.kt

@@ -16,7 +16,7 @@ class FFMpegVideoFrameView(
     val videoFile: File,
     override val startFrame: Int,
     override val endFrame: Int,
-    override val loop: Pair<Int, Int> = Pair(0, 0),
+    override var loop: Pair<Int, Int> = Pair(0, 0),
     effects: List<MotionEffect> = emptyList(),
 ) : FrameLayout(context),
     MotionView {

modules/lyrics-maker/build.gradle

@@ -53,10 +53,12 @@ dependencies {
     implementation libs.picasso
 
     implementation project(path: ':modules:motionlib')
+    implementation project(path: ':modules:motion-video-player')
     implementation project(path: ':modules:motion-store')
     implementation project(path: ':modules:metadata-extractor')
     implementation project(path: ':modules:ffmpeg-motion-ext')
     implementation project(path: ':modules:sdui')
+    implementation project(path: ':modules:templates')
 
     implementation platform(libs.androidx.compose.bom)
     implementation libs.bundles.compose

modules/lyrics-maker/src/main/java/com/tejpratapsingh/lyricsmaker/presentation/compose/AppNavHost.kt

@@ -24,6 +24,10 @@ sealed class Screen(
 
     object Lyrics : Screen("lyrics")
 
+    object TemplateSelector : Screen("template_selector/{projectId}") {
+        fun createRoute(projectId: String) = "template_selector/$projectId"
+    }
+
     object ProjectDetails : Screen("project_details/{projectId}") {
         fun createRoute(projectId: String) = "project_details/$projectId"
     }
@@ -106,11 +110,38 @@ fun AppNavHost(
 
                     projectsViewModel.loadProjects()
 
-                    navController.navigate(Screen.ProjectDetails.createRoute(projectId))
+                    navController.navigate(Screen.TemplateSelector.createRoute(projectId))
                 },
             )
         }
 
+        composable(route = Screen.TemplateSelector.route) { backStackEntry ->
+            val projectId = backStackEntry.arguments?.getString("projectId")
+            val projects = projectsViewModel.projects.collectAsStateWithLifecycle()
+            val project = projects.value.find { it.id == projectId }
+
+            project?.let {
+                LyricsTemplateSelector(
+                    project = it,
+                    onBack = { navController.popBackStack() },
+                    onTemplateSelected = { template ->
+                        it.metadata.addProperty("template", template.name)
+                        // Clear old SDUI if any
+                        it.metadata.remove("sdui")
+
+                        navController.context.asLyricsApp().motionStoreDao.upsert(it)
+                        projectsViewModel.loadProjects()
+
+                        navController.navigate(Screen.ProjectDetails.createRoute(it.id)) {
+                            // Pop the template selector so back from details goes to lyrics
+                            popUpTo(Screen.TemplateSelector.route) { inclusive = true }
+                        }
+                    },
+                    modifier = modifier,
+                )
+            }
+        }
+
         composable(route = Screen.ProjectDetails.route) { backStackEntry ->
             val projectId = backStackEntry.arguments?.getString("projectId")
             val projects = projectsViewModel.projects.collectAsStateWithLifecycle()