Implement Touch-to-Focus (28_FOCUS_POINT.md): cache MediaPipe category mask, add focus ring view, class-based alpha selection

2026-07-06 20:40:19 +07:00
parent 6636cdb418
commit e8fde43890
4 changed files with 344 additions and 5 deletions
@@ -69,6 +69,13 @@ class MainActivity : AppCompatActivity() {
    private var imageSegmenter: ImageSegmenter? = null
    private var isAiSupported = true

+    // Touch-to-Focus: ID lớp đối tượng được chạm chọn lấy nét (-1 = mặc định lấy nét người ID 1)
+    private var userSelectedClassFocus = -1
+    // Cache mặt nạ phân lớp mới nhất từ MediaPipe để phục vụ Touch-to-Focus
+    private var cachedCategoryMask: ByteArray? = null
+    private var cachedMaskWidth = 0
+    private var cachedMaskHeight = 0
+
    private fun getImageSegmenter(): ImageSegmenter? {
        synchronized(aiInferenceLock) {
            if (!isAiSupported) return null
@@ -705,6 +712,42 @@ class MainActivity : AppCompatActivity() {
                showSavePresetDialog(preset)
            }
        }
+
+        // Touch-to-Focus: Chạm vào kính ngắm để chọn điểm lấy nét
+        binding.viewFinder.setOnTouchListener { v, event ->
+            if (event.action == android.view.MotionEvent.ACTION_UP) {
+                val percentX = (event.x / v.width).coerceIn(0f, 1f)
+                val percentY = (event.y / v.height).coerceIn(0f, 1f)
+
+                // Cập nhật Class ID lấy nét từ điểm chạm
+                val mask = cachedCategoryMask
+                val mW = cachedMaskWidth
+                val mH = cachedMaskHeight
+                if (mask != null && mW > 0 && mH > 0) {
+                    val maskX = (percentX * mW).toInt().coerceIn(0, mW - 1)
+                    val maskY = (percentY * mH).toInt().coerceIn(0, mH - 1)
+                    userSelectedClassFocus = mask[maskY * mW + maskX].toInt()
+                }
+
+                // Hiện vòng tròn lấy nét màu cam tại vị trí chạm
+                val focusRing = binding.viewFocusRing
+                focusRing.x = event.x - focusRing.width / 2f
+                focusRing.y = event.y - focusRing.height / 2f
+                focusRing.visibility = android.view.View.VISIBLE
+                focusRing.alpha = 1f
+                focusRing.scaleX = 1.4f
+                focusRing.scaleY = 1.4f
+                focusRing.animate()
+                    .scaleX(1f).scaleY(1f)
+                    .alpha(0f)
+                    .setDuration(900)
+                    .withEndAction { focusRing.visibility = android.view.View.GONE }
+                    .start()
+
+                v.performClick()
+            }
+            true
+        }
    }

    private fun translateButtonToDock(button: android.view.View) {
@@ -1689,12 +1732,26 @@ class MainActivity : AppCompatActivity() {
                        val w = categoryMask.width
                        val h = categoryMask.height
                        val bufferCapacity = categoryMaskBuffer.capacity()
+
+                        // Cache mask bytes for Touch-to-Focus
+                        val rawBytes = ByteArray(bufferCapacity)
+                        categoryMaskBuffer.rewind()
+                        categoryMaskBuffer.get(rawBytes)
+                        cachedCategoryMask = rawBytes
+                        cachedMaskWidth = w
+                        cachedMaskHeight = h
+                        categoryMaskBuffer.rewind()
                        
-                        // Create and blur alpha mask
+                        // Create and blur alpha mask with Touch-to-Focus class selection
+                        val focusClassId = if (userSelectedClassFocus >= 0) userSelectedClassFocus else -1
                        val alphaMask = FloatArray(w * h)
                        for (i in 0 until (w * h)) {
-                            val classId = if (i < bufferCapacity) categoryMaskBuffer.get(i).toInt() else 0
-                            alphaMask[i] = if (classId in 1..5) 1.0f else 0.0f
+                            val classId = if (i < bufferCapacity) rawBytes[i].toInt() else 0
+                            alphaMask[i] = if (focusClassId >= 0) {
+                                if (classId == focusClassId) 1.0f else 0.0f
+                            } else {
+                                if (classId in 1..5) 1.0f else 0.0f
+                            }
                        }
                        blurAlphaMaskBox(alphaMask, w, h, radius = 3)
                        
@@ -1804,11 +1861,16 @@ class MainActivity : AppCompatActivity() {
                    val h = categoryMask.height
                    val bufferCapacity = categoryMaskBuffer.capacity()
                    
-                    // Create and blur alpha mask
+                    // Create and blur alpha mask with Touch-to-Focus class selection
+                    val focusClassId = if (userSelectedClassFocus >= 0) userSelectedClassFocus else -1
                    val alphaMask = FloatArray(w * h)
                    for (i in 0 until (w * h)) {
                        val classId = if (i < bufferCapacity) categoryMaskBuffer.get(i).toInt() else 0
-                        alphaMask[i] = if (classId in 1..5) 1.0f else 0.0f
+                        alphaMask[i] = if (focusClassId >= 0) {
+                            if (classId == focusClassId) 1.0f else 0.0f
+                        } else {
+                            if (classId in 1..5) 1.0f else 0.0f
+                        }
                    }
                    blurAlphaMaskBox(alphaMask, w, h, radius = 5)
                    
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="oval">
+    <stroke
+        android:width="2dp"
+        android:color="#FFCC00" />
+    <solid android:color="#00000000" />
+</shape>
@@ -143,6 +143,14 @@
            android:visibility="gone"
            android:text="3" />

+        <!-- Vòng tròn định vị lấy nét (Focus Ring) khi chạm vào Viewfinder -->
+        <View
+            android:id="@+id/viewFocusRing"
+            android:layout_width="60dp"
+            android:layout_height="60dp"
+            android:background="@drawable/bg_focus_ring"
+            android:visibility="gone" />
+
    </FrameLayout>

    <!-- ================= KHỐI 1: TIMELINE FRAMES & PRESETS ================= -->