Fixed reversing

.idea/deploymentTargetSelector.xml

@@ -4,7 +4,7 @@
     <selectionStates>
       <SelectionState runConfigName="app">
         <option name="selectionMode" value="DROPDOWN" />
-        <DropdownSelection timestamp="2025-08-26T11:06:03.805342749Z">
+        <DropdownSelection timestamp="2025-09-22T09:08:24.101225364Z">
           <Target type="DEFAULT_BOOT">
             <handle>
               <DeviceId pluginId="LocalEmulator" identifier="path=/home/secondbeam/.config/.android/avd/Virtual_Pixel_3.avd" />

app/src/main/java/com/mirenkov/ktheightmap/KhmParser.kt

@@ -1,9 +1,10 @@
 package com.mirenkov.ktheightmap
 
 import android.content.Context
-import android.util.Log
 import java.io.DataInputStream
 import java.io.FileInputStream
+import kotlin.math.max
+import kotlin.math.min
 
 private data class HeightInfo(
     val minLon: Float,
@@ -16,46 +17,116 @@ private data class HeightInfo(
 
 class KhmParser {
     companion object {
+        private var header: HeightInfo? = null
         const val HEIGHT_FILE: String = "height.khm"
+
         fun load(filePath: String, ctx: Context) {
             if (ctx.getFileStreamPath(HEIGHT_FILE).exists()) {
-                Log.i(TAG, "height.khm already exists")
                 return
             }
 
             val inp = FileInputStream(filePath)
             ctx.openFileOutput(HEIGHT_FILE, Context.MODE_PRIVATE).use {
                 it.write(inp.readBytes())
-                Log.i(TAG, "Copied %s to height.khm".format(filePath))
             }
         }
 
         private fun getOffset(header: HeightInfo, x: Int, y: Int): Int {
-            Log.i(TAG, "Offset for (%d, %d) = %d".format(x, y, y * header.height + x))
             return (x * header.width + y) * 2
         }
 
         private fun readHeader(dis: DataInputStream): HeightInfo {
-            return with(dis) {
+            if (header == null) {
+                header = with(dis) {
                     val minLon = readFloat()
                     val minLat = readFloat()
                     val lonPerValue = readFloat()
                     val latPerValue = readFloat()
                     val width = readInt()
                     val height = readInt()
-                Log.i(TAG, "Header: %.6f, %.6f, %.6f, %.6f, %d, %d".format(minLon, minLat, lonPerValue, latPerValue, width, height))
                     HeightInfo(minLon, minLat, lonPerValue, latPerValue, width, height)
                 }
+            } else {
+                dis.skipBytes(4 * 6)
+            }
+            return header!!
+        }
+
+        private fun inBounds(header: HeightInfo, lon: Float, lat: Float): Boolean {
+            val maxLon = header.minLon + (header.lonPerValue * header.width)
+            val maxLat = header.minLat + (header.latPerValue * header.height)
+            val miLon = min(header.minLon, maxLon)
+            val maLon = max(header.minLon, maxLon)
+            val miLat = min(header.minLat, maxLat)
+            val maLat = max(header.minLat, maxLat)
+            return lon > miLon && lat > miLat && lon < maLon && lat < maLat
         }
 
         fun getHeight(lon: Float, lat: Float, ctx: Context): UShort {
             val dis = DataInputStream(ctx.openFileInput(HEIGHT_FILE))
+            dis.use {
                 val header = readHeader(dis)
+                if (!inBounds(header, lon, lat))
+                    return 0u
                 val x = ((lon - header.minLon) / header.lonPerValue).toInt()
                 val y = ((lat - header.minLat) / header.latPerValue).toInt()
                 val offset = getOffset(header, x, y)
                 dis.skipBytes(offset)
-            return dis.readUnsignedShort().toUShort()
+                val height = dis.readUnsignedShort().toUShort()
+                return height
+            }
+        }
+
+
+        @OptIn(ExperimentalUnsignedTypes::class)
+        fun getHeightsMul(ctx: Context, coords: Array<Pair<Float, Float>>): Pair<UShortArray, Array<Pair<Float, Float>>> {
+            if (coords.isEmpty()) return Pair(ushortArrayOf(), coords)
+            val dis = DataInputStream(ctx.openFileInput(HEIGHT_FILE))
+            dis.use {
+                val header = readHeader(dis)
+
+                val reversed = coords[0].first < coords[coords.size - 1].first
+
+                val glist: MutableMap<Pair<Float, Float>, Int> = mutableMapOf()
+
+                for (coord in coords) {
+                    val x = ((coord.first - header.minLon) / header.lonPerValue).toInt()
+                    val y = ((coord.second - header.minLat) / header.latPerValue).toInt()
+                    val offset = getOffset(header, x, y)
+                    glist.put(coord, offset)
+                }
+                val sortedGlist = glist.toList().sortedBy { (_, v) -> v }.toMap()
+                val glistKeys = sortedGlist.keys.toTypedArray()
+
+                val cutOffsets = IntArray(glist.size) {-1}
+                if (inBounds(header, coords[0].first, coords[0].second)) {
+                    val key = glistKeys[0]
+                    cutOffsets[0] = sortedGlist.getOrDefault(key, 0)
+                }
+                for (i in 1 until sortedGlist.size) {
+                    if (inBounds(header, coords[i].first, coords[i].second) && cutOffsets[i-1] >= 0) {
+                        val prevKey = glistKeys[i-1]
+                        val key = glistKeys[i]
+                        cutOffsets[i] = sortedGlist.getOrDefault(key, 0) - sortedGlist.getOrDefault(prevKey, 0) - 2
+                    } else break
+                }
+
+                return Pair(
+                    UShortArray(coords.size) { i ->
+                    if (cutOffsets[i] > 0) {
+                        dis.skipBytes(cutOffsets[i])
+                        dis.readUnsignedShort().toUShort()
+                    } else 0u },
+                    if (reversed) coords else coords.reversed().toTypedArray())
+            }
+        }
+
+        fun getLonPerValue(): Float {
+            return header?.lonPerValue ?: 0F
+        }
+
+        fun getLatPerValue(): Float {
+            return header?.latPerValue ?: 0F
         }
     }
 }

app/src/main/java/com/mirenkov/ktheightmap/MainActivity.kt

@@ -3,7 +3,6 @@ package com.mirenkov.ktheightmap
 import android.app.Application
 import android.content.Intent
 import android.os.Bundle
-import android.util.Log
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
@@ -32,7 +31,6 @@ import androidx.compose.material3.TextField
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.MutableState
 import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableFloatStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
@@ -43,7 +41,6 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.rotate
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.input.KeyboardType
-import androidx.compose.ui.text.toUpperCase
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
@@ -122,12 +119,13 @@ fun Main(vm: TileViewModel = viewModel()) {
     }
 }
 
+@Suppress("VariableNeverRead", "AssignedValueIsNeverRead")
 @Composable
 fun ToolButton(viewModel: TileViewModel) {
     val context = LocalContext.current
     var expanded by rememberSaveable{ mutableStateOf(false) }
     var debug by rememberSaveable{ viewModel.debug }
-    var logRequested by remember{ viewModel.logRequested }
+    var pointRequested by remember{ viewModel.pointRequested }
     val dialogShown = rememberSaveable{ mutableStateOf(false) }
     FloatingActionButton(
         onClick = {
@@ -147,9 +145,9 @@ fun ToolButton(viewModel: TileViewModel) {
                 }
             )
             DropdownMenuItem(
-                text = { Text("Log") },
+                text = { Text("Place point") },
                 onClick = {
-                    logRequested = true
+                    pointRequested = true
                     expanded = false
                 }
             )
@@ -175,7 +173,6 @@ fun ToolButton(viewModel: TileViewModel) {
 @Suppress("VariableNeverRead", "AssignedValueIsNeverRead")
 @Composable
 fun SetLocationDialog(vm: TileViewModel, dialogShown: MutableState<Boolean>) {
-    val ctx = LocalContext.current
     var showLocationDialog by dialogShown
     if (showLocationDialog) {
         var latitudeText by remember { vm.latitudeText }
@@ -210,12 +207,8 @@ fun SetLocationDialog(vm: TileViewModel, dialogShown: MutableState<Boolean>) {
             confirmButton = { TextButton(onClick = {
                 val latitude = latitudeText.text.toDoubleOrNull() ?: 0.0
                 val longitude = longitudeText.text.toDoubleOrNull() ?: 0.0
-                Log.i(TAG, "Lat: %.6f, Lon: %.6f".format(latitude, longitude))
-                Log.i(TAG, "X = %.6f".format(SphereMercator.mercateLon(longitude, vm.scale.floatValue.toInt(), -TILE_SIZE.toDouble())))
-                Log.i(TAG, "Y = %.6f".format(SphereMercator.mercateLat(latitude, vm.scale.floatValue.toInt(), -TILE_SIZE.toDouble())))
                 offsetX = SphereMercator.mercateLon(longitude, vm.scale.floatValue.toInt(),  -vm.halvedOffsetX!!.toDouble() - TILE_SIZE).toFloat()
                 offsetY = SphereMercator.mercateLat(latitude, vm.scale.floatValue.toInt(), -vm.halvedOffsetY!!.toDouble() - TILE_SIZE).toFloat()
-                Log.i(TAG, "%d".format(KhmParser.getHeight(longitude.toFloat(), latitude.toFloat(), ctx).toInt()))
             }) {
                     Text("Confirm".uppercase())
                 } },

app/src/main/java/com/mirenkov/ktheightmap/MapCanvas.kt

@@ -1,11 +1,12 @@
 package com.mirenkov.ktheightmap
 
-import android.util.Log
 import androidx.compose.foundation.Canvas
 import androidx.compose.foundation.gestures.detectDragGestures
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
@@ -16,6 +17,7 @@ import androidx.compose.ui.graphics.Path
 import androidx.compose.ui.graphics.asImageBitmap
 import androidx.compose.ui.graphics.drawscope.Stroke
 import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.ParagraphStyle
 import androidx.compose.ui.text.SpanStyle
 import androidx.compose.ui.text.buildAnnotatedString
@@ -24,7 +26,11 @@ import androidx.compose.ui.text.rememberTextMeasurer
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.withStyle
 import kotlin.math.absoluteValue
+import kotlin.math.floor
+import kotlin.math.pow
+import kotlin.math.sqrt
 
+@OptIn(ExperimentalUnsignedTypes::class)
 @Composable
 fun MapCanvas(
     viewModel: TileViewModel,
@@ -33,18 +39,30 @@ fun MapCanvas(
     tileContainer: TileContainer,
     modifier: Modifier = Modifier
 ) {
+    val ctx = LocalContext.current
     var offsetX by rememberSaveable { viewModel.mapOffsetX }
     var offsetY by rememberSaveable { viewModel.mapOffsetY }
     val scale by rememberSaveable { viewModel.scale }
     val textMeasurer = rememberTextMeasurer()
     val debug by rememberSaveable { viewModel.debug }
-    var logRequested by rememberSaveable { viewModel.logRequested }
+    var pointRequested by rememberSaveable { viewModel.pointRequested }
+    var pointLat by rememberSaveable { viewModel.rememberedPointLat }
+    var pointLon by rememberSaveable { viewModel.rememberedPointLon }
+    var invokeHeightCalc by remember { mutableStateOf(false) }
     Canvas(
         modifier = modifier.fillMaxSize()
             .pointerInput(Unit) {
-                detectDragGestures { _, distance ->
+                detectDragGestures (
+                    onDragEnd = {
+                        invokeHeightCalc = true
+                    },
+                    onDragCancel = {
+                        invokeHeightCalc = true
+                    }
+                ) { _, distance ->
                     offsetX -= distance.x
                     offsetY -= distance.y
+                    invokeHeightCalc = false
                 }
             }
     ) {
@@ -55,16 +73,6 @@ fun MapCanvas(
         val halvedX = viewModel.halvedOffsetX!!
         val halvedY = viewModel.halvedOffsetY!!
 
-        drawRect(
-            color = backColor,
-            size = size
-        )
-
-        if (logRequested) {
-            Log.i(TAG, "Offset: %.6f, %.6f".format(offsetX, offsetY))
-            logRequested = false
-        }
-
         val oldLevel = tileContainer.getLevel()
         val level = scale.toInt()
         val levelDiff = level - oldLevel
@@ -84,12 +92,27 @@ fun MapCanvas(
                 offsetY += halvedY + TILE_SIZE
             }
         }
-        val tileOffsetX = (offsetX / TILE_SIZE).toInt()
-        val tileOffsetY = (offsetY / TILE_SIZE).toInt()
 
         val centerTileX = (1 + (offsetX + halvedX) / TILE_SIZE).toDouble()
         val centerTileY = (1 + (offsetY + halvedY) / TILE_SIZE).toDouble()
 
+        val lon = SphereMercator.mercateX(centerTileX, level).toFloat()
+        val lat = SphereMercator.mercateY(centerTileY, level).toFloat()
+
+        if (pointRequested) {
+            if (pointLat == 0F) {
+                pointLat = lat
+                pointLon = lon
+            } else {
+                pointLat = 0F
+                pointLon = 0F
+            }
+            pointRequested = false
+        }
+
+        val tileOffsetX = (offsetX / TILE_SIZE).toInt()
+        val tileOffsetY = (offsetY / TILE_SIZE).toInt()
+
         val strippedOffsetX = offsetX % TILE_SIZE
         val strippedOffsetY = offsetY % TILE_SIZE
 
@@ -108,6 +131,13 @@ fun MapCanvas(
         val latLonSize = Size(216F, 96F + additionalSize)
         val latLonOffset = Offset(16F, 16F)
 
+        // Background
+        drawRect(
+            color = backColor,
+            size = size
+        )
+
+        // Tiles
         for (cellX in 0 .. gridWidth + 2) {
             val tileX = tileOffsetX + cellX
             val localOffsetX = TILE_SIZE * (cellX - 1)
@@ -119,6 +149,7 @@ fun MapCanvas(
                 val bitmap = tile.toBitmap()
                 val totalOffset = Offset(localOffsetX, localOffsetY) - offset
 
+                // Tile
                 bitmap?.let {
                     val imageBitmap = bitmap.asImageBitmap()
                     drawImage(
@@ -127,6 +158,7 @@ fun MapCanvas(
                     )
                 }
 
+                // Debug grid
                 if (debug) {
                     drawRect(
                         color = gridColor,
@@ -150,7 +182,63 @@ fun MapCanvas(
                         size = Size(TILE_SIZE, TILE_SIZE)
                     )
                 }
+            }
+        }
+        // Placed point and line to center
+        if (pointLat != 0F) {
+            val pointOffsetX = SphereMercator.mercateLon(pointLon.toDouble(), level, -TILE_SIZE.toDouble()).toFloat() - offsetX
+            val pointOffsetY = SphereMercator.mercateLat(pointLat.toDouble(), level, -TILE_SIZE.toDouble()).toFloat() - offsetY
+            drawRect(
+                color = gridColor,
+                size = Size(8F, 8F),
+                topLeft = Offset(pointOffsetX - 4, pointOffsetY - 4)
+            )
+            drawLine(
+                color = gridColor,
+                start = Offset(pointOffsetX, pointOffsetY),
+                end = Offset(halvedX, halvedY)
+            )
+            val startHeight = KhmParser.getHeight(pointLon, pointLat, ctx)
+            if (pointOffsetX >= 0 && pointOffsetY >= 0 && pointOffsetX < size.width && pointOffsetY < size.height)
+                drawText(
+                    textMeasurer = textMeasurer,
+                    text = buildAnnotatedString { withStyle(SpanStyle(color = Color.White)) {
+                        append("${startHeight}m")
+                    } },
+                    topLeft = Offset(pointOffsetX, pointOffsetY - 32)
+                )
+            if (invokeHeightCalc) {
+                val latPV = KhmParser.getLatPerValue()
+                val lonPV = KhmParser.getLonPerValue()
+                val valueDistance = sqrt(latPV.pow(2) + lonPV.pow(2))
+                val latDiff = lat - pointLat
+                val lonDiff = lon - pointLon
+                val distance = sqrt((latDiff).pow(2) + (lonDiff).pow(2))
+                val valuesCount = floor(distance / valueDistance).toInt()
+                val array: Array<Pair<Float, Float>> = Array(valuesCount) { step ->
+                    val interCoef = 1F - step.toFloat() / valuesCount
+                    Pair(lon - lonDiff * interCoef, lat - latDiff * interCoef)
+                }
+                val heightPair = KhmParser.getHeightsMul(ctx, array)
+                val heights = heightPair.first
+                val coords = heightPair.second
 
+                for (step in 0 until coords.size) {
+                    val stepLat = coords[step].second
+                    val stepLon = coords[step].first
+                    val stepOffsetX = SphereMercator.mercateLon(stepLon.toDouble(), level, -TILE_SIZE.toDouble()).toFloat() - offsetX
+                    val stepOffsetY = SphereMercator.mercateLat(stepLat.toDouble(), level, -TILE_SIZE.toDouble()).toFloat() - offsetY
+                    if (stepOffsetX >= 0 && stepOffsetY >= 0 && stepOffsetX < size.width && stepOffsetY < size.height)
+                        drawRect(
+                            color = if (heights[step] > startHeight) Color.Red else Color.Green,
+                            size = Size(8F, 8F),
+                            topLeft = Offset(stepOffsetX - 4, stepOffsetY - 4)
+                        )
+                }
+            }
+        }
+
+        // Cursor path
         val path = Path()
         path.moveTo(halvedX - crossRadius, halvedY)
         path.lineTo(halvedX + crossRadius, halvedY)
@@ -158,26 +246,27 @@ fun MapCanvas(
         path.lineTo(halvedX, halvedY + crossRadius)
         path.close()
 
+        // Cursor
         drawPath(
             path,
             Color.White,
             style = Stroke(width = 6F)
         )
 
+        // Info box
         drawRect(
             color = backColor,
             size = latLonSize,
             topLeft = latLonOffset
         )
 
+        // Info box content
         drawText(
             textMeasurer = textMeasurer,
             text = buildAnnotatedString {
                 withStyle(ParagraphStyle(textAlign = TextAlign.Center)) {
                     withStyle(SpanStyle(color = gridColor)) {
-                                val lon = SphereMercator.mercateX(centerTileX, level)
-                                val lat = SphereMercator.mercateY(centerTileY, level)
-                                append("%.6f\n%.6f".format(lon, lat))
+                        append("%.6f\n%.6f".format(lat, lon))
                         if (debug) {
                             append("\n%.0f\n%.0f".format(offsetX, offsetY))
                         }
@@ -187,7 +276,16 @@ fun MapCanvas(
             size = latLonSize,
             topLeft = latLonOffset
         )
-            }
-        }
+
+        // Height under cursor
+        drawText(
+            textMeasurer = textMeasurer,
+            text = buildAnnotatedString {
+                withStyle(SpanStyle(color = Color.White)) {
+                    append("${KhmParser.getHeight(lon, lat, ctx)}m")
+                }
+            },
+            topLeft = Offset(halvedX + crossRadius, halvedY + crossRadius)
+        )
     }
 }

app/src/main/java/com/mirenkov/ktheightmap/SettingsActivity.kt

@@ -89,10 +89,7 @@ fun SettingsMain(vm: TileViewModel, launcher: ActivityResultLauncher<DocumentFil
                             val t = getTile(it.x, it.y, it.level)
                             if (t == null) {
                                 pushTile(it)
-                                Log.i(TAG, "pushed to db: %d, %d, %d".format(it.level, it.x, it.y))
                             }
-                            else
-                                Log.i(TAG, "found in db: %d, %d, %d".format(t.level, t.x, t.y))
                         }
                     }
                 } },
@@ -124,7 +121,6 @@ suspend fun processZip(filePath: String?): List<Tile> = coroutineScope {
                 if (entry == null)
                 break
             }
-            Log.i(TAG, "got list")
         }
     }
     return@coroutineScope list

app/src/main/java/com/mirenkov/ktheightmap/TileViewModel.kt

@@ -10,7 +10,7 @@ class TileViewModel(application: Application): ViewModel() {
     val repository: TileRepository
 
     var debug = mutableStateOf(false)
-    var logRequested = mutableStateOf(false)
+    var pointRequested = mutableStateOf(false)
 
     var latitudeText = mutableStateOf(TextFieldValue(""))
     var longitudeText = mutableStateOf(TextFieldValue(""))
@@ -22,6 +22,9 @@ class TileViewModel(application: Application): ViewModel() {
     var halvedOffsetX: Float? = null
     var halvedOffsetY: Float? = null
 
+    var rememberedPointLon = mutableFloatStateOf(0F)
+    var rememberedPointLat = mutableFloatStateOf(0F)
+
     init {
         val tileDb = TileDB.getInstance(application)
         val tileDao = tileDb.tileDao()