From f089879d1b7d0448657789072d1bd969106caac6 Mon Sep 17 00:00:00 2001
From: 2ndbeam <2ndbeam@disroot.org>
Date: Tue, 2 Sep 2025 15:39:25 +0300
Subject: [PATCH] MERCATE LOOOOOOOOOOOOOOOOOOOOOON

---
 .../com/mirenkov/ktheightmap/MainActivity.kt  |  8 ++---
 .../com/mirenkov/ktheightmap/MapCanvas.kt     | 29 ++++++++++++-------
 .../mirenkov/ktheightmap/SphereMercator.kt    |  2 ++
 .../com/mirenkov/ktheightmap/TileViewModel.kt |  3 ++
 4 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/app/src/main/java/com/mirenkov/ktheightmap/MainActivity.kt b/app/src/main/java/com/mirenkov/ktheightmap/MainActivity.kt
index 2d9e05e..4deea14 100644
--- a/app/src/main/java/com/mirenkov/ktheightmap/MainActivity.kt
+++ b/app/src/main/java/com/mirenkov/ktheightmap/MainActivity.kt
@@ -156,7 +156,6 @@ fun ToolButton(viewModel: TileViewModel) {
             DropdownMenuItem(
                 text = { Text("Set location") },
                 onClick = {
-                    expanded = false
                     dialogShown.value = true
                 }
             )
@@ -205,9 +204,10 @@ fun SetLocationDialog(vm: TileViewModel, dialogShown: MutableState<Boolean>) {
                 }
             },
             confirmButton = { TextButton(onClick = {
-                Log.i(TAG, "Lat: %.6f, Lon: %.6f".format(
-                    latitudeText.text.toDoubleOrNull() ?: 0.0, longitudeText.text.toDoubleOrNull() ?: 0.0
-                ))
+                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())))
             }) {
                     Text("Confirm".uppercase())
                 } },
diff --git a/app/src/main/java/com/mirenkov/ktheightmap/MapCanvas.kt b/app/src/main/java/com/mirenkov/ktheightmap/MapCanvas.kt
index 09684bc..8aa8619 100644
--- a/app/src/main/java/com/mirenkov/ktheightmap/MapCanvas.kt
+++ b/app/src/main/java/com/mirenkov/ktheightmap/MapCanvas.kt
@@ -51,6 +51,13 @@ fun MapCanvas(
                 }
             }
     ) {
+        if (viewModel.halvedOffsetX == null) {
+            viewModel.halvedOffsetX = size.width / 2
+            viewModel.halvedOffsetY = size.height / 2
+        }
+        val halvedX = viewModel.halvedOffsetX!!
+        val halvedY = viewModel.halvedOffsetY!!
+
         drawRect(
             color = backColor,
             size = size
@@ -67,8 +74,8 @@ fun MapCanvas(
 
         if (levelDiff < 0) {
             repeat (levelDiff.absoluteValue) {
-                offsetX -= size.width / 2F + TILE_SIZE
-                offsetY -= size.height / 2F + TILE_SIZE
+                offsetX -= halvedX + TILE_SIZE
+                offsetY -= halvedY + TILE_SIZE
                 offsetX /= 2F
                 offsetY /= 2F
             }
@@ -76,15 +83,15 @@ fun MapCanvas(
             repeat (levelDiff) {
                 offsetX *= 2F
                 offsetY *= 2F
-                offsetX += size.width / 2F + TILE_SIZE
-                offsetY += size.height / 2F + TILE_SIZE
+                offsetX += halvedX + TILE_SIZE
+                offsetY += halvedY + TILE_SIZE
             }
         }
         val tileOffsetX = (offsetX / TILE_SIZE).toInt()
         val tileOffsetY = (offsetY / TILE_SIZE).toInt()
 
-        val centerTileX = (1 + (offsetX + size.width / 2) / TILE_SIZE).toDouble()
-        val centerTileY = (1 + (offsetY + size.height / 2) / TILE_SIZE).toDouble()
+        val centerTileX = (1 + (offsetX + halvedX) / TILE_SIZE).toDouble()
+        val centerTileY = (1 + (offsetY + halvedY) / TILE_SIZE).toDouble()
 
         val strippedOffsetX = offsetX % TILE_SIZE
         val strippedOffsetY = offsetY % TILE_SIZE
@@ -101,7 +108,7 @@ fun MapCanvas(
         val crossRadius = 24F
 
         val additionalSize = if (debug) 96F else 0F
-        val latLonSize = Size(196F, 96F + additionalSize)
+        val latLonSize = Size(216F, 96F + additionalSize)
         val latLonOffset = Offset(16F, 16F)
 
         for (cellX in 0 .. gridWidth + 2) {
@@ -148,10 +155,10 @@ fun MapCanvas(
                 }
 
                 val path = Path()
-                path.moveTo(size.width / 2 - crossRadius, size.height / 2)
-                path.lineTo(size.width / 2 + crossRadius, size.height / 2)
-                path.moveTo(size.width / 2, size.height / 2 - crossRadius)
-                path.lineTo(size.width / 2, size.height / 2 + crossRadius)
+                path.moveTo(halvedX - crossRadius, halvedY)
+                path.lineTo(halvedX + crossRadius, halvedY)
+                path.moveTo(halvedX, halvedY - crossRadius)
+                path.lineTo(halvedX, halvedY + crossRadius)
                 path.close()
 
                 drawPath(
diff --git a/app/src/main/java/com/mirenkov/ktheightmap/SphereMercator.kt b/app/src/main/java/com/mirenkov/ktheightmap/SphereMercator.kt
index 051b375..4d44954 100644
--- a/app/src/main/java/com/mirenkov/ktheightmap/SphereMercator.kt
+++ b/app/src/main/java/com/mirenkov/ktheightmap/SphereMercator.kt
@@ -52,5 +52,7 @@ class SphereMercator {
         fun mercateX(x: Double, level: Int): Double = sx2lon((x * TILE_SIZE), level) - 180.0
 
         fun mercateY(y: Double, level: Int): Double = -sy2lat((y - ((1 shl (level - 1)).toDouble() / 2.0)) * TILE_SIZE, level - 1)
+
+        fun mercateLon(longitude: Double, level: Int, offset: Double): Double = lon2sx(longitude + 180.0, level) + offset
     }
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/mirenkov/ktheightmap/TileViewModel.kt b/app/src/main/java/com/mirenkov/ktheightmap/TileViewModel.kt
index 4032537..06e829d 100644
--- a/app/src/main/java/com/mirenkov/ktheightmap/TileViewModel.kt
+++ b/app/src/main/java/com/mirenkov/ktheightmap/TileViewModel.kt
@@ -19,6 +19,9 @@ class TileViewModel(application: Application): ViewModel() {
     val mapOffsetY = mutableFloatStateOf(-1157.2814F)
     val scale = mutableFloatStateOf(1F)
 
+    var halvedOffsetX: Float? = null
+    var halvedOffsetY: Float? = null
+
     init {
         val tileDb = TileDB.getInstance(application)
         val tileDao = tileDb.tileDao()