Merge pull request #259 from podusowski/position-mod

position module

walkers/src/center.rs

@@ -1,6 +1,9 @@
 use egui::{Response, Vec2};
 
-use crate::{map::AdjustedPosition, mercator::Pixels, Position};
+use crate::{
+    position::{AdjustedPosition, Pixels},
+    Position,
+};
 
 /// Position at the map's center. Initially, the map follows `my_position` argument which typically
 /// is meant to be fed by a GPS sensor or other geo-localization method. If user drags the map,

walkers/src/lib.rs

@@ -7,12 +7,14 @@ pub mod extras;
 mod io;
 mod map;
 mod mercator;
+mod position;
 pub mod sources;
 mod tiles;
 mod zoom;
 
 pub use download::{HeaderValue, HttpOptions};
 pub use map::{Map, MapMemory, Plugin, Projector};
-pub use mercator::{lat_lon, lon_lat, screen_to_position, Position, TileId};
+pub use mercator::{screen_to_position, TileId};
+pub use position::{lat_lon, lon_lat, Position};
 pub use tiles::{HttpTiles, Texture, TextureWithUv, Tiles};
 pub use zoom::InvalidZoom;

walkers/src/map.rs

@@ -4,7 +4,8 @@ use egui::{Mesh, PointerButton, Rect, Response, Sense, Ui, UiBuilder, Vec2, Widg
 
 use crate::{
     center::Center,
-    mercator::{project, screen_to_position, tile_id, Pixels, PixelsExt, TileId},
+    mercator::{project, tile_id, TileId},
+    position::{AdjustedPosition, Pixels, PixelsExt},
     tiles,
     zoom::{InvalidZoom, Zoom},
     Position, Tiles,
@@ -336,52 +337,6 @@ impl Widget for Map<'_, '_, '_> {
     }
 }
 
-/// [`Position`] alone is not able to represent detached (e.g. after map gets dragged) position
-/// due to insufficient accuracy.
-#[derive(Debug, Clone, PartialEq)]
-pub struct AdjustedPosition {
-    /// Base geographical position.
-    pub position: Position,
-
-    /// Offset in pixels.
-    pub offset: Pixels,
-}
-
-impl AdjustedPosition {
-    pub(crate) fn new(position: Position, offset: Pixels) -> Self {
-        Self { position, offset }
-    }
-
-    /// Calculate the real position, i.e. including the offset.
-    pub(crate) fn position(&self, zoom: f64) -> Position {
-        screen_to_position(project(self.position, zoom) - self.offset, zoom)
-    }
-
-    /// Recalculate `position` so that `offset` is zero.
-    pub(crate) fn zero_offset(self, zoom: f64) -> Self {
-        Self {
-            position: screen_to_position(project(self.position, zoom) - self.offset, zoom),
-            offset: Default::default(),
-        }
-    }
-
-    pub(crate) fn shift(self, offset: Vec2) -> Self {
-        Self {
-            position: self.position,
-            offset: self.offset + Pixels::new(offset.x as f64, offset.y as f64),
-        }
-    }
-}
-
-impl From<Position> for AdjustedPosition {
-    fn from(position: Position) -> Self {
-        Self {
-            position,
-            offset: Default::default(),
-        }
-    }
-}
-
 /// State of the map widget which must persist between frames.
 #[derive(Debug, Default, Clone)]
 pub struct MapMemory {

walkers/src/mercator.rs

@@ -3,26 +3,17 @@
 //! <https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames>
 //! <https://www.netzwolf.info/osm/tilebrowser.html?lat=51.157800&lon=6.865500&zoom=14>
 
+use crate::{
+    lon_lat,
+    position::{Pixels, Position},
+};
+use std::f64::consts::PI;
+
 // zoom level   tile coverage  number of tiles  tile size(*) in degrees
 // 0            1 tile         1 tile           360° x 170.1022°
 // 1            2 × 2 tiles    4 tiles          180° x 85.0511°
 // 2            4 × 4 tiles    16 tiles         90° x [variable]
 
-/// Geographical position with latitude and longitude.
-pub type Position = geo_types::Point;
-
-/// Construct `Position` from latitude and longitude.
-pub fn lat_lon(lat: f64, lon: f64) -> Position {
-    Position::new(lon, lat)
-}
-
-/// Construct `Position` from longitude and latitude. Note that it is common standard to write
-/// coordinates starting with the latitude instead (e.g. `51.104465719934176, 17.075169894118684` is
-/// the [Wrocław's zoo](https://zoo.wroclaw.pl/en/)).
-pub fn lon_lat(lon: f64, lat: f64) -> Position {
-    Position::new(lon, lat)
-}
-
 /// Zoom specifies how many pixels are in the whole map. For example, zoom 0 means that the whole
 /// map is just one 256x256 tile, zoom 1 means that it is 2x2 tiles, and so on.
 pub(crate) fn total_pixels(zoom: f64) -> f64 {
@@ -36,21 +27,6 @@ pub fn total_tiles(zoom: u8) -> u32 {
 /// Size of a single tile in pixels. Walkers uses 256px tiles as most of the tile sources do.
 const TILE_SIZE: u32 = 256;
 
-/// Location projected on the screen or an abstract bitmap.
-pub type Pixels = geo_types::Point;
-
-use std::f64::consts::PI;
-
-pub trait PixelsExt {
-    fn to_vec2(&self) -> egui::Vec2;
-}
-
-impl PixelsExt for Pixels {
-    fn to_vec2(&self) -> egui::Vec2 {
-        egui::Vec2::new(self.x() as f32, self.y() as f32)
-    }
-}
-
 /// Project the position into the Mercator projection and normalize it to 0-1 range.
 fn mercator_normalized(position: Position) -> (f64, f64) {
     // Project into Mercator (cylindrical map projection).
@@ -160,6 +136,7 @@ pub fn screen_to_position(pixels: Pixels, zoom: f64) -> Position {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::lat_lon;
 
     #[test]
     fn projecting_position_and_tile() {

walkers/src/position.rs

@@ -0,0 +1,78 @@
+//! Types and functions for working with positions.
+
+use crate::{mercator::project, screen_to_position};
+use egui::Vec2;
+
+/// Geographical position with latitude and longitude.
+pub type Position = geo_types::Point;
+
+/// Construct `Position` from latitude and longitude.
+pub fn lat_lon(lat: f64, lon: f64) -> Position {
+    Position::new(lon, lat)
+}
+
+/// Construct `Position` from longitude and latitude. Note that it is common standard to write
+/// coordinates starting with the latitude instead (e.g. `51.104465719934176, 17.075169894118684` is
+/// the [Wrocław's zoo](https://zoo.wroclaw.pl/en/)).
+pub fn lon_lat(lon: f64, lat: f64) -> Position {
+    Position::new(lon, lat)
+}
+
+/// [`Position`] alone is not able to represent detached (e.g. after map gets dragged) position
+/// due to insufficient accuracy.
+#[derive(Debug, Clone, PartialEq)]
+pub struct AdjustedPosition {
+    /// Base geographical position.
+    pub position: Position,
+
+    /// Offset in pixels.
+    pub offset: Pixels,
+}
+
+impl AdjustedPosition {
+    pub(crate) fn new(position: Position, offset: Pixels) -> Self {
+        Self { position, offset }
+    }
+
+    /// Calculate the real position, i.e. including the offset.
+    pub(crate) fn position(&self, zoom: f64) -> Position {
+        screen_to_position(project(self.position, zoom) - self.offset, zoom)
+    }
+
+    /// Recalculate `position` so that `offset` is zero.
+    pub(crate) fn zero_offset(self, zoom: f64) -> Self {
+        Self {
+            position: screen_to_position(project(self.position, zoom) - self.offset, zoom),
+            offset: Default::default(),
+        }
+    }
+
+    pub(crate) fn shift(self, offset: Vec2) -> Self {
+        Self {
+            position: self.position,
+            offset: self.offset + Pixels::new(offset.x as f64, offset.y as f64),
+        }
+    }
+}
+
+impl From<Position> for AdjustedPosition {
+    fn from(position: Position) -> Self {
+        Self {
+            position,
+            offset: Default::default(),
+        }
+    }
+}
+
+/// Location projected on the screen or an abstract bitmap.
+pub type Pixels = geo_types::Point;
+
+pub trait PixelsExt {
+    fn to_vec2(&self) -> egui::Vec2;
+}
+
+impl PixelsExt for Pixels {
+    fn to_vec2(&self) -> egui::Vec2 {
+        egui::Vec2::new(self.x() as f32, self.y() as f32)
+    }
+}