From 47532b85120d6edd406954f9220d3318c35f9da1 Mon Sep 17 00:00:00 2001
From: Cory McWilliams <cory@unprompted.com>
Date: Sun, 17 Sep 2023 20:52:12 +0000
Subject: [PATCH] Snapping to grid.

git-svn-id: https://www.unprompted.com/svn/projects/tildefriends/trunk@4465 ed5197a5-7fde-0310-b194-c3ffbd925b24
---
 apps/gg/script.js | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/apps/gg/script.js b/apps/gg/script.js
index 62e82fb0..0a60f45b 100644
--- a/apps/gg/script.js
+++ b/apps/gg/script.js
@@ -18,8 +18,11 @@ const k_store = {
 	'🦞': 15,
 	'🛶': 10,
 	'🏠': 10,
+	'⛰': 10,
 };
 
+const k_marker_snap = {x: 5, y: 1};
+
 class GgAppElement extends LitElement {
 	static get properties() {
 		return {
@@ -54,6 +57,7 @@ class GgAppElement extends LitElement {
 		this.load().catch(function(e) {
 			console.log('load error', e);
 		});
+		this.to_build = '🏠';
 	}
 
 	async load() {
@@ -363,6 +367,22 @@ class GgAppElement extends LitElement {
 			.openOn(this.leaflet);
 	}
 
+	snap_to_grid(latlng, fudge) {
+		let position = this.leaflet.options.crs.latLngToPoint(latlng, this.leaflet.getZoom());
+		position.x = Math.round(position.x / 16) * 16 + (fudge?.x ?? 0);
+		position.y = Math.round(position.y / 16) * 16 + (fudge?.y ?? 0);
+		position = this.leaflet.options.crs.pointToLatLng(position, this.leaflet.getZoom());
+		return position;
+	}
+
+	on_marker_move(event) {
+		if (!this.no_snap && this.marker) {
+			this.no_snap = true;
+			this.marker.setLatLng(this.snap_to_grid(this.marker.getLatLng(), k_marker_snap));
+			this.no_snap = false;
+		}
+	}
+
 	on_mouse_down(event) {
 		if (this.marker) {
 			this.marker.remove();
@@ -370,8 +390,9 @@ class GgAppElement extends LitElement {
 		}
 
 		if (this.to_build) {
-			this.marker = L.marker(event.latlng, {icon: L.divIcon({className: 'build-icon'}), draggable: true}).addTo(this.leaflet);
+			this.marker = L.marker(this.snap_to_grid(event.latlng, k_marker_snap), {icon: L.divIcon({className: 'build-icon'}), draggable: true}).addTo(this.leaflet);
 			this.marker.on({click: this.on_marker_click.bind(this)});
+			this.marker.on({drag: this.on_marker_move.bind(this)});
 		}
 	}
 
@@ -409,23 +430,25 @@ class GgAppElement extends LitElement {
 				for (let activity of self.loaded_activities) {
 					self.draw_activity_to_tile(image_data, mini.width, mini.height, ul, lr, activity);
 				}
+				context.textAlign = 'left';
+				context.textBaseline = 'top';
 				for (let x = 0; x < mini.width; x++) {
 					for (let y = 0; y < mini.height; y++) {
 						let start = (y * mini.width + x) * 4;
 						let pixel = self.color_to_emoji(image_data.data.slice(start, start + 4));
 						if (pixel) {
-							context.fillText(pixel, x * size.x / mini.width, y * size.y / mini.height + 10);
+							context.fillText(pixel, x * size.x / mini.width, y * size.y / mini.height);
 						}
 					}
 				}
 				for (let placed of self.placed_emojis) {
-					let position = self.leaflet.options.crs.latLngToPoint(placed.position, coords.z);
+					let position = self.leaflet.options.crs.latLngToPoint(self.snap_to_grid(placed.position), coords.z);
 					let tile_x = Math.floor(position.x / size.x);
 					let tile_y = Math.floor(position.y / size.y);
 					position.x = position.x - tile_x * size.x;
 					position.y = position.y - tile_y * size.y;
 					if (tile_x == coords.x && tile_y == coords.y) {
-						context.fillText(placed.emoji, position.x, position.y + 10);
+						context.fillText(placed.emoji, position.x, position.y);
 					}
 				}
 				return tile;