From dfc4531bfae224d6ed33ff577f24befdafa107bd Mon Sep 17 00:00:00 2001
From: evlist <vdv@dyomedea.com>
Date: Thu, 13 Oct 2022 14:39:03 +0200
Subject: [PATCH] Moving stuff around.

---
 svgmap/src/components/map/Map.css          |  6 +++
 svgmap/src/components/map/Map.tsx          | 26 ++++++++++-
 svgmap/src/components/map/MouseHandler.tsx | 50 ++++++++++------------
 svgmap/src/components/map/Viewport.tsx     | 47 +++-----------------
 4 files changed, 58 insertions(+), 71 deletions(-)

diff --git a/svgmap/src/components/map/Map.css b/svgmap/src/components/map/Map.css
index 34812f7..d961862 100644
--- a/svgmap/src/components/map/Map.css
+++ b/svgmap/src/components/map/Map.css
@@ -1,3 +1,9 @@
 .map {
   overflow: hidden;
 }
+
+.handler {
+  position: fixed;
+  height: 100%;
+  width: 100%;
+}
diff --git a/svgmap/src/components/map/Map.tsx b/svgmap/src/components/map/Map.tsx
index ba68acf..fea65e2 100644
--- a/svgmap/src/components/map/Map.tsx
+++ b/svgmap/src/components/map/Map.tsx
@@ -1,4 +1,4 @@
-import { IonContent, IonApp } from '@ionic/react';
+import { IonContent } from '@ionic/react';
 import react, { useState } from 'react';
 
 import './Map.css';
@@ -13,13 +13,35 @@ interface MapProperties {
 const Map: react.FC<MapProperties> = (props: MapProperties) => {
   const boardSize = Math.max(props.width, props.height) * 2;
 
+  const [shift, setShift] = useState({ x: 0, y: 0 });
+  const [zoom, setZoom] = useState(1);
+
+  const addShift = (deltaShift: { x: number; y: number }) => {
+    setShift({ x: shift.x + deltaShift.x, y: shift.y + deltaShift.y });
+  };
+
+  const addZoom = (zoomFactor: number, center: { x: number; y: number }) => {
+    setShift({
+      x: (shift.x - center.x) * (zoomFactor - 1),
+      y: (shift.y - center.y) * (zoomFactor - 1),
+    });
+    setZoom(zoom * zoomFactor);
+  };
+
   return (
     <IonContent fullscreen={true}>
       <div
         className='map'
         style={{ width: props.width + 'px', height: props.height + 'px' }}
       >
-        <MouseHandler shift={{ x: 0, y: 0 }} zoom={1} boardSize={boardSize} />
+        <MouseHandler
+          shift={shift}
+          addShift={addShift}
+          zoom={zoom}
+          addZoom={addZoom}
+          boardSize={boardSize}
+        />
+        <Viewport boardSize={boardSize} shift={shift} zoom={zoom} />
       </div>
     </IonContent>
   );
diff --git a/svgmap/src/components/map/MouseHandler.tsx b/svgmap/src/components/map/MouseHandler.tsx
index 32ab746..e5b210e 100644
--- a/svgmap/src/components/map/MouseHandler.tsx
+++ b/svgmap/src/components/map/MouseHandler.tsx
@@ -1,10 +1,17 @@
 import react, { useState } from 'react';
-import Viewport from './Viewport';
+import './Map.css';
+
+interface Point {
+  x: number;
+  y: number;
+}
 
 interface MouseHandlerProperties {
   boardSize: number;
-  shift: { x: number; y: number };
+  shift: Point;
+  addShift: (shift: Point) => void;
   zoom: number;
+  addZoom: (zoomFactor: number, center: Point) => void;
 }
 
 const MouseHandler: react.FC<MouseHandlerProperties> = (
@@ -18,12 +25,12 @@ const MouseHandler: react.FC<MouseHandlerProperties> = (
 
   const [mouseState, setMouseState] = useState(initialMouseState);
 
-  const [shift, setShift] = useState(props.shift);
-  const [zoom, setZoom] = useState(props.zoom);
-
   console.log('MouseHandler, mouseState: ' + JSON.stringify(mouseState));
   console.log(
-    'MouseHandler, shift: ' + JSON.stringify(shift) + ', zoom:' + zoom
+    'MouseHandler, shift: ' +
+      JSON.stringify(props.shift) +
+      ', zoom:' +
+      props.zoom
   );
 
   const genericHandler = (event: any) => {
@@ -69,9 +76,9 @@ const MouseHandler: react.FC<MouseHandlerProperties> = (
           y: event.pageY - mouseState.starting.y,
         })}`
       );
-      setShift({
-        x: shift.x + (event.pageX - mouseState.starting.x),
-        y: shift.y + (event.pageY - mouseState.starting.y),
+      props.addShift({
+        x: event.pageX - mouseState.starting.x,
+        y: event.pageY - mouseState.starting.y,
       });
       setMouseState({
         down: true,
@@ -84,17 +91,9 @@ const MouseHandler: react.FC<MouseHandlerProperties> = (
     }
   };
 
-  const doScale = (x: number, y: number, factor: number) => {
-    setShift({
-      x: shift.x + (shift.x - x) * (factor - 1),
-      y: shift.y + (shift.y - y) * (factor - 1),
-    });
-    setZoom(zoom * factor);
-  };
-
   const doubleClickHandler = (event: any) => {
     genericHandler(event);
-    doScale(event.pageX, event.pageY, Math.SQRT2);
+    props.addZoom(Math.SQRT2, { x: event.pageX, y: event.pageY });
   };
 
   const initialWheelState = {
@@ -109,11 +108,10 @@ const MouseHandler: react.FC<MouseHandlerProperties> = (
       event.deltaMode === WheelEvent.DOM_DELTA_PIXEL &&
       Date.now() - wheelState.timestamp > 100
     ) {
-      doScale(
-        event.pageX,
-        event.pageY,
-        event.deltaY < 0 ? Math.SQRT2 : Math.SQRT1_2
-      );
+      props.addZoom(event.deltaY < 0 ? Math.SQRT2 : Math.SQRT1_2, {
+        x: event.pageX,
+        y: event.pageY,
+      });
 
       setWheelState({
         timestamp: Date.now(),
@@ -122,16 +120,14 @@ const MouseHandler: react.FC<MouseHandlerProperties> = (
   };
 
   return (
-    <div
+    <div className='handler'
       onMouseDown={mouseDownHandler}
       onMouseMove={mouseMoveHandler}
       onMouseUp={mouseUpHandler}
       onMouseLeave={mouseLeaveHandler}
       onDoubleClick={doubleClickHandler}
       onWheel={wheelEventHandler}
-    >
-      <Viewport boardSize={props.boardSize} shift={shift} zoom={zoom} />
-    </div>
+    ></div>
   );
 };
 
diff --git a/svgmap/src/components/map/Viewport.tsx b/svgmap/src/components/map/Viewport.tsx
index 9310aa4..a8806e0 100644
--- a/svgmap/src/components/map/Viewport.tsx
+++ b/svgmap/src/components/map/Viewport.tsx
@@ -1,4 +1,5 @@
 import react from 'react';
+import TiledLayer from './TiledLayer';
 
 interface ViewportProperties {
   boardSize: number;
@@ -6,55 +7,17 @@ interface ViewportProperties {
   zoom: number;
 }
 
-/**
- *
- * Let's call:
- *   - x and y the SVG coordinates
- *   - X and Y the screen coordinates (pixels on screen)
- *
- *  X0 = (x + shift.x * zoom) * zoom
- * or
- *  x = X0 * zoom - shift.x
- * id for Y
- *
- *  To add a new shift of S screen pixels, we need to apply a zoom of S/zoom
- *
- *  How can we zoom so that X and x stay constant ?
- *
- *  Knowing X0, x0, zoom0, zoom1 and shift.x0,
- *
- *
- *  X0 = (x0 + shift.x0 *zoom0) * zoom0
- *  X1 = (x1 + shift.x1 *zoom1) * zoom1
- *  X0 = X1 (=X)
- *  x0 = x1 (=x)
- * =>
- *  (x + shift.x1*zoom1) * zoom1 = (x + shift.x0 * zoom0) * zoom0
- * =>
- *  (x + shift.x1*zoom1) = (x + shift.x0*zoom0) * zoom0 / zoom1
- *  shift.x1 = ((x + shift.x0) * zoom0 / zoom1 - x) / zoom1
- *
- * x = 333
- * 282 => -25,5
- *
- */
-
-/**
-  * 
-  *       viewBox={`${-props.shift.x} ${-props.shift.y} ${
-        props.boardSize / props.zoom
-      } ${props.boardSize / props.zoom}`}
-
-  * 
-  */
-
 const Viewport: react.FC<ViewportProperties> = (props: ViewportProperties) => {
   return (
     <svg height={props.boardSize} width={props.boardSize}>
+      <defs>
+        <TiledLayer id='tl16' zoomLevel={16} />
+      </defs>
       <g
         transform={`translate(${props.shift.x}, ${props.shift.y}) scale(${props.zoom})`}
       >
         <circle cx='50' cy='50' r='50' />
+        <use x={0} y={0} href='#tl16' />
       </g>
     </svg>
   );