From 0efd583006a2e9b3967cae067ec67526a4284443 Mon Sep 17 00:00:00 2001
From: Jason Reed <jcreed@gmail.com>
Date: Sun, 10 Dec 2023 18:08:36 -0500
Subject: [PATCH] Zoom with +/- keys (fix #117)

---
 src/core/action.ts    |  1 +
 src/core/reduce.ts    | 37 +++++++++++++++++++++----------------
 src/core/reduceKey.ts | 19 ++++++++++++++++++-
 src/ui/key.ts         |  2 ++
 4 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/src/core/action.ts b/src/core/action.ts
index aae21ff..51b268b 100644
--- a/src/core/action.ts
+++ b/src/core/action.ts
@@ -2,6 +2,7 @@ import { ViewData } from '../ui/ui-helpers';
 import { Point } from '../util/types';
 import { SceneState } from './state';
 
+// All of these p are p_in_canvas
 export type GameAction =
   | { t: 'none' }
   | { t: 'key', code: string }
diff --git a/src/core/reduce.ts b/src/core/reduce.ts
index 54b94ba..30d07a6 100644
--- a/src/core/reduce.ts
+++ b/src/core/reduce.ts
@@ -261,6 +261,26 @@ export function keyCaptured(keyCode: string): boolean {
   }
 }
 
+export function reduceZoom(state: GameState, p_in_canvas: Point, delta: number): GameState {
+  const sf = delta < 0 ? 1.1 : 1 / 1.1;
+  const zoomed_canvas_of_unzoomed_canvas = composen(
+    translate(p_in_canvas),
+    scale({ x: sf, y: sf }),
+    translate(vscale(p_in_canvas, -1)),
+  );
+  const canvas_from_world = compose(zoomed_canvas_of_unzoomed_canvas, state.coreState.canvas_from_world);
+  const MAX_ZOOM_OUT = 7.5;
+  const MAX_ZOOM_IN = 150;
+  if (canvas_from_world.scale.x < MAX_ZOOM_OUT || canvas_from_world.scale.y < MAX_ZOOM_OUT
+    || canvas_from_world.scale.x > MAX_ZOOM_IN || canvas_from_world.scale.y > MAX_ZOOM_IN) {
+    return state;
+  }
+  return produce(state, s => {
+    s.coreState.canvas_from_world = canvas_from_world;
+  });
+
+}
+
 function reduceGameAction(state: GameState, action: GameAction): effectful.Result<SceneState, Effect> {
   function gs(state: GameState): effectful.Result<SceneState, Effect> {
     return { state: { t: 'game', gameState: state, revision: 0 }, effects: [] };
@@ -271,22 +291,7 @@ function reduceGameAction(state: GameState, action: GameAction): effectful.Resul
     }
     case 'none': return gs(state);
     case 'wheel': {
-      const sf = action.delta < 0 ? 1.1 : 1 / 1.1;
-      const zoomed_canvas_of_unzoomed_canvas = composen(
-        translate(action.p),
-        scale({ x: sf, y: sf }),
-        translate(vscale(action.p, -1)),
-      );
-      const canvas_from_world = compose(zoomed_canvas_of_unzoomed_canvas, state.coreState.canvas_from_world);
-      const MAX_ZOOM_OUT = 7.5;
-      const MAX_ZOOM_IN = 150;
-      if (canvas_from_world.scale.x < MAX_ZOOM_OUT || canvas_from_world.scale.y < MAX_ZOOM_OUT
-        || canvas_from_world.scale.x > MAX_ZOOM_IN || canvas_from_world.scale.y > MAX_ZOOM_IN) {
-        return gs(state);
-      }
-      return gs(produce(state, s => {
-        s.coreState.canvas_from_world = canvas_from_world;
-      }));
+      return gs(reduceZoom(state, action.p, action.delta));
     }
     case 'mouseDown': {
       const wp = getWidgetPoint(state.coreState, action.p);
diff --git a/src/core/reduceKey.ts b/src/core/reduceKey.ts
index 152bc61..bb8fcab 100644
--- a/src/core/reduceKey.ts
+++ b/src/core/reduceKey.ts
@@ -1,7 +1,9 @@
-import { getWidgetPoint } from "../ui/widget-helpers";
+import { canvas_bds_in_canvas, getWidgetPoint } from "../ui/widget-helpers";
 import { debugTiles } from "../util/debug";
 import { produce } from "../util/produce";
+import { midpointOfRect } from "../util/util";
 import { tryKillTileOfState } from "./kill-helpers";
+import { reduceZoom } from "./reduce";
 import { getScore, incrementScore, setScore } from "./scoring";
 import { GameState } from "./state";
 import { addWorldTiles, checkValid, drawOfState, dropTopHandTile, withCoreState } from "./state-helpers";
@@ -10,6 +12,21 @@ import { dynamiteIntent, reduceToolSelect } from "./tools";
 
 export function reduceKey(state: GameState, code: string): GameState {
   switch (code) {
+    case '=':  // fallthrough intentional
+    case '+':
+      if (state.mouseState.t == 'up') {
+        return reduceZoom(state, state.mouseState.p_in_canvas, -1);
+      }
+      else
+        return reduceZoom(state, midpointOfRect(canvas_bds_in_canvas), -1);
+      break;
+    case '-':
+      if (state.mouseState.t == 'up') {
+        return reduceZoom(state, state.mouseState.p_in_canvas, 1);
+      }
+      else
+        return reduceZoom(state, midpointOfRect(canvas_bds_in_canvas), 1);
+      break;
     case '<space>': {
       return withCoreState(state, cs => drawOfState(cs));
     }
diff --git a/src/ui/key.ts b/src/ui/key.ts
index 8b2ca9c..b93ccd0 100644
--- a/src/ui/key.ts
+++ b/src/ui/key.ts
@@ -7,6 +7,8 @@ const table: { [k: number]: string } = {
   219: '[',
   220: '\\',
   221: ']',
+  173: '-',
+  61: '=',
   8: '<backspace>',
   9: '<tab>',
   32: '<space>',