[Sigma] Normalize the focusDistance

package.json

@@ -61,6 +61,7 @@
 		"eslint-plugin-unused-imports": "^2.0.0",
 		"eslint-plugin-vue": "^9.17.0",
 		"file-saver": "^2.0.5",
+		"linearly": "^0.12.1",
 		"npm-run-all": "^4.1.5",
 		"prettier": "^2.3.2",
 		"stylus": "^0.60.0",

src/TethrPTPUSB/TethrSigma.ts

@@ -1,4 +1,5 @@
 import {BiMap} from 'bim'
+import {scalar} from 'linearly'
 import {isEqual, minBy} from 'lodash'
 import sleep from 'sleep-promise'
 import {MemoizeExpiring} from 'typescript-memoize'
@@ -253,7 +254,8 @@ export class TethrSigma extends TethrPTPUSB {
 	}
 
 	async getCanStartLiveviewDesc() {
-		return createReadonlyConfigDesc(true)
+		const {lvImageTransfer} = await this.getCamCanSetInfo5()
+		return createReadonlyConfigDesc(lvImageTransfer.length > 0)
 	}
 
 	async setColorMode(colorMode: string): Promise<OperationResult> {
@@ -486,8 +488,12 @@ export class TethrSigma extends TethrPTPUSB {
 
 	async getFocusDistanceDesc(): Promise<ConfigDesc<number>> {
 		const {focusPosition: range} = await this.getCamCanSetInfo5()
-		const value = (await this.getCamStatus()).focusPosition[0]
+		const focusPosition = (await this.getCamStatus()).focusPosition[0]
+
+		// Small value means far direction, so invert the min/max and normalize it
+		const value = scalar.invlerp(range[1], range[0], focusPosition)
 
+		// Only writable when AF is on
 		const writable = range.length === 2 && !!(await this.getCanRunAutoFocus())
 
 		if (writable) {
@@ -496,9 +502,9 @@ export class TethrSigma extends TethrPTPUSB {
 				value,
 				option: {
 					type: 'range',
-					min: range[0],
-					max: range[1],
-					step: 1,
+					min: 0,
+					max: 1,
+					step: 0,
 				},
 			}
 		} else {
@@ -512,8 +518,14 @@ export class TethrSigma extends TethrPTPUSB {
 	async setFocusDistance(
 		value: number
 	): Promise<{status: OperationResultStatus}> {
+		const {focusPosition: range} = await this.getCamCanSetInfo5()
+
+		const focusPosition = scalar.round(scalar.lerp(range[1], range[0], value))
+
+		console.error(value, focusPosition)
+
 		const data = encodeIFD({
-			focusPosition: {tag: 81, type: IFDType.Short, value: [value]},
+			focusPosition: {tag: 81, type: IFDType.Short, value: [focusPosition]},
 		})
 
 		try {

yarn.lock

@@ -1844,6 +1844,11 @@ levn@^0.4.1:
     prelude-ls "^1.2.1"
     type-check "~0.4.0"
 
+linearly@^0.12.1:
+  version "0.12.1"
+  resolved "https://registry.yarnpkg.com/linearly/-/linearly-0.12.1.tgz#a58a14fdbfc7e419ac21fad5cd459b7dccff414f"
+  integrity sha512-mGdv/cSZENtaf0vJZiKwjOggOIhID8JZNJa8aIafsa0ipLvDuu+R01rPtk4oy8IQkcEcqVLnIeH5MHNG8SuYFA==
+
 load-json-file@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/load-json-file/-/load-json-file-4.0.0.tgz#2f5f45ab91e33216234fd53adab668eb4ec0993b"