From 106d733fec8ae2bc6e94c398e68363ea1ca10af7 Mon Sep 17 00:00:00 2001
From: Surma <surma@surma.dev>
Date: Mon, 2 Nov 2020 16:56:45 +0000
Subject: [PATCH] Add rotate support

---
 cli/rollup.config.js | 19 +++++++++++--------
 cli/src/codecs.js    | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/cli/rollup.config.js b/cli/rollup.config.js
index a00aaae9..64fe6d1f 100644
--- a/cli/rollup.config.js
+++ b/cli/rollup.config.js
@@ -3,8 +3,8 @@ import cjs from "@rollup/plugin-commonjs";
 import asset from "./lib/asset-plugin.js";
 import json from "./lib/json-plugin.js";
 import autojson from "./lib/autojson-plugin.js";
-import { getBabelOutputPlugin } from '@rollup/plugin-babel';
-import { builtinModules } from 'module';
+import { getBabelOutputPlugin } from "@rollup/plugin-babel";
+import { builtinModules } from "module";
 
 /** @type {import('rollup').RollupOptions} */
 export default ({
@@ -29,12 +29,15 @@ export default ({
       minified: true,
       comments: false,
       presets: [
-        ['@babel/preset-env', {
-          targets: {
-            node: 12
-          },
-          loose: true
-        }]
+        [
+          "@babel/preset-env",
+          {
+            targets: {
+              node: 12
+            },
+            loose: true
+          }
+        ]
       ]
     })
   ],
diff --git a/cli/src/codecs.js b/cli/src/codecs.js
index d38b4f5c..62e02487 100644
--- a/cli/src/codecs.js
+++ b/cli/src/codecs.js
@@ -36,6 +36,9 @@ import * as resize from "../../codecs/resize/pkg/squoosh_resize.js";
 import resizeWasm from "asset-url:../../codecs/resize/pkg/squoosh_resize_bg.wasm";
 const resizePromise = resize.default(fsp.readFile(pathify(resizeWasm)));
 
+// rotate
+import rotateWasm from "asset-url:../../codecs/rotate/rotate.wasm";
+
 // ImageQuant
 import imageQuant from "../../codecs/imagequant/imagequant.js";
 import imageQuantWasm from "asset-url:../../codecs/imagequant/imagequant.wasm";
@@ -127,6 +130,7 @@ export const preprocessors = {
       linearRGB: true
     }
   },
+  // TODO: Need to handle SVGs and HQX
   quant: {
     name: "ImageQuant",
     description: "Reduce the number of colors used (aka. paletting)",
@@ -143,6 +147,35 @@ export const preprocessors = {
       numColors: 255,
       dither: 1.0
     }
+  },
+  rotate: {
+    name: "Rotate",
+    description: "Rotate image",
+    instantiate: async () => {
+      return async (buffer, width, height, { degrees }) => {
+        const sameDimensions = degrees == 0 || degrees == 180;
+        const size = width * height * 4;
+        const { instance } = await WebAssembly.instantiate(
+          await fsp.readFile(pathify(rotateWasm))
+        );
+        const { memory } = instance.exports;
+        const pagesNeeded = Math.ceil(
+          (size * 2 - memory.buffer.byteLength) / (64 * 1024)
+        );
+        memory.grow(pagesNeeded);
+        const view = new Uint8ClampedArray(memory.buffer);
+        view.set(buffer, 8);
+        instance.exports.rotate(width, height, degrees);
+        return new ImageData(
+          new Uint8ClampedArray(view.slice(size + 8, size * 2 + 8)),
+          sameDimensions ? width : height,
+          sameDimensions ? height : width
+        );
+      };
+    },
+    defaultOptions: {
+      numRotations: 0
+    }
   }
 };