Merge pull request #458 from jviide/rust-rotate

Fix buffer offset/size calculations in rotate/processor.ts
This commit is contained in:
Surma
2019-02-11 22:42:07 +00:00
committed by GitHub

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@@ -11,7 +11,7 @@ export async function rotate(
// Number of wasm memory pages (á 64KiB) needed to store the image twice. // Number of wasm memory pages (á 64KiB) needed to store the image twice.
const bytesPerImage = data.width * data.height * 4; const bytesPerImage = data.width * data.height * 4;
const numPagesNeeded = Math.ceil(bytesPerImage * 2 / (64 * 1024) + 4); const numPagesNeeded = Math.ceil((bytesPerImage * 2 + 4) / (64 * 1024));
// Only count full pages, just to be safe. // Only count full pages, just to be safe.
const numPagesAvailable = Math.floor(instance.exports.memory.buffer.byteLength / (64 * 1024)); const numPagesAvailable = Math.floor(instance.exports.memory.buffer.byteLength / (64 * 1024));
const additionalPagesToAllocate = numPagesNeeded - numPagesAvailable; const additionalPagesToAllocate = numPagesNeeded - numPagesAvailable;
@@ -20,13 +20,13 @@ export async function rotate(
instance.exports.memory.grow(additionalPagesToAllocate); instance.exports.memory.grow(additionalPagesToAllocate);
} }
const view = new Uint8ClampedArray(instance.exports.memory.buffer); const view = new Uint8ClampedArray(instance.exports.memory.buffer);
view.set(data.data); view.set(data.data, 4);
instance.exports.rotate(data.width, data.height, opts.rotate); instance.exports.rotate(data.width, data.height, opts.rotate);
const flipDimensions = opts.rotate % 180 !== 0; const flipDimensions = opts.rotate % 180 !== 0;
return new ImageData( return new ImageData(
view.slice(bytesPerImage, bytesPerImage * 2), view.slice(bytesPerImage + 4, bytesPerImage * 2 + 4),
flipDimensions ? data.height : data.width, flipDimensions ? data.height : data.width,
flipDimensions ? data.width : data.height, flipDimensions ? data.width : data.height,
); );