feat(gatsby-transformer-sharp): add inside and outside fit options

docs/docs/gatsby-image.md

@@ -129,7 +129,7 @@ file(relativePath: { eq: "images/default.jpg" }) {
 }
 ```
 
-Read more in the [gatsby-plugin-sharp](/packages/gatsby-plugin-sharp/?=#fixed) README.
+Read more about fixed image queries in the [gatsby-plugin-sharp](/packages/gatsby-plugin-sharp/#fixed) README.
 
 ### Images that stretch across a _fluid_ container
 
@@ -177,18 +177,17 @@ In a query, you can specify options for fluid images.
 - `maxHeight`(int)
 - `quality` (int, default: 50)
 - `srcSetBreakpoints` (array of int, default: [])
-- `fit` (string, default: `[sharp.fit.cover][6]`)
 - `background` (string, default: `rgba(0,0,0,1)`)
 
 #### Returns
 
 - `base64` (string)
-- `src` (string)
-- `width` (int)
-- `height` (int)
 - `aspectRatio` (float)
 - `src` (string)
 - `srcSet` (string)
+- `srcSetType` (string)
+- `sizes` (string)
+- `originalImg` (string)
 
 This is where fragments like `GatsbyImageSharpFluid` come in handy, as they'll return all the above items in one line without having to type them all out:
 
@@ -204,7 +203,7 @@ file(relativePath: { eq: "images/default.jpg" }) {
 }
 ```
 
-Read more in the [gatsby-plugin-sharp](/packages/gatsby-plugin-sharp/?=#fluid) README.
+Read more about fluid image queries in the [gatsby-plugin-sharp](/packages/gatsby-plugin-sharp/#fluid) README.
 
 ### Resized images
 
@@ -240,15 +239,19 @@ allImageSharp {
 }
 ```
 
+Read more about resized image queries in the [gatsby-plugin-sharp](/packages/gatsby-plugin-sharp/#resize) README.
+
 ### Shared query parameters
 
-In addition to `gatsby-plugin-sharp` settings in `gatsby-config.js`, there are additional query options that apply to both _fluid_ and _fixed_ images:
+In addition to `gatsby-plugin-sharp` settings in `gatsby-config.js`, there are additional query options that apply to _fluid_, _fixed_, and _resized_ images:
 
-- `grayscale` (bool, default: false)
-- `duotone` (bool|obj, default: false)
-- `toFormat` (string, default: \`\`)
-- `cropFocus` (string, default: `[sharp.strategy.attention][6]`)
-- `pngCompressionSpeed` (int, default: 4)
+- [`grayscale`](/packages/gatsby-plugin-sharp/#grayscale) (bool, default: false)
+- [`duotone`](/packages/gatsby-plugin-sharp/#duotone) (bool|obj, default: false)
+- [`toFormat`](/packages/gatsby-plugin-sharp/#toformat) (string, default: \`\`)
+- [`cropFocus`](/packages/gatsby-plugin-sharp/#cropfocus) (string, default: `ATTENTION`)
+- [`fit`](/packages/gatsby-plugin-sharp/#fit) (string, default: `COVER`)
+- [`pngCompressionSpeed`](/packages/gatsby-plugin-sharp/#pngcompressionspeed) (int, default: 4)
+- [`rotate`](/packages/gatsby-plugin-sharp/#rotate) (int, default: 0)
 
 Here's an example of using the `duotone` option with a fixed image:
 
@@ -286,13 +289,13 @@ fixed(
   <figcaption>Grayscale | Before - After</figcaption>
 </figure>
 
-Read more in the [`gatsby-plugin-sharp`](/packages/gatsby-plugin-sharp) README.
+Read more about shared image query parameters in the [`gatsby-plugin-sharp`](/packages/gatsby-plugin-sharp/#shared-options) README.
 
 ## Image query fragments
 
 GraphQL includes a concept called "query fragments", which are a part of a query that can be reused. To ease building with `gatsby-image`, Gatsby image processing plugins which support `gatsby-image` ship with fragments which you can easily include in your queries.
 
-> Note: using fragments in your queries depends on which data source(s) you have configured. Read more in the [gatsby-image](/packages/gatsby-image#fragments) README.
+> Note: using fragments in your queries depends on which data source(s) you have configured. Read more about image query fragments in the [gatsby-image](/packages/gatsby-image/#fragments) README.
 
 ### Common fragments with `gatsby-transformer-sharp`
 

packages/gatsby-plugin-sharp/README.md

@@ -101,11 +101,10 @@ a base64 image to use as a placeholder) you need to implement the "blur up"
 technique popularized by Medium and Facebook (and also available as a Gatsby
 plugin for Markdown content as gatsby-remark-images).
 
-When both a `maxWidth` and `maxHeight` are provided, sharp will use `COVER` as a fit strategy by default. This might not be ideal so you can now choose between `COVER`, `CONTAIN` and `FILL` as a fit strategy. To see them in action the [CSS property object-fit](https://developer.mozilla.org/en-US/docs/Web/CSS/object-fit) comes close to its implementation.
-
-#### Note
-
-fit strategies `CONTAIN` and `FILL` will not work when `cropFocus` is assigned to [sharp.strategy][6]. The `cropFocus` option cannot be `ENTROPY` or `ATTENTION`
+When both a `maxWidth` and `maxHeight` are provided, sharp will [resize the image][6] using
+`COVER` as a fit strategy by default. You can choose between `COVER`, `CONTAIN`, `FILL`,
+`INSIDE`, and `OUTSIDE` as a fit strategy. See the [fit parameter below](#fit)
+for more details.
 
 #### Parameters
 
@@ -116,7 +115,6 @@ fit strategies `CONTAIN` and `FILL` will not work when `cropFocus` is assigned t
 - `pngQuality` (int)
 - `webpQuality` (int)
 - `srcSetBreakpoints` (array of int, default: [])
-- `fit` (string, default: '[sharp.fit.cover][6]')
 - `background` (string, default: 'rgba(0,0,0,1)')
 - [deprecated] `sizeByPixelDensity` (bool, default: false)
   - Pixel density is only used in vector images, which Gatsby’s implementation of Sharp doesn’t support. This option is currently a no-op and will be removed in the next major version of Gatsby.
@@ -139,8 +137,10 @@ following:
 - `grayscale` (bool, default: false)
 - `duotone` (bool|obj, default: false)
 - `toFormat` (string, default: '')
-- `cropFocus` (string, default: '[sharp.strategy.attention][6]')
+- `cropFocus` (string, default: 'ATTENTION')
+- `fit` (string, default: 'COVER')
 - `pngCompressionSpeed` (int, default: 4)
+- `rotate` (int, default: 0)
 
 #### toFormat
 
@@ -151,7 +151,25 @@ Convert the source image to one of the following available options: `NO_CHANGE`,
 
 Change the cropping focus. Available options: `CENTER`, `NORTH`, `NORTHEAST`,
 `EAST`, `SOUTHEAST`, `SOUTH`, `SOUTHWEST`, `WEST`, `NORTHWEST`, `ENTROPY`,
-`ATTENTION`. See Sharp's [crop][6].
+`ATTENTION`. See Sharp's [resize][6].
+
+#### fit
+
+Select the fit strategy for sharp to use when resizing images. Available options
+are: `COVER`, `CONTAIN`, `FILL`, `INSIDE`, `OUTSIDE`. See Sharp's [resize][6].
+
+**Note:** The fit strategies `CONTAIN` and `FILL` will not work when `cropFocus` is
+set to `ENTROPY` or `ATTENTION`.
+
+The following image shows the effects of each fit option. You can see that the
+`INSIDE` option results in one dimension being smaller than requested, while
+the `OUTSIDE` option results in one dimension being larger than requested.
+![Sharp transform fit options](./sharp-transform-fit-options.png)
+
+#### pngCompressionSpeed
+
+Change the speed/quality tradeoff for PNG compression from 1 (brute-force) to
+10 (fastest). See pngquant's [options][19].
 
 #### rotate
 
@@ -357,3 +375,4 @@ If updating these doesn't fix the issue, your project probably uses other plugin
 [16]: https://github.com/mozilla/mozjpeg
 [17]: https://www.sno.phy.queensu.ca/~phil/exiftool/
 [18]: https://www.npmjs.com/package/color
+[19]: https://pngquant.org/#options

packages/gatsby-plugin-sharp/src/index.js

@@ -45,6 +45,67 @@ exports.setBoundActionCreators = actions => {
   boundActionCreators = actions
 }
 
+function calculateImageDimensionsAndAspectRatio(file, options) {
+  // Calculate the eventual width/height of the image.
+  const dimensions = getImageSize(file)
+  const imageAspectRatio = dimensions.width / dimensions.height
+
+  let width = options.width
+  let height = options.height
+
+  switch (options.fit) {
+    case sharp.fit.fill: {
+      width = options.width ? options.width : dimensions.width
+      height = options.height ? options.height : dimensions.height
+      break
+    }
+    case sharp.fit.inside: {
+      const widthOption = options.width
+        ? options.width
+        : Number.MAX_SAFE_INTEGER
+      const heightOption = options.height
+        ? options.height
+        : Number.MAX_SAFE_INTEGER
+
+      width = Math.min(widthOption, Math.round(heightOption * imageAspectRatio))
+      height = Math.min(
+        heightOption,
+        Math.round(widthOption / imageAspectRatio)
+      )
+      break
+    }
+    case sharp.fit.outside: {
+      const widthOption = options.width ? options.width : 0
+      const heightOption = options.height ? options.height : 0
+
+      width = Math.max(widthOption, Math.round(heightOption * imageAspectRatio))
+      height = Math.max(
+        heightOption,
+        Math.round(widthOption / imageAspectRatio)
+      )
+      break
+    }
+
+    default: {
+      if (options.width && !options.height) {
+        width = options.width
+        height = Math.round(options.width / imageAspectRatio)
+      }
+
+      if (options.height && !options.width) {
+        width = Math.round(options.height * imageAspectRatio)
+        height = options.height
+      }
+    }
+  }
+
+  return {
+    width,
+    height,
+    aspectRatio: width / height,
+  }
+}
+
 function prepareQueue({ file, args }) {
   const { pathPrefix, ...options } = args
   const argsDigestShort = createArgsDigest(options)
@@ -60,30 +121,10 @@ function prepareQueue({ file, args }) {
   // make sure outputDir is created
   fs.ensureDirSync(outputDir)
 
-  let width
-  let height
-  // Calculate the eventual width/height of the image.
-  const dimensions = getImageSize(file)
-  let aspectRatio = dimensions.width / dimensions.height
-
-  // If the width/height are both set, we're cropping so just return
-  // that.
-  if (options.width && options.height) {
-    width = options.width
-    height = options.height
-    // Recalculate the aspectRatio for the cropped photo
-    aspectRatio = width / height
-  } else if (options.width) {
-    // Use the aspect ratio of the image to calculate what will be the resulting
-    // height.
-    width = options.width
-    height = Math.round(options.width / aspectRatio)
-  } else {
-    // Use the aspect ratio of the image to calculate what will be the resulting
-    // width.
-    height = options.height
-    width = Math.round(options.height * aspectRatio)
-  }
+  const { width, height, aspectRatio } = calculateImageDimensionsAndAspectRatio(
+    file,
+    options
+  )
 
   // encode the file name for URL
   const encodedImgSrc = `/${encodeURIComponent(file.name)}.${options.toFormat}`
@@ -263,9 +304,21 @@ async function generateBase64({ file, args = {}, reporter }) {
     args.toFormat = forceBase64Format
   }
 
+  console.log({
+    src: file.absolutePath,
+    width: options.width,
+    height: options.height,
+    position: options.cropFocus,
+    fit: options.fit,
+    background: options.background,
+  })
   pipeline
-    .resize(options.width, options.height, {
+    .resize({
+      width: options.width,
+      height: options.height,
       position: options.cropFocus,
+      fit: options.fit,
+      background: options.background,
     })
     .png({
       compressionLevel: options.pngCompressionLevel,
@@ -508,14 +561,19 @@ async function fluid({ file, args = {}, reporter, cache }) {
   let base64Image
   if (options.base64) {
     const base64Width = options.base64Width || defaultBase64Width()
-    const base64Height = Math.max(1, Math.round((base64Width * height) / width))
+    const base64Height = Math.max(
+      1,
+      Math.round(base64Width / images[0].aspectRatio)
+    )
     const base64Args = {
       duotone: options.duotone,
       grayscale: options.grayscale,
       rotate: options.rotate,
       trim: options.trim,
       toFormat: options.toFormat,
       toFormatBase64: options.toFormatBase64,
+      cropFocus: options.cropFocus,
+      fit: options.fit,
       width: base64Width,
       height: base64Height,
     }
@@ -626,16 +684,23 @@ async function fixed({ file, args = {}, reporter, cache }) {
 
   let base64Image
   if (options.base64) {
+    const base64Width = options.base64Width || defaultBase64Width()
+    const base64Height = Math.max(
+      1,
+      Math.round(base64Width / images[0].aspectRatio)
+    )
     const base64Args = {
-      // height is adjusted accordingly with respect to the aspect ratio
-      width: options.base64Width,
       duotone: options.duotone,
       grayscale: options.grayscale,
       rotate: options.rotate,
+      trim: options.trim,
       toFormat: options.toFormat,
       toFormatBase64: options.toFormatBase64,
+      cropFocus: options.cropFocus,
+      fit: options.fit,
+      width: base64Width,
+      height: base64Height,
     }
-
     // Get base64 version
     base64Image = await base64({
       file,

packages/gatsby-transformer-sharp/src/types.js

@@ -26,6 +26,8 @@ const ImageFitType = new GraphQLEnumType({
     COVER: { value: sharp.fit.cover },
     CONTAIN: { value: sharp.fit.contain },
     FILL: { value: sharp.fit.fill },
+    INSIDE: { value: sharp.fit.inside },
+    OUTSIDE: { value: sharp.fit.outside },
   },
 })