# Tint changes during Origin Trial

## Changes for M99

### Deprecated Features

The following features have been deprecated and will be removed in M102:

* The `[[block]]` attribute has been deprecated. [tint:1324](https://crbug.com/tint/1324)
* `elseif` has been replaced with `else if` [tint:1289](https://crbug.com/tint/1289)

### New Features

* Vector and matrix element type can now be inferred from constructor argument types. [tint:1334](https://crbug.com/tint/1334)
* Added builtins `degrees()` and `radians()` for converting between degrees and radians. [tint:1329](https://crbug.com/tint/1329)
* `let` arrays and matrices can now be dynamically indexed. [tint:1352](https://crbug.com/tint/1352)

### Fixes

* Fixed an issue where for-loops that contain array or structure constructors in the loop initializer statements, condition expressions or continuing statements could fail to compile. [tint:1364](https://crbug.com/tint/1364)

## Changes for M98

### Breaking Changes

* Taking the address of a vector component is no longer allowed.
* Module-scope declarations can no longer alias a builtin name. [tint:1318](https://crbug.com/tint/1318)
* It is now an error to call a function either directly or transitively, from a loop continuing block, that uses `discard`. [tint:1302](https://crbug.com/tint/1302)

### Deprecated Features

* The `isNan()`, `isInf()`, `isFinite()` and `isNormal()` builtins has been deprecated and will be removed in M101. [tint:1312](https://crbug.com/tint/1312)

### New Features

* New texture gather builtins: `textureGather()` and `textureGatherCompare()`. [tint:1330](https://crbug.com/tint/1330)
* Shadowing is now fully supported. [tint:819](https://crbug.com/tint/819)
* The `dot()` builtin now supports integer vector types.
* Identifiers can now start with a single leading underscore.  [tint:1292](https://crbug.com/tint/1292)
* Control flow analysis has been improved, and functions no longer need to `return` if the statement is unreachable. [tint:1302](https://crbug.com/tint/1302)
* Unreachable statements now produce a warning instead of an error, to allow WGSL code to be updated to the new analysis behavior. These warnings may become errors in the future [gpuweb#2378](https://github.com/gpuweb/gpuweb/issues/2378)

### Fixes

* Fixed an issue where using a module-scoped `let` in a `workgroup_size` may result in a compilation error. [tint:1320](https://crbug.com/tint/1320)

## Changes for M97

### Breaking Changes

* Deprecated `modf()` and `frexp()` builtin overloads that take a pointer second parameter have been removed.
* Deprecated texture builtin functions that accepted a `read` access controlled storage texture have been removed.
* Storage textures must now only use the `write` access control.

### Deprecated Features

* The `ignore()` builtin has been replaced with phony-assignment. [gpuweb#2127](https://github.com/gpuweb/gpuweb/pull/2127)

### New Features

* `any()` and `all()` now support a `bool` parameter. These simply return the passed argument. [tint:1253](https://crbug.com/tint/1253)
* Call statements may now include functions that return a value (`ignore()` is no longer needed).
* The `interpolate(flat)` attribute can now be specified on integral user-defined IO. It will eventually become an error to define integral user-defined IO without this attribute.
* Matrix construction from scalar element values is now supported.

### Fixes

* Swizzling of `vec3` types in `storage` and `uniform` buffers has been fixed for Metal 1.x. [tint:1249](https://crbug.com/tint/1249)
* Calling a function that returns an unused value no longer produces an FXC compilation error. [tint:1259](https://crbug.com/tint/1259)
* `abs()` fixed for unsigned integers on SPIR-V backend

## Changes for M95

### New Features

* The size of an array can now be defined using a non-overridable module-scope constant
* The `num_workgroups` builtin is now supported.

### Fixes

* Hex floats: now correctly errors when the magnitude is non-zero, and the exponent would cause overflow. [tint:1150](https://crbug.com/tint/1150), [tint:1166](https://crbug.com/tint/1166)
* Identifiers beginning with an underscore are now correctly rejected.  [tint:1179](https://crbug.com/tint/1179)