fix: add InvariantStatement (#28)

Author: CodyJasonBennett

README.md

@@ -26,6 +26,7 @@ Tools and IntelliSense for GLSL and WGSL.
     - [DiscardStatement](#discardstatement)
     - [PreprocessorStatement](#preprocessorstatement)
     - [PrecisionStatement](#precisionstatement)
+    - [InvariantStatement](#invariantstatement)
     - Control Flow
       - [ReturnStatement](#returnstatement)
       - [BreakStatement](#breakstatement)
@@ -406,6 +407,17 @@ interface PrecisionStatement extends Node {
 }
 ```
 
+### InvariantStatement
+
+A GLSL invariant statement.
+
+```ts
+interface InvariantStatement extends Node {
+  type: 'InvariantStatement'
+  typeSpecifier: Identifier
+}
+```
+
 ### ReturnStatement
 
 A return statement with an optional argument.

src/ast.ts

@@ -361,6 +361,14 @@ export interface PrecisionStatement extends Node {
   typeSpecifier: Identifier
 }
 
+/**
+ * A GLSL invariant statement.
+ */
+export interface InvariantStatement extends Node {
+  type: 'InvariantStatement'
+  typeSpecifier: Identifier
+}
+
 export type Expression =
   | Literal
   | Identifier
@@ -392,6 +400,7 @@ export type Statement =
   | StructDeclaration
   | PreprocessorStatement
   | PrecisionStatement
+  | InvariantStatement
 
 export type AST =
   | Program

src/generator.ts

@@ -37,6 +37,8 @@ function format(node: AST | null): string {
     }
     case 'PrecisionStatement':
       return `precision ${node.precision} ${node.typeSpecifier.name};`
+    case 'InvariantStatement':
+      return `invariant ${format(node.typeSpecifier)};`
     case 'ReturnStatement':
       return node.argument ? `return ${format(node.argument)};` : 'return;'
     case 'BreakStatement':

src/parser.ts

@@ -15,6 +15,7 @@ import {
   Identifier,
   IfStatement,
   InterpolationQualifier,
+  InvariantStatement,
   LayoutQualifier,
   Literal,
   LogicalOperator,
@@ -594,6 +595,13 @@ function parsePreprocessor(tokens: Token[]): PreprocessorStatement {
   return { type: 'PreprocessorStatement', name, value }
 }
 
+function parseInvariant(tokens: Token[]): InvariantStatement {
+  consume(tokens, 'invariant')
+  const typeSpecifier = parseExpression(tokens) as Identifier
+  consume(tokens, ';')
+  return { type: 'InvariantStatement', typeSpecifier }
+}
+
 function parseStatements(tokens: Token[]): Statement[] {
   const body: Statement[] = []
   let scopeIndex = 0
@@ -619,6 +627,7 @@ function parseStatements(tokens: Token[]): Statement[] {
     else if (token.value === 'do') statement = parseDoWhile(tokens)
     else if (token.value === 'switch') statement = parseSwitch(tokens)
     else if (token.value === 'precision') statement = parsePrecision(tokens)
+    else if (token.value === 'invariant') statement = parseInvariant(tokens)
     else if (VARIABLE_REGEX.test(token.value) && tokens[1].value !== '[') statement = parseIndeterminate(tokens)
     else {
       const expression = parseExpression(tokens)

src/visitor.ts

@@ -38,6 +38,9 @@ export function visit(node: AST, visitors: Visitors, ancestors: AST[] = []): voi
     case 'PrecisionStatement':
       visit(node.typeSpecifier, visitors, ancestors)
       break
+    case 'InvariantStatement':
+      visit(node.typeSpecifier, visitors, ancestors)
+      break
     case 'ReturnStatement':
       if (node.argument) visit(node.argument, visitors, ancestors)
       break

tests/__snapshots__/index.test.ts.snap

@@ -16,7 +16,7 @@ int y;
 #else
 float z;
 #endif
-};struct f{float intensity;vec3 position;float one,two;};uniform f Light[4];void main(){vec4 g=vec4(Light[0].position.xyz*Light[0].intensity,0.0);vec4 h=projectionMatrix*modelViewMatrix*vec4(0,0,0,1);vec4 i=d.projectionMatrix*d.modelViewMatrix*vec4(0,0,0,1);if(false){}pc_FragColor=vec4(texture(map,vUv).rgb,0.0);float j=0.0;pc_FragColor.a+=1.0+j;}"
+};struct f{float intensity;vec3 position;float one,two;};uniform f Light[4];invariant g;void main(){vec4 h=vec4(Light[0].position.xyz*Light[0].intensity,0.0);vec4 i=projectionMatrix*modelViewMatrix*vec4(0,0,0,1);vec4 j=d.projectionMatrix*d.modelViewMatrix*vec4(0,0,0,1);if(false){}g=vec4(texture(map,vUv).rgb,0.0);float k=0.0;g.a+=1.0+k;}"
 `;
 
 exports[`minify > can mangle GLSL 2`] = `
@@ -52,7 +52,7 @@ int y;
 #else
 float z;
 #endif
-};struct m{float intensity;vec3 position;float one,two;};uniform m n[4];void main(){vec4 o=vec4(n[0].position.xyz*n[0].intensity,0.0);vec4 p=projectionMatrix*modelViewMatrix*vec4(0,0,0,1);vec4 q=k.projectionMatrix*k.modelViewMatrix*vec4(0,0,0,1);if(false){}h=vec4(texture(f,g).rgb,0.0);float e=0.0;h.a+=1.0+e;}"
+};struct m{float intensity;vec3 position;float one,two;};uniform m n[4];invariant h;void main(){vec4 o=vec4(n[0].position.xyz*n[0].intensity,0.0);vec4 p=projectionMatrix*modelViewMatrix*vec4(0,0,0,1);vec4 q=k.projectionMatrix*k.modelViewMatrix*vec4(0,0,0,1);if(false){}h=vec4(texture(f,g).rgb,0.0);float e=0.0;h.a+=1.0+e;}"
 `;
 
 exports[`minify > can mangle externals in GLSL 2`] = `
@@ -116,7 +116,7 @@ int y;
 #else
 float z;
 #endif
-};struct LightData{float intensity;vec3 position;float one,two;};uniform LightData Light[4];void main(){vec4 lightNormal=vec4(Light[0].position.xyz*Light[0].intensity,0.0);vec4 clipPosition=projectionMatrix*modelViewMatrix*vec4(0,0,0,1);vec4 clipPositionGlobals=globals.projectionMatrix*globals.modelViewMatrix*vec4(0,0,0,1);if(false){}pc_FragColor=vec4(texture(map,vUv).rgb,0.0);float bar=0.0;pc_FragColor.a+=1.0+bar;}"
+};struct LightData{float intensity;vec3 position;float one,two;};uniform LightData Light[4];invariant pc_FragColor;void main(){vec4 lightNormal=vec4(Light[0].position.xyz*Light[0].intensity,0.0);vec4 clipPosition=projectionMatrix*modelViewMatrix*vec4(0,0,0,1);vec4 clipPositionGlobals=globals.projectionMatrix*globals.modelViewMatrix*vec4(0,0,0,1);if(false){}pc_FragColor=vec4(texture(map,vUv).rgb,0.0);float bar=0.0;pc_FragColor.a+=1.0+bar;}"
 `;
 
 exports[`minify > can minify WGSL 1`] = `"struct LightData{intensity:f32,position:vec3<f32>,one:f32,two:f32,};struct Uniforms{projectionMatrix:mat4x4<f32>,modelViewMatrix:mat4x4<f32>,normalMatrix:mat3x3<f32>,one:f32,two:f32,lights:array<LightData,4>,};@binding(0)@group(0)var<uniform>uniforms:Uniforms;@binding(1)@group(0)var sample:sampler;@binding(2)@group(0)var map:texture_2d<f32>;struct VertexIn{@location(0)position:vec4<f32>,@location(1)uv:vec2<f32>,};struct VertexOut{@builtin(position)position:vec4<f32>,@location(0)uv:vec2<f32>,};@vertex fn vert_main(input:VertexIn)->VertexOut{var output:VertexOut;output.position=input.position;output.uv=input.uv;return output;}@fragment fn frag_main(uv:vec2<f32>)->vec4<f32>{var lightNormal=vec4<f32>(uniforms.lights[0].position*uniforms.lights[0].intensity,0.0);var clipPosition=uniforms.projectionMatrix*uniforms.modelViewMatrix*vec4<f32>(0.0,0.0,0.0,1.0);var color=textureSample(map,sample,uv);color.a+=1.0;return color;}"`;
@@ -1228,6 +1228,28 @@ exports[`tokenize > can tokenize GLSL 1`] = `
     "type": "whitespace",
     "value": "
 
+  ",
+  },
+  {
+    "type": "keyword",
+    "value": "invariant",
+  },
+  {
+    "type": "whitespace",
+    "value": " ",
+  },
+  {
+    "type": "identifier",
+    "value": "pc_FragColor",
+  },
+  {
+    "type": "symbol",
+    "value": ";",
+  },
+  {
+    "type": "whitespace",
+    "value": "
+
   ",
   },
   {

tests/generator.test.ts

@@ -55,6 +55,8 @@ const glsl = /* glsl */ `#version 300 es
   };
   uniform LightData Light[4];
 
+  invariant pc_FragColor;
+
   void main() {
     vec4 lightNormal = vec4(Light[0].position.xyz * Light[0].intensity, 0.0);
     vec4 clipPosition = projectionMatrix * modelViewMatrix * vec4(0, 0, 0, 1);

tests/index.test.ts

@@ -55,6 +55,8 @@ const glsl = /* glsl */ `#version 300 es
   };
   uniform LightData Light[4];
 
+  invariant pc_FragColor;
+
   void main() {
     vec4 lightNormal = vec4(Light[0].position.xyz * Light[0].intensity, 0.0);
     vec4 clipPosition = projectionMatrix * modelViewMatrix * vec4(0, 0, 0, 1);

tests/parser.test.ts

@@ -22,6 +22,7 @@ import {
   WhileStatement,
   Identifier,
   ArraySpecifier,
+  InvariantStatement,
 } from 'shaderkit'
 
 describe('parser', () => {
@@ -773,6 +774,18 @@ describe('parser', () => {
     ])
   })
 
+  it('parses invariant statements', () => {
+    expect(parse('invariant position;').body).toStrictEqual<[InvariantStatement]>([
+      {
+        type: 'InvariantStatement',
+        typeSpecifier: {
+          name: 'position',
+          type: 'Identifier',
+        },
+      },
+    ])
+  })
+
   it('parses preprocessor statements', () => {
     expect(parse('#\n').body).toStrictEqual<[PreprocessorStatement]>([
       {