feat(shader-ast): add builtins, discard, add/refactor ControlFlow n…

…ode type - add texelFetch() - add dFdx / dFdy / fwidth()
thi-ng · Jun 30, 2019 · 663e992 · 663e992
1 parent 72867ff
commit 663e992
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Showing 3 changed files with 42 additions and 11 deletions.
diff --git a/packages/shader-ast/src/api.ts b/packages/shader-ast/src/api.ts
@@ -13,10 +13,9 @@ import {
 export type Tag =
     | "arg"
     | "assign"
-    | "break"
     | "call"
     | "call_i"
-    | "cont"
+    | "ctrl"
     | "decl"
     | "fn"
     | "for"
@@ -522,6 +521,11 @@ export interface Ternary<T extends Type> extends Term<T> {
     f: Term<T>;
 }
 
+export interface ControlFlow extends Term<"void"> {
+    tag: "ctrl";
+    id: string;
+}
+
 export interface FuncReturn<T extends Type> extends Term<T> {
     val?: Term<any>;
 }

diff --git a/packages/shader-ast/src/ast.ts b/packages/shader-ast/src/ast.ts
@@ -29,6 +29,7 @@ import {
     BVec4Term,
     Comparable,
     ComparisonOperator,
+    ControlFlow,
     Decl,
     FloatTerm,
     FnBody0,
@@ -1059,12 +1060,14 @@ export const whileLoop = (test: BoolTerm, body: Term<any>[]): WhileLoop => ({
     scope: scope(body)
 });
 
-export const brk: Term<"void"> = {
-    tag: "break",
-    type: "void"
-};
+const ctrl = (id: string): ControlFlow => ({
+    tag: "ctrl",
+    type: "void",
+    id
+});
 
-export const cont: Term<"void"> = {
-    tag: "cont",
-    type: "void"
-};
+export const brk = ctrl("break");
+
+export const cont = ctrl("continue");
+
+export const discard = ctrl("discard");
diff --git a/packages/shader-ast/src/builtins.ts b/packages/shader-ast/src/builtins.ts
@@ -19,7 +19,7 @@ import {
     Vec3Term,
     Vec4Term
 } from "./api";
-import { builtinCall, FLOAT0 } from "./ast";
+import { builtinCall, FLOAT0, INT0 } from "./ast";
 
 const primOp1 = (name: string) => <T extends Prim>(a: Term<T>) =>
     builtinCall(name, a.type, a);
@@ -321,3 +321,27 @@ export function textureOffset(sampler: Sym<Sampler>, uv: Term<Vec>, off: Term<IV
     f.type === "float" && (f.info = "n");
     return f;
 }
+
+// prettier-ignore
+export function texelFetch(sampler: Sampler2DSym, uv: IVec2Term, lod?: IntTerm): FnCall<"vec4">;
+// prettier-ignore
+export function texelFetch(sampler: Sampler3DSym, uvw: IVec3Term, lod?: IntTerm): FnCall<"vec4">;
+// prettier-ignore
+export function texelFetch(sampler: Sym<Sampler>, uv: Term<IVec>, lod?: IntTerm): FnCall<"vec4"> {
+    return builtinCall(
+        "texelFetch",
+        "vec4",
+        sampler,
+        uv,
+        lod || INT0
+    );
+}
+
+export const dFdx = <T extends Prim>(sym: Sym<T>) =>
+    builtinCall("dFdx", sym.type, sym);
+
+export const dFdy = <T extends Prim>(sym: Sym<T>) =>
+    builtinCall("dFdy", sym.type, sym);
+
+export const fwidth = <T extends Prim>(sym: Sym<T>) =>
+    builtinCall("fwidth", sym.type, sym);