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refactor(shader-ast-glsl): split into separate files
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@postspectacular
postspectacular committed Aug 18, 2019
1 parent 9a4881b commit 0d6758f
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Showing 3 changed files with 237 additions and 229 deletions.
30 changes: 30 additions & 0 deletions packages/shader-ast-glsl/src/api.ts
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import { Fn } from "@thi.ng/api";
import {
FloatSym,
Sym,
Term,
Vec2Sym,
Vec4Sym
} from "@thi.ng/shader-ast";

export const enum GLSLVersion {
GLES_100 = "100",
GLES_300 = "300 es"
}

export interface GLSLOpts {
type: "vs" | "fs";
version: GLSLVersion;
versionPragma: boolean;
prelude: string;
}

export interface GLSLTarget extends Fn<Term<any>, string> {
gl_FragColor: Vec4Sym;
gl_FragCoord: Vec4Sym;
gl_FragData: Sym<"vec4[]">;
gl_FrontFacing: Sym<"bool">;
gl_PointCoord: Vec2Sym;
gl_PointSize: FloatSym;
gl_Position: Vec4Sym;
}
231 changes: 2 additions & 229 deletions packages/shader-ast-glsl/src/index.ts
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import { Fn } from "@thi.ng/api";
import { isBoolean, isNumber } from "@thi.ng/checks";
import { unsupported } from "@thi.ng/errors";
import {
defTarget,
FloatSym,
FnCall,
FuncArg,
isMat,
isVec,
itemType,
Sym,
sym,
Term,
Type,
Vec2Sym,
Vec4Sym
} from "@thi.ng/shader-ast";

export const enum GLSLVersion {
GLES_100 = "100",
GLES_300 = "300 es"
}

export interface GLSLOpts {
type: "vs" | "fs";
version: GLSLVersion;
versionPragma: boolean;
prelude: string;
}

export interface GLSLTarget extends Fn<Term<any>, string> {
gl_FragColor: Vec4Sym;
gl_FragCoord: Vec4Sym;
gl_FragData: Sym<"vec4[]">;
gl_FrontFacing: Sym<"bool">;
gl_PointCoord: Vec2Sym;
gl_PointSize: FloatSym;
gl_Position: Vec4Sym;
}

const RE_SEMI = /[};]$/;

/**
* GLSL code gen, targets GLSL ES 3.00 (WebGL2) by default.
*
* Use options object to configure shader type and GLSL version: `100`
* for WebGL, 300 for WebGL2. Currently, the only differences in terms
* of code generation, not correctness, are:
*
* - attribute, varying, uniform declarations
* - texture lookup function naming
*
* Unsupported features in GLSL 100:
*
* - Fragment shader output vars
*
* @param opts
*/
export const targetGLSL = (opts?: Partial<GLSLOpts>) => {
const _opts: GLSLOpts = {
type: "fs",
version: GLSLVersion.GLES_300,
versionPragma: true,
prelude: "",
...opts
};
const isVS = _opts.type === "vs";

// TODO update once we have struct support
const $type = (t: Type) => t;

const $list = (body: Term<any>[], sep = ", ") => body.map(emit).join(sep);

const $fn = (t: FnCall<any>) => `${t.id}(${$list(t.args)})`;

const $decl = (sym: Sym<any> | FuncArg<any>, arg = false) => {
const { id, type, opts, init } = <Sym<any>>sym;
const res: string[] = [];
if (opts.type) {
let type: string;
if (_opts.version < GLSLVersion.GLES_300) {
if (isVS) {
type = (<any>{
in: "attribute",
out: "varying",
uni: "uniform"
})[opts.type];
} else {
type = (<any>{
in: "varying",
out: null,
uni: "uniform"
})[opts.type];
!type &&
unsupported(
"GLSL 100 doesn't support fragment shader output variables"
);
}
} else {
opts.loc != null && res.push(`layout(location=${opts.loc}) `);
type = opts.type === "uni" ? "uniform" : opts.type;
}
res.push(type + " ");
} else {
opts.const && res.push("const ");
arg && opts.q && res.push(opts.q + " ");
}
opts.prec && res.push(opts.prec + " ");
res.push($type(itemType(type)), " ", id);
opts.num && res.push(`[${opts.num}]`);
init && res.push(" = ", emit(init));
return res.join("");
};

const emit: Fn<Term<any>, string> = defTarget({
arg: (t) => $decl(t, true),

array_init: (t) =>
_opts.version >= GLSLVersion.GLES_300
? `${t.type}(${$list(t.init)})`
: unsupported(
`array initializers not available in GLSL ${
_opts.version
}`
),

assign: (t) => emit(t.l) + " = " + emit(t.r),

ctrl: (t) => t.id,

call: $fn,

call_i: (t) =>
t.id === "texture" && _opts.version < GLSLVersion.GLES_300
? `${t.id}${(<Sym<any>>t.args[0]).type.substr(7)}(${$list(
t.args
)})`
: $fn(t),

decl: (t) => $decl(t.id),

fn: (t) =>
`${$type(t.type)} ${t.id}(${$list(t.args)}) ${emit(t.scope)}`,

for: (t) =>
`for(${t.init ? emit(t.init) : ""}; ${emit(t.test)}; ${
t.iter ? emit(t.iter) : ""
}) ${emit(t.scope)}`,

idx: (t) => `${emit(t.val)}[${emit(t.id)}]`,

if: (t) => {
const res = `if (${emit(t.test)}) ` + emit(t.t);
return t.f ? res + " else " + emit(t.f) : res;
},

lit: (t) => {
const v = t.val;
switch (t.type) {
case "bool":
return isBoolean(v) ? String(v) : `bool(${emit(v)})`;
case "float":
return isNumber(v)
? v === Math.trunc(v)
? v + ".0"
: String(v)
: `float(${emit(v)})`;
case "int":
case "uint":
return isNumber(v) ? String(v) : `${t.type}(${emit(v)})`;
default: {
if (isVec(t) || isMat(t)) {
return `${t.type}(${$list(v)})`;
}
return unsupported(`unknown type: ${t.type}`);
}
}
},

op1: (t) =>
t.post ? `(${emit(t.val)}${t.op})` : `(${t.op}${emit(t.val)})`,

op2: (t) => `(${emit(t.l)} ${t.op} ${emit(t.r)})`,

ret: (t) => "return" + (t.val ? " " + emit(t.val) : ""),

scope: (t) => {
let res = t.body
.map(emit)
.reduce(
(acc, x) => (acc.push(RE_SEMI.test(x) ? x : x + ";"), acc),
<string[]>[]
)
.join("\n");
res += t.body.length && !RE_SEMI.test(res) ? ";" : "";
if (!t.global) {
return `{\n${res}\n}`;
}
if (_opts.prelude) {
res = _opts.prelude + "\n" + res;
}
if (_opts.versionPragma) {
res = `#version ${_opts.version}\n` + res;
}
return res;
},

swizzle: (t) => `${emit(t.val)}.${t.id}`,

sym: (t) => t.id,

ternary: (t) => `(${emit(t.test)} ? ${emit(t.t)} : ${emit(t.f)})`,

while: (t) => `while (${emit(t.test)}) ${emit(t.scope)}`
});

Object.assign(emit, <GLSLTarget>{
gl_FragColor: sym("vec4", "gl_FragColor"),
gl_FragCoord: sym("vec4", "gl_FragCoord", { const: true }),
gl_FragData: sym("vec4[]", "gl_FragData", { num: 1 }),
gl_FrontFacing: sym("bool", "gl_FrontFacing", { const: true }),
gl_PointCoord: sym("vec2", "gl_PointCoord", { const: true }),
gl_PointSize: sym("float", "gl_PointSize"),
gl_Position: sym("vec4", "gl_Position")
});

return <GLSLTarget>emit;
};
export * from "./api";
export * from "./target";
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