Extract the uniform helper to its own module

Author: TristanCacqueray

packages/shader/index.mjs

@@ -1,234 +1,2 @@
-/*
-shader.mjs - implements the `loadShader` helper and `shader` pattern function
-Copyright (C) 2024 Strudel contributors
-This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program.  If not, see <https://www.gnu.org/licenses/>.
-*/
-
-import { PicoGL } from 'picogl';
-import { register, logger } from '@strudel/core';
-
-// The standard fullscreen vertex shader.
-const vertexShader = `#version 300 es
-precision highp float;
-layout(location=0) in vec2 position;
-void main() {
-  gl_Position = vec4(position, 1, 1);
-}
-`;
-
-// Make the fragment source, similar to the one from shadertoy.
-function mkFragmentShader(code) {
-  return `#version 300 es
-precision highp float;
-out vec4 oColor;
-uniform float iTime;
-uniform vec2 iResolution;
-
-${code}
-
-void main(void) {
-  mainImage(oColor, gl_FragCoord.xy);
-}
-`;
-}
-
-// Modulation helpers.
-const hardModulation = () => {
-  let val = 0;
-  return {
-    get: () => val,
-    set: (v) => {
-      val = v;
-    },
-  };
-};
-
-const decayModulation = (decay) => {
-  let val = 0;
-  let desired = 0;
-  return {
-    get: (ts) => {
-      val += (desired - val) / decay;
-      return val;
-    },
-    set: (v) => {
-      desired = val + v;
-    },
-  };
-};
-
-// Set an uniform value (from a pattern).
-function setUniform(instance, name, value, position) {
-  const uniform = instance.uniforms[name];
-  if (uniform) {
-    if (uniform.count == 0) {
-      // This is a single value
-      uniform.mod.set(value);
-    } else {
-      // This is an array
-      const idx = position % uniform.mod.length;
-      uniform.mod[idx].set(value);
-    }
-  } else {
-    logger('[shader] unknown uniform: ' + name);
-  }
-
-  // Ensure the instance is drawn
-  instance.age = 0;
-  if (!instance.drawing) {
-    instance.drawing = requestAnimationFrame(instance.update);
-  }
-}
-
-// Update the uniforms for a given drawFrame call.
-function updateUniforms(drawFrame, elapsed, uniforms) {
-  Object.values(uniforms).forEach((uniform) => {
-    const value =
-      uniform.count == 0 ? uniform.mod.get(elapsed) : uniform.value.map((_, i) => uniform.mod[i].get(elapsed));
-    // Send the value to the GPU
-    drawFrame.uniform(uniform.name, value);
-  });
-}
-
-// Setup the instance's uniform after shader compilation.
-function setupUniforms(uniforms, program) {
-  Object.entries(program.uniforms).forEach(([name, uniform]) => {
-    if (name != 'iTime' && name != 'iResolution') {
-      // remove array suffix
-      const uname = name.replace('[0]', '');
-      const count = uniform.count | 0;
-      if (!uniforms[uname] || uniforms[uname].count != count) {
-        // TODO: keep the previous value when the count change...
-        uniforms[uname] = {
-          name,
-          count,
-          value: count == 0 ? 0 : new Float32Array(count),
-          mod: count == 0 ? decayModulation(50) : new Array(count).fill().map(() => decayModulation(50)),
-        };
-      }
-    }
-  });
-  // TODO: remove previous uniform that are no longer used...
-  return uniforms;
-}
-
-// Setup the canvas and return the WebGL context.
-function setupCanvas(name) {
-  // TODO: support custom size
-  const width = 400;
-  const height = 300;
-  const canvas = document.createElement('canvas');
-  canvas.id = 'cnv-' + name;
-  canvas.width = width;
-  canvas.height = height;
-  const top = 60 + Object.keys(_instances).length * height;
-  canvas.style = `pointer-events:none;width:${width}px;height:${height}px;position:fixed;top:${top}px;right:23px`;
-  document.body.append(canvas);
-  return canvas.getContext('webgl2');
-}
-
-// Setup the shader instance
-async function initializeShaderInstance(name, code) {
-  // Setup PicoGL app
-  const ctx = setupCanvas(name);
-  console.log(ctx);
-  const app = PicoGL.createApp(ctx);
-  app.resize(400, 300);
-
-  // Setup buffers
-  const resolution = new Float32Array([ctx.canvas.width, ctx.canvas.height]);
-
-  // Two triangle to cover the whole canvas
-  const positionBuffer = app.createVertexBuffer(
-    PicoGL.FLOAT,
-    2,
-    new Float32Array([-1, -1, -1, 1, 1, 1, 1, 1, 1, -1, -1, -1]),
-  );
-
-  // Setup the arrays
-  const arrays = app.createVertexArray().vertexAttributeBuffer(0, positionBuffer);
-
-  return app
-    .createPrograms([vertexShader, code])
-    .then(([program]) => {
-      const drawFrame = app.createDrawCall(program, arrays);
-      const instance = { app, code, program, arrays, drawFrame, uniforms: setupUniforms({}, program) };
-
-      // Render frame logic
-      let prev = performance.now() / 1000;
-      instance.age = 0;
-      instance.update = () => {
-        const now = performance.now() / 1000;
-        const elapsed = now - prev;
-        prev = now;
-        // console.log("drawing!")
-        app.clear();
-        instance.drawFrame.uniform('iResolution', resolution).uniform('iTime', now);
-
-        updateUniforms(instance.drawFrame, elapsed, instance.uniforms);
-
-        instance.drawFrame.draw();
-        if (instance.age++ < 100) requestAnimationFrame(instance.update);
-        else instance.drawing = false;
-      };
-      return instance;
-    })
-    .catch((err) => {
-      ctx.canvas.remove();
-      throw err;
-    });
-}
-
-// Update the instance program
-async function reloadShaderInstanceCode(instance, code) {
-  return instance.app.createPrograms([vertexShader, code]).then(([program]) => {
-    instance.program.delete();
-    instance.program = program;
-    instance.uniforms = setupUniforms(instance.uniforms, program);
-    instance.drawFrame = instance.app.createDrawCall(program, instance.arrays);
-  });
-}
-
-// Keep track of the running shader instances
-let _instances = {};
-export async function loadShader(code = '', name = 'default') {
-  if (code) {
-    code = mkFragmentShader(code);
-  }
-  if (!_instances[name]) {
-    _instances[name] = await initializeShaderInstance(name, code);
-    logger('[shader] ready');
-  } else if (_instances[name].code != code) {
-    await reloadShaderInstanceCode(_instances[name], code);
-    logger('[shader] reloaded');
-  }
-}
-
-export const shader = register('shader', (options, pat) => {
-  // Keep track of the pitches value: Map String Int
-  const pitches = { _count: 0 };
-
-  return pat.onTrigger((time_deprecate, hap, currentTime, cps, targetTime) => {
-    const instance = _instances[options.instance || 'default'];
-    if (!instance) {
-      logger('[shader] not loaded yet', 'warning');
-      return;
-    }
-
-    const value = options.gain || 1.0;
-    if (options.pitch !== undefined) {
-      const note = hap.value.note || hap.value.s;
-      if (pitches[note] === undefined) {
-        // Assign new value, the first note gets 0, then 1, then 2, ...
-        pitches[note] = Object.keys(pitches).length;
-      }
-      setUniform(instance, options.pitch, value, pitches[note]);
-    } else if (options.seq !== undefined) {
-      setUniform(instance, options.seq, value, pitches._count++);
-    } else if (options.uniform !== undefined) {
-      setUniform(instance, options.uniform, value);
-    } else {
-      console.error('Unknown shader options, need either pitch or uniform', options);
-    }
-  }, false);
-});
+export {loadShader} from './shader.mjs';
+export * from './uniform.mjs';