From 2cf77b05c0c2bc76066fcc5a0f7573eee45f4f0e Mon Sep 17 00:00:00 2001
From: Tristan de Cacqueray <tristan@midirus.com>
Date: Sun, 27 Oct 2024 08:50:59 -0400
Subject: [PATCH] Remove uniform pattern function and expose the shader
 instance

---
 packages/shader/index.mjs                 |   1 -
 packages/shader/shader.mjs                | 145 ++++++++++++----------
 packages/shader/uniform.mjs               | 125 -------------------
 test/__snapshots__/examples.test.mjs.snap |  30 -----
 test/runtime.mjs                          |   3 -
 5 files changed, 81 insertions(+), 223 deletions(-)
 delete mode 100644 packages/shader/uniform.mjs

diff --git a/packages/shader/index.mjs b/packages/shader/index.mjs
index 931421e83..8045a1724 100644
--- a/packages/shader/index.mjs
+++ b/packages/shader/index.mjs
@@ -1,2 +1 @@
 export * from './shader.mjs';
-export * from './uniform.mjs';
diff --git a/packages/shader/shader.mjs b/packages/shader/shader.mjs
index 6e1e0fad9..ed4a3992a 100644
--- a/packages/shader/shader.mjs
+++ b/packages/shader/shader.mjs
@@ -34,88 +34,104 @@ void main(void) {
 `;
 }
 
-// Modulation helpers to smooth the values.
+// Helper class to handle uniform updates
 class UniformValue {
-  constructor() {
-    this.value = 0;
-    this.desired = 0;
-    this.slow = 10;
+  constructor(name, count, draw) {
+    this.name = name;
+    this.draw = draw;
+    this.isArray = count > 0;
+    this.value = new Array(Math.max(1, count)).fill(0);
+    this.frameModifier = new Array(Math.max(1, count)).fill(null);
   }
 
-  get(elapsed) {
-    // Adjust the value according to the rate of change
-    const offset = (this.desired - this.value) / (this.slow * Math.max(1, elapsed * 60));
-    // Ignore small changes
-    if (Math.abs(offset) > 1e-3) this.value += offset;
-    return this.value;
-  }
-}
-
-// Set an uniform value (from a pattern).
-export function setUniform(instanceName, name, value, incr, position, slow) {
-  const instance = _instances[instanceName];
-  if (!instance) {
-    logger('[shader] not loaded yet', 'warning');
-    return;
+  incr(value, pos = 0) {
+    const idx = pos % this.value.length;
+    this.value[idx] += value;
+    this.frameModifier[idx] = null;
+    this.draw();
   }
 
-  // console.log('setUniform: ', name, value, position, slow);
-  const uniform = instance.uniforms[name];
-  if (uniform) {
-    let uniformValue;
-    if (uniform.count == 0) {
-      // This is a single value
-      uniformValue = uniform.value;
+  set(value, pos = 0) {
+    const idx = pos % this.value.length;
+    if (typeof value === 'function') {
+      this.frameModifier[idx] = value;
     } else {
-      // This is an array
-      const idx = position % uniform.value.length;
-      uniformValue = uniform.value[idx];
+      this.value[idx] = value;
+      this.frameModifier[idx] = null;
     }
-    uniformValue.slow = slow;
-    if (incr) uniformValue.desired += value;
-    else uniformValue.desired = value;
-  } else {
-    logger('[shader] unknown uniform: ' + name);
+    this.draw();
+  }
+
+  get(pos = 0) {
+    return this.value[pos % this.value.length];
+  }
+
+  _frameUpdate(elapsed) {
+    this.value = this.value.map((value, idx) =>
+      this.frameModifier[idx] ? this.frameModifier[idx](value, elapsed) : value,
+    );
+    return this.isArray ? this.value : this.value[0];
   }
 
-  // Ensure the instance is drawn
-  instance.age = 0;
-  if (!instance.drawing) {
-    instance.drawing = requestAnimationFrame(instance.update);
+  _resize(count) {
+    if (count != this.count) {
+      this.isArray = count > 0;
+      count = Math.max(1, count);
+      resizeArray(this.value, count, 0);
+      resizeArray(this.frameModifier, count, null);
+    }
   }
 }
 
-// Update the uniforms for a given drawFrame call.
-function updateUniforms(drawFrame, elapsed, uniforms) {
-  Object.values(uniforms).forEach((uniform) => {
-    const value = uniform.count == 0 ? uniform.value.get(elapsed) : uniform.value.map((v) => v.get(elapsed));
+// Shrink or extend an array
+function resizeArray(arr, size, defval) {
+  if (arr.length > size) arr.length = size;
+  else arr.push(...new Array(size - arr.length).fill(defval));
+}
 
-    // Send the value to the GPU
-    // console.log('updateUniforms:', uniform.name, value);
-    drawFrame.uniform(uniform.name, value);
-  });
+// Get the size of an uniform
+function uniformSize(funcName) {
+  if (funcName == 'uniform3fv') return 3;
+  else if (funcName == 'uniform4fv') return 4;
+  return 1;
 }
 
 // Setup the instance's uniform after shader compilation.
-function setupUniforms(uniforms, program) {
-  Object.entries(program.uniforms).forEach(([name, uniform]) => {
+function setupUniforms(instance) {
+  const newUniforms = new Set();
+  Object.entries(instance.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 values when the count change:
-        // if the count decreased, then drop the excess, else append new values
-        uniforms[uname] = {
-          name,
-          count,
-          value: count == 0 ? new UniformValue() : new Array(count).fill().map(() => new UniformValue()),
-        };
-      }
+      newUniforms.add(uname);
+      const count = (uniform.count | 0) * uniformSize(uniform.glFuncName);
+      if (!instance.uniforms[uname])
+        instance.uniforms[uname] = new UniformValue(name, count, () => {
+          // Start the drawing loop
+          instance.age = 0;
+          if (!instance.drawing) {
+            instance.drawing = requestAnimationFrame(instance.update);
+          }
+        });
+      else instance.uniforms[uname]._resize(count);
     }
   });
-  // TODO: remove previous uniform that are no longer used...
-  return uniforms;
+
+  // Remove deleted uniforms
+  Object.keys(instance.uniforms).forEach((name) => {
+    if (!newUniforms.has(name)) delete instance.uniforms[name];
+  });
+}
+
+// Update the uniforms for a given drawFrame call.
+function updateUniforms(drawFrame, elapsed, uniforms) {
+  Object.values(uniforms).forEach((uniform) => {
+    const value = uniform._frameUpdate(elapsed);
+
+    // Send the value to the GPU
+    // console.log('updateUniforms:', uniform.name, value);
+    drawFrame.uniform(uniform.name, value);
+  });
 }
 
 // Setup the canvas and return the WebGL context.
@@ -156,8 +172,8 @@ async function initializeShaderInstance(name, code) {
     .createPrograms([vertexShader, code])
     .then(([program]) => {
       const drawFrame = app.createDrawCall(program, arrays);
-      const instance = { app, code, program, arrays, drawFrame, uniforms: setupUniforms({}, program) };
-
+      const instance = { app, code, program, arrays, drawFrame, uniforms: {} };
+      setupUniforms(instance);
       // Render frame logic
       let prev = performance.now() / 1000;
       instance.age = 0;
@@ -189,8 +205,8 @@ 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);
+    setupUniforms(instance);
   });
 }
 
@@ -207,4 +223,5 @@ export async function loadShader(code = '', name = 'default') {
     await reloadShaderInstanceCode(_instances[name], code);
     logger('[shader] reloaded');
   }
+  return _instances[name];
 }
diff --git a/packages/shader/uniform.mjs b/packages/shader/uniform.mjs
deleted file mode 100644
index 6e08f361a..000000000
--- a/packages/shader/uniform.mjs
+++ /dev/null
@@ -1,125 +0,0 @@
-/*
-uniform.mjs - implements the `uniform` 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 { stack, reify, register, logger } from '@strudel/core';
-import { setUniform } from './shader.mjs';
-
-/**
- * Update a shader uniform value. A uniform name consists of
- *
- * - a name
- * - optional array position seperated by ':'. The position can be an index number, or 'seq' | 'random' to assign a different index per events.
- *
- * The uniform can also be configured with an object to pass extra options:
- *
- * @name uniform
- * @param {string} name: the uniform name and optional position.
- * @param {number} gain: the value multiplier - defaults to 1.
- * @param {number} slow: the value change rate, set to 1 for instant update - defaults to 10.
- * @param {boolean} onTrigger: update the uniform only when the pattern trigger. In that case, the uniform position is mapped to the event note/sound when it is not explicity set. onTrigger is automatically set when the pattern value is not a number.
- *
- * @example
- * pan(sine.uniform("iColor"))
- * @example
- * gain(".5 .3").uniform("mod:0 mod:1")
- * @example
- * dist("<.5 .3>".uniform("rotations:seq"))
- * @example
- * s("bd sd").uniform({name: 'rotations', gain: 0.2, slow: "<5 20>"})
- */
-export const uniform = register('uniform', (options, pat) => {
-  // The shader instance name
-  const instance = options.instance || 'default';
-
-  // Are the uniform updated on trigger
-  const onTrigger = options.onTrigger || false;
-
-  // Helper to assign uniform position
-  const pitches = { _count: 0 };
-  const getPosition = (value, dest) => {
-    if (typeof dest === 'number') return dest;
-    else if (dest == 'seq') return pitches._count++;
-    else if (dest == 'random') return Math.floor(Math.random() * 1024);
-    else if (onTrigger) {
-      const note = value.note || value.n || value.sound || value.s;
-      if (pitches[note] === undefined) {
-        // Assign new value, the first note gets 0, then 1, then 2, ...
-        pitches[note] = Object.keys(pitches).length - 1;
-      }
-      return pitches[note];
-    } else {
-      logger('Invalid position' + dest, 'error');
-    }
-  };
-  // Helper to decode the uniform position
-  const getUniformPosition = (value, dest) => {
-    if (typeof dest === 'string') {
-      return [dest, 0];
-    } else {
-      return [dest[0], getPosition(value, dest[1])];
-    }
-  };
-
-  // The option pattern context
-  const setCtx = (uniformParam) => (ctx) => ({
-    // The option name
-    uniformParam,
-    // Disable event trigger
-    onTrigger: () => {},
-    dominantTrigger: true,
-    ...ctx,
-  });
-
-  // Collect the option patterns
-  const optionsPats = [];
-  if (Array.isArray(options) || typeof options === 'string')
-    optionsPats.push(reify(options).withContext(setCtx('dest')));
-  else {
-    // dest was the initial name, that can be removed
-    if (options.dest) optionsPats.push(reify(options.dest).withContext(setCtx('dest')));
-    if (options.name) optionsPats.push(reify(options.name).withContext(setCtx('dest')));
-    if (options.gain) optionsPats.push(reify(options.gain).withContext(setCtx('gain')));
-    if (options.slow) optionsPats.push(reify(options.slow).withContext(setCtx('slow')));
-  }
-
-  // Run the base pattern along with all the options
-  return stack(pat, ...optionsPats).withHaps((haps) => {
-    // Collect the current options
-    let dest;
-    let gain = 1;
-    let slow = 10;
-    let source;
-    haps.forEach((hap) => {
-      if (hap.context.uniformParam == 'dest') {
-        dest = hap.value;
-      } else if (hap.context.uniformParam == 'gain') {
-        gain = hap.value;
-      } else if (hap.context.uniformParam == 'slow') {
-        slow = hap.value;
-      } else {
-        source = hap;
-      }
-    });
-
-    if (dest && source) {
-      if (typeof source.value !== 'number' || onTrigger) {
-        // Set the uniform when the source trigger
-        source.context.onTrigger = (_, hap) => {
-          const [uniform, position] = getUniformPosition(hap.value, dest);
-          setUniform(instance, uniform, (hap.value.gain || 1) * gain, true, position, slow);
-        };
-        source.context.dominantTrigger = false;
-      } else {
-        // Set the uniform now.
-        const [uniform, position] = getUniformPosition(source.value, dest);
-        setUniform(instance, uniform, source.value * gain, false, position, slow);
-      }
-    }
-
-    // The options haps are kept so that the current values are highlighted on screen
-    return haps;
-  });
-});
diff --git a/test/__snapshots__/examples.test.mjs.snap b/test/__snapshots__/examples.test.mjs.snap
index d06011d35..a3419e98d 100644
--- a/test/__snapshots__/examples.test.mjs.snap
+++ b/test/__snapshots__/examples.test.mjs.snap
@@ -8343,36 +8343,6 @@ exports[`runs examples > example "undegradeBy" example index 1 1`] = `
 ]
 `;
 
-exports[`runs examples > example "uniform" example index 0 1`] = `
-[
-  "[ ~show() {
-    return this.begin.show() + ' → ' + this.end.show();
-  } | pan:0.4999999999999998 ]",
-]
-`;
-
-exports[`runs examples > example "uniform" example index 1 1`] = `
-[
-  "[ 0/1 → 1/1 | gain:0.5 ]",
-  "[ 1/1 → 2/1 | gain:0.3 ]",
-  "[ 2/1 → 3/1 | gain:0.5 ]",
-  "[ 3/1 → 4/1 | gain:0.3 ]",
-]
-`;
-
-exports[`runs examples > example "uniform" example index 2 1`] = `
-[
-  "[ 0/1 → 1/2 | s:bd ]",
-  "[ 1/2 → 1/1 | s:sd ]",
-  "[ 1/1 → 3/2 | s:bd ]",
-  "[ 3/2 → 2/1 | s:sd ]",
-  "[ 2/1 → 5/2 | s:bd ]",
-  "[ 5/2 → 3/1 | s:sd ]",
-  "[ 3/1 → 7/2 | s:bd ]",
-  "[ 7/2 → 4/1 | s:sd ]",
-]
-`;
-
 exports[`runs examples > example "unison" example index 0 1`] = `
 [
   "[ 0/1 → 1/12 | note:d s:supersaw unison:1 ]",
diff --git a/test/runtime.mjs b/test/runtime.mjs
index 75105fbe1..19b716274 100644
--- a/test/runtime.mjs
+++ b/test/runtime.mjs
@@ -77,9 +77,6 @@ const toneHelpersMocked = {
 strudel.Pattern.prototype.osc = function () {
   return this;
 };
-strudel.Pattern.prototype.uniform = function () {
-  return this;
-};
 strudel.Pattern.prototype.csound = function () {
   return this;
 };