code cleanups and minor fixes

src/image/filterRenderer2D.js

@@ -0,0 +1,189 @@
+import { Shader } from "../webgl/p5.Shader";
+import { Texture } from "../webgl/p5.Texture";
+import { Image } from "./p5.Image";
+import * as constants from '../core/constants';
+
+import filterGrayFrag from '../webgl/shaders/filters/gray.frag';
+import filterErodeFrag from '../webgl/shaders/filters/erode.frag';
+import filterDilateFrag from '../webgl/shaders/filters/dilate.frag';
+import filterBlurFrag from '../webgl/shaders/filters/blur.frag';
+import filterPosterizeFrag from '../webgl/shaders/filters/posterize.frag';
+import filterOpaqueFrag from '../webgl/shaders/filters/opaque.frag';
+import filterInvertFrag from '../webgl/shaders/filters/invert.frag';
+import filterThresholdFrag from '../webgl/shaders/filters/threshold.frag';
+import filterShaderVert from '../webgl/shaders/filters/default.vert';
+
+class FilterRenderer2D {
+  /**
+   * Creates a new FilterRenderer2D instance.
+   * @param {p5} pInst - The p5.js instance.
+   * @param {string} operation - The filter operation type (e.g., constants.BLUR).
+   * @param {string} filterParameter - The strength of applying filter.
+   */
+  constructor(pInst, operation, filterParameter) {
+    this.pInst = pInst;
+    this.filterParameter = filterParameter;    
+    this.operation = operation;
+
+    // Create a canvas for applying WebGL-based filters
+    this.canvas = document.createElement('canvas');
+    this.canvas.width = pInst.width;
+    this.canvas.height = pInst.height;
+
+    // Initialize the WebGL context
+    this.gl = this.canvas.getContext('webgl');
+    if (!this.gl) {
+      console.error("WebGL not supported, cannot apply filter.");
+      return;
+    }
+
+    // Minimal renderer object required by p5.Shader and p5.Texture
+    this._renderer = {
+      GL: this.gl,
+      registerEnabled: new Set(),
+      _curShader: null,
+      _emptyTexture: null,
+      webglVersion: 'WEBGL',
+      states: {
+        textureWrapX: this.gl.CLAMP_TO_EDGE,
+        textureWrapY: this.gl.CLAMP_TO_EDGE,
+      },
+      _arraysEqual: (a, b) => JSON.stringify(a) === JSON.stringify(b),
+      _getEmptyTexture: () => {
+        if (!this._emptyTexture) {
+          const im = new Image(1, 1);
+          im.set(0, 0, 255);
+          this._emptyTexture = new Texture(this._renderer, im);
+        }
+        return this._emptyTexture;
+      },
+    };
+
+    // Fragment shaders mapped to filter operations
+    this.filterShaders = {
+      [constants.BLUR]: filterBlurFrag,
+      [constants.INVERT]: filterInvertFrag,
+      [constants.THRESHOLD]: filterThresholdFrag,
+      [constants.ERODE]: filterErodeFrag,
+      [constants.GRAY]: filterGrayFrag,
+      [constants.DILATE]: filterDilateFrag,
+      [constants.POSTERIZE]: filterPosterizeFrag,
+      [constants.OPAQUE]: filterOpaqueFrag,
+    };
+
+    this._shader = null;
+    this._initializeShader();
+  }
+
+  /**
+   * Initializes the shader program if it hasn't been already.
+   */
+  _initializeShader() {
+    if (this._shader) return; // Already initialized
+
+    const fragShaderSrc = this.filterShaders[this.operation];
+    if (!fragShaderSrc) {
+      console.error("No shader available for this operation:", this.operation);
+      return;
+    }
+
+    this._shader = new Shader(this._renderer, filterShaderVert, fragShaderSrc);
+  }
+
+  /**
+   * Binds a buffer to the drawing context
+   * when passed more than two arguments it also updates or initializes
+   * the data associated with the buffer
+   */
+  _bindBufferData(buffer, target, values, type, usage) {
+    const gl = this.gl;
+    gl.bindBuffer(target, buffer);
+    let data = values instanceof (type || Float32Array) ? values : new (type || Float32Array)(values);
+    gl.bufferData(target, data, usage || gl.STATIC_DRAW);
+  }
+
+  /**
+   * Prepares and runs the full-screen quad draw call.
+   */
+  _renderPass() {
+    const gl = this.gl;
+    this._shader.bindShader();
+
+    const pixelDensity = this.pInst._renderer.pixelDensity ? this.pInst._renderer.pixelDensity() : 1;
+
+    const texelSize = [
+      1 / (this.pInst.width * pixelDensity),
+      1 / (this.pInst.height * pixelDensity)
+    ];
+
+    const canvasTexture = new Texture(this._renderer, this.pInst._renderer.wrappedElt);
+
+    // Set uniforms for the shader
+    this._shader.setUniform('tex0', canvasTexture);
+    this._shader.setUniform('texelSize', texelSize);
+    this._shader.setUniform('canvasSize', [this.pInst.width, this.pInst.height]);
+    this._shader.setUniform('radius', Math.max(1, this.filterParameter));
+
+    // Identity matrices for projection/model-view (unsure)
+
+    // TODO: FIX IT
+    const identityMatrix = [1,0,0,0, 0,1,0,0, 0,0,1,0, 0,0,0,1];
+    this._shader.setUniform('uModelViewMatrix', identityMatrix);
+    this._shader.setUniform('uProjectionMatrix', identityMatrix);
+
+    // Set up the vertices and texture coordinates for a full-screen quad
+    const vertices = [-1, -1, 1, -1, -1, 1, 1, 1];
+    const texcoords = [0, 1, 1, 1, 0, 0, 1, 0];
+
+    // Create and bind buffers
+    const vertexBuffer = gl.createBuffer();
+    this._bindBufferData(vertexBuffer, gl.ARRAY_BUFFER, vertices, Float32Array, gl.STATIC_DRAW);
+    this._shader.enableAttrib(this._shader.attributes.aPosition, 2);
+
+    const texcoordBuffer = gl.createBuffer();
+    this._bindBufferData(texcoordBuffer, gl.ARRAY_BUFFER, texcoords, Float32Array, gl.STATIC_DRAW);
+    this._shader.enableAttrib(this._shader.attributes.aTexCoord, 2);
+
+    // Draw the quad
+    gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);
+
+    // Unbind the shader and texture
+    this._shader.unbindShader();
+  }
+
+  /**
+   * Applies the filter operation. If the filter requires multiple passes (e.g. blur),
+   * it handles those internally.
+   */
+  applyFilter() {
+    if (!this._shader) {
+      console.error("Cannot apply filter: shader not initialized.");
+      return;
+    }
+
+    // For blur, we typically do two passes: one horizontal, one vertical.
+    if (this.operation === constants.BLUR) {
+      // Horizontal pass
+      this._renderPass();
+      this._shader.setUniform('direction', [0,1]);
+
+      // Draw the result onto itself
+      this.pInst.clear();
+      this.pInst.drawingContext.drawImage(this.canvas, 0, 0, this.pInst.width, this.pInst.height);
+
+      // Vertical pass
+      this._renderPass();
+      this._shader.setUniform('direction', [1,0]);
+
+      this.pInst.clear();
+      this.pInst.drawingContext.drawImage(this.canvas, 0, 0, this.pInst.width, this.pInst.height);
+    } else {
+      // Single-pass filters
+      this._renderPass();
+      this.pInst.clear();
+      this.pInst.drawingContext.drawImage(this.canvas, 0, 0, this.pInst.width, this.pInst.height);
+    }
+  }
+}
+
+export default FilterRenderer2D;

src/image/index.js

@@ -2,10 +2,14 @@ import image from './image.js';
 import loadingDisplaying from './loading_displaying.js';
 import p5image from './p5.Image.js';
 import pixels from './pixels.js';
+import shader from '../webgl/p5.Shader.js';
+import texture from '../webgl/p5.Texture.js';
 
 export default function(p5){
   p5.registerAddon(image);
   p5.registerAddon(loadingDisplaying);
   p5.registerAddon(p5image);
   p5.registerAddon(pixels);
+  p5.registerAddon(shader);
+  p5.registerAddon(texture);
 }