More cleanup

index.html

@@ -70,17 +70,6 @@
         makePalette(regl, data)
       );
 
-      // All this takes place in a full screen quad.
-      const fullScreenQuad = makeFullScreenQuad(regl, uniforms);
-      const renderer = makeMatrixRenderer(regl, config);
-      const bloomPass = makeBloomPass(regl, config, renderer.fbo);
-      const colorPass = makeColorPass(regl, config, bloomPass.fbo);
-      const drawToScreen = regl({
-        uniforms: {
-          tex: colorPass.fbo
-        }
-      });
-
       const resize = () => {
         canvas.width = canvas.clientWidth;
         canvas.height = canvas.clientHeight;
@@ -88,27 +77,29 @@
       window.onresize = resize;
       resize();
 
-      fullScreenQuad(renderer.update);
-
       document.body.onload = async () => {
-        const resources = await loadImages(regl, {
+        const images = await loadImages(regl, {
           msdfTex: config.glyphTexURL,
-          backgroundTex:
-            config.effect === "image" ? config.backgroundImage : null
+          bgTex: config.effect === "image" ? config.bgURL : null
         });
 
-        const loop = regl.frame(({ viewportWidth, viewportHeight }) => {
-          // All the FBOs except the compute FBOs need to be sized to the window.
-          renderer.resize(viewportWidth, viewportHeight);
-          bloomPass.resize(viewportWidth, viewportHeight);
-          colorPass.resize(viewportWidth, viewportHeight);
+        // All this takes place in a full screen quad.
+        const fullScreenQuad = makeFullScreenQuad(regl, uniforms);
+        const renderer = makeMatrixRenderer(regl, config, images);
+        const bloomPass = makeBloomPass(regl, config, renderer.output);
+        const colorPass = makeColorPass(regl, config, images, bloomPass.output);
+        const drawToScreen = regl({
+          uniforms: {
+            tex: colorPass.output
+          }
+        });
 
-          // And here is the full draw sequence.
+        const passes = [renderer, bloomPass, colorPass];
+
+        const loop = regl.frame(({ viewportWidth, viewportHeight }) => {
+          passes.forEach(pass => pass.resize(viewportWidth, viewportHeight));
           fullScreenQuad(() => {
-            renderer.update();
-            renderer.render(resources);
-            bloomPass.render();
-            colorPass.render(resources);
+            passes.forEach(pass => pass.render());
             drawToScreen();
           });
         });

js/bloomPass.js

@@ -13,7 +13,7 @@ const levelStrengths = Array(pyramidHeight)
 export default (regl, config, input) => {
   if (config.effect === "none") {
     return {
-      fbo: input,
+      output: input,
       resize: () => {},
       render: () => {}
     };
@@ -22,7 +22,7 @@ export default (regl, config, input) => {
   const highPassPyramid = makePyramid(regl, pyramidHeight);
   const horizontalBlurPyramid = makePyramid(regl, pyramidHeight);
   const verticalBlurPyramid = makePyramid(regl, pyramidHeight);
-  const fbo = makePassFBO(regl);
+  const output = makePassFBO(regl);
 
   // The high pass restricts the blur to bright things in our input texture.
   const highPass = regl({
@@ -103,11 +103,11 @@ export default (regl, config, input) => {
         verticalBlurPyramid.map((fbo, index) => [`tex_${index}`, fbo])
       )
     ),
-    framebuffer: fbo
+    framebuffer: output
   });
 
   return {
-    fbo,
+    output,
     resize: (viewportWidth, viewportHeight) => {
       // The blur pyramids can be lower resolution than the screen.
       resizePyramid(
@@ -128,7 +128,7 @@ export default (regl, config, input) => {
         viewportHeight,
         config.bloomSize
       );
-      fbo.resize(viewportWidth, viewportHeight);
+      output.resize(viewportWidth, viewportHeight);
     },
     render: () => {
       highPassPyramid.forEach(fbo => highPass({ fbo, tex: input }));

js/colorPass.js

@@ -63,20 +63,20 @@ const colorizeByStripes = regl =>
     }
   });
 
-const colorizeByImage = regl =>
+const colorizeByImage = (regl, bgTex) =>
   regl({
     frag: `
     precision mediump float;
     uniform sampler2D tex;
-    uniform sampler2D backgroundTex;
+    uniform sampler2D bgTex;
     varying vec2 vUV;
 
     void main() {
-      gl_FragColor = vec4(texture2D(backgroundTex, vUV).rgb * (pow(texture2D(tex, vUV).r, 1.5) * 0.995 + 0.005), 1.0);
+      gl_FragColor = vec4(texture2D(bgTex, vUV).rgb * (pow(texture2D(tex, vUV).r, 1.5) * 0.995 + 0.005), 1.0);
     }
   `,
     uniforms: {
-      backgroundTex: regl.prop("backgroundTex")
+      bgTex
     }
   });
 
@@ -87,35 +87,35 @@ const colorizersByEffect = {
   image: colorizeByImage
 };
 
-export default (regl, config, inputFBO) => {
-  const fbo = makePassFBO(regl);
-
+export default (regl, config, { bgTex }, input) => {
   if (config.effect === "none") {
     return {
-      fbo: inputFBO,
+      output: input,
       resize: () => {},
       render: () => {}
     };
   }
 
+  const output = makePassFBO(regl);
+
   const colorize = regl({
     uniforms: {
       tex: regl.prop("tex")
     },
-    framebuffer: fbo
+    framebuffer: output
   });
 
   const colorizer = (config.effect in colorizersByEffect
     ? colorizersByEffect[config.effect]
-    : colorizeByPalette)(regl);
+    : colorizeByPalette)(regl, bgTex);
 
   return {
-    fbo,
-    resize: fbo.resize,
+    output,
+    resize: output.resize,
     render: resources => {
       colorize(
         {
-          tex: inputFBO
+          tex: input
         },
         () => colorizer(resources)
       );

js/config.js

@@ -204,7 +204,7 @@ export default (searchString, makePaletteTexture) => {
     config.animationSpeed * config.fallSpeed == 0
       ? 1
       : Math.min(1, Math.abs(config.animationSpeed * config.fallSpeed));
-  config.backgroundImage = getParam(
+  config.bgURL = getParam(
     "url",
     "https://upload.wikimedia.org/wikipedia/commons/0/0a/Flammarion_Colored.jpg"
   );

js/renderer.js

@@ -1,27 +1,20 @@
-import { makePassFBO } from "./utils.js";
+import { makePassFBO, makeDoubleBuffer } from "./utils.js";
 
-export default (regl, config) => {
+export default (regl, config, { msdfTex }) => {
   // These two framebuffers are used to compute the raining code.
   // they take turns being the source and destination of the "compute" shader.
   // The half float data type is crucial! It lets us store almost any real number,
   // whereas the default type limits us to integers between 0 and 255.
 
-  // These FBOs are smaller than the screen, because their pixels correspond
+  // This double buffer is smaller than the screen, because its pixels correspond
   // with glyphs in the final image, and the glyphs are much larger than a pixel.
-  const state = Array(2)
-    .fill()
-    .map(() =>
-      regl.framebuffer({
-        color: regl.texture({
-          radius: config.numColumns,
-          wrapT: "clamp",
-          type: "half float"
-        }),
-        depthStencil: false
-      })
-    );
+  const doubleBuffer = makeDoubleBuffer(regl, {
+    radius: config.numColumns,
+    wrapT: "clamp",
+    type: "half float"
+  });
 
-  const fbo = makePassFBO(regl);
+  const output = makePassFBO(regl);
 
   const update = regl({
     frag: `
@@ -195,10 +188,10 @@ export default (regl, config) => {
     `,
 
     uniforms: {
-      lastState: ({ tick }) => state[tick % 2]
+      lastState: doubleBuffer.back
     },
 
-    framebuffer: ({ tick }) => state[(tick + 1) % 2] // The crucial state FBO alternator
+    framebuffer: doubleBuffer.front
   });
 
   // We render the code into an FBO using MSDFs: https://github.com/Chlumsky/msdfgen
@@ -290,19 +283,21 @@ export default (regl, config) => {
     `,
 
     uniforms: {
-      msdfTex: regl.prop("msdfTex"),
+      msdfTex,
       height: regl.context("viewportWidth"),
       width: regl.context("viewportHeight"),
-      lastState: ({ tick }) => state[tick % 2]
+      lastState: doubleBuffer.front
     },
 
-    framebuffer: fbo
+    framebuffer: output
   });
 
   return {
-    resize: fbo.resize,
-    fbo,
-    update,
-    render
+    resize: output.resize,
+    output,
+    render: resources => {
+      update();
+      render(resources);
+    }
   };
 };

js/utils.js

@@ -17,6 +17,21 @@ const makePyramid = (regl, height) =>
     .fill()
     .map(_ => makePassFBO(regl));
 
+const makeDoubleBuffer = (regl, props) => {
+  const state = Array(2)
+    .fill()
+    .map(() =>
+      regl.framebuffer({
+        color: regl.texture(props),
+        depthStencil: false
+      })
+    );
+  return {
+    front: ({ tick }) => state[tick % 2],
+    back: ({ tick }) => state[(tick + 1) % 2]
+  };
+};
+
 const resizePyramid = (pyramid, vw, vh, scale) =>
   pyramid.forEach((fbo, index) =>
     fbo.resize(
@@ -48,7 +63,7 @@ const loadImage = async (regl, url) => {
   });
 };
 
-const makeFullScreenQuad = (regl, uniforms) =>
+const makeFullScreenQuad = (regl, uniforms = {}, context = {}) =>
   regl({
     vert: `
     precision mediump float;
@@ -78,6 +93,8 @@ const makeFullScreenQuad = (regl, uniforms) =>
       time: regl.context("time")
     },
 
+    context,
+
     depth: { enable: false },
     count: 3
   });
@@ -95,6 +112,7 @@ const makePalette = (regl, data) =>
 export {
   makePassTexture,
   makePassFBO,
+  makeDoubleBuffer,
   makePyramid,
   resizePyramid,
   loadImage,