render target blending, more sliders

font.js

@@ -86,7 +86,7 @@ class FontRenderer {
 
       const configurationBuffer = device.createBuffer({
         label: `configuration buffer ${i}`,
-        size: 4 * 4,
+        size: this.sliderArray.byteLength,
         usage: GPUBufferUsage.UNIFORM | GPUBufferUsage.COPY_DST,
       });
 
@@ -195,7 +195,7 @@ class FontRenderer {
           buffer: { type: "read-only-storage" }
         }, { // configuration
           binding: 1,
-          visibility: GPUShaderStage.VERTEX,
+          visibility: GPUShaderStage.VERTEX | GPUShaderStage.FRAGMENT,
           buffer: { type: "uniform" }
         }]
       }),
@@ -210,6 +210,7 @@ class FontRenderer {
       ],
     });
 
+    console.log(canvasFormat);
     this.renderPipeline = device.createRenderPipeline({
       label: `${label} pipeline`,
       layout: pipelineLayout,
@@ -221,6 +222,17 @@ class FontRenderer {
         module: shaderModule,
         entryPoint: "fragmentMain",
         targets: [{
+          blend: {
+            color: {
+              dstFactor: "one-minus-src-alpha",
+              srcFactor: "src-alpha",
+            },
+            alpha: {
+              dstFactor: "one-minus-src-alpha",
+              srcFactor: "src-alpha",
+            },
+            operation: "add",
+          },
           format: canvasFormat,
         }]
       },
@@ -229,11 +241,18 @@ class FontRenderer {
       },
       depthStencil: {
         depthWriteEnabled: true,
-        depthCompare: "less",
+        depthCompare: "always",
         format: "depth24plus",
       },
     });
 
+    //////////////////////////////////////////////////////////////////////
+    // sliders
+    //////////////////////////////////////////////////////////////////////
+
+    this.sliders = makeSliders();
+    this.sliderArray = new Float32Array(4 * 4);
+
     //////////////////////////////////////////////////////////////////////
     // buffers
     //////////////////////////////////////////////////////////////////////
@@ -252,13 +271,6 @@ class FontRenderer {
         resource: { buffer: viewUniformBuffer },
       }],
     });
-
-    //////////////////////////////////////////////////////////////////////
-    // sliders
-    //////////////////////////////////////////////////////////////////////
-
-    this.sliders = makeSliders();
-    this.sliderArray = new Float32Array(4);
   }
 
   update(device, frameNumber)
@@ -277,6 +289,19 @@ class FontRenderer {
     this.sliderArray[0] = configuration.scale;
     this.sliderArray[1] = configuration.translateX;
     this.sliderArray[2] = configuration.translateY;
+
+    this.sliderArray[4] = configuration.distanceThreshold;
+    this.sliderArray[5] = configuration.distanceScale;
+    this.sliderArray[6] = configuration.distanceOffset;
+
+    this.sliderArray[8] = configuration.outlineThreshold;
+    this.sliderArray[9] = configuration.outlineScale;
+    this.sliderArray[10] = configuration.outlineOffset;
+
+    this.sliderArray[12] = configuration.colorMix;
+    this.sliderArray[13] = configuration.colorScale;
+    this.sliderArray[14] = configuration.colorOffset;
+
     device.queue.writeBuffer(this.frames[frameNumber].configurationBuffer, 0,
                              this.sliderArray);
   }
@@ -289,7 +314,9 @@ class FontRenderer {
     renderPass.setBindGroup(1, this.perFontBindGroup);
     renderPass.setBindGroup(2, this.frames[frameNumber].bindGroup);
 
-    renderPass.drawIndexed(6, this.instanceCount);
+    for (let i = 0; i < this.instanceCount; i++) {
+      renderPass.drawIndexed(6, 1, 0, 0, i);
+    }
   }
 }
 

font.wgsl

@@ -10,6 +10,19 @@ struct Config {
   scale: f32,
   translateX: f32,
   translateY: f32,
+  padding0: f32,
+  distanceThreshold: f32,
+  distanceScale: f32,
+  distanceOffset: f32,
+  padding1: f32,
+  outlineThreshold: f32,
+  outlineScale: f32,
+  outlineOffset: f32,
+  padding2: f32,
+  colorMix: f32,
+  colorScale: f32,
+  colorOffset: f32,
+  padding3: f32,
 };
 
 struct GlyphBuffer {
@@ -70,21 +83,45 @@ fn vertexMain(input: VertexInput) -> VertexOutput
   return output;
 }
 
+fn blend(dst: vec4f, src: vec4f, distance: f32, threshold: f32, scale: f32, offset: f32) -> vec4f
+{
+  let scaledDistance = (distance - threshold) * scale + offset;
+  let alpha = clamp(scaledDistance, 0.0, 1.0);
+  let opacity = clamp(src.a * alpha - dst.a, 0.0, 1.0);
+  return opacity * src + (1.0 - opacity) * dst;
+}
+
+fn palette(t: f32) -> vec4f
+{
+  let a = vec3f(0.5, 0.5, 0.5);
+  let b = vec3f(0.5, 0.5, 0.5);
+  let c = vec3f(1.0, 1.0, 1.0);
+  let d = vec3f(0.00, 0.33, 0.67);
+  //0.263,0.416,0.557
+  let color = a + b * cos(6.28318 * (c * t + d));
+  return vec4f(color, 1);
+}
+
 @fragment
 fn fragmentMain(input: VertexOutput) -> @location(0) vec4f
 {
-  var color = vec3f(input.texture.xy, 0);
-
   let p = glyphBuffer[input.glyphIndex].texPosition;
   let s = glyphBuffer[input.glyphIndex].texSize;
 
   let base = textureSample(fontTexture, linearSampler, input.texture * s + p);
+  let distance = base.x;
 
-  let t = f32(base.x > 0.5);
+  let insideColorW = vec4f(1, 1, 1, 1);
+  let insideColorP = palette(distance * config.colorScale + config.colorOffset);
+  let insideColor = mix(insideColorW, insideColorP, config.colorMix);
+  let outlineColor = vec4f(0, 0, 0, 1);
 
-  if (base.x < 0.5) {
+  var color = vec4f(0, 0, 0, 0);
-    discard;
+  color = blend(color, insideColor, distance,
-  }
+  config.distanceThreshold, config.distanceScale, config.distanceOffset);
 
-  return vec4f(t, t, t, 1);
+  color = blend(color, outlineColor, distance,
+                config.distanceThreshold - config.outlineThreshold,
+                config.outlineScale, config.outlineOffset);
+  return color;
 }

fontSliders.js

@@ -6,6 +6,18 @@ function makeSliders()
     scale: new Slider("scale", 0.0, 0.05),
     translateX: new Slider("translate x", -10, 10),
     translateY: new Slider("translate y", -10, 10),
+
+    distanceThreshold: new Slider("dist. threshold", 0.0, 1.0),
+    distanceScale: new Slider("distance scale", 0.0, 200.0),
+    distanceOffset: new Slider("distance offset", -20.0, 20.0),
+
+    outlineThreshold: new Slider("outline threshold", 0.0, 1.0),
+    outlineScale: new Slider("outline scale", 0.0, 200.0),
+    outlineOffset: new Slider("outline offset", -20.0, 20.0),
+
+    colorMix: new Slider("color mix", 0.0, 1.0),
+    colorScale: new Slider("color scale", 0.0, 10.0),
+    colorOffset: new Slider("color offset", 0.0, 3.1415),
   };
 }
 

index.html

@@ -41,13 +41,13 @@
           background: #eee;
       }
       .control-main {
-          width: 310px;
+          width: 340px;
           float: right;
           margin-right: 15px;
           background: #444;
       }
       .label {
-          width: calc(30% - 0.3rem);
+          width: calc(35% - 0.3rem);
           float: left;
           clear: left;
           overflow: hidden;
@@ -55,7 +55,7 @@
           margin-top: 0.25rem;
       }
       .value {
-          width: calc(70% - 0.2rem);
+          width: calc(65% - 0.2rem);
           float: left;
           margin-top: 0.1rem;
           margin-right: 0.2rem;

index.js

@@ -25,6 +25,7 @@ const canvasFormat = navigator.gpu.getPreferredCanvasFormat();
 context.configure({
   device: device,
   format: canvasFormat,
+  alphaMode: 'premultiplied',
 });
 
 const encoder = device.createCommandEncoder();

slider.js

@@ -57,7 +57,7 @@ class Slider {
       localStorage.setItem(this.label, rawValue);
     }
     if (this.high > 10) {
-      this.span.innerHTML = value.toFixed(0);
+      this.span.innerHTML = value.toFixed(2);
     } else {
       this.span.innerHTML = value.toFixed(4);
     }

src/font_layout/api.cpp

@@ -51,6 +51,6 @@ extern "C" {
 
   void font_layout__draw(FontLayout * font_layout)
   {
-    font_layout->draw_string("asdf qwer");
+    font_layout->draw_string("hexagon grid");
   }
 };