Add whitebox bevel material for advanced rendering

src/rendering/whitebox-bevel-material.ts

@@ -0,0 +1,99 @@
+import type { MeshStandardMaterial, Shader } from "three";
+
+import type {
+  AdvancedRenderingSettings,
+  AdvancedRenderingWhiteboxBevelSettings
+} from "../document/world-settings";
+
+const WHITEBOX_BEVEL_MIN_DETERMINANT = 1e-5;
+const WHITEBOX_BEVEL_MAX_EDGE_WIDTH = 0.49;
+
+function formatShaderFloat(value: number) {
+  return value.toFixed(4);
+}
+
+export function shouldApplyWhiteboxBevel(
+  settings: Pick<AdvancedRenderingSettings, "enabled" | "whiteboxBevel">
+): boolean {
+  return (
+    settings.enabled &&
+    settings.whiteboxBevel.enabled &&
+    settings.whiteboxBevel.edgeWidth > 0 &&
+    settings.whiteboxBevel.normalStrength > 0
+  );
+}
+
+export function applyWhiteboxBevelToMaterial(
+  material: MeshStandardMaterial,
+  settings: AdvancedRenderingWhiteboxBevelSettings
+) {
+  const edgeWidth = Math.min(
+    Math.max(settings.edgeWidth, 0),
+    WHITEBOX_BEVEL_MAX_EDGE_WIDTH
+  );
+  const normalStrength = Math.max(settings.normalStrength, 0);
+  const shaderKey = `whitebox-bevel:${formatShaderFloat(edgeWidth)}:${formatShaderFloat(normalStrength)}`;
+
+  material.onBeforeCompile = (shader: Shader) => {
+    shader.vertexShader = shader.vertexShader
+      .replace(
+        "#include <common>",
+        `#include <common>
+attribute vec2 faceUv;
+varying vec2 vWhiteboxFaceUv;`
+      )
+      .replace(
+        "#include <uv_vertex>",
+        `#include <uv_vertex>
+vWhiteboxFaceUv = faceUv;`
+      );
+
+    shader.fragmentShader = shader.fragmentShader
+      .replace(
+        "#include <common>",
+        `#include <common>
+varying vec2 vWhiteboxFaceUv;`
+      )
+      .replace(
+        "#include <normal_fragment_maps>",
+        `#include <normal_fragment_maps>
+vec2 whiteboxFaceUv = clamp(vWhiteboxFaceUv, 0.0, 1.0);
+float whiteboxBevelLeft = 1.0 - smoothstep(0.0, ${formatShaderFloat(edgeWidth)}, whiteboxFaceUv.x);
+float whiteboxBevelRight = 1.0 - smoothstep(0.0, ${formatShaderFloat(edgeWidth)}, 1.0 - whiteboxFaceUv.x);
+float whiteboxBevelBottom = 1.0 - smoothstep(0.0, ${formatShaderFloat(edgeWidth)}, whiteboxFaceUv.y);
+float whiteboxBevelTop = 1.0 - smoothstep(0.0, ${formatShaderFloat(edgeWidth)}, 1.0 - whiteboxFaceUv.y);
+float whiteboxBevelMask = max(max(whiteboxBevelLeft, whiteboxBevelRight), max(whiteboxBevelBottom, whiteboxBevelTop));
+vec3 whiteboxFacePosition = -vViewPosition;
+vec3 whiteboxDpdx = dFdx(whiteboxFacePosition);
+vec3 whiteboxDpdy = dFdy(whiteboxFacePosition);
+vec2 whiteboxDuvdx = dFdx(whiteboxFaceUv);
+vec2 whiteboxDuvdy = dFdy(whiteboxFaceUv);
+float whiteboxDeterminant = whiteboxDuvdx.x * whiteboxDuvdy.y - whiteboxDuvdx.y * whiteboxDuvdy.x;
+
+if (whiteboxBevelMask > 0.0 && abs(whiteboxDeterminant) > ${WHITEBOX_BEVEL_MIN_DETERMINANT.toFixed(5)}) {
+  vec3 whiteboxTangent = normalize(
+    (whiteboxDpdx * whiteboxDuvdy.y - whiteboxDpdy * whiteboxDuvdx.y) /
+      whiteboxDeterminant
+  );
+  vec3 whiteboxBitangent = normalize(
+    (-whiteboxDpdx * whiteboxDuvdy.x + whiteboxDpdy * whiteboxDuvdx.x) /
+      whiteboxDeterminant
+  );
+
+  whiteboxTangent = normalize(whiteboxTangent - normal * dot(normal, whiteboxTangent));
+  whiteboxBitangent = normalize(whiteboxBitangent - normal * dot(normal, whiteboxBitangent));
+
+  vec3 whiteboxBevelDirection =
+    whiteboxTangent * (whiteboxBevelRight - whiteboxBevelLeft) +
+    whiteboxBitangent * (whiteboxBevelTop - whiteboxBevelBottom);
+  vec3 whiteboxBeveledNormal = normalize(
+    normal + whiteboxBevelDirection * ${formatShaderFloat(normalStrength)}
+  );
+  normal = normalize(mix(normal, whiteboxBeveledNormal, whiteboxBevelMask));
+}`
+      );
+  };
+
+  material.customProgramCacheKey = () => shaderKey;
+  material.needsUpdate = true;
+}