fix(image-pipeline): harden worker preview path

hooks/use-pipeline-preview.ts

@@ -5,6 +5,7 @@ import { useEffect, useMemo, useRef, useState } from "react";
 import { hashPipeline, type PipelineStep } from "@/lib/image-pipeline/contracts";
 import { emptyHistogram, type HistogramData } from "@/lib/image-pipeline/histogram";
 import {
+  getLastBackendDiagnostics,
   isPipelineAbortError,
   renderPreviewWithWorkerFallback,
   type PreviewRenderResult,
@@ -155,6 +156,19 @@ export function usePipelinePreview(options: UsePipelinePreviewOptions): {
             renderError instanceof Error
               ? renderError.message
               : "Preview rendering failed";
+
+          if (process.env.NODE_ENV !== "production") {
+            console.error("[usePipelinePreview] render failed", {
+              message,
+              sourceUrl,
+              pipelineHash,
+              previewWidth,
+              includeHistogram: options.includeHistogram,
+              diagnostics: getLastBackendDiagnostics(),
+              error: renderError,
+            });
+          }
+
           setError(message);
         })
         .finally(() => {

lib/image-pipeline/backend/feature-flags.ts

@@ -65,9 +65,10 @@ function parseBooleanFlag(value: unknown): boolean | undefined {
 function readFlagFromRuntimeStore(
   key: (typeof IMAGE_PIPELINE_BACKEND_FLAG_KEYS)[keyof typeof IMAGE_PIPELINE_BACKEND_FLAG_KEYS],
 ): unknown {
-  const runtimeStore =
-    globalThis.__LEMONSPACE_FEATURE_FLAGS__ ??
-    (typeof window !== "undefined" ? window.__LEMONSPACE_FEATURE_FLAGS__ : undefined);
+  const runtimeStore = (globalThis as typeof globalThis & {
+    __LEMONSPACE_FEATURE_FLAGS__?: RuntimeFeatureFlagStore;
+  }).__LEMONSPACE_FEATURE_FLAGS__;
+
   if (runtimeStore && key in runtimeStore) {
     return runtimeStore[key];
   }

lib/image-pipeline/backend/webgl/webgl-backend.ts

@@ -8,10 +8,141 @@ import {
   normalizeLightAdjustData,
 } from "@/lib/image-pipeline/adjustment-types";
 import type { PipelineStep } from "@/lib/image-pipeline/contracts";
-import colorAdjustFragmentShaderSource from "@/lib/image-pipeline/backend/webgl/shaders/color-adjust.frag.glsl?raw";
-import curvesFragmentShaderSource from "@/lib/image-pipeline/backend/webgl/shaders/curves.frag.glsl?raw";
-import detailAdjustFragmentShaderSource from "@/lib/image-pipeline/backend/webgl/shaders/detail-adjust.frag.glsl?raw";
-import lightAdjustFragmentShaderSource from "@/lib/image-pipeline/backend/webgl/shaders/light-adjust.frag.glsl?raw";
+
+const CURVES_FRAGMENT_SHADER_SOURCE = `
+precision mediump float;
+
+varying vec2 vUv;
+uniform sampler2D uSource;
+uniform float uGamma;
+
+void main() {
+  vec4 color = texture2D(uSource, vUv);
+  color.rgb = pow(max(color.rgb, vec3(0.0)), vec3(max(uGamma, 0.001)));
+  gl_FragColor = color;
+}
+`;
+
+const COLOR_ADJUST_FRAGMENT_SHADER_SOURCE = `
+precision mediump float;
+
+varying vec2 vUv;
+uniform sampler2D uSource;
+uniform vec3 uColorShift;
+
+void main() {
+  vec4 color = texture2D(uSource, vUv);
+  color.rgb = clamp(color.rgb + uColorShift, 0.0, 1.0);
+  gl_FragColor = color;
+}
+`;
+
+const LIGHT_ADJUST_FRAGMENT_SHADER_SOURCE = `
+precision mediump float;
+
+varying vec2 vUv;
+uniform sampler2D uSource;
+uniform float uExposureFactor;
+uniform float uContrastFactor;
+uniform float uBrightnessShift;
+uniform float uHighlights;
+uniform float uShadows;
+uniform float uWhites;
+uniform float uBlacks;
+uniform float uVignetteAmount;
+uniform float uVignetteSize;
+uniform float uVignetteRoundness;
+
+float toByte(float value) {
+  return clamp(floor(value + 0.5), 0.0, 255.0);
+}
+
+void main() {
+  vec4 color = texture2D(uSource, vUv);
+  vec3 rgb = color.rgb * 255.0;
+
+  rgb *= uExposureFactor;
+  rgb = (rgb - 128.0) * uContrastFactor + 128.0 + uBrightnessShift;
+
+  float luma = dot(rgb, vec3(0.2126, 0.7152, 0.0722));
+  float highlightsBoost = (luma / 255.0) * uHighlights * 40.0;
+  float shadowsBoost = ((255.0 - luma) / 255.0) * uShadows * 40.0;
+  float whitesBoost = (luma / 255.0) * uWhites * 35.0;
+  float blacksBoost = ((255.0 - luma) / 255.0) * uBlacks * 35.0;
+  float totalBoost = highlightsBoost + shadowsBoost + whitesBoost + blacksBoost;
+  rgb = vec3(
+    toByte(rgb.r + totalBoost),
+    toByte(rgb.g + totalBoost),
+    toByte(rgb.b + totalBoost)
+  );
+
+  if (uVignetteAmount > 0.0) {
+    vec2 centeredUv = (vUv - vec2(0.5)) / vec2(0.5);
+    float radialDistance = length(centeredUv);
+    float softEdge = pow(1.0 - clamp(radialDistance, 0.0, 1.0), 1.0 + uVignetteRoundness);
+    float strength = 1.0 - uVignetteAmount * (1.0 - softEdge) * (1.5 - uVignetteSize);
+    rgb = vec3(
+      toByte(rgb.r * strength),
+      toByte(rgb.g * strength),
+      toByte(rgb.b * strength)
+    );
+  }
+
+  gl_FragColor = vec4(clamp(rgb / 255.0, 0.0, 1.0), color.a);
+}
+`;
+
+const DETAIL_ADJUST_FRAGMENT_SHADER_SOURCE = `
+precision mediump float;
+
+varying vec2 vUv;
+uniform sampler2D uSource;
+uniform float uSharpenBoost;
+uniform float uClarityBoost;
+uniform float uDenoiseLuma;
+uniform float uDenoiseColor;
+uniform float uGrainAmount;
+uniform float uGrainScale;
+uniform float uImageWidth;
+
+float pseudoNoise(float seed) {
+  float x = sin(seed * 12.9898) * 43758.5453;
+  return fract(x);
+}
+
+void main() {
+  vec4 color = texture2D(uSource, vUv);
+  vec3 rgb = color.rgb * 255.0;
+
+  float luma = dot(rgb, vec3(0.2126, 0.7152, 0.0722));
+
+  rgb.r = rgb.r + (rgb.r - luma) * uSharpenBoost * 0.6;
+  rgb.g = rgb.g + (rgb.g - luma) * uSharpenBoost * 0.6;
+  rgb.b = rgb.b + (rgb.b - luma) * uSharpenBoost * 0.6;
+
+  float midtoneFactor = 1.0 - abs(luma / 255.0 - 0.5) * 2.0;
+  float clarityScale = 1.0 + uClarityBoost * midtoneFactor * 0.7;
+  rgb = (rgb - 128.0) * clarityScale + 128.0;
+
+  if (uDenoiseLuma > 0.0 || uDenoiseColor > 0.0) {
+    rgb = rgb * (1.0 - uDenoiseLuma * 0.2) + vec3(luma) * uDenoiseLuma * 0.2;
+
+    float average = (rgb.r + rgb.g + rgb.b) / 3.0;
+    rgb = rgb * (1.0 - uDenoiseColor * 0.2) + vec3(average) * uDenoiseColor * 0.2;
+  }
+
+  if (uGrainAmount > 0.0) {
+    float pixelX = floor(gl_FragCoord.x);
+    float pixelY = floor(gl_FragCoord.y);
+    float pixelIndex = ((pixelY * max(1.0, uImageWidth)) + pixelX) * 4.0;
+    float grainSeed = (pixelIndex + 1.0) / max(0.5, uGrainScale);
+    float grain = (pseudoNoise(grainSeed) - 0.5) * uGrainAmount * 40.0;
+    rgb += vec3(grain);
+  }
+
+  gl_FragColor = vec4(clamp(rgb / 255.0, 0.0, 1.0), color.a);
+}
+`;
 
 const VERTEX_SHADER_SOURCE = `
 attribute vec2 aPosition;
@@ -406,10 +537,10 @@ export function createWebglPreviewBackend(): ImagePipelineBackend {
     const gl = createGlContext();
     context = {
       gl,
-      curvesProgram: compileProgram(gl, curvesFragmentShaderSource),
-      colorAdjustProgram: compileProgram(gl, colorAdjustFragmentShaderSource),
-      lightAdjustProgram: compileProgram(gl, lightAdjustFragmentShaderSource),
-      detailAdjustProgram: compileProgram(gl, detailAdjustFragmentShaderSource),
+      curvesProgram: compileProgram(gl, CURVES_FRAGMENT_SHADER_SOURCE),
+      colorAdjustProgram: compileProgram(gl, COLOR_ADJUST_FRAGMENT_SHADER_SOURCE),
+      lightAdjustProgram: compileProgram(gl, LIGHT_ADJUST_FRAGMENT_SHADER_SOURCE),
+      detailAdjustProgram: compileProgram(gl, DETAIL_ADJUST_FRAGMENT_SHADER_SOURCE),
       quadBuffer: createQuadBuffer(gl),
     };
 

lib/image-pipeline/image-pipeline.worker.ts

@@ -113,6 +113,16 @@ async function handlePreviewRequest(requestId: number, payload: PreviewWorkerPay
       [pixels],
     );
   } catch (error: unknown) {
+    if (typeof console !== "undefined" && process.env.NODE_ENV !== "production") {
+      console.error("[image-pipeline.worker] preview request failed", {
+        requestId,
+        sourceUrl: payload.sourceUrl,
+        previewWidth: payload.previewWidth,
+        includeHistogram: payload.includeHistogram,
+        error,
+      });
+    }
+
     postMessageSafe({
       kind: "error",
       requestId,
@@ -139,6 +149,16 @@ async function handleFullRequest(requestId: number, payload: RenderFullOptions):
       payload: result,
     });
   } catch (error: unknown) {
+    if (typeof console !== "undefined" && process.env.NODE_ENV !== "production") {
+      console.error("[image-pipeline.worker] preview request failed", {
+        requestId,
+        sourceUrl: payload.sourceUrl,
+        previewWidth: payload.previewWidth,
+        includeHistogram: payload.includeHistogram,
+        error,
+      });
+    }
+
     postMessageSafe({
       kind: "error",
       requestId,

lib/image-pipeline/worker-client.ts

@@ -137,6 +137,14 @@ function shouldFallbackToMainThread(error: unknown): error is WorkerUnavailableE
   return error instanceof WorkerUnavailableError;
 }
 
+function logWorkerClientDebug(event: string, details: Record<string, unknown>): void {
+  if (process.env.NODE_ENV === "production") {
+    return;
+  }
+
+  console.error(`[worker-client] ${event}`, details);
+}
+
 function updateLastBackendDiagnostics(metadata: BackendDiagnosticsMetadata | undefined): void {
   if (!metadata) {
     return;
@@ -178,6 +186,13 @@ function getWorker(): Worker {
 
       if (message.kind === "error") {
         updateLastBackendDiagnostics(message.payload.diagnostics);
+        logWorkerClientDebug("worker response error", {
+          requestId: message.requestId,
+          pendingKind: pending.kind,
+          errorName: message.payload.name,
+          errorMessage: message.payload.message,
+          diagnostics: message.payload.diagnostics,
+        });
         const workerError = new Error(message.payload.message);
         workerError.name = message.payload.name;
         pending.reject(workerError);
@@ -336,9 +351,23 @@ async function runPreviewRequest(options: {
     }
 
     if (!shouldFallbackToMainThread(error)) {
+      logWorkerClientDebug("preview request failed without fallback", {
+        sourceUrl: options.sourceUrl,
+        previewWidth: options.previewWidth,
+        includeHistogram: options.includeHistogram,
+        diagnostics: getLastBackendDiagnostics(),
+        error,
+      });
       throw error;
     }
 
+    logWorkerClientDebug("preview request falling back to main-thread", {
+      sourceUrl: options.sourceUrl,
+      previewWidth: options.previewWidth,
+      includeHistogram: options.includeHistogram,
+      error,
+    });
+
     return await renderPreview(options);
   }
 }