make OpenCL optional for skpdiff

experimental/skpdiff/SkCLImageDiffer.cpp

Index: experimental/skpdiff/SkCLImageDiffer.cpp
diff --git a/experimental/skpdiff/SkCLImageDiffer.cpp b/experimental/skpdiff/SkCLImageDiffer.cpp
index 0c27e0989b6c852fdfbf169821cfc0a5fbb2a721..d1e6958ab9f77cb1324ab545d19bc3699f87fe85 100644
--- a/experimental/skpdiff/SkCLImageDiffer.cpp
+++ b/experimental/skpdiff/SkCLImageDiffer.cpp
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2013 Google Inc.
  *
@@ -18,7 +17,6 @@ SkCLImageDiffer::SkCLImageDiffer() {
     fIsGood = false;
 }
 
-
 bool SkCLImageDiffer::init(cl_device_id device, cl_context context) {
     fContext = context;
     fDevice = device;
@@ -122,139 +120,3 @@ bool SkCLImageDiffer::makeImage2D(SkBitmap* bitmap, cl_mem* image) {
 
     return true;
 }
-
-
-////////////////////////////////////////////////////////////////
-
-struct SkDifferentPixelsImageDiffer::QueuedDiff {
-    bool finished;
-    double result;
-    int numDiffPixels;
-    SkIPoint* poi;
-    cl_mem baseline;
-    cl_mem test;
-    cl_mem resultsBuffer;
-    cl_mem poiBuffer;
-};
-
-const char* SkDifferentPixelsImageDiffer::getName() {
-    return "different_pixels";
-}
-
-int SkDifferentPixelsImageDiffer::queueDiff(SkBitmap * baseline, SkBitmap * test) {
-    int diffID = fQueuedDiffs.count();
-    double startTime = get_seconds();
-    QueuedDiff* diff = fQueuedDiffs.push();
-
-    // If we never end up running the kernel, include some safe defaults in the result.
-    diff->finished = false;
-    diff->result = -1.0;
-    diff->numDiffPixels = 0;
-    diff->poi = NULL;
-
-    // Ensure the images are comparable
-    if (baseline->width() != test->width() || baseline->height() != test->height() ||
-                    baseline->width() <= 0 || baseline->height() <= 0) {
-        diff->finished = true;
-        return diffID;
-    }
-
-    // Upload images to the CL device
-    if (!this->makeImage2D(baseline, &diff->baseline) || !this->makeImage2D(test, &diff->test)) {
-        diff->finished = true;
-        fIsGood = false;
-        return -1;
-    }
-
-    // A small hack that makes calculating percentage difference easier later on.
-    diff->result = 1.0 / ((double)baseline->width() * baseline->height());
-
-    // Make a buffer to store results into. It must be initialized with pointers to memory.
-    static const int kZero = 0;
-    // We know OpenCL won't write to it because we use CL_MEM_COPY_HOST_PTR
-    diff->resultsBuffer = clCreateBuffer(fContext, CL_MEM_READ_WRITE | CL_MEM_COPY_HOST_PTR,
-                                         sizeof(int), (int*)&kZero, NULL);
-
-    diff->poiBuffer = clCreateBuffer(fContext, CL_MEM_WRITE_ONLY,
-                                     sizeof(int) * 2 * baseline->width() * baseline->height(),
-                                     NULL, NULL);
-
-    // Set all kernel arguments
-    cl_int setArgErr = clSetKernelArg(fKernel, 0, sizeof(cl_mem), &diff->baseline);
-    setArgErr       |= clSetKernelArg(fKernel, 1, sizeof(cl_mem), &diff->test);
-    setArgErr       |= clSetKernelArg(fKernel, 2, sizeof(cl_mem), &diff->resultsBuffer);
-    setArgErr       |= clSetKernelArg(fKernel, 3, sizeof(cl_mem), &diff->poiBuffer);
-    if (CL_SUCCESS != setArgErr) {
-        SkDebugf("Set arg failed: %s\n", cl_error_to_string(setArgErr));
-        fIsGood = false;
-        return -1;
-    }
-
-    // Queue this diff on the CL device
-    cl_event event;
-    const size_t workSize[] = { baseline->width(), baseline->height() };
-    cl_int enqueueErr;
-    enqueueErr = clEnqueueNDRangeKernel(fCommandQueue, fKernel, 2, NULL, workSize,
-                                        NULL, 0, NULL, &event);
-    if (CL_SUCCESS != enqueueErr) {
-        SkDebugf("Enqueue failed: %s\n", cl_error_to_string(enqueueErr));
-        fIsGood = false;
-        return -1;
-    }
-
-    // This makes things totally synchronous. Actual queue is not ready yet
-    clWaitForEvents(1, &event);
-    diff->finished = true;
-
-    // Immediate read back the results
-    clEnqueueReadBuffer(fCommandQueue, diff->resultsBuffer, CL_TRUE, 0,
-                        sizeof(int), &diff->numDiffPixels, 0, NULL, NULL);
-    diff->result *= (double)diff->numDiffPixels;
-    diff->result = (1.0 - diff->result);
-
-    diff->poi = SkNEW_ARRAY(SkIPoint, diff->numDiffPixels);
-    clEnqueueReadBuffer(fCommandQueue, diff->poiBuffer, CL_TRUE, 0,
-                        sizeof(SkIPoint) * diff->numDiffPixels, diff->poi, 0, NULL, NULL);
-
-    // Release all the buffers created
-    clReleaseMemObject(diff->poiBuffer);
-    clReleaseMemObject(diff->resultsBuffer);
-    clReleaseMemObject(diff->baseline);
-    clReleaseMemObject(diff->test);
-
-    SkDebugf("Time: %f\n", (get_seconds() - startTime));
-
-    return diffID;
-}
-
-void SkDifferentPixelsImageDiffer::deleteDiff(int id) {
-    QueuedDiff* diff = &fQueuedDiffs[id];
-    if (NULL != diff->poi) {
-        SkDELETE_ARRAY(diff->poi);
-        diff->poi = NULL;
-    }
-}
-
-bool SkDifferentPixelsImageDiffer::isFinished(int id) {
-    return fQueuedDiffs[id].finished;
-}
-
-double SkDifferentPixelsImageDiffer::getResult(int id) {
-    return fQueuedDiffs[id].result;
-}
-
-int SkDifferentPixelsImageDiffer::getPointsOfInterestCount(int id) {
-    return fQueuedDiffs[id].numDiffPixels;
-}
-
-SkIPoint* SkDifferentPixelsImageDiffer::getPointsOfInterest(int id) {
-    return fQueuedDiffs[id].poi;
-}
-
-bool SkDifferentPixelsImageDiffer::onInit() {
-    if (!loadKernelFile("experimental/skpdiff/diff_pixels.cl", "diff", &fKernel)) {
-        return false;
-    }
-
-    return true;
-}