add skpdiff tool to compare bitmaps

experimental/skpdiff/main.cpp

Index: experimental/skpdiff/main.cpp
diff --git a/experimental/skpdiff/main.cpp b/experimental/skpdiff/main.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..21bf7169d4dfa607bf627724612bb4cc9f85c675
--- /dev/null
+++ b/experimental/skpdiff/main.cpp
@@ -0,0 +1,127 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#define __NO_STD_VECTOR // Uses cl::vectpr instead of std::vectpr
+#define __NO_STD_STRING // Uses cl::STRING_CLASS instead of std::string
+#include <CL/cl.hpp>
+
+#include "SkOSFile.h"
+#include "SkStream.h"
+#include "SkString.h"
+#include "SkTArray.h"
+#include "SkTDArray.h"
+
+#include "SkImageDiffer.h"
+#include "SkCLImageDiffer.h"
+#include "skpdiff_util.h"
+
+/// A callback for any OpenCL errors
+CL_CALLBACK void error_notify(const char* errorInfo, const void* privateInfoSize, ::size_t cb, void* userData) {
+    SkDebugf("OpenCL error notify: %s\n", errorInfo);
+    exit(1);
+}
+
+/// Creates a device and context with OpenCL
+static bool init_device_and_context(cl::Device* device, cl::Context* context) {
+    // Query for a platform
+    cl::vector<cl::Platform> platformList;
+    cl::Platform::get(&platformList);
+    SkDebugf("The number of platforms is %u\n", platformList.size());
+
+    // Print some information about the platform for debugging
+    cl::Platform& platform = platformList[0];
+    cl::STRING_CLASS platformName;
+    platform.getInfo(CL_PLATFORM_NAME, &platformName);
+    SkDebugf("Platform index 0 is named %s\n", platformName.c_str());
+
+    // Query for a device
+    cl::vector<cl::Device> deviceList;
+    platform.getDevices(CL_DEVICE_TYPE_GPU, &deviceList);
+    SkDebugf("The number of GPU devices is %u\n", deviceList.size());
+
+    // Print some information about the device for debugging
+    *device = deviceList[0];
+    cl::STRING_CLASS deviceName;
+    device->getInfo(CL_DEVICE_NAME, &deviceName);
+    SkDebugf("Device index 0 is named %s\n", deviceName.c_str());
+
+    // Create a CL context and check for all errors
+    cl_int contextErr = CL_SUCCESS;
+    *context = cl::Context(deviceList, NULL, error_notify, NULL, &contextErr);
+    if (contextErr != CL_SUCCESS) {
+        SkDebugf("Context creation failed: %s\n", cl_error_to_string(contextErr));
+        return false;
+    }
+
+    return true;
+}
+
+/// Compares two directories of images with the given differ
+static void diff_directories(const char baselinePath[], const char testPath[], SkImageDiffer* differ) {
+    // Get the files in the baseline, we will then look for those inside the test path
+    SkTArray<SkString> baselineEntries;
+    if (!get_directory(baselinePath, &baselineEntries)) {
+        SkDebugf("Unable to open path \"%s\"\n", baselinePath);
+        return;
+    }
+
+    SkTDArray<int> queuedDiffIDs;
+    for (int baselineIndex = 0; baselineIndex < baselineEntries.count(); baselineIndex++) {
+        const char* baseFilename = baselineEntries[baselineIndex].c_str();
+        SkDebugf("%s\n", baseFilename);
+
+        // Find the real location of each file to compare
+        SkString baselineFile = SkOSPath::SkPathJoin(baselinePath, baseFilename);
+        SkString testFile = SkOSPath::SkPathJoin(testPath, baseFilename);
+
+        // Check that the test file exists and is a file
+        if (sk_exists(testFile.c_str()) && !sk_isdir(testFile.c_str())) {
+            // Queue up the comparison with the differ
+            int diffID = differ->queueDiffOfFile(baselineFile.c_str(), testFile.c_str());
+            if (diffID >= 0) {
+                queuedDiffIDs.push(diffID);
+                SkDebugf("Result: %f\n", differ->getResult(diffID));
+            }
+        } else {
+            SkDebugf("Baseline file \"%s\" has no corresponding test file\n", baselineFile.c_str());
+        }
+    }
+}
+
+static void print_help()
+{
+    SkDebugf(
+    "Usage:\n" \
+    "skpdiff <baseline directory> <test directory>\n\n"
+    );
+}
+
+int main(int argc, char** argv) {
+    if (argc != 3)
+    {
+        print_help();
+        return 1;
+    }
+
+    // Setup OpenCL
+    cl::Device device;
+    cl::Context context;
+    if (!init_device_and_context(&device, &context)) {
+        return 1;
+    }
+
+    // Setup our differ of choice
+    SkCLImageDiffer* differ = SkNEW(SkDifferentPixelsImageDiffer);
+    if (!differ->init(device(), context())) {
+        return 1;
+    }
+
+    // Diff our folders
+    diff_directories(argv[1], argv[2], differ);
+
+    return 0;
+}