Revert "migrate skpdiff to tools"

This reverts commit 58a7ec70ce6b4548793a2ddc37c63d3d44edbc36.

git-svn-id: http://skia.googlecode.com/svn/trunk@10226 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/experimental/skpdiff/main.cpp b/experimental/skpdiff/main.cpp
new file mode 100644
index 0000000..d258c14
--- /dev/null
+++ b/experimental/skpdiff/main.cpp
@@ -0,0 +1,192 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#if SK_SUPPORT_OPENCL
+#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>
+#endif
+
+#include "SkCommandLineFlags.h"
+#include "SkGraphics.h"
+#include "SkStream.h"
+#include "SkTDArray.h"
+
+#include "SkDifferentPixelsMetric.h"
+#include "SkDiffContext.h"
+#include "SkImageDiffer.h"
+#include "SkPMetric.h"
+#include "skpdiff_util.h"
+
+#include "SkForceLinking.h"
+__SK_FORCE_IMAGE_DECODER_LINKING;
+
+// Command line argument definitions go here
+DEFINE_bool2(list, l, false, "List out available differs");
+DEFINE_string2(differs, d, "", "The names of the differs to use or all of them by default");
+DEFINE_string2(folders, f, "", "Compare two folders with identical subfile names: <baseline folder> <test folder>");
+DEFINE_string2(patterns, p, "", "Use two patterns to compare images: <baseline> <test>");
+DEFINE_string2(output, o, "skpdiff_output.json", "Writes the output of these diffs to output: <output>");
+DEFINE_bool(jsonp, true, "Output JSON with padding");
+
+#if SK_SUPPORT_OPENCL
+/// 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;
+}
+
+static bool init_cl_diff(SkImageDiffer* differ) {
+    // Setup OpenCL
+    cl::Device device;
+    cl::Context context;
+    if (!init_device_and_context(&device, &context)) {
+        return false;
+    }
+
+    // Setup our differ of choice
+    SkCLImageDiffer* clDiffer = (SkCLImageDiffer*)differ;
+    return clDiffer->init(device(), context());
+}
+#endif
+
+// TODO Find a better home for the diff registry. One possibility is to have the differs self
+// register.
+
+// List here every differ
+SkDifferentPixelsMetric gDiffPixel;
+SkPMetric gPDiff;
+
+// A null terminated array of pointer to every differ declared above
+SkImageDiffer* gDiffers[] = { &gDiffPixel, &gPDiff, NULL };
+
+int main(int argc, char** argv) {
+    // Setup command line parsing
+    SkCommandLineFlags::SetUsage("Compare images using various metrics.");
+    SkCommandLineFlags::Parse(argc, argv);
+
+    // Needed by various Skia components
+    SkAutoGraphics ag;
+
+    if (FLAGS_list) {
+        SkDebugf("Available Metrics:\n");
+    }
+
+    // Figure which differs the user chose, and optionally print them if the user requests it
+    SkTDArray<SkImageDiffer*> chosenDiffers;
+    for (int differIndex = 0; NULL != gDiffers[differIndex]; differIndex++) {
+        SkImageDiffer* differ = gDiffers[differIndex];
+        if (FLAGS_list) {
+            SkDebugf("    %s", differ->getName());
+            SkDebugf("\n");
+        }
+
+        // Check if this differ was chosen by any of the flags. Initialize them if they were chosen.
+        if (FLAGS_differs.isEmpty()) {
+            // If no differs were chosen, they all get added
+            if (differ->requiresOpenCL()) {
+#if SK_SUPPORT_OPENCL
+                init_cl_diff(differ);
+                chosenDiffers.push(differ);
+#endif
+            } else {
+                chosenDiffers.push(differ);
+            }
+        } else {
+            for (int flagIndex = 0; flagIndex < FLAGS_differs.count(); flagIndex++) {
+                if (SkString(FLAGS_differs[flagIndex]).equals(differ->getName())) {
+                    // Initialize OpenCL for the differ if it needs it and support was compiled in.
+                    if (differ->requiresOpenCL()) {
+#if SK_SUPPORT_OPENCL
+                        init_cl_diff(differ);
+                        chosenDiffers.push(differ);
+#endif
+                    } else {
+                        chosenDiffers.push(differ);
+                    }
+                    break;
+                }
+            }
+        }
+    }
+
+    // Don't attempt to initialize the differ if we aren't going to use it
+    if (FLAGS_folders.isEmpty() && FLAGS_patterns.isEmpty()) {
+        return 0;
+    }
+
+    // Validate command line flags
+    if (!FLAGS_folders.isEmpty()) {
+        if (2 != FLAGS_folders.count()) {
+            SkDebugf("Folders flag expects two arguments: <baseline folder> <test folder>\n");
+            return 1;
+        }
+    }
+
+    if (!FLAGS_patterns.isEmpty()) {
+        if (2 != FLAGS_patterns.count()) {
+            SkDebugf("Patterns flag expects two arguments: <baseline pattern> <test pattern>\n");
+            return 1;
+        }
+    }
+
+    SkDiffContext ctx;
+    ctx.setDiffers(chosenDiffers);
+
+    // Perform a folder diff if one is requested
+    if (!FLAGS_folders.isEmpty()) {
+        ctx.diffDirectories(FLAGS_folders[0], FLAGS_folders[1]);
+    }
+
+    // Perform a pattern diff if one is requested
+    if (!FLAGS_patterns.isEmpty()) {
+        ctx.diffPatterns(FLAGS_patterns[0], FLAGS_patterns[1]);
+    }
+
+    // Output to the file specified
+    if (!FLAGS_output.isEmpty()) {
+        SkFILEWStream outputStream(FLAGS_output[0]);
+        ctx.outputRecords(outputStream, FLAGS_jsonp);
+    }
+
+    return 0;
+}