Add imgblur tool to assist BlurMaskFilter debugging

tools/imgblur.cpp

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkCommandLineFlags.h"
+#include "SkCommonFlags.h"
+#include "SkImageDecoder.h"
+#include "SkStream.h"
+#include "SkTypes.h"
+
+#include "sk_tool_utils.h"
+
+DEFINE_string(in, "input.png", "Input image");
+DEFINE_string(out, "blurred.png", "Output image");
+DEFINE_double(sigma, 1, "Sigma to be used for blur (> 0.0f)");
+
+
+// This tool just performs a blur on an input image
+// Return codes:
+static const int kSuccess = 0;
+static const int kError = 1;
+
+int tool_main(int argc, char** argv);
+int tool_main(int argc, char** argv) {
+    SkCommandLineFlags::SetUsage("Brute force blur of an image.");
+    SkCommandLineFlags::Parse(argc, argv);
+
+    if (FLAGS_sigma <= 0) {
+        if (!FLAGS_quiet) {
+            SkDebugf("Sigma must be greater than zero (it is %f).\n", FLAGS_sigma);
+        }
+        return kError;       
+    }
+
+    SkFILEStream inputStream(FLAGS_in[0]);
+    if (!inputStream.isValid()) {
+        if (!FLAGS_quiet) {
+            SkDebugf("Couldn't open file: %s\n", FLAGS_in[0]);
+        }
+        return kError;
+    }
+
+    SkAutoTDelete<SkImageDecoder> codec(SkImageDecoder::Factory(&inputStream));
+    if (!codec) {
+        if (!FLAGS_quiet) {
+            SkDebugf("Couldn't create codec for: %s.\n", FLAGS_in[0]);
+        }
+        return kError;
+    }
+
+    SkBitmap src;
+
+    inputStream.rewind();
+    SkImageDecoder::Result res = codec->decode(&inputStream, &src,
+                                               kN32_SkColorType,
+                                               SkImageDecoder::kDecodePixels_Mode);
+    if (SkImageDecoder::kSuccess != res) {
+        if (!FLAGS_quiet) {
+            SkDebugf("Couldn't decode image: %s.\n", FLAGS_in[0]);
+        }    
+        return kError;
+    }
+
+    SkBitmap dst = sk_tool_utils::slow_blur(src, (float) FLAGS_sigma);
+
+    if (!SkImageEncoder::EncodeFile(FLAGS_out[0], dst, SkImageEncoder::kPNG_Type, 100)) {
+        if (!FLAGS_quiet) {
+            SkDebugf("Couldn't write to file: %s\n", FLAGS_out[0]);
+        }
+        return kError;       
+    }
+
+    return kSuccess;
+}
+
+#if !defined SK_BUILD_FOR_IOS
+int main(int argc, char * const argv[]) {
+    return tool_main(argc, (char**) argv);
+}
+#endif