Adding the render_pictures test tool

Submitted on behalf of keyar@chromium.org

Review URL: https://codereview.appspot.com/6300056/



git-svn-id: http://skia.googlecode.com/svn/trunk@4235 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tools/render_pictures_main.cpp b/tools/render_pictures_main.cpp
new file mode 100644
index 0000000..0e7232e
--- /dev/null
+++ b/tools/render_pictures_main.cpp
@@ -0,0 +1,129 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#include "SkBitmap.h"
+#include "SkCanvas.h"
+#include "SkColorPriv.h"
+#include "SkImageEncoder.h"
+#include "SkOSFile.h"
+#include "SkPicture.h"
+#include "SkStream.h"
+#include "SkString.h"
+
+
+static void usage(const char* argv0) {
+    SkDebugf("SkPicture rendering tool\n");
+    SkDebugf("\n"
+"Usage: \n"
+"     %s <inputDir> <outputDir> \n\n"
+, argv0);
+    SkDebugf(
+"     inputDir:  directory to read the serialized SkPicture files.\n");
+    SkDebugf(
+"     outputDir: directory to write the rendered images.\n");
+}
+
+static void make_filepath(SkString* path, const char* dir,
+                          const SkString& name) {
+    size_t len = strlen(dir);
+    path->set(dir);
+    if (0 < len  && '/' != dir[len - 1]) {
+        path->append("/");
+    }
+    path->append(name);
+}
+
+static void open_picture_stream(const char* inputDir,
+                                const SkString& inputFilename,
+                                SkFILEStream* inputStream) {
+    SkString inputPath;
+    make_filepath(&inputPath, inputDir, inputFilename);
+    inputStream->setPath(inputPath.c_str());
+    if (!inputStream->isValid()) {
+        SkDebugf("Could not open file %s\n", inputPath.c_str());
+    }
+}
+
+static void make_output_filepath(SkString* path, const char* dir,
+                                 const SkString& name) {
+    make_filepath(path, dir, name);
+    path->remove(path->size() - 3, 3);
+    path->append("png");
+}
+
+static void setup_bitmap(SkPicture& picture, SkBitmap* bitmap) {
+    bitmap->setConfig(SkBitmap::kARGB_8888_Config, picture.width(),
+                     picture.height());
+    bitmap->allocPixels();
+    bitmap->eraseColor(0);
+}
+
+static void generate_image_from_picture(SkPicture& pict, SkBitmap* bitmap) {
+    setup_bitmap(pict, bitmap);
+    SkCanvas canvas(*bitmap);
+    canvas.drawPicture(pict);
+}
+
+/* since PNG insists on unpremultiplying our alpha, we take no precision chances
+    and force all pixels to be 100% opaque, otherwise on compare we may not get
+    a perfect match.
+ */
+static void force_all_opaque(const SkBitmap& bitmap) {
+    SkAutoLockPixels lock(bitmap);
+    for (int y = 0; y < bitmap.height(); y++) {
+        for (int x = 0; x < bitmap.width(); x++) {
+            *bitmap.getAddr32(x, y) |= (SK_A32_MASK << SK_A32_SHIFT);
+        }
+    }
+}
+
+static bool write_bitmap(const SkString& path, const SkBitmap& bitmap) {
+    SkBitmap copy;
+    bitmap.copyTo(&copy, SkBitmap::kARGB_8888_Config);
+    force_all_opaque(copy);
+    return SkImageEncoder::EncodeFile(path.c_str(), copy,
+                                      SkImageEncoder::kPNG_Type, 100);
+}
+
+static void write_output(const char* outputDir, const SkString& inputFilename,
+                         const SkBitmap& bitmap) {
+    SkString outputPath;
+    make_output_filepath(&outputPath, outputDir, inputFilename);
+    bool isWritten = write_bitmap(outputPath, bitmap);
+    if (!isWritten) {
+        SkDebugf("Could not write to file %s\n", outputPath.c_str());
+    }
+}
+
+static void render_picture(const char* inputDir, const char* outputDir,
+                           const SkString& inputFilename) {
+    SkFILEStream inputStream;
+    open_picture_stream(inputDir, inputFilename, &inputStream);
+    SkPicture picture(&inputStream);
+    SkBitmap bitmap;
+    generate_image_from_picture(picture, &bitmap);
+    write_output(outputDir, inputFilename, bitmap);
+}
+
+int main(int argc, char* const argv[]) {
+    const char* inputDir;
+    const char* outputDir;
+    if (argc != 3) {
+        usage(argv[0]);
+    }
+
+    inputDir = argv[1];
+    outputDir = argv[2];
+
+    SkOSFile::Iter iter(inputDir, "skp");
+    SkString inputFilename;
+
+    while(iter.next(&inputFilename)) {
+        render_picture(inputDir, outputDir, inputFilename);
+    }
+}