pdfviewer: All NulCanvas (does not draw operations), TrackDevice (trackes what pixels have been cha…

experimental/PdfViewer/pdf_viewer_main.cpp

 #include "SkCanvas.h"
 #include "SkCommandLineFlags.h"
 #include "SkDevice.h"
 #include "SkGraphics.h"
 #include "SkImageDecoder.h"
 #include "SkImageEncoder.h"
 #include "SkOSFile.h"
 #include "SkPicture.h"
 #include "SkStream.h"
 #include "SkTypeface.h"
 #include "SkTArray.h"
 #include "picture_utils.h"
+#include "SkNulCanvas.h"
 
 #include "SkPdfRenderer.h"
 
 DEFINE_string2(readPath, r, "", "pdf files or directories of pdf files to process.");
 DEFINE_string2(writePath, w, "", "Directory to write the rendered pages.");
 DEFINE_bool2(noExtensionForOnePagePdf, n, false, "No page extension if only one page.");
 DEFINE_bool2(showMemoryUsage, m, false, "Show Memory usage.");
 DEFINE_string2(pages, p, "all", "What pages to render and how:\n"
                                 "\tall - all pages\n"
                                 "\treverse - all pages, in reverse order\n"
                                 "\tfirst - first page\n"
                                 "\tlast - last page\n"
                                 "\tnumber - a specific page number\n"
                );
 DEFINE_double(DPI, 72, "DPI to be used for rendering (scale).");
 DEFINE_int32(benchLoad, 0, "Load the pdf file minimally N times, without any rendering and \n"
              "\tminimal parsing to ensure correctness. Default 0 (disabled).");
 DEFINE_int32(benchRender, 0, "Render the pdf content N times. Default 0 (disabled)");
+DEFINE_string2(config, c, "8888", "Canvas to render:\n"
+                                  "\t8888 - all pages\n"
+                                  "\tnul - all pages, in reverse order\n"
+               );
 
 
 // TODO(edisonn): add config for device target(gpu, raster, pdf), + ability not to render at all
 
 /**
  * Given list of directories and files to use as input, expects to find .pdf
  * files and it will convert them to .png files writing them in the same directory
  * one file for each page.
  *
  * Returns zero exit code if all .pdf files were converted successfully,
@@ skipping 62 matching lines @@
 
 extern "C" SkBitmap* gDumpBitmap;
 extern "C" SkCanvas* gDumpCanvas;
 
 static bool render_page(const SkString& outputDir,
                         const SkString& inputFilename,
                         const SkPdfRenderer& renderer,
                         int page) {
     SkRect rect = renderer.MediaBox(page < 0 ? 0 :page);
 
-    SkBitmap bitmap;
-    SkScalar width = SkScalarMul(rect.width(),  SkDoubleToScalar(sqrt(FLAGS_DPI / 72.0)));
-    SkScalar height = SkScalarMul(rect.height(),  SkDoubleToScalar(sqrt(FLAGS_DPI / 72.0)));
+    // Exercise all pdf codepaths as in normal rendering, but no actual bits are changed.
+    if (!FLAGS_config.isEmpty() && strcmp(FLAGS_config[0], "nul") == 0) {
+        SkBitmap bitmap;
+        SkAutoTUnref<SkDevice> device(SkNEW_ARGS(SkDevice, (bitmap)));
+        SkNulCanvas canvas(device);
+        renderer.renderPage(page < 0 ? 0 : page, &canvas, rect);
+    } else {
+        // 8888
+        SkRect rect = renderer.MediaBox(page < 0 ? 0 :page);
 
-    rect = SkRect::MakeWH(width, height);
+        SkBitmap bitmap;
+        SkScalar width = SkScalarMul(rect.width(),  SkDoubleToScalar(sqrt(FLAGS_DPI / 72.0)));
+        SkScalar height = SkScalarMul(rect.height(),  SkDoubleToScalar(sqrt(FLAGS_DPI / 72.0)));
+
+        rect = SkRect::MakeWH(width, height);
 
 #ifdef PDF_DEBUG_3X
-    setup_bitmap(&bitmap, 3 * (int)SkScalarToDouble(width), 3 * (int)SkScalarToDouble(height));
+        setup_bitmap(&bitmap, 3 * (int)SkScalarToDouble(width), 3 * (int)SkScalarToDouble(height));
 #else
-    setup_bitmap(&bitmap, (int)SkScalarToDouble(width), (int)SkScalarToDouble(height));
+        setup_bitmap(&bitmap, (int)SkScalarToDouble(width), (int)SkScalarToDouble(height));
 #endif
-    SkAutoTUnref<SkDevice> device(SkNEW_ARGS(SkDevice, (bitmap)));
-    SkCanvas canvas(device);
+        SkAutoTUnref<SkDevice> device(SkNEW_ARGS(SkDevice, (bitmap)));
+        SkCanvas canvas(device);
 
-    gDumpBitmap = &bitmap;
+        gDumpBitmap = &bitmap;
 
-    gDumpCanvas = &canvas;
-    renderer.renderPage(page < 0 ? 0 : page, &canvas, rect);
+        gDumpCanvas = &canvas;
+        renderer.renderPage(page < 0 ? 0 : page, &canvas, rect);
 
-    SkString outputPath;
-    if (!make_output_filepath(&outputPath, outputDir, inputFilename, page)) {
-        return false;
+        SkString outputPath;
+        if (!make_output_filepath(&outputPath, outputDir, inputFilename, page)) {
+            return false;
+        }
+        SkImageEncoder::EncodeFile(outputPath.c_str(), bitmap, SkImageEncoder::kPNG_Type, 100);
+
+        if (FLAGS_showMemoryUsage) {
+            SkDebugf("Memory usage after page %i rendered: %u\n", page < 0 ? 0 : page, (unsigned int)renderer.bytesUsed());
+        }
     }
-    SkImageEncoder::EncodeFile(outputPath.c_str(), bitmap, SkImageEncoder::kPNG_Type, 100);
-
-    if (FLAGS_showMemoryUsage) {
-        SkDebugf("Memory usage after page %i rendered: %u\n", page < 0 ? 0 : page, (unsigned int)renderer.bytesUsed());
-    }
-
     return true;
 }
 
 /** Reads an skp file, renders it to pdf and writes the output to a pdf file
  * @param inputPath The skp file to be read.
  * @param outputDir Output dir.
  * @param renderer The object responsible to render the skp object into pdf.
  */
 static bool process_pdf(const SkString& inputPath, const SkString& outputDir,
                         SkPdfRenderer& renderer) {
@@ skipping 118 matching lines @@
     }
 
     return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS
 int main(int argc, char * const argv[]) {
     return tool_main(argc, (char**) argv);
 }
 #endif