Make SkShaper a module

Change-Id: I3709e49ba865f14260660cc07a762b9ac837cb3c
Reviewed-on: https://skia-review.googlesource.com/130602
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Herb Derby <herb@google.com>

1 files changed, 222 insertions, 0 deletions

diff --git a/tools/using_skia_and_harfbuzz.cpp b/tools/using_skia_and_harfbuzz.cpp
new file mode 100644
index 0000000000..5a74866794
--- /dev/null
+++ b/tools/using_skia_and_harfbuzz.cpp
@@ -0,0 +1,222 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+// This sample progam demonstrates how to use Skia and HarfBuzz to
+// produce a PDF file from UTF-8 text in stdin.
+
+#include <cassert>
+#include <cstdlib>
+#include <iostream>
+#include <map>
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include "SkCanvas.h"
+#include "SkDocument.h"
+#include "SkShaper.h"
+#include "SkStream.h"
+#include "SkTextBlob.h"
+#include "SkTypeface.h"
+
+// Options /////////////////////////////////////////////////////////////////////
+
+struct BaseOption {
+    std::string selector;
+    std::string description;
+    virtual void set(std::string _value) = 0;
+    virtual std::string valueToString() = 0;
+
+    BaseOption(std::string _selector, std::string _description)
+        : selector(_selector), description(_description) {}
+
+    virtual ~BaseOption() {}
+
+    static void Init(const std::vector<BaseOption*> &, int argc, char **argv);
+};
+
+template <class T>
+struct Option : BaseOption {
+    T value;
+    Option(std::string selector, std::string description, T defaultValue)
+        : BaseOption(selector, description), value(defaultValue) {}
+};
+
+void BaseOption::Init(const std::vector<BaseOption*> &option_list,
+                      int argc, char **argv) {
+    std::map<std::string, BaseOption *> options;
+    for (BaseOption *opt : option_list) {
+        options[opt->selector] = opt;
+    }
+    for (int i = 1; i < argc; i++) {
+        std::string option_selector(argv[i]);
+        auto it = options.find(option_selector);
+        if (it != options.end()) {
+            if (i >= argc) {
+                break;
+            }
+            const char *option_value = argv[i + 1];
+            it->second->set(option_value);
+            i++;
+        } else {
+            printf("Ignoring unrecognized option: %s.\n", argv[i]);
+            printf("Usage: %s {option value}\n", argv[0]);
+            printf("\tTakes text from stdin and produces pdf file.\n");
+            printf("Supported options:\n");
+            for (BaseOption *opt : option_list) {
+                printf("\t%s\t%s (%s)\n", opt->selector.c_str(),
+                       opt->description.c_str(), opt->valueToString().c_str());
+            }
+            exit(-1);
+        }
+    }
+}
+
+struct DoubleOption : Option<double> {
+    virtual void set(std::string _value) { value = atof(_value.c_str()); }
+    virtual std::string valueToString() {
+        std::ostringstream stm;
+        stm << value;
+        return stm.str();
+    }
+    DoubleOption(std::string selector,
+                 std::string description,
+                 double defaultValue)
+        : Option<double>(selector, description, defaultValue) {}
+};
+
+struct StringOption : Option<std::string> {
+    virtual void set(std::string _value) { value = _value; }
+    virtual std::string valueToString() { return value; }
+    StringOption(std::string selector,
+                 std::string description,
+                 std::string defaultValue)
+        : Option<std::string>(selector, description, defaultValue) {}
+};
+
+// Config //////////////////////////////////////////////////////////////////////
+
+struct Config {
+    DoubleOption page_width = DoubleOption("-w", "Page width", 600.0f);
+    DoubleOption page_height = DoubleOption("-h", "Page height", 800.0f);
+    StringOption title = StringOption("-t", "PDF title", "---");
+    StringOption author = StringOption("-a", "PDF author", "---");
+    StringOption subject = StringOption("-k", "PDF subject", "---");
+    StringOption keywords = StringOption("-c", "PDF keywords", "---");
+    StringOption creator = StringOption("-t", "PDF creator", "---");
+    StringOption font_file = StringOption("-f", ".ttf font file", "");
+    DoubleOption font_size = DoubleOption("-z", "Font size", 8.0f);
+    DoubleOption left_margin = DoubleOption("-m", "Left margin", 20.0f);
+    DoubleOption line_spacing_ratio =
+            DoubleOption("-h", "Line spacing ratio", 0.25f);
+    StringOption output_file_name =
+            StringOption("-o", ".pdf output file name", "out-skiahf.pdf");
+
+    Config(int argc, char **argv) {
+        BaseOption::Init(std::vector<BaseOption*>{
+                &page_width, &page_height, &title, &author, &subject,
+                &keywords, &creator, &font_file, &font_size, &left_margin,
+                &line_spacing_ratio, &output_file_name}, argc, argv);
+    }
+};
+
+// Placement ///////////////////////////////////////////////////////////////////
+
+class Placement {
+public:
+    Placement(const Config* conf, SkDocument *doc)
+        : config(conf), document(doc), pageCanvas(nullptr) {
+        white_paint.setColor(SK_ColorWHITE);
+        glyph_paint.setColor(SK_ColorBLACK);
+        glyph_paint.setFlags(SkPaint::kAntiAlias_Flag |
+                             SkPaint::kSubpixelText_Flag);
+        glyph_paint.setTextSize(SkDoubleToScalar(config->font_size.value));
+    }
+
+    void WriteLine(const SkShaper& shaper, const char *text, size_t textBytes) {
+        SkTextBlobBuilder textBlobBuilder;
+        SkPoint endPoint = shaper.shape(&textBlobBuilder, glyph_paint, text, textBytes, true,
+                                        SkPoint{0, 0},
+                                        config->page_width.value - 2*config->left_margin.value);
+        sk_sp<const SkTextBlob> blob = textBlobBuilder.make();
+        // If we don't have a page, or if we're not at the start of the page and the blob won't fit
+        if (!pageCanvas ||
+              (current_y > config->line_spacing_ratio.value * config->font_size.value &&
+               current_y + endPoint.y() > config->page_height.value)
+        ) {
+            if (pageCanvas) {
+                document->endPage();
+            }
+            pageCanvas = document->beginPage(
+                    SkDoubleToScalar(config->page_width.value),
+                    SkDoubleToScalar(config->page_height.value));
+            pageCanvas->drawPaint(white_paint);
+            current_x = config->left_margin.value;
+            current_y = config->line_spacing_ratio.value * config->font_size.value;
+        }
+        pageCanvas->drawTextBlob(
+                blob.get(), SkDoubleToScalar(current_x),
+                SkDoubleToScalar(current_y), glyph_paint);
+        // Advance to the next line.
+        current_y += endPoint.y() + config->line_spacing_ratio.value * config->font_size.value;
+    }
+
+private:
+    const Config* config;
+    SkDocument *document;
+    SkCanvas *pageCanvas;
+    SkPaint white_paint;
+    SkPaint glyph_paint;
+    double current_x;
+    double current_y;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+static sk_sp<SkDocument> MakePDFDocument(const Config &config, SkWStream *wStream) {
+    SkDocument::PDFMetadata pdf_info;
+    pdf_info.fTitle = config.title.value.c_str();
+    pdf_info.fAuthor = config.author.value.c_str();
+    pdf_info.fSubject = config.subject.value.c_str();
+    pdf_info.fKeywords = config.keywords.value.c_str();
+    pdf_info.fCreator = config.creator.value.c_str();
+    #if 0
+        SkTime::DateTime now;
+        SkTime::GetDateTime(&now);
+        pdf_info.fCreation.fEnabled = true;
+        pdf_info.fCreation.fDateTime = now;
+        pdf_info.fModified.fEnabled = true;
+        pdf_info.fModified.fDateTime = now;
+        pdf_info.fPDFA = true;
+    #endif
+    return SkDocument::MakePDF(wStream, pdf_info);
+}
+
+int main(int argc, char **argv) {
+    Config config(argc, argv);
+    SkFILEWStream wStream(config.output_file_name.value.c_str());
+    sk_sp<SkDocument> doc = MakePDFDocument(config, &wStream);
+    assert(doc);
+    Placement placement(&config, doc.get());
+
+    const std::string &font_file = config.font_file.value;
+    sk_sp<SkTypeface> typeface;
+    if (font_file.size() > 0) {
+        typeface = SkTypeface::MakeFromFile(font_file.c_str(), 0 /* index */);
+    }
+    SkShaper shaper(typeface);
+    assert(shaper.good());
+    //SkString line("This is هذا هو الخط a line.");
+    //SkString line("⁧This is a line هذا هو الخط.⁩");
+    for (std::string line; std::getline(std::cin, line);) {
+        placement.WriteLine(shaper, line.c_str(), line.size());
+    }
+
+    doc->close();
+    wStream.flush();
+    return 0;
+}