Add Chinese fling sample

Change-Id: Id27877c4d816ec83460f50a3a0d9cc0299ea6849
Reviewed-on: https://skia-review.googlesource.com/34780
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>

4 files changed, 136 insertions, 5 deletions

diff --git a/gn/samples.gni b/gn/samples.gni
index edb2fe8608..b61ec349ad 100644
--- a/gn/samples.gni
+++ b/gn/samples.gni
@@ -29,6 +29,7 @@ samples_sources = [
   "$_samplecode/SampleCCPRGeometry.cpp",
   "$_samplecode/SampleCamera.cpp",
   "$_samplecode/SampleChart.cpp",
+  "$_samplecode/SampleChineseFling.cpp",
   "$_samplecode/SampleCircle.cpp",
   "$_samplecode/SampleClip.cpp",
   "$_samplecode/SampleClipDrawMatch.cpp",
diff --git a/samplecode/SampleChineseFling.cpp b/samplecode/SampleChineseFling.cpp
new file mode 100644
index 0000000000..036f834931
--- /dev/null
+++ b/samplecode/SampleChineseFling.cpp
@@ -0,0 +1,123 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "Resources.h"
+#include "SampleCode.h"
+#include "sk_tool_utils.h"
+
+#include "SkCanvas.h"
+#include "SkFontMgr.h"
+#include "SkRandom.h"
+#include "SkTypeface.h"
+#include "SkTextBlob.h"
+
+static void make_paint(SkPaint* paint, sk_sp<SkTypeface> typeface) {
+  static const int kTextSize = 56;
+
+  paint->setAntiAlias(true);
+  paint->setColor(0xDE000000);
+  paint->setTypeface(typeface);
+  paint->setTextSize(kTextSize);
+  paint->setTextEncoding(SkPaint::kUTF32_TextEncoding);
+}
+
+static void get_unicode_row(SkUnichar base, SkUnichar glyphs[16]) {
+    for (int i = 0x0; i <= 0xF; ++i) {
+        glyphs[i] = base;
+        glyphs[i] |= i;
+    }
+}
+
+static sk_sp<SkTypeface> chinese_typeface() {
+#ifdef SK_BUILD_FOR_ANDROID
+    return MakeResourceAsTypeface("/fonts/NotoSansCJK-Regular.ttc");
+#elif defined(SK_BUILD_FOR_WIN32)
+    return SkTypeface::MakeFromName("SimSun", SkFontStyle());
+#elif defined(SK_BUILD_FOR_MAC)
+    return SkTypeface::MakeFromName("Hiragino Sans GB W3", SkFontStyle());
+#elif defined(SK_BUILD_FOR_IOS)
+    return SkTypeface::MakeFromName("Hiragino Sans GB W3", SkFontStyle());
+#elif defined(SK_BUILD_FOR_UNIX)
+    return SkTypeface::MakeFromName("Noto Sans CJK SC", SkFontStyle());
+#else
+    return nullptr;
+#endif
+}
+
+class ChineseFlingView : public SampleView {
+public:
+    ChineseFlingView() {}
+
+protected:
+    bool onQuery(SkEvent* evt) override {
+        if (SampleCode::TitleQ(*evt)) {
+            SampleCode::TitleR(evt, "chinese-fling");
+            return true;
+        }
+        return this->INHERITED::onQuery(evt);
+    }
+
+    void onDrawContent(SkCanvas* canvas) override {
+        if (!fInitialized) {
+            this->init();
+            fInitialized = true;
+        }
+
+        canvas->clear(0xFFDDDDDD);
+
+        SkPaint paint;
+        make_paint(&paint, fTypeface);
+
+        for (SkScalar y = 0.0f; y < 1024.0f; ) {
+            int index = fRand.nextRangeU(0, fBlobs.count()-1);
+
+            y += -fMetrics.fAscent;
+            canvas->drawTextBlob(fBlobs[index], 0, y, paint);
+
+            y += fMetrics.fDescent + fMetrics.fLeading;
+        }
+
+        this->inval(nullptr);
+    }
+
+private:
+    void init() {
+        fTypeface = chinese_typeface();
+
+        SkPaint paint;
+        make_paint(&paint, fTypeface);
+
+        paint.getFontMetrics(&fMetrics);
+
+        SkUnichar glyphs[16];
+
+        for (int32_t i = 0x4F00; i < 0x9FA0; i += 0x10) {
+
+            get_unicode_row(i, glyphs);
+
+            SkTextBlobBuilder builder;
+
+            sk_tool_utils::add_to_text_blob_w_len(&builder, (const char*) glyphs, 16*4, paint,
+                                                  0, 0);
+
+            fBlobs.emplace_back(builder.make());
+        }
+    }
+
+    bool                        fInitialized = false;
+    sk_sp<SkTypeface>           fTypeface;
+    SkPaint::FontMetrics        fMetrics;
+    SkTArray<sk_sp<SkTextBlob>> fBlobs;
+    SkRandom                    fRand;
+
+    typedef SkView INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static SkView* MyFactory() { return new ChineseFlingView; }
+static SkViewRegister reg(MyFactory);
diff --git a/tools/sk_tool_utils.cpp b/tools/sk_tool_utils.cpp
index 380e1d78bc..f1968742d4 100644
--- a/tools/sk_tool_utils.cpp
+++ b/tools/sk_tool_utils.cpp
@@ -247,12 +247,11 @@ SkBitmap create_string_bitmap(int w, int h, SkColor c, int x, int y,
     return result;
 }
 
-void add_to_text_blob(SkTextBlobBuilder* builder, const char* text, const SkPaint& origPaint,
-                      SkScalar x, SkScalar y) {
+void add_to_text_blob_w_len(SkTextBlobBuilder* builder, const char* text, size_t len,
+                            const SkPaint& origPaint, SkScalar x, SkScalar y) {
     SkPaint paint(origPaint);
     SkTDArray<uint16_t> glyphs;
 
-    size_t len = strlen(text);
     glyphs.append(paint.textToGlyphs(text, len, nullptr));
     paint.textToGlyphs(text, len, glyphs.begin());
 
@@ -262,6 +261,11 @@ void add_to_text_blob(SkTextBlobBuilder* builder, const char* text, const SkPain
     memcpy(run.glyphs, glyphs.begin(), glyphs.count() * sizeof(uint16_t));
 }
 
+void add_to_text_blob(SkTextBlobBuilder* builder, const char* text,
+                      const SkPaint& origPaint, SkScalar x, SkScalar y) {
+    add_to_text_blob_w_len(builder, text, strlen(text), origPaint, x, y);
+}
+
 #if !defined(__clang__) && defined(_MSC_VER)
     // MSVC takes ~2 minutes to compile this function with optimization.
     // We don't really care to wait that long for this function.
diff --git a/tools/sk_tool_utils.h b/tools/sk_tool_utils.h
index dc8c8c10a0..b1bde770ea 100644
--- a/tools/sk_tool_utils.h
+++ b/tools/sk_tool_utils.h
@@ -129,8 +129,11 @@ namespace sk_tool_utils {
                                   int textSize, const char* str);
 
     // A helper for inserting a drawtext call into a SkTextBlobBuilder
-    void add_to_text_blob(SkTextBlobBuilder* builder, const char* text, const SkPaint& origPaint,
-                          SkScalar x, SkScalar y);
+    void add_to_text_blob_w_len(SkTextBlobBuilder* builder, const char* text, size_t len,
+                                const SkPaint& origPaint, SkScalar x, SkScalar y);
+
+    void add_to_text_blob(SkTextBlobBuilder* builder, const char* text,
+                          const SkPaint& origPaint, SkScalar x, SkScalar y);
 
     void make_big_path(SkPath& path);