Create new GM to target translations problems in GrAtlasTextContext

gm/textblobblockreordering.cpp

Index: gm/textblobblockreordering.cpp
diff --git a/gm/textblobblockreordering.cpp b/gm/textblobblockreordering.cpp
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+++ b/gm/textblobblockreordering.cpp
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+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gm.h"
+
+#include "SkCanvas.h"
+#include "SkTextBlob.h"
+
+namespace skiagm {
+class TextBlobBlockReordering : public GM {
+public:
+    // This gm tests that textblobs translate properly when their draw order is different from their
+    // flush order
+    TextBlobBlockReordering() { }
+
+protected:
+    void onOnceBeforeDraw() override {
+        SkTextBlobBuilder builder;
+
+        // make textblob
+        // Large text is used to trigger atlas eviction
+        SkPaint paint;
+        paint.setTextSize(56);
+        const char* text = "AB";
+        sk_tool_utils::set_portable_typeface(&paint);
+
+        SkRect bounds;
+        paint.measureText(text, strlen(text), &bounds);
+
+        SkScalar yOffset = bounds.height();
+        sk_tool_utils::add_to_text_blob(&builder, text, paint, 0, yOffset - 30);
+
+        // build
+        fBlob.reset(builder.build());
+    }
+
+    SkString onShortName() override {
+        return SkString("textblobblockreordering");
+    }
+
+    SkISize onISize() override {
+        return SkISize::Make(kWidth, kHeight);
+    }
+
+    // This draws the same text blob 3 times.  The second draw used a different
+    // xfer mode so it doens't get batched with the first and third.
+    // ultimately thye iwll be flushed in the order first, third, and then second
+    void onDraw(SkCanvas* canvas) override {
+        canvas->drawColor(sk_tool_utils::color_to_565(SK_ColorGRAY));
+
+        SkPaint paint;
+        canvas->translate(10, 40);
+
+        SkRect bounds = fBlob->bounds();
+        const int yDelta = SkScalarFloorToInt(bounds.height()) + 20;
+        const int xDelta = SkScalarFloorToInt(bounds.width());
+        
+        canvas->drawTextBlob(fBlob, 0, 0, paint);
+        
+        canvas->translate(SkIntToScalar(xDelta), SkIntToScalar(yDelta));
+
+	// draw a rect where the text should be, and then twiddle the xfermode
+        // so we don't batch
+        SkPaint redPaint;
+        redPaint.setColor(SK_ColorRED);
+        canvas->drawRect(bounds, redPaint);
+        SkPaint srcInPaint(paint);
+        srcInPaint.setXfermodeMode(SkXfermode::kSrcIn_Mode);
+        canvas->drawTextBlob(fBlob, 0, 0, srcInPaint);
+
+        canvas->translate(SkIntToScalar(xDelta), SkIntToScalar(yDelta));
+        canvas->drawTextBlob(fBlob, 0, 0, paint);
+    }
+
+private:
+    SkAutoTUnref<const SkTextBlob> fBlob;
+
+    static const int kWidth = 275;
+    static const int kHeight = 200;
+
+    typedef GM INHERITED;
+};
+ 
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM(return new TextBlobBlockReordering;)
+}