Add new GM to stress test the GPU font cache for cases similar to

gm/fontcache.cpp

+/*
+ * Copyright 2013 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 "SkGraphics.h"
+#include "SkTypeface.h"
+
+// GM to stress the GPU font cache 
+
+const char* gFamilyNames[] = {
+    "sans-serif", "serif", "monospace"
+};
+
+const SkTypeface::Style gStyles[] = {
+    SkTypeface::kNormal, SkTypeface::kItalic
+};
+

[robertphillips, 2013/10/09 15:23:49]

Is "20" missing on purpose?

+const int gTextSizes[] = {
+    10, 12, 14, 16, 18, 22, 24, 26, 28, 30
+};
+

[robertphillips, 2013/10/09 15:23:49]

DrawString?

+static SkScalar drawString(SkCanvas* canvas, const SkString& text, SkScalar x,
+                           SkScalar y, const SkPaint& paint) {
+    canvas->drawText(text.c_str(), text.size(), x, y, paint);
+    return x + paint.measureText(text.c_str(), text.size());
+}
+
+class FontCacheGM : public skiagm::GM {
+public:
+    FontCacheGM() {

[robertphillips, 2013/10/09 15:23:49]

Is this init expensive? Should it be moved to onOnceBeforeDraw?

+        fTypefaceCount = 0;

[robertphillips, 2013/10/09 15:23:49]

Where does 16*1024*1024 come from?

+        SkGraphics::SetFontCacheLimit(16 * 1024 * 1024);

[robertphillips, 2013/10/09 15:23:49]

should "unsigned long" just be size_t?

+        for (unsigned long i = 0; i < SK_ARRAY_COUNT(gFamilyNames); ++i) {
+            for (unsigned long j = 0; j < SK_ARRAY_COUNT(gStyles); ++j) {
+                fTypefaces[fTypefaceCount++] = SkTypeface::CreateFromName(gFamilyNames[i],
+                                                                          gStyles[j]);
+            }
+        }
+        fName.set("fontcache");
+    }
+

[robertphillips, 2013/10/09 15:23:49]

virtual?

+    ~FontCacheGM() {
+        for (size_t i = 0; i < fTypefaceCount; ++i) {
+            SkSafeUnref(fTypefaces[i]);
+        }
+    }
+    
+protected:

[robertphillips, 2013/10/09 15:23:49]

override

+    virtual SkString onShortName() {
+        return fName;
+    }
+

[robertphillips, 2013/10/09 15:23:49]

override

+    virtual SkISize onISize() {
+        return SkISize::Make(640, 320);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        SkScalar y = 32;
+        SkPaint paint;
+        paint.setAntiAlias(true);
+        paint.setLCDRenderText(true);
+        paint.setSubpixelText(true);
+
+        SkString text("Ham");
+
+        // draw some initial text to partially fill the GPU cache
+        for (size_t i = 0; i < 2; ++i) {
+            paint.setTypeface(fTypefaces[i]);
+            SkScalar x = 20;
+            
+            for (size_t j = 0; j < SK_ARRAY_COUNT(gTextSizes); ++j) {
+                paint.setTextSize(gTextSizes[j]);
+                x = drawString(canvas, text, x, y, paint) + 20;
+            }
+            y += 32;
+        }
+        
+        // force a flush
+        canvas->flush();
+        
+        // draw again, and more to overflow the cache
+        for (size_t i = 0; i < fTypefaceCount; ++i) {
+            paint.setTypeface(fTypefaces[i]);
+            SkScalar x = 20;
+            
+            for (size_t j = 0; j < SK_ARRAY_COUNT(gTextSizes); ++j) {
+                paint.setTextSize(gTextSizes[j]);
+                x = drawString(canvas, text, x, y, paint) + 20;
+            }
+            y += 32;
+        }
+        
+    }
+
+    virtual uint32_t onGetFlags() const SK_OVERRIDE {
+        // this GM is meant only for the GPU
+        return kGPUOnly_Flag;
+    }
+
+private:
+    SkTypeface* fTypefaces[SK_ARRAY_COUNT(gFamilyNames)*SK_ARRAY_COUNT(gStyles)];

[robertphillips, 2013/10/09 15:23:49]

Technically I don't think fTypefaceCount needs to be a member variable since it
should always be num(gFamilyNames) * num(gStyles), right?

+    size_t fTypefaceCount;
+    SkString fName;
+    typedef GM INHERITED;
+};
+
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return SkNEW(FontCacheGM); )
+