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
+};
+
+const SkScalar gTextSizes[] = {
+    12, 14, 16, 18, 20, 22, 24, 26, 28, 30
+};
+
+#define TYPEFACE_COUNT (SK_ARRAY_COUNT(gFamilyNames)*SK_ARRAY_COUNT(gStyles))
+
+static SkScalar draw_string(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() {
+        for (size_t i = 0; i < TYPEFACE_COUNT; ++i) {
+            fTypefaces[i] = NULL;
+        }
+    }
+
+    virtual ~FontCacheGM() {
+        for (size_t i = 0; i < TYPEFACE_COUNT; ++i) {
+            SkSafeUnref(fTypefaces[i]);
+        }
+    }
+    
+protected:
+    virtual SkString onShortName() SK_OVERRIDE {
+        return fName;
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE {
+        return SkISize::Make(640, 320);
+    }
+
+    virtual void onOnceBeforeDraw() SK_OVERRIDE {
+        int typefaceCount = 0;
+        for (size_t i = 0; i < SK_ARRAY_COUNT(gFamilyNames); ++i) {
+            for (size_t j = 0; j < SK_ARRAY_COUNT(gStyles); ++j) {
+                fTypefaces[typefaceCount++] = SkTypeface::CreateFromName(gFamilyNames[i],
+                                                                          gStyles[j]);
+            }
+        }
+    }
+    
+    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 = draw_string(canvas, text, x, y, paint) + 19;
+            }
+            y += 32;
+        }
+        
+        // force a flush
+        canvas->flush();
+        
+        // draw again, and more to overflow the cache
+        for (size_t i = 0; i < TYPEFACE_COUNT; ++i) {
+            paint.setTypeface(fTypefaces[i]);
+            SkScalar x = 20;
+            
+            for (size_t j = 0; j < SK_ARRAY_COUNT(gTextSizes); ++j) {
+                paint.setTextSize(gTextSizes[j]);
+                x = draw_string(canvas, text, x, y, paint) + 19;
+            }
+            y += 32;
+        }
+        
+    }
+
+    virtual uint32_t onGetFlags() const SK_OVERRIDE {
+        // this GM is meant only for the GPU
+        return kGPUOnly_Flag;
+    }
+
+private:
+    SkTypeface* fTypefaces[TYPEFACE_COUNT];
+    SkString fName;
+    typedef GM INHERITED;
+};
+
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return SkNEW(FontCacheGM); )
+