saveLayer experiments

Change-Id: Ic4f916cf3483244d5a79e32dc287a01dac41a650
Reviewed-on: https://skia-review.googlesource.com/7106
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>

1 files changed, 61 insertions, 16 deletions

diff --git a/gm/savelayer.cpp b/gm/savelayer.cpp
index 9b4db3530b..8f2d5c8299 100644
--- a/gm/savelayer.cpp
+++ b/gm/savelayer.cpp
@@ -7,17 +7,20 @@
 
 #include "gm.h"
 
-static void saveLayer(SkCanvas* canvas, SkScalar l, SkScalar t, SkScalar r, SkScalar b) {
-    uint32_t flag = 1U << 31;
+// This GM tests out the deprecated Android-specific unclipped saveLayer "feature".
+// In particular, it attempts to compare the performance of unclipped saveLayers with alternatives.
+
+static void save_layer_unclipped(SkCanvas* canvas,
+                                 SkScalar l, SkScalar t, SkScalar r, SkScalar b) {
+    static const uint32_t kSecretDeprecated_DontClipToLayerFlag = 1U << 31;
     SkRect rect = SkRect::MakeLTRB(l, t, r, b);
-    canvas->saveLayer({ &rect, nullptr, nullptr, flag });
+    canvas->saveLayer({ &rect, nullptr, nullptr, kSecretDeprecated_DontClipToLayerFlag });
 }
 
 static void do_draw(SkCanvas* canvas) {
     SkPaint paint;
     SkRandom rand;
 
-    SkAutoCanvasRestore acr(canvas, true);
     for (int i = 0; i < 20; ++i) {
         paint.setColor(rand.nextU() | (0xFF << 24));
         canvas->drawRect({ 15, 15, 290, 40 }, paint);
@@ -25,18 +28,60 @@ static void do_draw(SkCanvas* canvas) {
     }
 }
 
-DEF_SIMPLE_GM(savelayer_unclipped, canvas, 320, 640) {
-    const SkScalar L = 10;
-    const SkScalar T = 10;
-    const SkScalar R = 310;
-    const SkScalar B = 630;
+class UnclippedSaveLayerGM : public skiagm::GM {
+public:
+    enum class Mode {
+        kClipped,
+        kUnclipped
+    };
+
+    UnclippedSaveLayerGM(Mode mode) : fMode(mode) { this->setBGColor(SK_ColorWHITE); }
 
-    canvas->clipRect({ L, T, R, B });
+protected:
+    bool runAsBench() const override { return true; }
 
-    for (int i = 0; i < 100; ++i) {
-        SkAutoCanvasRestore acr(canvas, true);
-        saveLayer(canvas, L, T, R, T + 20);
-        saveLayer(canvas, L, B - 20, R, B);
-        do_draw(canvas);
+    SkString onShortName() override {
+        if (Mode::kClipped == fMode) {
+            return SkString("savelayer_unclipped");
+        } else {
+            SkASSERT(Mode::kUnclipped == fMode);
+            return SkString("savelayer_clipped");
+        }
     }
-}
+
+    SkISize onISize() override { return SkISize::Make(320, 640); }
+
+    void onDraw(SkCanvas* canvas) override {
+        const SkScalar L = 10;
+        const SkScalar T = 10;
+        const SkScalar R = 310;
+        const SkScalar B = 630;
+
+        canvas->clipRect({ L, T, R, B });
+
+        for (int i = 0; i < 100; ++i) {
+            SkAutoCanvasRestore acr(canvas, true);
+            if (Mode::kClipped == fMode) {
+                save_layer_unclipped(canvas, L, T, R, T + 20);
+                save_layer_unclipped(canvas, L, B - 20, R, B);
+            } else {
+                SkASSERT(Mode::kUnclipped == fMode);
+                canvas->saveLayer({ L, T, R, B }, nullptr);
+            } 
+
+            do_draw(canvas);
+        }
+    }
+
+private:
+    Mode fMode;
+
+    typedef skiagm::GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM(return new UnclippedSaveLayerGM(UnclippedSaveLayerGM::Mode::kClipped);)
+DEF_GM(return new UnclippedSaveLayerGM(UnclippedSaveLayerGM::Mode::kUnclipped);)
+
+