Add test for platform encoders, turn off platform encoders by default

gm/encode-platform.cpp

Index: gm/encode-platform.cpp
diff --git a/gm/encode-platform.cpp b/gm/encode-platform.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..90f6aa9b9479e929b76588dad66091f75b29837b
--- /dev/null
+++ b/gm/encode-platform.cpp
@@ -0,0 +1,121 @@
+/*
+ * 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 "Resources.h"
+#include "SkCanvas.h"
+#include "SkData.h"
+#include "SkImageEncoder.h"
+#include "SkUnPreMultiply.h"
+
+namespace skiagm {
+
+static void make_opaque_256(SkBitmap* bitmap) {
+    GetResourceAsBitmap("mandrill_256.png", bitmap);
+}
+
+static void make_premul_256(SkBitmap* bitmap) {
+    SkBitmap tmp;
+    GetResourceAsBitmap("yellow_rose.png", &tmp);
+    tmp.extractSubset(bitmap, SkIRect::MakeWH(256, 256));
+    bitmap->lockPixels();
+}
+
+static void make_unpremul_256(SkBitmap* bitmap) {
+    make_premul_256(bitmap);
+    for (int y = 0; y < bitmap->height(); y++) {
+        for (int x = 0; x < bitmap->width(); x++) {
+            SkPMColor* pixel = bitmap->getAddr32(x, y);
+            *pixel = SkUnPreMultiply::UnPreMultiplyPreservingByteOrder(*pixel);
+        }
+    }
+    bitmap->setAlphaType(kUnpremul_SkAlphaType);
+}
+
+static SkImageEncoder* make_encoder(SkImageEncoder::Type type) {
+#if defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)
+    return CreateImageEncoder_CG(type);
+#elif defined(SK_BUILD_FOR_WIN)
+    return CreateImageEncoder_WIC(type);
+#else
+    switch (type) {
+        case SkImageEncoder::kPNG_Type:
+            return CreatePNGImageEncoder();
+        case SkImageEncoder::kJPEG_Type:
+            return CreateJPEGImageEncoder();
+        case SkImageEncoder::kWEBP_Type:
+            return CreateWEBPImageEncoder();
+        default:
+            SkASSERT(false);
+            return nullptr;
+    }
+#endif
+}
+
+#if defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)
+static SkImageEncoder::Type kTypes[] {
+        SkImageEncoder::kPNG_Type, SkImageEncoder::kJPEG_Type, SkImageEncoder::kGIF_Type,
+        SkImageEncoder::kBMP_Type, SkImageEncoder::kICO_Type,
+};
+#elif defined(SK_BUILD_FOR_WIN)
+// Use PNG multiple times because our WIC encoder does not support GIF, BMP, or ICO.
+static SkImageEncoder::Type kTypes[] {
+        SkImageEncoder::kPNG_Type, SkImageEncoder::kJPEG_Type, SkImageEncoder::kPNG_Type,
+        SkImageEncoder::kPNG_Type, SkImageEncoder::kPNG_Type,
+};
+#else
+// Use WEBP in place of GIF.  Use PNG two extra times.  We don't support GIF, BMP, or ICO.
+static SkImageEncoder::Type kTypes[] {
+        SkImageEncoder::kPNG_Type, SkImageEncoder::kJPEG_Type, SkImageEncoder::kWEBP_Type,
+        SkImageEncoder::kPNG_Type, SkImageEncoder::kPNG_Type,
+};
+#endif
+
+
+class EncodePlatformGM : public GM {
+public:
+    EncodePlatformGM() {}
+
+protected:
+    SkString onShortName() override {
+        return SkString("encode-platform");
+    }
+
+    SkISize onISize() override {
+        return SkISize::Make(256 * SK_ARRAY_COUNT(kTypes), 256 * 3);
+    }
+
+    void onDraw(SkCanvas* canvas) override {
+        SkBitmap opaqueBm, premulBm, unpremulBm;
+        make_opaque_256(&opaqueBm);
+        make_premul_256(&premulBm);
+        make_unpremul_256(&unpremulBm);
+
+        for (SkImageEncoder::Type type : kTypes) {
+            SkAutoTDelete<SkImageEncoder> encoder(make_encoder(type));
+            sk_sp<SkData> opaqueData(encoder->encodeData(opaqueBm, 100));
+            sk_sp<SkData> premulData(encoder->encodeData(premulBm, 100));
+            sk_sp<SkData> unpremulData(encoder->encodeData(unpremulBm, 100));
+
+            sk_sp<SkImage> opaqueImage = SkImage::MakeFromEncoded(opaqueData);
+            sk_sp<SkImage> premulImage = SkImage::MakeFromEncoded(premulData);
+            sk_sp<SkImage> unpremulImage = SkImage::MakeFromEncoded(unpremulData);
+
+            canvas->drawImage(opaqueImage.get(), 0.0f, 0.0f);
+            canvas->drawImage(premulImage.get(), 0.0f, 256.0f);
+            canvas->drawImage(unpremulImage.get(), 0.0f, 512.0f);
+
+            canvas->translate(256.0f, 0.0f);
+        }
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+DEF_GM( return new EncodePlatformGM; )
+}