Support RGBA/BGRA Premul/Unpremul from SkPNGImageEncoder

tests/CodecTest.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Resources.h"
 #include "SkAndroidCodec.h"
 #include "SkBitmap.h"
@@ skipping 1056 matching lines @@
     SkAutoMalloc pixelStorage(dstInfo.getSafeSize(rowBytes));
     SkCodec::Result result = codec->getAndroidPixels(dstInfo, pixelStorage.get(), rowBytes, &opts);
     REPORTER_ASSERT(r, SkCodec::kSuccess == result);
 }
 
 DEF_TEST(Codec_ColorXform, r) {
     check_color_xform(r, "mandrill_512_q075.jpg");
     check_color_xform(r, "mandrill_512.png");
 }
 
-static void check_round_trip(skiatest::Reporter* r, const SkBitmap& bm1) {
-    SkColorType origColorType = bm1.colorType();
-    SkAlphaType origAlphaType = bm1.alphaType();
+static bool color_type_match(SkColorType origColorType, SkColorType codecColorType) {
+    switch (origColorType) {
+        case kRGBA_8888_SkColorType:
+        case kBGRA_8888_SkColorType:
+            return kRGBA_8888_SkColorType == codecColorType ||
+                   kBGRA_8888_SkColorType == codecColorType;
+        default:
+            return origColorType == codecColorType;
+    }
+}
+
+static bool alpha_type_match(SkAlphaType origAlphaType, SkAlphaType codecAlphaType) {
+    switch (origAlphaType) {
+        case kUnpremul_SkAlphaType:
+        case kPremul_SkAlphaType:
+            return kUnpremul_SkAlphaType == codecAlphaType ||
+                    kPremul_SkAlphaType == codecAlphaType;
+        default:
+            return origAlphaType == codecAlphaType;
+    }
+}
+
+static void check_round_trip(skiatest::Reporter* r, SkCodec* origCodec, const SkImageInfo& info) {
+    SkBitmap bm1;
+    bm1.allocPixels(info);
+    SkCodec::Result result = origCodec->getPixels(info, bm1.getPixels(), bm1.rowBytes());
+    REPORTER_ASSERT(r, SkCodec::kSuccess == result);
 
     // Encode the image to png.
     sk_sp<SkData> data =
             sk_sp<SkData>(SkImageEncoder::EncodeData(bm1, SkImageEncoder::kPNG_Type, 100));
 
-    // Prepare to decode.  The codec should recognize that the PNG is 565.
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(data.get()));
-    REPORTER_ASSERT(r, origColorType == codec->getInfo().colorType());
-    REPORTER_ASSERT(r, origAlphaType == codec->getInfo().alphaType());
+    REPORTER_ASSERT(r, color_type_match(info.colorType(), codec->getInfo().colorType()));
+    REPORTER_ASSERT(r, alpha_type_match(info.alphaType(), codec->getInfo().alphaType()));
 
     SkBitmap bm2;
-    bm2.allocPixels(codec->getInfo());
-    SkCodec::Result result = codec->getPixels(codec->getInfo(), bm2.getPixels(), bm2.rowBytes());
+    bm2.allocPixels(info);
+    result = codec->getPixels(info, bm2.getPixels(), bm2.rowBytes());
     REPORTER_ASSERT(r, SkCodec::kSuccess == result);
 
     SkMD5::Digest d1, d2;
     md5(bm1, &d1);
     md5(bm2, &d2);
     REPORTER_ASSERT(r, d1 == d2);
 }
 
 DEF_TEST(Codec_PngRoundTrip, r) {
-    // Create an arbitrary 565 bitmap.
     const char* path = "mandrill_512_q075.jpg";
     SkAutoTDelete<SkStream> stream(resource(path));
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.release()));
+
+    // Test 565
     SkImageInfo info565 = codec->getInfo().makeColorType(kRGB_565_SkColorType);
-    SkBitmap bm1;
-    bm1.allocPixels(info565);
-    SkCodec::Result result = codec->getPixels(info565, bm1.getPixels(), bm1.rowBytes());
-    REPORTER_ASSERT(r, SkCodec::kSuccess == result);
-    check_round_trip(r, bm1);
+    check_round_trip(r, codec.get(), info565);
 
-    // Create an arbitrary gray bitmap.
+    // Test RGBA opaque
+    SkImageInfo infoRGBA = codec->getInfo().makeColorType(kRGBA_8888_SkColorType);
+    check_round_trip(r, codec.get(), infoRGBA);
+
+    // Test BGRA opaque
+    SkImageInfo infoBGRA = codec->getInfo().makeColorType(kBGRA_8888_SkColorType);
+    check_round_trip(r, codec.get(), infoBGRA);
+
+    // Test Gray
     path = "grayscale.jpg";
     stream.reset(resource(path));
     codec.reset(SkCodec::NewFromStream(stream.release()));
-    SkBitmap bm2;
-    bm2.allocPixels(codec->getInfo());
-    result = codec->getPixels(codec->getInfo(), bm2.getPixels(), bm2.rowBytes());
-    REPORTER_ASSERT(r, SkCodec::kSuccess == result);
-    check_round_trip(r, bm2);
+    check_round_trip(r, codec.get(), codec->getInfo());
+
+    path = "arrow.png";
+    stream.reset(resource(path));
+    codec.reset(SkCodec::NewFromStream(stream.release()));
+
+    // Test RGBA/BGRA with alpha
+    SkImageInfo infoRGBAPremul = codec->getInfo().makeColorType(kRGBA_8888_SkColorType)
+                                                 .makeAlphaType(kPremul_SkAlphaType)
+                                                 .makeColorSpace(nullptr);
+    check_round_trip(r, codec.get(), infoRGBAPremul);
+    SkImageInfo infoBGRAPremul = codec->getInfo().makeColorType(kBGRA_8888_SkColorType)
+                                                 .makeAlphaType(kPremul_SkAlphaType)
+                                                 .makeColorSpace(nullptr);
+    check_round_trip(r, codec.get(), infoBGRAPremul);
+    SkImageInfo infoRGBAUnpremul = codec->getInfo().makeColorType(kRGBA_8888_SkColorType)
+                                                   .makeAlphaType(kUnpremul_SkAlphaType)
+                                                   .makeColorSpace(nullptr);
+    check_round_trip(r, codec.get(), infoRGBAUnpremul);
+    SkImageInfo infoBGRAUnpremul = codec->getInfo().makeColorType(kBGRA_8888_SkColorType)
+                                                   .makeAlphaType(kUnpremul_SkAlphaType)
+                                                   .makeColorSpace(nullptr);
+    check_round_trip(r, codec.get(), infoBGRAUnpremul);
 }
 
 static void test_conversion_possible(skiatest::Reporter* r, const char* path,
                                      bool testScanlineDecoder) {
     SkAutoTDelete<SkStream> stream(resource(path));
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.release()));
     SkImageInfo infoF16 = codec->getInfo().makeColorType(kRGBA_F16_SkColorType);
 
     SkBitmap bm;
     bm.allocPixels(infoF16);
@@ skipping 11 matching lines @@
         result = codec->startScanlineDecode(infoF16);
         REPORTER_ASSERT(r, SkCodec::kSuccess == result);
     }
 }
 
 DEF_TEST(Codec_F16ConversionPossible, r) {
     test_conversion_possible(r, "color_wheel.webp", false);
     test_conversion_possible(r, "mandrill_512_q075.jpg", true);
     test_conversion_possible(r, "yellow_rose.png", true);
 }