Publicly expose one accelerated swizzle.

tests/SwizzlerTest.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 "SkSwizzle.h"
 #include "SkSwizzler.h"
 #include "Test.h"
 #include "SkOpts.h"
 
 // These are the values that we will look for to indicate that the fill was successful
 static const uint8_t kFillIndex = 0x11;
 static const uint8_t kFillGray = 0x22;
 static const uint16_t kFill565 = 0x3344;
 static const uint32_t kFillColor = 0x55667788;
 
@@ skipping 132 matching lines @@
     REPORTER_ASSERT(r, dst == 0xFACAAD04);
 
     // swap red and blue
     SkOpts::RGBA_to_BGRA(&dst, &src, 1);
     REPORTER_ASSERT(r, dst == 0xFA04B0CE);
 
     // all together now
     SkOpts::RGBA_to_bgrA(&dst, &src, 1);
     REPORTER_ASSERT(r, dst == 0xFA04ADCA);
 }
+
+DEF_TEST(PublicSwizzleOpts, r) {
+    uint32_t dst, src;
+
+    // forall c, c*255 == c, c*0 == 0
+    for (int c = 0; c <= 255; c++) {

[mtklein, 2016/03/23 17:35:13]

We making these public too?

[tomhudson, 2016/03/23 17:38:48]

My bad.
Done.

+        src = (255<<24) | c;
+        SkOpts::RGBA_to_rgbA(&dst, &src, 1);
+        REPORTER_ASSERT(r, dst == src);
+        SkOpts::RGBA_to_bgrA(&dst, &src, 1);
+        REPORTER_ASSERT(r, dst == (uint32_t)((255<<24) | (c<<16)));
+
+        src = (0<<24) | c;
+        SkOpts::RGBA_to_rgbA(&dst, &src, 1);
+        REPORTER_ASSERT(r, dst == 0);
+        SkOpts::RGBA_to_bgrA(&dst, &src, 1);
+        REPORTER_ASSERT(r, dst == 0);
+    }
+
+    // check a totally arbitrary color
+    src = 0xFACEB004;
+    SkSwapRB(&dst, &src, 1);
+    REPORTER_ASSERT(r, dst == 0xFA04B0CE);
+}