Add a macro for querying the byte order of SkPMColor.

include/core/SkPostConfig.h

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkPostConfig_DEFINED
@@ skipping 169 matching lines @@
         #define SK_B32_SHIFT    8
         #define SK_A32_SHIFT    0
     #else
         #define SK_R32_SHIFT    0
         #define SK_G32_SHIFT    8
         #define SK_B32_SHIFT    16
         #define SK_A32_SHIFT    24
     #endif
 #endif
 
+/**
+ * SK_PM_BYTE_ORDER_IS can be used to query the byte order of SkPMColor at compile time. E.g.:
+ * #if SK_PM_BYTE_ORDER_IS(B, G, R, A)

[epoger, 2013/03/11 17:26:32]

Clever!!!  Very nice.

+ *     SkDebugf("GDI-compatible SkPMColor");
+ * #endif
+ */
+#ifdef SK_CPU_BENDIAN
+    #define SK_PM_BYTE_ORDER_IS(C0, C1, C2, C3)     \
+        (SK_ ## C3 ## 32_SHIFT == 0  &&             \
+         SK_ ## C2 ## 32_SHIFT == 8  &&             \
+         SK_ ## C1 ## 32_SHIFT == 16 &&             \
+         SK_ ## C0 ## 32_SHIFT == 24)
+#else
+    #define SK_PM_BYTE_ORDER_IS(C0, C1, C2, C3)     \
+        (SK_ ## C0 ## 32_SHIFT == 0  &&             \
+         SK_ ## C1 ## 32_SHIFT == 8  &&             \
+         SK_ ## C2 ## 32_SHIFT == 16 &&             \
+         SK_ ## C3 ## 32_SHIFT == 24)
+#endif
+
 //  stdlib macros
 
 #if 0
 #if !defined(strlen) && defined(SK_DEBUG)
     extern size_t sk_strlen(const char*);
     #define strlen(s)   sk_strlen(s)
 #endif
 #ifndef sk_strcpy
     #define sk_strcpy(dst, src)     strcpy(dst, src)
 #endif
@@ skipping 132 matching lines @@
 #else
 #define SK_SIZE_T_SPECIFIER "%zu"
 #endif
 #endif
 
 //////////////////////////////////////////////////////////////////////
 
 #ifndef SK_ALLOW_STATIC_GLOBAL_INITIALIZERS
 #define SK_ALLOW_STATIC_GLOBAL_INITIALIZERS 1
 #endif