hide Config8888 entirely

include/core/SkColorPriv.h

Index: include/core/SkColorPriv.h
diff --git a/include/core/SkColorPriv.h b/include/core/SkColorPriv.h
index 7a74c4a034b24a079504fd790a92bcd67014f73f..de2b6489403debc6385859425606fcbd5d5de6e1 100644
--- a/include/core/SkColorPriv.h
+++ b/include/core/SkColorPriv.h
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2006 The Android Open Source Project
  *
@@ -6,7 +5,6 @@
  * found in the LICENSE file.
  */
 
-
 #ifndef SkColorPriv_DEFINED
 #define SkColorPriv_DEFINED
 
@@ -18,6 +16,80 @@
 #include "SkColor.h"
 #include "SkMath.h"
 
+//////////////////////////////////////////////////////////////////////////////
+
+#define SkASSERT_IS_BYTE(x)     SkASSERT(0 == ((x) & 0xFF))

[bsalomon, 2014/03/19 12:36:48]

Isn't this asserting that the lower 8 are zero?

[reed1, 2014/03/19 17:59:58]

Doh!

+
+/*
+ *  Skia's 32bit backend only supports 1 sizzle order at a time (compile-time).
+ *  This is specified by 4 defines SK_A32_SHIFT, SK_R32_SHIFT, ... for G and B.
+ *
+ *  For easier compatibility with Skia's GPU backend, we further restrict these
+ *  to either (in memory-byte-order) RGBA or BGRA. Note that this "order" does
+ *  not directly correspond to the same shift-order, since we have to take endianess
+ *  into account.
+ *
+ *  Here we enforce this constraint.
+ */
+
+#ifdef SK_CPU_BENDIAN
+    #define SK_RGBA_R32_SHIFT   24
+    #define SK_RGBA_G32_SHIFT   16
+    #define SK_RGBA_B32_SHIFT   8
+    #define SK_RGBA_A32_SHIFT   0
+
+    #define SK_BGRA_B32_SHIFT   24
+    #define SK_BGRA_G32_SHIFT   16
+    #define SK_BGRA_R32_SHIFT   8
+    #define SK_BGRA_A32_SHIFT   0
+#else
+    #define SK_RGBA_R32_SHIFT   0
+    #define SK_RGBA_G32_SHIFT   8
+    #define SK_RGBA_B32_SHIFT   16
+    #define SK_RGBA_A32_SHIFT   24
+
+    #define SK_BGRA_B32_SHIFT   0
+    #define SK_BGRA_G32_SHIFT   8
+    #define SK_BGRA_R32_SHIFT   16
+    #define SK_BGRA_A32_SHIFT   24
+#endif
+
+// Now we check that we are in a support shift-order
+
+#if     SK_A32_SHIFT == SK_RGBA_A32_SHIFT &&    \
+        SK_R32_SHIFT == SK_RGBA_R32_SHIFT &&    \
+        SK_G32_SHIFT == SK_RGBA_G32_SHIFT &&    \
+        SK_B32_SHIFT == SK_RGBA_B32_SHIFT
+    #define SK_PMCOLOR_IS_RGBA

[bsalomon, 2014/03/19 12:36:48]

It'd be nice to allow the user (SkUserConfig.h, gyp file, ...) to specify these
directly instead of the SHIFT values.

In the transition time we'd have to check for either and if both are defined
verify that they're consistent.

[reed1, 2014/03/19 17:59:58]

I can try adding checks now that if they've specified PMCOLOR_IS already, that
everything makes sense. I agree that, down the road, we may want to *only*
expose that as a settable define.

+#elif   SK_A32_SHIFT == SK_BGRA_A32_SHIFT &&    \
+        SK_R32_SHIFT == SK_BGRA_R32_SHIFT &&    \
+        SK_G32_SHIFT == SK_BGRA_G32_SHIFT &&    \
+        SK_B32_SHIFT == SK_BGRA_B32_SHIFT
+    #define SK_PMCOLOR_IS_BGRA
+#else
+    #error "need 32bit packing to be either RGBA or BGRA"
+#endif
+
+static inline uint32_t SkPackARGB_as_RGBA(U8CPU a, U8CPU r, U8CPU g, U8CPU b) {
+    SkASSERT_IS_BYTE(a);
+    SkASSERT_IS_BYTE(r);
+    SkASSERT_IS_BYTE(g);
+    SkASSERT_IS_BYTE(b);
+    return (a << SK_RGBA_A32_SHIFT) | (r << SK_RGBA_R32_SHIFT) |
+           (g << SK_RGBA_G32_SHIFT) | (b << SK_RGBA_B32_SHIFT);
+}
+
+static inline uint32_t SkPackARGB_as_BGRA(U8CPU a, U8CPU r, U8CPU g, U8CPU b) {
+    SkASSERT_IS_BYTE(a);
+    SkASSERT_IS_BYTE(r);
+    SkASSERT_IS_BYTE(g);
+    SkASSERT_IS_BYTE(b);
+    return (a << SK_BGRA_A32_SHIFT) | (r << SK_BGRA_R32_SHIFT) |
+           (g << SK_BGRA_G32_SHIFT) | (b << SK_BGRA_B32_SHIFT);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
 ///@{
 /** See ITU-R Recommendation BT.709 at http://www.itu.int/rec/R-REC-BT.709/ .*/
 #define SK_ITU_BT709_LUM_COEFF_R (0.2126f)
@@ -239,6 +311,16 @@ static inline SkPMColor SkPackARGB32(U8CPU a, U8CPU r, U8CPU g, U8CPU b) {
            (g << SK_G32_SHIFT) | (b << SK_B32_SHIFT);
 }
 
+static inline uint32_t SkPackPMColor_as_RGBA(SkPMColor c) {
+    return SkPackARGB_as_RGBA(SkGetPackedA32(c), SkGetPackedR32(c),
+                              SkGetPackedG32(c), SkGetPackedB32(c));
+}
+
+static inline uint32_t SkPackPMColor_as_BGRA(SkPMColor c) {
+    return SkPackARGB_as_BGRA(SkGetPackedA32(c), SkGetPackedR32(c),
+                              SkGetPackedG32(c), SkGetPackedB32(c));
+}
+
 /**
  * Abstract 4-byte interpolation, implemented on top of SkPMColor
  * utility functions. Third parameter controls blending of the first two: