Sort config IDs by smaller color component depth.

This helps select configs without alpha component.
Also fixed handling of EGL_DONT_CARE and EGL_BUFFER_SIZE.

Bug 21538709

Change-Id: I432a71e5df2a0da19a0c38195edf6c42c2d8b9aa
Reviewed-on: https://swiftshader-review.googlesource.com/3370
Reviewed-by: Alexis Hétu <sugoi@google.com>
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>

src/OpenGL/libEGL/Config.cpp

diff --git a/src/OpenGL/libEGL/Config.cpp b/src/OpenGL/libEGL/Config.cpp
index ecafb74..f35a207 100644
--- a/src/OpenGL/libEGL/Config.cpp
+++ b/src/OpenGL/libEGL/Config.cpp
@@ -34,48 +34,44 @@
 
     switch (renderTargetFormat)
     {
-      case sw::FORMAT_A1R5G5B5:
-        mBufferSize = 16;
+    case sw::FORMAT_A1R5G5B5:
         mRedSize = 5;
         mGreenSize = 5;
         mBlueSize = 5;
         mAlphaSize = 1;
         break;
-      case sw::FORMAT_A2R10G10B10:
-        mBufferSize = 32;
+    case sw::FORMAT_A2R10G10B10:
         mRedSize = 10;
         mGreenSize = 10;
         mBlueSize = 10;
         mAlphaSize = 2;
         break;
-      case sw::FORMAT_A8R8G8B8:
-        mBufferSize = 32;
+    case sw::FORMAT_A8R8G8B8:
         mRedSize = 8;
         mGreenSize = 8;
         mBlueSize = 8;
         mAlphaSize = 8;
         mBindToTextureRGBA = EGL_TRUE;
         break;
-      case sw::FORMAT_R5G6B5:
-        mBufferSize = 16;
+    case sw::FORMAT_R5G6B5:
         mRedSize = 5;
         mGreenSize = 6;
         mBlueSize = 5;
         mAlphaSize = 0;
         break;
-      case sw::FORMAT_X8R8G8B8:
-        mBufferSize = 32;
+    case sw::FORMAT_X8R8G8B8:
         mRedSize = 8;
         mGreenSize = 8;
         mBlueSize = 8;
         mAlphaSize = 0;
         mBindToTextureRGB = EGL_TRUE;
         break;
-      default:
+    default:
         UNREACHABLE();   // Other formats should not be valid
     }
 
     mLuminanceSize = 0;
+    mBufferSize = mRedSize + mGreenSize + mBlueSize + mLuminanceSize + mAlphaSize;
     mAlphaMaskSize = 0;
     mColorBufferType = EGL_RGB_BUFFER;
     mConfigCaveat = isSlowConfig() ? EGL_SLOW_CONFIG : EGL_NONE;
@@ -124,7 +120,7 @@
 //      mDepthSize = 24;
 //      mStencilSize = 8;
 //      break;
-	  default:
+	default:
 		UNREACHABLE();
 	}
 
@@ -167,22 +163,16 @@
             return x.attribute < y.attribute;      \
         }
 
-	#define SORT_LARGER(attribute)                \
-        if(x.attribute != y.attribute)             \
-        {                                          \
-            return x.attribute > y.attribute;      \
-        }
-
     META_ASSERT(EGL_NONE < EGL_SLOW_CONFIG && EGL_SLOW_CONFIG < EGL_NON_CONFORMANT_CONFIG);
     SORT_SMALLER(mConfigCaveat);
 
     META_ASSERT(EGL_RGB_BUFFER < EGL_LUMINANCE_BUFFER);
     SORT_SMALLER(mColorBufferType);
 
-	SORT_LARGER(mRedSize);
-	SORT_LARGER(mGreenSize);
-	SORT_LARGER(mBlueSize);
-	SORT_LARGER(mAlphaSize);
+	SORT_SMALLER(mRedSize);
+	SORT_SMALLER(mGreenSize);
+	SORT_SMALLER(mBlueSize);
+	SORT_SMALLER(mAlphaSize);
     
 	SORT_SMALLER(mBufferSize);
     SORT_SMALLER(mSampleBuffers);
@@ -193,7 +183,6 @@
     SORT_SMALLER(mNativeVisualType);
 
     #undef SORT_SMALLER
-	#undef SORT_LARGER
 
 	// Strict ordering requires sorting all non-equal fields above
 	assert(memcmp(&x, &y, sizeof(Config)) == 0);
@@ -201,22 +190,22 @@
     return false;
 }
 
-// Function object used by STL sorting routines for ordering Configs according to [EGL] section 3.4.1 page 24.

-class SortConfig

-{

-public:

-    explicit SortConfig(const EGLint *attribList);

-

-    bool operator()(const Config *x, const Config *y) const;

-

-private:

-    EGLint wantedComponentsSize(const Config *config) const;

-

-    bool mWantRed;

-    bool mWantGreen;

-    bool mWantBlue;

-    bool mWantAlpha;

-    bool mWantLuminance;

+// Function object used by STL sorting routines for ordering Configs according to [EGL] section 3.4.1 page 24.
+class SortConfig
+{
+public:
+    explicit SortConfig(const EGLint *attribList);
+
+    bool operator()(const Config *x, const Config *y) const;
+
+private:
+    EGLint wantedComponentsSize(const Config *config) const;
+
+    bool mWantRed;
+    bool mWantGreen;
+    bool mWantBlue;
+    bool mWantAlpha;
+    bool mWantLuminance;
 };
 
 SortConfig::SortConfig(const EGLint *attribList)
@@ -318,6 +307,11 @@
 
         while(attribute[0] != EGL_NONE)
         {
+			if(attribute[1] == EGL_DONT_CARE)
+			{
+				continue;
+			}
+
             switch(attribute[0])
             {
             case EGL_BUFFER_SIZE:                match = config->mBufferSize >= attribute[1];                      break;