blend-strings: removes the AUTO_COMPOSITE function enum

This was mistakenly added some time ago because at some point when we
were discussing how to handle premultiplied alpha in Clutter/Cogl we
were considering having a magic "just do the right thing" option which
was later abandoned.

cogl/cogl-blend-string.c

@@ -103,7 +103,6 @@ static CoglBlendStringColorSourceInfo tex_combine_texture_n_color_source = {
 /* NB: These must be sorted so any name that's a subset of another
  * comes later than the longer name. */
 static CoglBlendStringFunctionInfo tex_combine_functions[] = {
-  DEFINE_FUNCTION (AUTO_COMPOSITE, 14, 0),
   DEFINE_FUNCTION (REPLACE, 7, 1),
   DEFINE_FUNCTION (MODULATE, 8, 2),
   DEFINE_FUNCTION (ADD_SIGNED, 10, 2),
@@ -115,7 +114,6 @@ static CoglBlendStringFunctionInfo tex_combine_functions[] = {
 };
 
 static CoglBlendStringFunctionInfo blend_functions[] = {
-  DEFINE_FUNCTION (AUTO_COMPOSITE, 14, 0),
   DEFINE_FUNCTION (ADD, 3, 2)
 };
 

cogl/cogl-blend-string.h

@@ -94,7 +94,6 @@ typedef struct _CoglBlendStringArgument
 typedef enum _CoglBlendStringFunctionType
 {
   /* shared */
-  COGL_BLEND_STRING_FUNCTION_AUTO_COMPOSITE,
   COGL_BLEND_STRING_FUNCTION_ADD,
 
   /* texture combine only */

cogl/cogl-material.c

@@ -1222,9 +1222,6 @@ setup_texture_combine_state (CoglBlendStringStatement *statement,
 
   switch (statement->function->type)
     {
-    case COGL_BLEND_STRING_FUNCTION_AUTO_COMPOSITE:
-      *texture_combine_func = GL_MODULATE; /* FIXME */
-      break;
     case COGL_BLEND_STRING_FUNCTION_REPLACE:
       *texture_combine_func = GL_REPLACE;
       break;