C API: add sk_xfermode.h, impl, test

include/c/sk_types.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 // EXPERIMENTAL EXPERIMENTAL EXPERIMENTAL EXPERIMENTAL
 // DO NOT USE -- FOR INTERNAL TESTING ONLY
 
@@ skipping 90 matching lines @@
 typedef struct sk_data_t sk_data_t;
 typedef struct sk_image_t sk_image_t;
 typedef struct sk_maskfilter_t sk_maskfilter_t;
 typedef struct sk_paint_t sk_paint_t;
 typedef struct sk_path_t sk_path_t;
 typedef struct sk_picture_t sk_picture_t;
 typedef struct sk_picture_recorder_t sk_picture_recorder_t;
 typedef struct sk_shader_t sk_shader_t;
 typedef struct sk_surface_t sk_surface_t;
 
+typedef enum {
+    CLEAR_SK_XFERMODE_MODE,
+    SRC_SK_XFERMODE_MODE,
+    DST_SK_XFERMODE_MODE,
+    SRCOVER_SK_XFERMODE_MODE,
+    DSTOVER_SK_XFERMODE_MODE,
+    SRCIN_SK_XFERMODE_MODE,
+    DSTIN_SK_XFERMODE_MODE,
+    SRCOUT_SK_XFERMODE_MODE,
+    DSTOUT_SK_XFERMODE_MODE,
+    SRCATOP_SK_XFERMODE_MODE,
+    DSTATOP_SK_XFERMODE_MODE,
+    XOR_SK_XFERMODE_MODE,
+    PLUS_SK_XFERMODE_MODE,
+    MODULATE_SK_XFERMODE_MODE,
+    SCREEN_SK_XFERMODE_MODE,
+    OVERLAY_SK_XFERMODE_MODE,
+    DARKEN_SK_XFERMODE_MODE,
+    LIGHTEN_SK_XFERMODE_MODE,
+    COLORDODGE_SK_XFERMODE_MODE,
+    COLORBURN_SK_XFERMODE_MODE,
+    HARDLIGHT_SK_XFERMODE_MODE,
+    SOFTLIGHT_SK_XFERMODE_MODE,
+    DIFFERENCE_SK_XFERMODE_MODE,
+    EXCLUSION_SK_XFERMODE_MODE,
+    MULTIPLY_SK_XFERMODE_MODE,
+    HUE_SK_XFERMODE_MODE,
+    SATURATION_SK_XFERMODE_MODE,
+    COLOR_SK_XFERMODE_MODE,
+    LUMINOSITY_SK_XFERMODE_MODE,
+} sk_xfermode_mode_t;
+
 //////////////////////////////////////////////////////////////////////////////////////////
 
 #ifdef __cplusplus
     class SkCanvas;
     void sk_test_capi(SkCanvas*);
 #endif
 
 SK_C_PLUS_PLUS_END_GUARD
 
 #endif