separate c headers

BUG=skia:

Review URL: https://codereview.chromium.org/728323002
diff --git a/include/c/sk_canvas.h b/include/c/sk_canvas.h
new file mode 100644
index 0000000..a99d1b8
--- /dev/null
+++ b/include/c/sk_canvas.h
@@ -0,0 +1,33 @@
+/*
+ * 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
+
+#ifndef sk_canvas_DEFINED
+#define sk_canvas_DEFINED
+
+#include "sk_types.h"
+
+SK_C_PLUS_PLUS_BEGIN_GUARD
+
+void sk_canvas_save(sk_canvas_t*);
+void sk_canvas_save_layer(sk_canvas_t*, const sk_rect_t*, const sk_paint_t*);
+void sk_canvas_restore(sk_canvas_t*);
+
+void sk_canvas_translate(sk_canvas_t*, float dx, float dy);
+void sk_canvas_scale(sk_canvas_t*, float sx, float sy);
+
+void sk_canvas_draw_paint(sk_canvas_t*, const sk_paint_t*);
+void sk_canvas_draw_rect(sk_canvas_t*, const sk_rect_t*, const sk_paint_t*);
+void sk_canvas_draw_oval(sk_canvas_t*, const sk_rect_t*, const sk_paint_t*);
+void sk_canvas_draw_path(sk_canvas_t*, const sk_path_t*, const sk_paint_t*);
+void sk_canvas_draw_image(sk_canvas_t*, const sk_image_t*, float x, float y, const sk_paint_t*);
+
+SK_C_PLUS_PLUS_END_GUARD
+
+#endif
diff --git a/include/c/sk_image.h b/include/c/sk_image.h
new file mode 100644
index 0000000..2449563
--- /dev/null
+++ b/include/c/sk_image.h
@@ -0,0 +1,31 @@
+/*
+ * 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
+
+#ifndef sk_image_DEFINED
+#define sk_image_DEFINED
+
+#include "sk_types.h"
+
+SK_C_PLUS_PLUS_BEGIN_GUARD
+
+/**
+ *  Return a new image that has made a copy of the provided pixels, or NULL on failure.
+ *  Balance with a call to sk_image_unref().
+ */
+sk_image_t* sk_image_new_raster_copy(const sk_imageinfo_t*, const void* pixels, size_t rowBytes);
+void sk_image_ref(const sk_image_t*);
+void sk_image_unref(const sk_image_t*);
+int sk_image_get_width(const sk_image_t*);
+int sk_image_get_height(const sk_image_t*);
+uint32_t sk_image_get_unique_id(const sk_image_t*);
+
+SK_C_PLUS_PLUS_END_GUARD
+
+#endif
diff --git a/include/c/sk_paint.h b/include/c/sk_paint.h
new file mode 100644
index 0000000..840433b
--- /dev/null
+++ b/include/c/sk_paint.h
@@ -0,0 +1,27 @@
+/*
+ * 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
+
+#ifndef sk_paint_DEFINED
+#define sk_paint_DEFINED
+
+#include "sk_types.h"
+
+SK_C_PLUS_PLUS_BEGIN_GUARD
+
+sk_paint_t* sk_paint_new();
+void sk_paint_delete(sk_paint_t*);
+bool sk_paint_is_antialias(const sk_paint_t*);
+void sk_paint_set_antialias(sk_paint_t*, bool);
+sk_color_t sk_paint_get_color(const sk_paint_t*);
+void sk_paint_set_color(sk_paint_t*, sk_color_t);
+
+SK_C_PLUS_PLUS_END_GUARD
+
+#endif
diff --git a/include/c/sk_path.h b/include/c/sk_path.h
new file mode 100644
index 0000000..801e148
--- /dev/null
+++ b/include/c/sk_path.h
@@ -0,0 +1,45 @@
+/*
+ * 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
+
+#ifndef sk_path_DEFINED
+#define sk_path_DEFINED
+
+#include "sk_types.h"
+
+SK_C_PLUS_PLUS_BEGIN_GUARD
+
+typedef enum {
+    CW_SK_PATH_DIRECTION,
+    CCW_SK_PATH_DIRECTION,
+} sk_path_direction_t;
+
+sk_path_t* sk_path_new();
+void sk_path_delete(sk_path_t*);
+
+void sk_path_move_to(sk_path_t*, float x, float y);
+void sk_path_line_to(sk_path_t*, float x, float y);
+void sk_path_quad_to(sk_path_t*, float x0, float y0, float x1, float y1);
+void sk_path_conic_to(sk_path_t*, float x0, float y0, float x1, float y1, float w);
+void sk_path_cubic_to(sk_path_t*, float x0, float y0, float x1, float y1, float x2, float y2);
+void sk_path_close(sk_path_t*);
+
+void sk_path_add_rect(sk_path_t*, const sk_rect_t*, sk_path_direction_t);
+void sk_path_add_oval(sk_path_t*, const sk_rect_t*, sk_path_direction_t);
+
+/**
+ *  If the path is empty, return false and set the rect parameter to [0, 0, 0, 0].
+ *  else return true and set the rect parameter to the bounds of the control-points
+ *  of the path.
+ */
+bool sk_path_get_bounds(const sk_path_t*, sk_rect_t*);
+
+SK_C_PLUS_PLUS_END_GUARD
+
+#endif
diff --git a/include/c/sk_surface.h b/include/c/sk_surface.h
index 5fcf9dd..96aa32f 100644
--- a/include/c/sk_surface.h
+++ b/include/c/sk_surface.h
@@ -8,103 +8,12 @@
 // EXPERIMENTAL EXPERIMENTAL EXPERIMENTAL EXPERIMENTAL
 // DO NOT USE -- FOR INTERNAL TESTING ONLY
 
-#ifndef sk_types_DEFINED
-#define sk_types_DEFINED
+#ifndef sk_surface_DEFINED
+#define sk_surface_DEFINED
 
-#include <stdint.h>
-#include <stddef.h>
+#include "sk_types.h"
 
-#ifndef __cplusplus
-#include <stdbool.h>
-#endif
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-typedef uint32_t sk_color_t;
-
-#define sk_color_set_argb(a, r, g, b)   (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
-#define sk_color_get_a(c)               (((c) >> 24) & 0xFF)
-#define sk_color_get_r(c)               (((c) >> 16) & 0xFF)
-#define sk_color_get_g(c)               (((c) >>  8) & 0xFF)
-#define sk_color_get_b(c)               (((c) >>  0) & 0xFF)
-
-typedef enum {
-    UNKNOWN_SK_COLORTYPE,
-    RGBA_8888_SK_COLORTYPE,
-    BGRA_8888_SK_COLORTYPE,
-    ALPHA_8_SK_COLORTYPE,
-} sk_colortype_t;
-
-typedef enum {
-    OPAQUE_SK_ALPHATYPE,
-    PREMUL_SK_ALPHATYPE,
-    UNPREMUL_SK_ALPHATYPE,
-} sk_alphatype_t;
-
-sk_colortype_t sk_colortype_get_default_8888();
-
-typedef struct {
-    int32_t         width;
-    int32_t         height;
-    sk_colortype_t  colorType;
-    sk_alphatype_t  alphaType;
-} sk_imageinfo_t;
-
-typedef struct {
-    float   left;
-    float   top;
-    float   right;
-    float   bottom;
-} sk_rect_t;
-
-typedef struct sk_path_t sk_path_t;
-
-sk_path_t* sk_path_new();
-void sk_path_delete(sk_path_t*);
-void sk_path_move_to(sk_path_t*, float x, float y);
-void sk_path_line_to(sk_path_t*, float x, float y);
-void sk_path_quad_to(sk_path_t*, float x0, float y0, float x1, float y1);
-void sk_path_close(sk_path_t*);
-
-typedef struct sk_paint_t sk_paint_t;
-
-sk_paint_t* sk_paint_new();
-void sk_paint_delete(sk_paint_t*);
-bool sk_paint_is_antialias(const sk_paint_t*);
-void sk_paint_set_antialias(sk_paint_t*, bool);
-sk_color_t sk_paint_get_color(const sk_paint_t*);
-void sk_paint_set_color(sk_paint_t*, sk_color_t);
-
-typedef struct sk_canvas_t sk_canvas_t;
-typedef struct sk_image_t sk_image_t;
-
-void sk_canvas_save(sk_canvas_t*);
-void sk_canvas_save_layer(sk_canvas_t*, const sk_rect_t*, const sk_paint_t*);
-void sk_canvas_restore(sk_canvas_t*);
-
-void sk_canvas_translate(sk_canvas_t*, float dx, float dy);
-void sk_canvas_scale(sk_canvas_t*, float sx, float sy);
-
-void sk_canvas_draw_paint(sk_canvas_t*, const sk_paint_t*);
-void sk_canvas_draw_rect(sk_canvas_t*, const sk_rect_t*, const sk_paint_t*);
-void sk_canvas_draw_oval(sk_canvas_t*, const sk_rect_t*, const sk_paint_t*);
-void sk_canvas_draw_path(sk_canvas_t*, const sk_path_t*, const sk_paint_t*);
-void sk_canvas_draw_image(sk_canvas_t*, const sk_image_t*, float x, float y, const sk_paint_t*);
-
-/**
- *  Return a new image that has made a copy of the provided pixels, or NULL on failure.
- *  Balance with a call to sk_image_unref().
- */
-sk_image_t* sk_image_new_raster_copy(const sk_imageinfo_t*, const void* pixels, size_t rowBytes);
-void sk_image_ref(const sk_image_t*);
-void sk_image_unref(const sk_image_t*);
-int sk_image_get_width(const sk_image_t*);
-int sk_image_get_height(const sk_image_t*);
-uint32_t sk_image_get_unique_id(const sk_image_t*);
-
-typedef struct sk_surface_t sk_surface_t;
+SK_C_PLUS_PLUS_BEGIN_GUARD
 
 sk_surface_t* sk_surface_new_raster(const sk_imageinfo_t*);
 sk_surface_t* sk_surface_new_raster_direct(const sk_imageinfo_t*, void* pixels, size_t rowBytes);
@@ -115,12 +24,17 @@
  *  so the returned object is only valid while the owning surface is valid.
  */
 sk_canvas_t* sk_surface_get_canvas(sk_surface_t*);
+
+/**
+ *  Call sk_image_unref() when the returned image is no longer used.
+ */
 sk_image_t* sk_surface_new_image_snapshot(sk_surface_t*);
 
 #ifdef __cplusplus
     class SkCanvas;
     void sk_test_capi(SkCanvas*);
-}
 #endif
 
+SK_C_PLUS_PLUS_END_GUARD
+
 #endif
diff --git a/include/c/sk_types.h b/include/c/sk_types.h
new file mode 100644
index 0000000..71ce219
--- /dev/null
+++ b/include/c/sk_types.h
@@ -0,0 +1,82 @@
+/*
+ * 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
+
+#ifndef sk_types_DEFINED
+#define sk_types_DEFINED
+
+#include <stdint.h>
+#include <stddef.h>
+
+#ifdef __cplusplus
+    #define SK_C_PLUS_PLUS_BEGIN_GUARD    extern "C" {
+    #define SK_C_PLUS_PLUS_END_GUARD      }
+#else
+    #include <stdbool.h>
+    #define SK_C_PLUS_PLUS_BEGIN_GUARD
+    #define SK_C_PLUS_PLUS_END_GUARD
+#endif
+
+///////////////////////////////////////////////////////////////////////////////////////
+
+SK_C_PLUS_PLUS_BEGIN_GUARD
+
+typedef uint32_t sk_color_t;
+
+#define sk_color_set_argb(a, r, g, b)   (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
+#define sk_color_get_a(c)               (((c) >> 24) & 0xFF)
+#define sk_color_get_r(c)               (((c) >> 16) & 0xFF)
+#define sk_color_get_g(c)               (((c) >>  8) & 0xFF)
+#define sk_color_get_b(c)               (((c) >>  0) & 0xFF)
+
+typedef enum {
+    UNKNOWN_SK_COLORTYPE,
+    RGBA_8888_SK_COLORTYPE,
+    BGRA_8888_SK_COLORTYPE,
+    ALPHA_8_SK_COLORTYPE,
+} sk_colortype_t;
+
+typedef enum {
+    OPAQUE_SK_ALPHATYPE,
+    PREMUL_SK_ALPHATYPE,
+    UNPREMUL_SK_ALPHATYPE,
+} sk_alphatype_t;
+
+sk_colortype_t sk_colortype_get_default_8888();
+
+typedef struct {
+    int32_t         width;
+    int32_t         height;
+    sk_colortype_t  colorType;
+    sk_alphatype_t  alphaType;
+} sk_imageinfo_t;
+
+typedef struct {
+    float   left;
+    float   top;
+    float   right;
+    float   bottom;
+} sk_rect_t;
+
+typedef struct sk_canvas_t sk_canvas_t;
+typedef struct sk_image_t sk_image_t;
+typedef struct sk_paint_t sk_paint_t;
+typedef struct sk_path_t sk_path_t;
+typedef struct sk_surface_t sk_surface_t;
+
+//////////////////////////////////////////////////////////////////////////////////////////
+
+#ifdef __cplusplus
+    class SkCanvas;
+    void sk_test_capi(SkCanvas*);
+#endif
+
+SK_C_PLUS_PLUS_END_GUARD
+
+#endif
diff --git a/src/c/sk_surface.cpp b/src/c/sk_surface.cpp
index ec16fc2..45a1ef9 100644
--- a/src/c/sk_surface.cpp
+++ b/src/c/sk_surface.cpp
@@ -5,6 +5,10 @@
  * found in the LICENSE file.
  */
 
+#include "sk_canvas.h"
+#include "sk_image.h"
+#include "sk_paint.h"
+#include "sk_path.h"
 #include "sk_surface.h"
 
 #include "SkCanvas.h"
@@ -87,10 +91,34 @@
     return true;
 }
 
+const struct {
+    sk_path_direction_t fC;
+    SkPath::Direction   fSk;
+} gPathDirMap[] = {
+    { CW_SK_PATH_DIRECTION,  SkPath::kCW_Direction },
+    { CCW_SK_PATH_DIRECTION, SkPath::kCCW_Direction },
+};
+
+static bool from_c_path_direction(sk_path_direction_t cdir, SkPath::Direction* dir) {
+    for (size_t i = 0; i < SK_ARRAY_COUNT(gPathDirMap); ++i) {
+        if (gPathDirMap[i].fC == cdir) {
+            if (dir) {
+                *dir = gPathDirMap[i].fSk;
+            }
+            return true;
+        }
+    }
+    return false;
+}
+
 static const SkRect& AsRect(const sk_rect_t& crect) {
     return reinterpret_cast<const SkRect&>(crect);
 }
 
+static SkRect* as_rect(sk_rect_t* crect) {
+    return reinterpret_cast<SkRect*>(crect);
+}
+
 static const SkPath& AsPath(const sk_path_t& cpath) {
     return reinterpret_cast<const SkPath&>(cpath);
 }
@@ -208,10 +236,48 @@
     as_path(cpath)->quadTo(x0, y0, x1, y1);
 }
 
+void sk_path_conic_to(sk_path_t* cpath, float x0, float y0, float x1, float y1, float w) {
+    as_path(cpath)->conicTo(x0, y0, x1, y1, w);
+}
+
+void sk_path_cubic_to(sk_path_t* cpath, float x0, float y0, float x1, float y1, float x2, float y2) {
+    as_path(cpath)->cubicTo(x0, y0, x1, y1, x2, y2);
+}
+
 void sk_path_close(sk_path_t* cpath) {
     as_path(cpath)->close();
 }
 
+void sk_path_add_rect(sk_path_t* cpath, const sk_rect_t* crect, sk_path_direction_t cdir) {
+    SkPath::Direction dir;
+    if (!from_c_path_direction(cdir, &dir)) {
+        return;
+    }
+    as_path(cpath)->addRect(AsRect(*crect), dir);
+}
+
+void sk_path_add_oval(sk_path_t* cpath, const sk_rect_t* crect, sk_path_direction_t cdir) {
+    SkPath::Direction dir;
+    if (!from_c_path_direction(cdir, &dir)) {
+        return;
+    }
+    as_path(cpath)->addOval(AsRect(*crect), dir);
+}
+
+bool sk_path_get_bounds(const sk_path_t* cpath, sk_rect_t* crect) {
+    const SkPath& path = AsPath(*cpath);
+    SkRect* rect = as_rect(crect);
+
+    if (path.isEmpty()) {
+        if (rect) {
+            rect->setEmpty();
+        }
+        return false;
+    }
+    *rect = path.getBounds();
+    return true;
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////
 
 void sk_canvas_save(sk_canvas_t* ccanvas) {
diff --git a/tests/CTest.cpp b/tests/CTest.cpp
index f663dcf..8127e9b 100644
--- a/tests/CTest.cpp
+++ b/tests/CTest.cpp
@@ -5,7 +5,10 @@
  * found in the LICENSE file.
  */
 
+#include "sk_canvas.h"
+#include "sk_paint.h"
 #include "sk_surface.h"
+
 #include "Test.h"
 
 static void test_c(skiatest::Reporter* reporter) {