Experimental Go bindings for Skia

This CL implements Go bindings for a subset of the functions in the C API. 
It implements a Go version of the C demo program in 
experimental/c-api-example/skia-c-example.c and the output is identical. 
(Checked by hand). 

The main purpose is to establish a pattern of calling the Skia C API that 
is memory safe and provides a idiomatic Go interface to Skia. 

Follow up CLs will cover the entire C API, add documentation and establish 
a pattern to distribute the bindings more easily.

BUG=
Change-Id: I96ff7c3715164c533202ce300ab0312b1b07f884

Change-Id: I96ff7c3715164c533202ce300ab0312b1b07f884
Reviewed-on: https://skia-review.googlesource.com/10032
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Stephan Altmueller <stephana@google.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/experimental/go-skia/types.go b/experimental/go-skia/types.go
new file mode 100644
index 0000000000..637eceea96
--- /dev/null
+++ b/experimental/go-skia/types.go
@@ -0,0 +1,65 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+// Created by cgo -godefs. Enum fields in structs were fixed by hand.
+// command: go tool cgo -godefs ctypes.go > types.go
+//
+// The purpose of this file is to have Go structs with the same memory
+// layout as their C counterparts. For enums we want the underlying primitive
+// types to match.
+//
+// TODO(stephan): Add tests that allow to detect failure on platforms other
+// than Linux and changes in the underlying C types.
+
+package skia
+
+type Color uint32
+
+type ColorType uint32
+
+const (
+	UNKNOWN_COLORTYPE   ColorType = 0x0
+	RGBA_8888_COLORTYPE ColorType = 0x1
+	BGRA_8888_COLORTYPE ColorType = 0x2
+	ALPHA_8_COLORTYPE   ColorType = 0x3
+)
+
+type AlphaType uint32
+
+const (
+	OPAQUE_ALPHATYPE   AlphaType = 0x0
+	PREMUL_ALPHATYPE   AlphaType = 0x1
+	UNPREMUL_ALPHATYPE AlphaType = 0x2
+)
+
+type PixelGeometry uint32
+
+const (
+	UNKNOWN_SK_PIXELGEOMETRY PixelGeometry = 0x0
+	RGB_H_SK_PIXELGEOMETRY   PixelGeometry = 0x1
+	BGR_H_SK_PIXELGEOMETRY   PixelGeometry = 0x2
+	RGB_V_SK_PIXELGEOMETRY   PixelGeometry = 0x3
+	BGR_V_SK_PIXELGEOMETRY   PixelGeometry = 0x4
+)
+
+type ImageInfo struct {
+	Width     int32
+	Height    int32
+	ColorType ColorType
+	AlphaType AlphaType
+}
+
+type SurfaceProps struct {
+	PixelGeometry PixelGeometry
+}
+
+type Rect struct {
+	Left   float32
+	Top    float32
+	Right  float32
+	Bottom float32
+}