Attach YUV420 to RGB converter to GLContext

ui/gl/yuv420_rgb_converter.h

Index: ui/gl/yuv420_rgb_converter.h
diff --git a/ui/gl/yuv420_rgb_converter.h b/ui/gl/yuv420_rgb_converter.h
new file mode 100644
index 0000000000000000000000000000000000000000..de6b7f3bfdc16dca07fc93ff4eb9a0c1ea584039
--- /dev/null
+++ b/ui/gl/yuv420_rgb_converter.h
@@ -0,0 +1,32 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_GL_YUV420_RGB_CONVERTER_H_
+#define UI_GL_YUV420_RGB_CONVERTER_H_
+
+#include "ui/gfx/geometry/size.h"
+
+namespace gfx {

[Daniele Castagna, 2016/04/16 02:45:59]

Shouldn't this be gl?

[ccameron, 2016/04/16 16:19:19]

Done.

+
+class YUV420RGBConverter {

[Daniele Castagna, 2016/04/16 02:45:59]

I'm not sure about the name.
YUV420 doesn't identify a specific YUV format (I guess you could say both NV12
and I420 are YUV420). Maybe we don't really want to specify one though.
For CrOS we'll have to implement something similar to this converter for UYVY.

We could just call this class YUVToRBGConverter and have different CopyTexImage
methods, one for each source format.

Conversely, in case we want to have one class for each format, we should
probably be more specific about the YUV format in the name of the class.

[ccameron, 2016/04/16 16:19:19]

I changed the structure from YUV420RGBConverter to YUVToRGBConverter, and then
added a specific method for 420 biplanar to RGB.

+ public:
+  YUV420RGBConverter();
+  ~YUV420RGBConverter();
+  void CopyTexImage(unsigned target,
+                    unsigned y_texture,
+                    unsigned uv_texture,
+                    const gfx::Size& size);
+
+ private:
+  unsigned framebuffer_ = 0;
+  unsigned vertex_shader_ = 0;
+  unsigned fragment_shader_ = 0;
+  unsigned program_ = 0;
+  int size_location_ = -1;
+  unsigned vertex_buffer_ = 0;
+};
+
+}  // namespace gfx
+
+#endif  // UI_GL_YUV420_RGB_CONVERTER_H_