// Copyright 2016 The SwiftShader Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef sw_Stream_hpp
#define sw_Stream_hpp

#include "System/Types.hpp"

namespace sw
{
	enum StreamType ENUM_UNDERLYING_TYPE_UNSIGNED_INT
	{
		STREAMTYPE_COLOR,     // 4 normalized unsigned bytes, ZYXW order
		STREAMTYPE_FLOAT,     // Normalization ignored
		STREAMTYPE_BYTE,
		STREAMTYPE_SBYTE,
		STREAMTYPE_SHORT,
		STREAMTYPE_USHORT,
		STREAMTYPE_INT,
		STREAMTYPE_UINT,
		STREAMTYPE_HALF,      // Normalization ignored
		STREAMTYPE_2_10_10_10_INT,
		STREAMTYPE_2_10_10_10_UINT,

		STREAMTYPE_LAST = STREAMTYPE_2_10_10_10_UINT
	};

	struct StreamResource
	{
		const void *buffer;
		unsigned int vertexStride;
		unsigned int instanceStride;
	};

	struct Stream : public StreamResource
	{
		Stream(const void *buffer = nullptr, unsigned int vertexStride = 0)
		{
			this->buffer = buffer;
			this->vertexStride = vertexStride;
			this->instanceStride = 0;
		}

		Stream &define(StreamType type, unsigned char count, bool normalized = false)
		{
			this->type = type;
			this->count = count;
			this->normalized = normalized;

			return *this;
		}

		Stream &define(const void *buffer, StreamType type, unsigned char count, bool normalized = false)
		{
			this->buffer = buffer;
			this->type = type;
			this->count = count;
			this->normalized = normalized;

			return *this;
		}

		Stream &defaults()
		{
			static const float4 null = {0, 0, 0, 1};

			buffer = &null;
			vertexStride = 0;
			instanceStride = 0;
			type = STREAMTYPE_FLOAT;
			count = 0;
			normalized = false;
			offset = 0;
			binding = 0;

			return *this;
		}

		operator bool() const   // Returns true if stream contains data
		{
			return count != 0;
		}

		StreamType type;
		unsigned char count;
		bool normalized;
		unsigned int offset;
		unsigned int binding;
	};
}

#endif   // sw_Stream_hpp