/*
 * Copyright 2011-2015 Branimir Karadzic. All rights reserved.
 * License: http://www.opensource.org/licenses/BSD-2-Clause
 */

#ifndef BGFX_COMPUTE_H_HEADER_GUARD
#define BGFX_COMPUTE_H_HEADER_GUARD

#include "bgfx_shader.sh"

#ifndef __cplusplus

#if BGFX_SHADER_LANGUAGE_HLSL

float uintBitsToFloat(uint  _x) { return asfloat(_x); }
vec2  uintBitsToFloat(uint2 _x) { return asfloat(_x); }
vec3  uintBitsToFloat(uint3 _x) { return asfloat(_x); }
vec4  uintBitsToFloat(uint4 _x) { return asfloat(_x); }

uint  floatBitsToUint(float _x) { return asuint(_x); }
uvec2 floatBitsToUint(vec2  _x) { return asuint(_x); }
uvec3 floatBitsToUint(vec3  _x) { return asuint(_x); }
uvec4 floatBitsToUint(vec4  _x) { return asuint(_x); }

int   floatBitsToInt(float _x) { return asint(_x); }
ivec2 floatBitsToInt(vec2  _x) { return asint(_x); }
ivec3 floatBitsToInt(vec3  _x) { return asint(_x); }
ivec4 floatBitsToInt(vec4  _x) { return asint(_x); }

uint  bitfieldReverse(uint  _x) { return reversebits(_x); }
uint2 bitfieldReverse(uint2 _x) { return reversebits(_x); }
uint3 bitfieldReverse(uint3 _x) { return reversebits(_x); }
uint4 bitfieldReverse(uint4 _x) { return reversebits(_x); }

uint packHalf2x16(vec2 _x)
{
	return (f32tof16(_x.x)<<16) | f32tof16(_x.y);
}

vec2 unpackHalf2x16(uint _x)
{
	return vec2(f16tof32(_x >> 16), f16tof32(_x) );
}

#define SHARED groupshared

#define r32ui  uint
#define r32f   float
#define rg16f  float2
#define rgba8  float4

#define IMAGE2D_RO( _name, _format, _reg) Texture2D<_format>   _name : register(t[_reg])
#define UIMAGE2D_RO(_name, _format, _reg) Texture2D<_format>   _name : register(t[_reg])
#define IMAGE2D_WR( _name, _format, _reg) RWTexture2D<_format> _name : register(u[_reg])
#define UIMAGE2D_WR(_name, _format, _reg) RWTexture2D<_format> _name : register(u[_reg])
#define IMAGE2D_RW( _name, _reg) RWTexture2D<float> _name : register(u[_reg])
#define UIMAGE2D_RW(_name, _reg) RWTexture2D<uint>  _name : register(u[_reg])

#define BUFFER_RO(_name, _struct, _reg) Buffer<_struct>   _name : register(b[_reg])
#define BUFFER_RW(_name, _struct, _reg) RWBuffer<_struct> _name : register(u[_reg])
#define BUFFER_WR(_name, _struct, _reg) BUFFER_RW(_name, _struct, _reg)

#define NUM_THREADS(_x, _y, _z) [numthreads(_x, _y, _z)]

#define __IMAGE_IMPL(_textureType, _storeComponents, _type, _loadComponents) \
			_type imageLoad(Texture2D<_textureType> _image, ivec2 _uv) \
			{ \
				return _image[_uv]._loadComponents; \
			} \
			\
			void imageStore(RWTexture2D<_textureType> _image, ivec2 _uv, _type _value) \
			{ \
				_image[_uv] = _value._storeComponents; \
			}

__IMAGE_IMPL(float, x,    vec4,  xxxx)
__IMAGE_IMPL(vec2,  xy,   vec4,  xyyy)
__IMAGE_IMPL(vec3,  xyz,  vec4,  xyzz)
__IMAGE_IMPL(vec4,  xyzw, vec4,  xyzw)
__IMAGE_IMPL(uint,  x,    uvec4, xxxx)
__IMAGE_IMPL(uvec2, xy,   uvec4, xyyy)
__IMAGE_IMPL(uvec3, xyz,  uvec4, xyzz)
__IMAGE_IMPL(uvec4, xyzw, uvec4, xyzw)
__IMAGE_IMPL(int,   x,    ivec4, xxxx)
__IMAGE_IMPL(ivec2, xy,   ivec4, xyyy)
__IMAGE_IMPL(ivec3, xyz,  ivec4, xyzz)
__IMAGE_IMPL(ivec4, xyzw, ivec4, xyzw)

uint4 imageLoad(RWTexture2D<uint> _image, ivec2 _uv)
{
	uint rr = _image[_uv.xy];
	return uint4(rr, rr, rr, rr);
}

ivec2 imageSize(Texture2D _image)
{
	ivec2 result;
	_image.GetDimensions(result.x, result.y);
	return result;
}

ivec2 imageSize(RWTexture2D<float4> _image)
{
	ivec2 result;
	_image.GetDimensions(result.x, result.y);
	return result;
}

ivec2 imageSize(RWTexture2D<uint> _image)
{
	ivec2 result;
	_image.GetDimensions(result.x, result.y);
	return result;
}

#define __ATOMIC_IMPL_TYPE(_genType, _glFunc, _dxFunc) \
			_genType _glFunc(_genType _mem, _genType _data) \
			{ \
				_genType result; \
				_dxFunc(_mem, _data, result); \
				return result; \
			}

#define __ATOMIC_IMPL(_glFunc, _dxFunc) \
			__ATOMIC_IMPL_TYPE(int,  _glFunc, _dxFunc) \
			__ATOMIC_IMPL_TYPE(uint, _glFunc, _dxFunc)

__ATOMIC_IMPL(atomicAdd,      InterlockedAdd);
__ATOMIC_IMPL(atomicAnd,      InterlockedAnd);
__ATOMIC_IMPL(atomicExchange, InterlockedExchange);
__ATOMIC_IMPL(atomicMax,      InterlockedMax);
__ATOMIC_IMPL(atomicMin,      InterlockedMin);
__ATOMIC_IMPL(atomicOr,       InterlockedOr);
__ATOMIC_IMPL(atomicXor,      InterlockedXor);

int atomicCompSwap(int _mem, int _compare, int _data)
{
	int result;
	InterlockedCompareExchange(_mem, _compare, _data, result);
	return result;
}

uint atomicCompSwap(uint _mem, uint _compare, uint _data)
{
	uint result;
	InterlockedCompareExchange(_mem, _compare, _data, result);
	return result;
}

// InterlockedCompareStore

#define barrier()                    GroupMemoryBarrierWithGroupSync()
#define memoryBarrier()              GroupMemoryBarrierWithGroupSync()
#define memoryBarrierAtomicCounter() GroupMemoryBarrierWithGroupSync()
#define memoryBarrierBuffer()        GroupMemoryBarrierWithGroupSync()
#define memoryBarrierImage()         GroupMemoryBarrierWithGroupSync()
#define memoryBarrierShared()        GroupMemoryBarrierWithGroupSync()
#define groupMemoryBarrier()         GroupMemoryBarrierWithGroupSync()

#else

#define SHARED shared

#define __IMAGE_XX(_name, _format, _reg, _image, _access) \
			layout(_format, binding=_reg) _access uniform highp _image _name

#define readwrite
#define IMAGE2D_RO( _name, _format, _reg) __IMAGE_XX(_name, _format, _reg, image2D,  readonly)
#define UIMAGE2D_RO(_name, _format, _reg) __IMAGE_XX(_name, _format, _reg, uimage2D, readonly)
#define IMAGE2D_WR( _name, _format, _reg) __IMAGE_XX(_name, _format, _reg, image2D,  writeonly)
#define UIMAGE2D_WR(_name, _format, _reg) __IMAGE_XX(_name, _format, _reg, uimage2D, writeonly)
#define IMAGE2D_RW( _name, _reg) __IMAGE_XX(_name, r32f,  _reg, image2D,  readwrite)
#define UIMAGE2D_RW(_name, _reg) __IMAGE_XX(_name, r32ui, _reg, uimage2D, readwrite)

#define __BUFFER_XX(_name, _type, _reg, _access) \
			layout(std430, binding=_reg) _access buffer _name ## Buffer \
			{ \
				_type _name[]; \
			}

#define BUFFER_RO(_name, _type, _reg) __BUFFER_XX(_name, _type, _reg, readonly)
#define BUFFER_RW(_name, _type, _reg) __BUFFER_XX(_name, _type, _reg, readwrite)
#define BUFFER_WR(_name, _type, _reg) __BUFFER_XX(_name, _type, _reg, writeonly)

#define NUM_THREADS(_x, _y, _z) layout (local_size_x = _x, local_size_y = _y, local_size_z = _z) in;

#endif // BGFX_SHADER_LANGUAGE_HLSL

#endif // __cplusplus

#endif // BGFX_COMPUTE_H_HEADER_GUARD