//-----------------------------------------------------------------------------
// Copyright 2014-2018 RenderHeads Ltd.  All rights reserved.
//-----------------------------------------------------------------------------

// Each #kernel tells which function to compile; you can have many kernels
#pragma kernel RGBA_to_10RGBX

Texture2D input;
RWStructuredBuffer<uint> result;

struct Parameters{ 
	uint width;
	uint height;
	uint bufferWidth;
	uint bigEndian;
	uint leading;
	bool isLinear;
	bool flipX;
	bool flipY;
};

RWStructuredBuffer<Parameters> constBuffer;

[numthreads(8,8,1)]
void RGBA_to_10RGBX(uint3 id : SV_DispatchThreadID)
{
	if (id.x >= constBuffer[0].width || id.y >= constBuffer[0].height) 
	{
		return;
	}

	uint yFixed = constBuffer[0].height - id.y - 1;

	float4 rgba = input[uint2(id.x, yFixed)];
	if (constBuffer[0].isLinear == 1)
	{
		rgba = pow(abs(rgba), 1.0 / 2.2);
	}

	uint r = rgba.r * 1023 + 0.5;
	uint g = rgba.g * 1023 + 0.5;
	uint b = rgba.b * 1023 + 0.5;
	
	uint output = 0;
	if (constBuffer[0].leading == 1) 
	{
		if (constBuffer[0].bigEndian == 1) 
		{
			output |= b << 0;
			output |= g << 10;
			output |= r << 20;

			output |= 1023;
		}
		else 
		{
			output |= (r & 1008) >> 4;
			output |= (r & 15) << 12;
			output |= (g & 960) << 2;
			output |= (g & 63) << 18;
			output |= (b & 768) << 8;
			output |= (b & 255) << 24;
		}
	}
	else 
	{
		if (constBuffer[0].bigEndian == 1)
		{
			output |= (b & 252) << 26;
			output |= (b & 960) << 10;
			output |= (g & 15) << 20;
			output |= (g & 1008) << 4;
			output |= (r & 3) << 14;
			output |= (r & 1020) >> 2;
		}
		else
		{
			output |= (r << 22);
			output |= (g << 12);
			output |= (b << 2);
		}
	}

	uint bufferPos = constBuffer[0].bufferWidth * id.y + id.x;

	result[bufferPos] = output;
}