// SwiftShader Software Renderer
//
// Copyright(c) 2005-2013 TransGaming Inc.
//
// All rights reserved. No part of this software may be copied, distributed, transmitted,
// transcribed, stored in a retrieval system, translated into any human or computer
// language by any means, or disclosed to third parties without the explicit written
// agreement of TransGaming Inc. Without such an agreement, no rights or licenses, express
// or implied, including but not limited to any patent rights, are granted to you.
//

#include "Blitter.hpp"

#include "Common/Debug.hpp"
#include "Reactor/Reactor.hpp"

namespace sw
{
	Blitter::Blitter()
	{
		blitCache = new RoutineCache<BlitState>(1024);
	}

	Blitter::~Blitter()
	{
		delete blitCache;
	}

	void Blitter::blit(Surface *source, const SliceRect &sourceRect, Surface *dest, const SliceRect &destRect, bool filter)
	{
		if(blitReactor(source, sourceRect, dest, destRect, filter))
		{
			return;
		}

		SliceRect sRect = sourceRect;
		SliceRect dRect = destRect;

		bool flipX = destRect.x0 > destRect.x1;
		bool flipY = destRect.y0 > destRect.y1;

		if(flipX)
		{
			swap(dRect.x0, dRect.x1);
			swap(sRect.x0, sRect.x1);
		}
		if(flipY)
		{
			swap(dRect.y0, dRect.y1);
			swap(sRect.y0, sRect.y1);
		}

		source->lockInternal(sRect.x0, sRect.y0, sRect.slice, sw::LOCK_READONLY, sw::PUBLIC);
		dest->lockInternal(dRect.x0, dRect.y0, dRect.slice, sw::LOCK_WRITEONLY, sw::PUBLIC);

		float w = 1.0f / (dRect.x1 - dRect.x0) * (sRect.x1 - sRect.x0);
		float h = 1.0f / (dRect.y1 - dRect.y0) * (sRect.y1 - sRect.y0);

		const float xStart = (float)sRect.x0 + 0.5f * w;
		float y = (float)sRect.y0 + 0.5f * h;

		for(int j = dRect.y0; j < dRect.y1; j++)
		{
			float x = xStart;

			for(int i = dRect.x0; i < dRect.x1; i++)
			{
				sw::Color<float> color;

				if(!filter)
				{
					color = source->readInternal((int)x, (int)y);
				}
				else   // Bilinear filtering
				{
					color = source->sampleInternal(x, y);
				}

				dest->writeInternal(i, j, color);

				x += w;
			}

			y += h;
		}

		source->unlockInternal();
		dest->unlockInternal();
	}

	bool Blitter::read(Float4 &c, Pointer<Byte> element, Format format)
	{
		c = Float4(1.0f, 1.0f, 1.0f, 1.0f);

		switch(format)
		{
		case FORMAT_L8:
			c.xyz = Float(Int(*Pointer<Byte>(element)));
			break;
		case FORMAT_A8:
			c.xyz = 0.0f;
			c.w = Float(Int(*Pointer<Byte>(element)));
			break;
		case FORMAT_A8R8G8B8:
			c = Float4(*Pointer<Byte4>(element)).zyxw;
			break;
		case FORMAT_X8R8G8B8:
			c = Float4(*Pointer<Byte4>(element)).zyxw;
			c.w = 1.0f;
			break;
		case FORMAT_A16B16G16R16:
			c = Float4(*Pointer<UShort4>(element));
			break;
		case FORMAT_G16R16:
			// FIXME: Optimize
			c.x = Float(Int(*Pointer<UShort>(element + 0)));
			c.y = Float(Int(*Pointer<UShort>(element + 2)));
			break;
		case FORMAT_A32B32G32R32F:
			c = *Pointer<Float4>(element);
			break;
		case FORMAT_G32R32F:
			c.x = *Pointer<Float>(element + 0);
			c.y = *Pointer<Float>(element + 4);
			break;
		case FORMAT_R32F:
			c.x = *Pointer<Float>(element);
			break;
		default:
			return false;
		}

		return true;
	}

	bool Blitter::blitReactor(Surface *source, const SliceRect &sourceRect, Surface *dest, const SliceRect &destRect, bool filter)
	{
		Rect dRect = destRect;
		Rect sRect = sourceRect;
		if(destRect.x0 > destRect.x1)
		{
			swap(dRect.x0, dRect.x1);
			swap(sRect.x0, sRect.x1);
		}
		if(destRect.y0 > destRect.y1)
		{
			swap(dRect.y0, dRect.y1);
			swap(sRect.y0, sRect.y1);
		}

		BlitState state;

		state.sourceFormat = source->getInternalFormat();
		state.destFormat = dest->getInternalFormat();
		state.filter = filter;

		Routine *blitRoutine = blitCache->query(state);
		
		if(!blitRoutine)
		{
			Function<Void, Pointer<Byte> > function;
			{
				Pointer<Byte> blit(function.arg(0));

				Pointer<Byte> source = *Pointer<Pointer<Byte> >(blit + OFFSET(BlitData,source));
				Pointer<Byte> dest = *Pointer<Pointer<Byte> >(blit + OFFSET(BlitData,dest));
				Int sPitchB = *Pointer<Int>(blit + OFFSET(BlitData,sPitchB));
				Int dPitchB = *Pointer<Int>(blit + OFFSET(BlitData,dPitchB));

				Float x0 = *Pointer<Float>(blit + OFFSET(BlitData,x0));
				Float y0 = *Pointer<Float>(blit + OFFSET(BlitData,y0));
				Float w = *Pointer<Float>(blit + OFFSET(BlitData,w));
				Float h = *Pointer<Float>(blit + OFFSET(BlitData,h));

				Int x0d = *Pointer<Int>(blit + OFFSET(BlitData,x0d));
				Int x1d = *Pointer<Int>(blit + OFFSET(BlitData,x1d));
				Int y0d = *Pointer<Int>(blit + OFFSET(BlitData,y0d));
				Int y1d = *Pointer<Int>(blit + OFFSET(BlitData,y1d));

				Int sWidth = *Pointer<Int>(blit + OFFSET(BlitData,sWidth));
				Int sHeight = *Pointer<Int>(blit + OFFSET(BlitData,sHeight));

				Float y = y0;

				For(Int j = y0d, j < y1d, j++)
				{
					Float x = x0;
					Pointer<Byte> destLine = dest + j * dPitchB;

					For(Int i = x0d, i < x1d, i++)
					{
						Float4 color;

						if(!filter)
						{
							Int X = Int(x);
							Int Y = Int(y);

							Pointer<Byte> s = source + Y * sPitchB + X * Surface::bytes(state.sourceFormat);

							if(!read(color, s, state.sourceFormat))
							{
								return false;
							}
						}
						else   // Bilinear filtering
						{
							Float x0 = x - 0.5f;
							Float y0 = y - 0.5f;

							Int X0 = Max(Int(x0), 0);
							Int Y0 = Max(Int(y0), 0);
							
							Int X1 = IfThenElse(X0 + 1 >= sWidth, X0, X0 + 1);
							Int Y1 = IfThenElse(Y0 + 1 >= sHeight, Y0, Y0 + 1);

							Pointer<Byte> s00 = source + Y0 * sPitchB + X0 * Surface::bytes(state.sourceFormat);
							Pointer<Byte> s01 = source + Y0 * sPitchB + X1 * Surface::bytes(state.sourceFormat);
							Pointer<Byte> s10 = source + Y1 * sPitchB + X0 * Surface::bytes(state.sourceFormat);
							Pointer<Byte> s11 = source + Y1 * sPitchB + X1 * Surface::bytes(state.sourceFormat);

							Float4 c00; if(!read(c00, s00, state.sourceFormat)) return false;
							Float4 c01; if(!read(c01, s01, state.sourceFormat)) return false;
							Float4 c10; if(!read(c10, s10, state.sourceFormat)) return false;
							Float4 c11; if(!read(c11, s11, state.sourceFormat)) return false;

							Float4 fx = Float4(x0 - Float(X0));
							Float4 fy = Float4(y0 - Float(Y0));

							color = c00 * (Float4(1.0f) - fx) * (Float4(1.0f) - fy) +
							        c01 * fx * (Float4(1.0f) - fy) +
									c10 * (Float4(1.0f) - fx) * fy +
									c11 * fx * fy;
						}

						float4 unscale;

						switch(state.sourceFormat)
						{
						case FORMAT_L8:
						case FORMAT_A8:
						case FORMAT_A8R8G8B8:
						case FORMAT_X8R8G8B8:
							unscale = vector(255, 255, 255, 255);
							break;
						case FORMAT_A16B16G16R16:
						case FORMAT_G16R16:
							unscale = vector(65535, 65535, 65535, 65535);
							break;
						case FORMAT_A32B32G32R32F:
						case FORMAT_G32R32F:
						case FORMAT_R32F:
							unscale = vector(1.0f, 1.0f, 1.0f, 1.0f);
							break;
						default:
							return false;
						}

						float4 scale;

						switch(state.destFormat)
						{
						case FORMAT_L8:
						case FORMAT_A8:
						case FORMAT_A8R8G8B8:
						case FORMAT_X8R8G8B8:
							scale = vector(255, 255, 255, 255);
							break;
						case FORMAT_A16B16G16R16:
						case FORMAT_G16R16:
							scale = vector(65535, 65535, 65535, 65535);
							break;
						case FORMAT_A32B32G32R32F:
						case FORMAT_G32R32F:
						case FORMAT_R32F:
							scale = vector(1.0f, 1.0f, 1.0f, 1.0f);
							break;
						default:
							return false;
						}

						if(unscale != scale)
						{
							color *= Float4(scale.x / unscale.x, scale.y / unscale.y, scale.z / unscale.z, scale.w / unscale.w);
						}

						if(Surface::isFloatFormat(state.sourceFormat) && !Surface::isFloatFormat(state.destFormat))
						{
							color = Min(color, Float4(1.0f, 1.0f, 1.0f, 1.0f));

							color = Max(color, Float4(Surface::isUnsignedComponent(state.destFormat, 0) ? 0.0f : -1.0f,
							                          Surface::isUnsignedComponent(state.destFormat, 1) ? 0.0f : -1.0f,
													  Surface::isUnsignedComponent(state.destFormat, 2) ? 0.0f : -1.0f,
													  Surface::isUnsignedComponent(state.destFormat, 3) ? 0.0f : -1.0f));
						}

						Pointer<Byte> d = destLine + i * Surface::bytes(state.destFormat);

						switch(state.destFormat)
						{
						case FORMAT_L8:
							*Pointer<Byte>(d) = Byte(RoundInt(Float(color.x)));
							break;
						case FORMAT_A8:
							*Pointer<Byte>(d) = Byte(RoundInt(Float(color.w)));
							break;
						case FORMAT_A8R8G8B8:
							{
								UShort4 c0 = As<UShort4>(RoundShort4(color.zyxw));
								Byte8 c1 = Pack(c0, c0);
								*Pointer<UInt>(d) = UInt(As<Long>(c1));
							}
							break;
						case FORMAT_X8R8G8B8:
							{
								UShort4 c0 = As<UShort4>(RoundShort4(color.zyxw));
								Byte8 c1 = Pack(c0, c0);
								*Pointer<UInt>(d) = UInt(As<Long>(c1)) | 0xFF000000;
							}
							break;
						case FORMAT_A16B16G16R16:
							*Pointer<UShort4>(d) = UShort4(RoundInt(color));
							break;
						case FORMAT_G16R16:
							*Pointer<UInt>(d) = UInt(As<Long>(UShort4(RoundInt(color))));
							break;
						case FORMAT_A32B32G32R32F:
							*Pointer<Float4>(d) = color;
							break;
						case FORMAT_G32R32F:
							*Pointer<Float2>(d) = Float2(color);
							break;
						case FORMAT_R32F:
							*Pointer<Float>(d) = color.x;
							break;
						default:
							return false;
						}

						x += w;
					}

					y += h;
				}
			}

			blitRoutine = function(L"BlitRoutine");

			blitCache->add(state, blitRoutine);
		}

		void (*blitFunction)(const BlitData *data) = (void(*)(const BlitData*))blitRoutine->getEntry();

		BlitData data;

		data.source = source->lockInternal(0, 0, sourceRect.slice, sw::LOCK_READONLY, sw::PUBLIC);
		data.dest = dest->lockInternal(0, 0, destRect.slice, sw::LOCK_WRITEONLY, sw::PUBLIC);
		data.sPitchB = source->getInternalPitchB();
		data.dPitchB = dest->getInternalPitchB();

		data.w = 1.0f / (dRect.x1 - dRect.x0) * (sRect.x1 - sRect.x0);
		data.h = 1.0f / (dRect.y1 - dRect.y0) * (sRect.y1 - sRect.y0);
		data.x0 = (float)sRect.x0 + 0.5f * data.w;
		data.y0 = (float)sRect.y0 + 0.5f * data.h;
		
		data.x0d = dRect.x0;
		data.x1d = dRect.x1;
		data.y0d = dRect.y0;
		data.y1d = dRect.y1;

		data.sWidth = source->getInternalWidth();
		data.sHeight = source->getInternalHeight();

		blitFunction(&data);

		source->unlockInternal();
		dest->unlockInternal();

		return true;
	}
}