// Copyright 2013 Dolphin Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.

#include <algorithm>

#include "Common/Common.h"
#include "Core/HW/Memmap.h"

#include "VideoBackends/Software/BPMemLoader.h"
#include "VideoBackends/Software/EfbInterface.h"

#include "VideoCommon/LookUpTables.h"
#include "VideoCommon/PixelEngine.h"


static u8 efb[EFB_WIDTH*EFB_HEIGHT*6];

namespace EfbInterface
{
	u32 perf_values[PQ_NUM_MEMBERS];

	inline u32 GetColorOffset(u16 x, u16 y)
	{
		return (x + y * EFB_WIDTH) * 3;
	}

	inline u32 GetDepthOffset(u16 x, u16 y)
	{
		return (x + y * EFB_WIDTH) * 3 + DEPTH_BUFFER_START;
	}

	void DoState(PointerWrap &p)
	{
		p.DoArray(efb, EFB_WIDTH*EFB_HEIGHT*6);
	}

	static void SetPixelAlphaOnly(u32 offset, u8 a)
	{
		switch (bpmem.zcontrol.pixel_format)
		{
		case PEControl::RGB8_Z24:
		case PEControl::Z24:
		case PEControl::RGB565_Z16:
			// do nothing
			break;
		case PEControl::RGBA6_Z24:
			{
				u32 a32 = a;
				u32 *dst = (u32*)&efb[offset];
				u32 val = *dst & 0xffffffc0;
				val |= (a32 >> 2) & 0x0000003f;
				*dst = val;
			}
			break;
		default:
			ERROR_LOG(VIDEO, "Unsupported pixel format: %i", static_cast<int>(bpmem.zcontrol.pixel_format));
		}
	}

	static void SetPixelColorOnly(u32 offset, u8 *rgb)
	{
		switch (bpmem.zcontrol.pixel_format)
		{
		case PEControl::RGB8_Z24:
		case PEControl::Z24:
			{
				u32 src = *(u32*)rgb;
				u32 *dst = (u32*)&efb[offset];
				u32 val = *dst & 0xff000000;
				val |= src >> 8;
				*dst = val;
			}
			break;
		case PEControl::RGBA6_Z24:
			{
				u32 src = *(u32*)rgb;
				u32 *dst = (u32*)&efb[offset];
				u32 val = *dst & 0xff00003f;
				val |= (src >> 4) & 0x00000fc0; // blue
				val |= (src >> 6) & 0x0003f000; // green
				val |= (src >> 8) & 0x00fc0000; // red
				*dst = val;
			}
			break;
		case PEControl::RGB565_Z16:
			{
				INFO_LOG(VIDEO, "RGB565_Z16 is not supported correctly yet");
				u32 src = *(u32*)rgb;
				u32 *dst = (u32*)&efb[offset];
				u32 val = *dst & 0xff000000;
				val |= src >> 8;
				*dst = val;
			}
			break;
		default:
			ERROR_LOG(VIDEO, "Unsupported pixel format: %i", static_cast<int>(bpmem.zcontrol.pixel_format));
		}
	}

	static void SetPixelAlphaColor(u32 offset, u8 *color)
	{
		switch (bpmem.zcontrol.pixel_format)
		{
		case PEControl::RGB8_Z24:
		case PEControl::Z24:
			{
				u32 src = *(u32*)color;
				u32 *dst = (u32*)&efb[offset];
				u32 val = *dst & 0xff000000;
				val |= src >> 8;
				*dst = val;
			}
			break;
		case PEControl::RGBA6_Z24:
			{
				u32 src = *(u32*)color;
				u32 *dst = (u32*)&efb[offset];
				u32 val = *dst & 0xff000000;
				val |= (src >> 2) & 0x0000003f; // alpha
				val |= (src >> 4) & 0x00000fc0; // blue
				val |= (src >> 6) & 0x0003f000; // green
				val |= (src >> 8) & 0x00fc0000; // red
				*dst = val;
			}
			break;
		case PEControl::RGB565_Z16:
			{
				INFO_LOG(VIDEO, "RGB565_Z16 is not supported correctly yet");
				u32 src = *(u32*)color;
				u32 *dst = (u32*)&efb[offset];
				u32 val = *dst & 0xff000000;
				val |= src >> 8;
				*dst = val;
			}
			break;
		default:
			ERROR_LOG(VIDEO, "Unsupported pixel format: %i", static_cast<int>(bpmem.zcontrol.pixel_format));
		}
	}

	static void GetPixelColor(u32 offset, u8 *color)
	{
		switch (bpmem.zcontrol.pixel_format)
		{
		case PEControl::RGB8_Z24:
		case PEControl::Z24:
			{
				u32 src = *(u32*)&efb[offset];
				u32 *dst = (u32*)color;
				u32 val = 0xff | ((src & 0x00ffffff) << 8);
				*dst = val;
			}
			break;
		case PEControl::RGBA6_Z24:
			{
				u32 src = *(u32*)&efb[offset];
				color[ALP_C] = Convert6To8(src & 0x3f);
				color[BLU_C] = Convert6To8((src >> 6) & 0x3f);
				color[GRN_C] = Convert6To8((src >> 12) & 0x3f);
				color[RED_C] = Convert6To8((src >> 18) & 0x3f);
			}
			break;
		case PEControl::RGB565_Z16:
			{
				INFO_LOG(VIDEO, "RGB565_Z16 is not supported correctly yet");
				u32 src = *(u32*)&efb[offset];
				u32 *dst = (u32*)color;
				u32 val = 0xff | ((src & 0x00ffffff) << 8);
				*dst = val;
			}
			break;
		default:
			ERROR_LOG(VIDEO, "Unsupported pixel format: %i", static_cast<int>(bpmem.zcontrol.pixel_format));
		}
	}

	static void SetPixelDepth(u32 offset, u32 depth)
	{
		switch (bpmem.zcontrol.pixel_format)
		{
		case PEControl::RGB8_Z24:
		case PEControl::RGBA6_Z24:
		case PEControl::Z24:
			{
				u32 *dst = (u32*)&efb[offset];
				u32 val = *dst & 0xff000000;
				val |= depth & 0x00ffffff;
				*dst = val;
			}
			break;
		case PEControl::RGB565_Z16:
			{
				INFO_LOG(VIDEO, "RGB565_Z16 is not supported correctly yet");
				u32 *dst = (u32*)&efb[offset];
				u32 val = *dst & 0xff000000;
				val |= depth & 0x00ffffff;
				*dst = val;
			}
			break;
		default:
			ERROR_LOG(VIDEO, "Unsupported pixel format: %i", static_cast<int>(bpmem.zcontrol.pixel_format));
		}
	}

	static u32 GetPixelDepth(u32 offset)
	{
		u32 depth = 0;

		switch (bpmem.zcontrol.pixel_format)
		{
		case PEControl::RGB8_Z24:
		case PEControl::RGBA6_Z24:
		case PEControl::Z24:
			{
				depth = (*(u32*)&efb[offset]) & 0x00ffffff;
			}
			break;
		case PEControl::RGB565_Z16:
			{
				INFO_LOG(VIDEO, "RGB565_Z16 is not supported correctly yet");
				depth = (*(u32*)&efb[offset]) & 0x00ffffff;
			}
			break;
		default:
			ERROR_LOG(VIDEO, "Unsupported pixel format: %i", static_cast<int>(bpmem.zcontrol.pixel_format));
		}

		return depth;
	}

	static u32 GetSourceFactor(u8 *srcClr, u8 *dstClr, BlendMode::BlendFactor mode)
	{
		switch (mode)
		{
		case BlendMode::ZERO:
			return 0;
		case BlendMode::ONE:
			return 0xffffffff;
		case BlendMode::DSTCLR:
			return *(u32*)dstClr;
		case BlendMode::INVDSTCLR:
			return 0xffffffff - *(u32*)dstClr;
		case BlendMode::SRCALPHA:
			{
				u8 alpha = srcClr[ALP_C];
				u32 factor = alpha << 24 | alpha << 16 | alpha << 8 | alpha;
				return factor;
			}
		case BlendMode::INVSRCALPHA:
			{
				u8 alpha = 0xff - srcClr[ALP_C];
				u32 factor = alpha << 24 | alpha << 16 | alpha << 8 | alpha;
				return factor;
			}
		case BlendMode::DSTALPHA:
			{
				u8 alpha = dstClr[ALP_C];
				u32 factor = alpha << 24 | alpha << 16 | alpha << 8 | alpha;
				return factor;
			}
		case BlendMode::INVDSTALPHA:
			{
				u8 alpha = 0xff - dstClr[ALP_C];
				u32 factor = alpha << 24 | alpha << 16 | alpha << 8 | alpha;
				return factor;
			}
		}

		return 0;
	}

	static u32 GetDestinationFactor(u8 *srcClr, u8 *dstClr, BlendMode::BlendFactor mode)
	{
		switch (mode)
		{
		case BlendMode::ZERO:
			return 0;
		case BlendMode::ONE:
			return 0xffffffff;
		case BlendMode::SRCCLR:
			return *(u32*)srcClr;
		case BlendMode::INVSRCCLR:
			return 0xffffffff - *(u32*)srcClr;
		case BlendMode::SRCALPHA:
			{
				u8 alpha = srcClr[ALP_C];
				u32 factor = alpha << 24 | alpha << 16 | alpha << 8 | alpha;
				return factor;
			}
		case BlendMode::INVSRCALPHA:
			{
				u8 alpha = 0xff - srcClr[ALP_C];
				u32 factor = alpha << 24 | alpha << 16 | alpha << 8 | alpha;
				return factor;
			}
		case BlendMode::DSTALPHA:
			{
				u8 alpha = dstClr[ALP_C] & 0xff;
				u32 factor = alpha << 24 | alpha << 16 | alpha << 8 | alpha;
				return factor;
			}
		case BlendMode::INVDSTALPHA:
			{
				u8 alpha = 0xff - dstClr[ALP_C];
				u32 factor = alpha << 24 | alpha << 16 | alpha << 8 | alpha;
				return factor;
			}
		}

		return 0;
	}

	static void BlendColor(u8 *srcClr, u8 *dstClr)
	{
		u32 srcFactor = GetSourceFactor(srcClr, dstClr, bpmem.blendmode.srcfactor);
		u32 dstFactor = GetDestinationFactor(srcClr, dstClr, bpmem.blendmode.dstfactor);

		for (int i = 0; i < 4; i++)
		{
			// add MSB of factors to make their range 0 -> 256
			u32 sf = (srcFactor & 0xff);
			sf += sf >> 7;

			u32 df = (dstFactor & 0xff);
			df += df >> 7;

			u32 color = (srcClr[i] * sf + dstClr[i] * df) >> 8;
			dstClr[i] = (color>255)?255:color;

			dstFactor >>= 8;
			srcFactor >>= 8;
		}
	}

	static void LogicBlend(u32 srcClr, u32 &dstClr, BlendMode::LogicOp op)
	{
		switch (op)
		{
		case BlendMode::CLEAR:
			dstClr = 0;
			break;
		case BlendMode::AND:
			dstClr = srcClr & dstClr;
			break;
		case BlendMode::AND_REVERSE:
			dstClr = srcClr & (~dstClr);
			break;
		case BlendMode::COPY:
			dstClr = srcClr;
			break;
		case BlendMode::AND_INVERTED:
			dstClr = (~srcClr) & dstClr;
			break;
		case BlendMode::NOOP:
			// Do nothing
			break;
		case BlendMode::XOR:
			dstClr = srcClr ^ dstClr;
			break;
		case BlendMode::OR:
			dstClr = srcClr | dstClr;
			break;
		case BlendMode::NOR:
			dstClr = ~(srcClr | dstClr);
			break;
		case BlendMode::EQUIV:
			dstClr = ~(srcClr ^ dstClr);
			break;
		case BlendMode::INVERT:
			dstClr = ~dstClr;
			break;
		case BlendMode::OR_REVERSE:
			dstClr = srcClr | (~dstClr);
			break;
		case BlendMode::COPY_INVERTED:
			dstClr = ~srcClr;
			break;
		case BlendMode::OR_INVERTED:
			dstClr = (~srcClr) | dstClr;
			break;
		case BlendMode::NAND:
			dstClr = ~(srcClr & dstClr);
			break;
		case BlendMode::SET:
			dstClr = 0xffffffff;
			break;
		}
	}

	static void SubtractBlend(u8 *srcClr, u8 *dstClr)
	{
		for (int i = 0; i < 4; i++)
		{
			int c = (int)dstClr[i] - (int)srcClr[i];
			dstClr[i] = (c < 0)?0:c;
		}
	}

	void BlendTev(u16 x, u16 y, u8 *color)
	{
		u32 dstClr;
		u32 offset = GetColorOffset(x, y);

		u8 *dstClrPtr = (u8*)&dstClr;

		GetPixelColor(offset, dstClrPtr);

		if (bpmem.blendmode.blendenable)
		{
			if (bpmem.blendmode.subtract)
				SubtractBlend(color, dstClrPtr);
			else
				BlendColor(color, dstClrPtr);
		}
		else if (bpmem.blendmode.logicopenable)
		{
			LogicBlend(*((u32*)color), dstClr, bpmem.blendmode.logicmode);
		}
		else
		{
			dstClrPtr = color;
		}

		if (bpmem.dstalpha.enable)
			dstClrPtr[ALP_C] = bpmem.dstalpha.alpha;

		if (bpmem.blendmode.colorupdate)
		{
			if (bpmem.blendmode.alphaupdate)
				SetPixelAlphaColor(offset, dstClrPtr);
			else
				SetPixelColorOnly(offset, dstClrPtr);
		}
		else if (bpmem.blendmode.alphaupdate)
		{
			SetPixelAlphaOnly(offset, dstClrPtr[ALP_C]);
		}

		// branchless bounding box update
		PixelEngine::bbox[0] = std::min(x, PixelEngine::bbox[0]);
		PixelEngine::bbox[1] = std::max(x, PixelEngine::bbox[1]);
		PixelEngine::bbox[2] = std::min(y, PixelEngine::bbox[2]);
		PixelEngine::bbox[3] = std::max(y, PixelEngine::bbox[3]);
	}

	void SetColor(u16 x, u16 y, u8 *color)
	{
		u32 offset = GetColorOffset(x, y);
		if (bpmem.blendmode.colorupdate)
		{
			if (bpmem.blendmode.alphaupdate)
				SetPixelAlphaColor(offset, color);
			else
				SetPixelColorOnly(offset, color);
		}
		else if (bpmem.blendmode.alphaupdate)
		{
			SetPixelAlphaOnly(offset, color[ALP_C]);
		}
	}

	void SetDepth(u16 x, u16 y, u32 depth)
	{
		if (bpmem.zmode.updateenable)
			SetPixelDepth(GetDepthOffset(x, y), depth);
	}

	void GetColor(u16 x, u16 y, u8 *color)
	{
		u32 offset = GetColorOffset(x, y);
		GetPixelColor(offset, color);
	}

	// For internal used only, return a non-normalized value, which saves work later.
	void GetColorYUV(u16 x, u16 y, yuv444 *out)
	{
		u8 color[4];
		GetColor(x, y, color);

		// GameCube/Wii uses the BT.601 standard algorithm for converting to YCbCr; see
		// http://www.equasys.de/colorconversion.html#YCbCr-RGBColorFormatConversion
		out->Y = (u8)( 0.257f * color[RED_C] +  0.504f * color[GRN_C] +  0.098f * color[BLU_C]);
		out->U = (u8)(-0.148f * color[RED_C] + -0.291f * color[GRN_C] +  0.439f * color[BLU_C]);
		out->V = (u8)( 0.439f * color[RED_C] + -0.368f * color[GRN_C] + -0.071f * color[BLU_C]);
	}

	u32 GetDepth(u16 x, u16 y)
	{
		u32 offset = GetDepthOffset(x, y);
		return GetPixelDepth(offset);
	}

	u8 *GetPixelPointer(u16 x, u16 y, bool depth)
	{
		if (depth)
			return &efb[GetDepthOffset(x, y)];
		return &efb[GetColorOffset(x, y)];
	}

	void CopyToXFB(yuv422_packed* xfb_in_ram, u32 fbWidth, u32 fbHeight, const EFBRectangle& sourceRc, float Gamma) {
		// FIXME: We should do Gamma correction

		if (!xfb_in_ram)
		{
			WARN_LOG(VIDEO, "Tried to copy to invalid XFB address");
			return;
		}

		int left = sourceRc.left;
		int right = sourceRc.right;

		// this assumes copies will always start on an even (YU) pixel and the
		// copy always has an even width, which might not be true.
		if (left & 1 || right & 1) {
			WARN_LOG(VIDEO, "Trying to copy XFB to from unaligned EFB source");
			// this will show up as wrongly encoded
		}

		// Scanline buffer, leave room for borders
		yuv444 scanline[EFB_WIDTH+2];

		// our internal yuv444 type is not normalized, so black is {0, 0, 0} instead of {16, 128, 128}
		yuv444 black;
		black.Y = 0;
		black.U = 0;
		black.V = 0;

		scanline[0] = black; // black border at start
		scanline[right+1] = black; // black border at end

		for (u16 y = sourceRc.top; y < sourceRc.bottom; y++)
		{
			// Get a scanline of YUV pixels in 4:4:4 format

			for (int i = 1, x = left; x < right; i++, x++)
			{
				GetColorYUV(x, y, &scanline[i]);
			}

			// And Downsample them to 4:2:2
			for (int i = 1, x = left; x < right; i+=2, x+=2)
			{
				// YU pixel
				xfb_in_ram[x].Y = scanline[i].Y + 16;
				// we mix our color difrences in 10 bit space so it will round more accurately
				// U[i] = 1/4 * U[i-1] + 1/2 * U[i] + 1/4 * U[i+1]
				xfb_in_ram[x].UV = 128 + ((scanline[i-1].U + (scanline[i].U << 1) + scanline[i+1].U) >> 2);

				// YV pixel
				xfb_in_ram[x+1].Y = scanline[i+1].Y + 16;
				// V[i] = 1/4 * V[i-1] + 1/2 * V[i] + 1/4 * V[i+1]
				xfb_in_ram[x+1].UV = 128 + ((scanline[i].V + (scanline[i+1].V << 1) + scanline[i+2].V) >> 2);
			}
			xfb_in_ram += fbWidth;
		}
	}

	// Like CopyToXFB, but we copy directly into the opengl colour texture without going via GameCube main memory or doing a yuyv conversion
	void BypassXFB(u8* texture, u32 fbWidth, u32 fbHeight, const EFBRectangle& sourceRc, float Gamma) {
		if (fbWidth*fbHeight > 640*568) {
			ERROR_LOG(VIDEO, "Framebuffer is too large: %ix%i", fbWidth, fbHeight);
			return;
		}

		u32 color;
		u8* colorPtr = (u8*)&color;
		u32* texturePtr = (u32*)texture;
		u32 textureAddress = 0;

		int left = sourceRc.left;
		int right = sourceRc.right;

		for (u16 y = sourceRc.top; y < sourceRc.bottom; y++)
		{
			for (u16 x = left; x < right; x++)
			{
				GetColor(x, y, colorPtr);
				texturePtr[textureAddress++] = Common::swap32(color);
			}
		}
	}

	bool ZCompare(u16 x, u16 y, u32 z)
	{
		u32 offset = GetDepthOffset(x, y);
		u32 depth = GetPixelDepth(offset);

		bool pass;

		switch (bpmem.zmode.func)
		{
		case ZMode::NEVER:
			pass = false;
			break;
		case ZMode::LESS:
			pass = z < depth;
			break;
		case ZMode::EQUAL:
			pass = z == depth;
			break;
		case ZMode::LEQUAL:
			pass = z <= depth;
			break;
		case ZMode::GREATER:
			pass = z > depth;
			break;
		case ZMode::NEQUAL:
			pass = z != depth;
			break;
		case ZMode::GEQUAL:
			pass = z >= depth;
			break;
		case ZMode::ALWAYS:
			pass = true;
			break;
		default:
			pass = false;
			ERROR_LOG(VIDEO, "Bad Z compare mode %i", (int)bpmem.zmode.func);
		}

		if (pass && bpmem.zmode.updateenable)
		{
			SetPixelDepth(offset, z);
		}

		return pass;
	}
}