// Copyright (C) 2002-2012 Nikolaus Gebhardt / Thomas Alten
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h

#include "CImage.h"
#include "irrString.h"
#include "CColorConverter.h"
#include "CBlit.h"
#include "os.h"
#include "SoftwareDriver2_helper.h"

namespace irr
{
namespace video
{

//! Constructor from raw data
CImage::CImage(ECOLOR_FORMAT format, const core::dimension2d<u32>& size, void* data,
	bool ownForeignMemory, bool deleteMemory) : IImage(format, size, deleteMemory)
{
	if (ownForeignMemory)
	{
		Data = (u8*)data;
	}
	else
	{
		const u32 dataSize = getDataSizeFromFormat(Format, Size.Width, Size.Height);

		Data = new u8[align_next(dataSize,16)];
		memcpy(Data, data, dataSize);
		DeleteMemory = true;
	}
}


//! Constructor of empty image
CImage::CImage(ECOLOR_FORMAT format, const core::dimension2d<u32>& size) : IImage(format, size, true)
{
	Data = new u8[align_next(getDataSizeFromFormat(Format, Size.Width, Size.Height),16)];
	DeleteMemory = true;
}


//! sets a pixel
void CImage::setPixel(u32 x, u32 y, const SColor &color, bool blend)
{
	if (x >= Size.Width || y >= Size.Height)
		return;

	switch(Format)
	{
		case ECF_A1R5G5B5:
		{
			u16 * dest = (u16*) (Data + ( y * Pitch ) + ( x << 1 ));
			*dest = video::A8R8G8B8toA1R5G5B5( color.color );
		} break;

		case ECF_R5G6B5:
		{
			u16 * dest = (u16*) (Data + ( y * Pitch ) + ( x << 1 ));
			*dest = video::A8R8G8B8toR5G6B5( color.color );
		} break;

		case ECF_R8G8B8:
		{
			u8* dest = Data + ( y * Pitch ) + ( x * 3 );
			dest[0] = (u8)color.getRed();
			dest[1] = (u8)color.getGreen();
			dest[2] = (u8)color.getBlue();
		} break;

		case ECF_A8R8G8B8:
		{
			u32 * dest = (u32*) (Data + ( y * Pitch ) + ( x << 2 ));
			*dest = blend ? PixelBlend32 ( *dest, color.color ) : color.color;
		} break;

		IRR_CASE_IIMAGE_COMPRESSED_FORMAT
			os::Printer::log("IImage::setPixel method doesn't work with compressed images.", ELL_WARNING);
			return;

		case ECF_UNKNOWN:
			os::Printer::log("IImage::setPixel unknown format.", ELL_WARNING);
			return;

		default:
			break;
	}
}


//! returns a pixel
SColor CImage::getPixel(u32 x, u32 y) const
{
	if (x >= Size.Width || y >= Size.Height)
		return SColor(0);

	switch(Format)
	{
	case ECF_A1R5G5B5:
		return A1R5G5B5toA8R8G8B8(((u16*)Data)[y*Size.Width + x]);
	case ECF_R5G6B5:
		return R5G6B5toA8R8G8B8(((u16*)Data)[y*Size.Width + x]);
	case ECF_A8R8G8B8:
		return ((u32*)Data)[y*Size.Width + x];
	case ECF_R8G8B8:
		{
			u8* p = Data+(y*3)*Size.Width + (x*3);
			return SColor(255,p[0],p[1],p[2]);
		}

	IRR_CASE_IIMAGE_COMPRESSED_FORMAT
		os::Printer::log("IImage::getPixel method doesn't work with compressed images.", ELL_WARNING);
		break;

	case ECF_UNKNOWN:
		os::Printer::log("IImage::getPixel unknown format.", ELL_WARNING);
		break;

	default:
		break;
	}

	return SColor(0);
}


//! copies this surface into another at given position
void CImage::copyTo(IImage* target, const core::position2d<s32>& pos)
{
	if (IImage::isCompressedFormat(Format))
	{
		os::Printer::log("IImage::copyTo method doesn't work with compressed images.", ELL_WARNING);
		return;
	}

	if (!Blit(BLITTER_TEXTURE, target, 0, &pos, this, 0, 0)
		&& target && pos.X == 0 && pos.Y == 0 &&
		CColorConverter::canConvertFormat(Format, target->getColorFormat()))
	{
		// No fast blitting, but copyToScaling uses other color conversions and might work
		irr::core::dimension2du dim(target->getDimension());
		copyToScaling(target->getData(), dim.Width, dim.Height, target->getColorFormat(), target->getPitch());
	}
}


//! copies this surface partially into another at given position
void CImage::copyTo(IImage* target, const core::position2d<s32>& pos, const core::rect<s32>& sourceRect, const core::rect<s32>* clipRect)
{
	if (IImage::isCompressedFormat(Format))
	{
		os::Printer::log("IImage::copyTo method doesn't work with compressed images.", ELL_WARNING);
		return;
	}

	Blit(BLITTER_TEXTURE, target, clipRect, &pos, this, &sourceRect, 0);
}


//! copies this surface into another, using the alpha mask, a cliprect and a color to add with
void CImage::copyToWithAlpha(IImage* target, const core::position2d<s32>& pos, const core::rect<s32>& sourceRect, const SColor &color, const core::rect<s32>* clipRect, bool combineAlpha)
{
	if (IImage::isCompressedFormat(Format))
	{
		os::Printer::log("IImage::copyToWithAlpha method doesn't work with compressed images.", ELL_WARNING);
		return;
	}

	eBlitter op = combineAlpha ? BLITTER_TEXTURE_COMBINE_ALPHA :
		color.color == 0xFFFFFFFF ? BLITTER_TEXTURE_ALPHA_BLEND : BLITTER_TEXTURE_ALPHA_COLOR_BLEND;
	Blit(op,target, clipRect, &pos, this, &sourceRect, color.color);
}


//! copies this surface into another, if it has the exact same size and format.
bool CImage::copyToNoScaling(void *target, u32 width, u32 height, ECOLOR_FORMAT format, u32 pitch) const
{
	if (IImage::isCompressedFormat(Format))
	{
		os::Printer::log("IImage::copyToNoScaling method doesn't work with compressed images.", ELL_WARNING);
		return false;
	}

	if (!target || !width || !height || !Size.Width || !Size.Height)
		return false;

	const u32 bpp=getBitsPerPixelFromFormat(format)/8;
	if (0==pitch)
		pitch = width*bpp;

	if (!(Format==format && Size.Width==width && Size.Height==height))
		return false;

	if (pitch==Pitch)
	{
		memcpy(target, Data, (size_t)height*pitch);
	}
	else
	{
		u8* tgtpos = (u8*) target;
		u8* srcpos = Data;
		const u32 bwidth = width*bpp;
		const u32 rest = pitch-bwidth;
		for (u32 y=0; y<height; ++y)
		{
			// copy scanline
			memcpy(tgtpos, srcpos, bwidth);
			// clear pitch
			memset(tgtpos+bwidth, 0, rest);
			tgtpos += pitch;
			srcpos += Pitch;
		}
	}

	return true;
}


//! copies this surface into another, scaling it to the target image size
// note: this is very very slow.
void CImage::copyToScaling(void* target, u32 width, u32 height, ECOLOR_FORMAT format, u32 pitch)
{
	if (IImage::isCompressedFormat(Format))
	{
		os::Printer::log("IImage::copyToScaling method doesn't work with compressed images.", ELL_WARNING);
		return;
	}

	if (!target || !width || !height || !Size.Width || !Size.Height)
		return;

	const u32 bpp=getBitsPerPixelFromFormat(format)/8;
	if (0==pitch)
		pitch = width*bpp;

	if (copyToNoScaling(target, width, height, format, pitch))
		return;

	// NOTE: Scaling is coded to keep the border pixels intact.
	// Alternatively we could for example work with first pixel being taken at half step-size.
	// Then we have one more step here and it would be:
	//     sourceXStep = (f32)(Size.Width-1) / (f32)(width);
	//     And sx would start at 0.5f + sourceXStep / 2.f;
	//     Similar for y.
	// As scaling is done without any antialiasing it doesn't matter too much which outermost pixels we use and keeping
	// border pixels intact is probably mostly better (with AA the other solution would be more correct).
	// This is however unnecessary (and unexpected) for scaling to integer multiples, so don't do it there.
	f32 sourceXStep, sourceYStep;
	f32 sourceXStart = 0.f, sourceYStart = 0.f;
	if (width % Size.Width == 0)
		sourceXStep = (f32)(Size.Width) / (f32)(width);
	else
	{
		sourceXStep = width > 1 ? (f32)(Size.Width-1) / (f32)(width-1) : 0.f;
		sourceXStart = 0.5f;	// for rounding to nearest pixel
	}
	if (height % Size.Height == 0)
		sourceYStep = (f32)(Size.Height) / (f32)(height);
	else
	{
		sourceYStep = height > 1 ? (f32)(Size.Height-1) / (f32)(height-1) : 0.f;
		sourceYStart = 0.5f;	// for rounding to nearest pixel
	}

	s32 yval=0, syval=0;
	f32 sy = sourceYStart;
	for (u32 y=0; y<height; ++y)
	{
		f32 sx = sourceXStart;
		for (u32 x=0; x<width; ++x)
		{
			CColorConverter::convert_viaFormat(Data+ syval + ((s32)sx)*BytesPerPixel, Format, 1, ((u8*)target)+ yval + (x*bpp), format);
			sx+=sourceXStep;
		}
		sy+=sourceYStep;
		syval=(s32)(sy)*Pitch;
		yval+=pitch;
	}
}


//! copies this surface into another, scaling it to the target image size
// note: this is very very slow.
void CImage::copyToScaling(IImage* target)
{
	if (IImage::isCompressedFormat(Format))
	{
		os::Printer::log("IImage::copyToScaling method doesn't work with compressed images.", ELL_WARNING);
		return;
	}

	if (!target)
		return;

	const core::dimension2d<u32>& targetSize = target->getDimension();

	if (targetSize==Size)
	{
		copyTo(target);
		return;
	}

	copyToScaling(target->getData(), targetSize.Width, targetSize.Height, target->getColorFormat());
}


//! copies this surface into another, scaling it to fit it.
void CImage::copyToScalingBoxFilter(IImage* target, s32 bias, bool blend)
{
	if (IImage::isCompressedFormat(Format))
	{
		os::Printer::log("IImage::copyToScalingBoxFilter method doesn't work with compressed images.", ELL_WARNING);
		return;
	}

	const core::dimension2d<u32> destSize = target->getDimension();

	const f32 sourceXStep = (f32) Size.Width / (f32) destSize.Width;
	const f32 sourceYStep = (f32) Size.Height / (f32) destSize.Height;

	s32 fx = core::ceil32( sourceXStep );
	s32 fy = core::ceil32( sourceYStep );
	f32 sx;
	f32 sy;

	sy = 0.f;
	for ( u32 y = 0; y != destSize.Height; ++y )
	{
		sx = 0.f;
		for ( u32 x = 0; x != destSize.Width; ++x )
		{
			target->setPixel( x, y,
				getPixelBox( core::floor32(sx), core::floor32(sy), fx, fy, bias ), blend );
			sx += sourceXStep;
		}
		sy += sourceYStep;
	}
}


//! fills the surface with given color
void CImage::fill(const SColor &color)
{
	if (IImage::isCompressedFormat(Format))
	{
		os::Printer::log("IImage::fill method doesn't work with compressed images.", ELL_WARNING);
		return;
	}

	u32 c;

	switch ( Format )
	{
		case ECF_A1R5G5B5:
			c = color.toA1R5G5B5();
			c |= c << 16;
			break;
		case ECF_R5G6B5:
			c = video::A8R8G8B8toR5G6B5( color.color );
			c |= c << 16;
			break;
		case ECF_A8R8G8B8:
			c = color.color;
			break;
		case ECF_R8G8B8:
		{
			u8 rgb[3];
			CColorConverter::convert_A8R8G8B8toR8G8B8(&color, 1, rgb);
			const u32 size = getImageDataSizeInBytes();
			for (u32 i=0; i<size; i+=3)
			{
				memcpy(Data+i, rgb, 3);
			}
			return;
		}
		break;
		default:
		// TODO: Handle other formats
			return;
	}
	memset32( Data, c, getImageDataSizeInBytes() );
}


//! get a filtered pixel
inline SColor CImage::getPixelBox( s32 x, s32 y, s32 fx, s32 fy, s32 bias ) const
{
	if (IImage::isCompressedFormat(Format))
	{
		os::Printer::log("IImage::getPixelBox method doesn't work with compressed images.", ELL_WARNING);
		return SColor(0);
	}

	SColor c;
	s32 a = 0, r = 0, g = 0, b = 0;

	for ( s32 dx = 0; dx != fx; ++dx )
	{
		for ( s32 dy = 0; dy != fy; ++dy )
		{
			c = getPixel(	core::s32_min ( x + dx, Size.Width - 1 ) ,
							core::s32_min ( y + dy, Size.Height - 1 )
						);

			a += c.getAlpha();
			r += c.getRed();
			g += c.getGreen();
			b += c.getBlue();
		}

	}

	s32 sdiv = s32_log2_s32(fx * fy);

	a = core::s32_clamp( ( a >> sdiv ) + bias, 0, 255 );
	r = core::s32_clamp( ( r >> sdiv ) + bias, 0, 255 );
	g = core::s32_clamp( ( g >> sdiv ) + bias, 0, 255 );
	b = core::s32_clamp( ( b >> sdiv ) + bias, 0, 255 );

	c.set( a, r, g, b );
	return c;
}



} // end namespace video
} // end namespace irr
