// Copyright (C) 2002-2009 Nikolaus Gebhardt / Thomas Alten
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h

#ifndef _C_BLIT_H_INCLUDED_
#define _C_BLIT_H_INCLUDED_

#include "SoftwareDriver2_helper.h"

namespace irr
{

	struct SBlitJob
	{
		AbsRectangle Dest;
		AbsRectangle Source;

		u32 argb;

		void * src;
		void * dst;

		s32 width;
		s32 height;

		u32 srcPitch;
		u32 dstPitch;

		u32 srcPixelMul;
		u32 dstPixelMul;
	};


	// Bitfields Cohen Sutherland
	enum eClipCode
	{
		CLIPCODE_EMPTY	=	0,
		CLIPCODE_BOTTOM	=	1,
		CLIPCODE_TOP	=	2,
		CLIPCODE_LEFT	=	4,
		CLIPCODE_RIGHT	=	8
	};

inline u32 GetClipCode( const AbsRectangle &r, const core::position2d<s32> &p )
{
	u32 code = CLIPCODE_EMPTY;

	if ( p.X < r.x0 )
		code = CLIPCODE_LEFT;
	else
	if ( p.X > r.x1 )
		code = CLIPCODE_RIGHT;

	if ( p.Y < r.y0 )
		code |= CLIPCODE_TOP;
	else
	if ( p.Y > r.y1 )
		code |= CLIPCODE_BOTTOM;

	return code;
}


/*!
	Cohen Sutherland clipping
	@return: 1 if valid
*/

static int ClipLine(const AbsRectangle &clipping,
			core::position2d<s32> &p0,
			core::position2d<s32> &p1,
			const core::position2d<s32>& p0_in,
			const core::position2d<s32>& p1_in)
{
	u32 code0;
	u32 code1;
	u32 code;

	p0 = p0_in;
	p1 = p1_in;

	code0 = GetClipCode( clipping, p0 );
	code1 = GetClipCode( clipping, p1 );

	// trivial accepted
	while ( code0 | code1 )
	{
		s32 x=0;
		s32 y=0;

		// trivial reject
		if ( code0 & code1 )
			return 0;

		if ( code0 )
		{
			// clip first point
			code = code0;
		}
		else
		{
			// clip last point
			code = code1;
		}

		if ( (code & CLIPCODE_BOTTOM) == CLIPCODE_BOTTOM )
		{
			// clip bottom viewport
			y = clipping.y1;
			x = p0.X + ( p1.X - p0.X ) * ( y - p0.Y ) / ( p1.Y - p0.Y );
		}
		else
		if ( (code & CLIPCODE_TOP) == CLIPCODE_TOP )
		{
			// clip to viewport
			y = clipping.y0;
			x = p0.X + ( p1.X - p0.X ) * ( y - p0.Y ) / ( p1.Y - p0.Y );
		}
		else
		if ( (code & CLIPCODE_RIGHT) == CLIPCODE_RIGHT )
		{
			// clip right viewport
			x = clipping.x1;
			y = p0.Y + ( p1.Y - p0.Y ) * ( x - p0.X ) / ( p1.X - p0.X );
		}
		else
		if ( (code & CLIPCODE_LEFT) == CLIPCODE_LEFT )
		{
			// clip left viewport
			x = clipping.x0;
			y = p0.Y + ( p1.Y - p0.Y ) * ( x - p0.X ) / ( p1.X - p0.X );
		}

		if ( code == code0 )
		{
			// modify first point
			p0.X = x;
			p0.Y = y;
			code0 = GetClipCode( clipping, p0 );
		}
		else
		{
			// modify second point
			p1.X = x;
			p1.Y = y;
			code1 = GetClipCode( clipping, p1 );
		}
	}

	return 1;
}

/*
*/
inline void GetClip(AbsRectangle &clipping, video::IImage * t)
{
	clipping.x0 = 0;
	clipping.y0 = 0;
	clipping.x1 = t->getDimension().Width - 1;
	clipping.y1 = t->getDimension().Height - 1;
}

/*
	return alpha in [0;256] Granularity from 32-Bit ARGB
	add highbit alpha ( alpha > 127 ? + 1 )
*/
static inline u32 extractAlpha ( const u32 c )
{
	return ( c >> 24 ) + ( c >> 31 );
}

/*
	return alpha in [0;255] Granularity and 32-Bit ARGB
	add highbit alpha ( alpha > 127 ? + 1 )
*/
static inline u32 packAlpha ( const u32 c )
{
	return (c > 127 ? c - 1 : c) << 24;
}


/*!
	Scale Color by (1/value)
	value 0 - 256 ( alpha )
*/
inline u32 PixelLerp32 ( const u32 source, const u32 value )
{
	u32 srcRB = source & 0x00FF00FF;
	u32 srcXG = (source & 0xFF00FF00) >> 8;

	srcRB *= value;
	srcXG *= value;

	srcRB >>= 8;
	//srcXG >>= 8;

	srcXG &= 0xFF00FF00;
	srcRB &= 0x00FF00FF;

	return srcRB | srcXG;
}


/*
*/
static void RenderLine32_Decal(video::IImage *t,
				const core::position2d<s32> &p0,
				const core::position2d<s32> &p1,
				u32 argb )
{
	s32 dx = p1.X - p0.X;
	s32 dy = p1.Y - p0.Y;

	s32 c;
	s32 m;
	s32 d = 0;
	s32 run;

	s32 xInc = 4;
	s32 yInc = (s32) t->getPitch();

	if ( dx < 0 )
	{
		xInc = -xInc;
		dx = -dx;
	}

	if ( dy < 0 )
	{
		yInc = -yInc;
		dy = -dy;
	}

	u32 *dst;
	dst = (u32*) ( (u8*) t->lock() + ( p0.Y * t->getPitch() ) + ( p0.X << 2 ) );

	if ( dy > dx )
	{
		s32 tmp;
		tmp = dx;
		dx = dy;
		dy = tmp;
		tmp = xInc;
		xInc = yInc;
		yInc = tmp;
	}

	c = dx << 1;
	m = dy << 1;

	run = dx;
	while ( run )
	{
		*dst = argb;

		dst = (u32*) ( (u8*) dst + xInc );	// x += xInc
		d += m;
		if ( d > dx )
		{
			dst = (u32*) ( (u8*) dst + yInc );	// y += yInc
			d -= c;
		}
		run -= 1;
	}

	t->unlock();
}


/*
*/
static void RenderLine32_Blend(video::IImage *t,
				const core::position2d<s32> &p0,
				const core::position2d<s32> &p1,
				u32 argb, u32 alpha)
{
	s32 dx = p1.X - p0.X;
	s32 dy = p1.Y - p0.Y;

	s32 c;
	s32 m;
	s32 d = 0;
	s32 run;

	s32 xInc = 4;
	s32 yInc = (s32) t->getPitch();

	if ( dx < 0 )
	{
		xInc = -xInc;
		dx = -dx;
	}

	if ( dy < 0 )
	{
		yInc = -yInc;
		dy = -dy;
	}

	u32 *dst;
	dst = (u32*) ( (u8*) t->lock() + ( p0.Y * t->getPitch() ) + ( p0.X << 2 ) );

	if ( dy > dx )
	{
		s32 tmp;
		tmp = dx;
		dx = dy;
		dy = tmp;
		tmp = xInc;
		xInc = yInc;
		yInc = tmp;
	}

	c = dx << 1;
	m = dy << 1;

	run = dx;
	const u32 packA = packAlpha ( alpha );
	while ( run )
	{
		*dst = packA | PixelBlend32( *dst, argb, alpha );

		dst = (u32*) ( (u8*) dst + xInc );	// x += xInc
		d += m;
		if ( d > dx )
		{
			dst = (u32*) ( (u8*) dst + yInc );	// y += yInc
			d -= c;
		}
		run -= 1;
	}

	t->unlock();
}

/*
*/
static void RenderLine16_Decal(video::IImage *t,
				const core::position2d<s32> &p0,
				const core::position2d<s32> &p1,
				u32 argb )
{
	s32 dx = p1.X - p0.X;
	s32 dy = p1.Y - p0.Y;

	s32 c;
	s32 m;
	s32 d = 0;
	s32 run;

	s32 xInc = 2;
	s32 yInc = (s32) t->getPitch();

	if ( dx < 0 )
	{
		xInc = -xInc;
		dx = -dx;
	}

	if ( dy < 0 )
	{
		yInc = -yInc;
		dy = -dy;
	}

	u16 *dst;
	dst = (u16*) ( (u8*) t->lock() + ( p0.Y * t->getPitch() ) + ( p0.X << 1 ) );

	if ( dy > dx )
	{
		s32 tmp;
		tmp = dx;
		dx = dy;
		dy = tmp;
		tmp = xInc;
		xInc = yInc;
		yInc = tmp;
	}

	c = dx << 1;
	m = dy << 1;

	run = dx;
	while ( run )
	{
		*dst = (u16)argb;

		dst = (u16*) ( (u8*) dst + xInc );	// x += xInc
		d += m;
		if ( d > dx )
		{
			dst = (u16*) ( (u8*) dst + yInc );	// y += yInc
			d -= c;
		}
		run -= 1;
	}

	t->unlock();
}

/*
*/
static void RenderLine16_Blend(video::IImage *t,
				const core::position2d<s32> &p0,
				const core::position2d<s32> &p1,
				u16 argb,
				u16 alpha)
{
	s32 dx = p1.X - p0.X;
	s32 dy = p1.Y - p0.Y;

	s32 c;
	s32 m;
	s32 d = 0;
	s32 run;

	s32 xInc = 2;
	s32 yInc = (s32) t->getPitch();

	if ( dx < 0 )
	{
		xInc = -xInc;
		dx = -dx;
	}

	if ( dy < 0 )
	{
		yInc = -yInc;
		dy = -dy;
	}

	u16 *dst;
	dst = (u16*) ( (u8*) t->lock() + ( p0.Y * t->getPitch() ) + ( p0.X << 1 ) );

	if ( dy > dx )
	{
		s32 tmp;
		tmp = dx;
		dx = dy;
		dy = tmp;
		tmp = xInc;
		xInc = yInc;
		yInc = tmp;
	}

	c = dx << 1;
	m = dy << 1;

	run = dx;
	const u16 packA = alpha ? 0x8000 : 0;
	while ( run )
	{
		*dst = packA | PixelBlend16( *dst, argb, alpha );

		dst = (u16*) ( (u8*) dst + xInc );	// x += xInc
		d += m;
		if ( d > dx )
		{
			dst = (u16*) ( (u8*) dst + yInc );	// y += yInc
			d -= c;
		}
		run -= 1;
	}

	t->unlock();
}


/*!
*/
static void executeBlit_TextureCopy_x_to_x( const SBlitJob * job )
{
	const void *src = (void*) job->src;
	void *dst = (void*) job->dst;

	const u32 widthPitch = job->width * job->dstPixelMul;
	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		memcpy( dst, src, widthPitch );

		src = (void*) ( (u8*) (src) + job->srcPitch );
		dst = (void*) ( (u8*) (dst) + job->dstPitch );
	}
}


/*!
*/
static void executeBlit_TextureCopy_32_to_16( const SBlitJob * job )
{
	const u32 *src = static_cast<const u32*>(job->src);
	u16 *dst = static_cast<u16*>(job->dst);

	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		for ( s32 dx = 0; dx != job->width; ++dx )
		{
			//16 bit Blitter depends on pre-multiplied color
			const u32 s = PixelLerp32( src[dx] | 0xFF000000, extractAlpha( src[dx] ) );
			dst[dx] = video::A8R8G8B8toA1R5G5B5( s );
		}

		src = (u32*) ( (u8*) (src) + job->srcPitch );
		dst = (u16*) ( (u8*) (dst) + job->dstPitch );
	}
}

/*!
*/
static void executeBlit_TextureCopy_24_to_16( const SBlitJob * job )
{
	const void *src = (void*) job->src;
	u16 *dst = (u16*) job->dst;

	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		u8 * s = (u8*) src;

		for ( s32 dx = 0; dx != job->width; ++dx )
		{
			dst[dx] = video::RGBA16(s[0], s[1], s[2]);
			s += 3;
		}

		src = (void*) ( (u8*) (src) + job->srcPitch );
		dst = (u16*) ( (u8*) (dst) + job->dstPitch );
	}
}


/*!
*/
static void executeBlit_TextureCopy_16_to_32( const SBlitJob * job )
{
	const u16 *src = (u16*) job->src;
	u32 *dst = (u32*) job->dst;

	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		for ( s32 dx = 0; dx != job->width; ++dx )
		{
			dst[dx] = video::A1R5G5B5toA8R8G8B8( src[dx] );
		}

		src = (u16*) ( (u8*) (src) + job->srcPitch );
		dst = (u32*) ( (u8*) (dst) + job->dstPitch );
	}
}

static void executeBlit_TextureCopy_16_to_24( const SBlitJob * job )
{
	const u16 *src = (u16*) job->src;
	u8 *dst = (u8*) job->dst;

	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		for ( s32 dx = 0; dx != job->width; ++dx )
		{
			u32 colour = video::A1R5G5B5toA8R8G8B8( src[dx] );
			u8 * writeTo = &dst[dx * 3];
			*writeTo++ = (colour >> 16)& 0xFF;
			*writeTo++ = (colour >> 8) & 0xFF;
			*writeTo++ = colour & 0xFF;
		}

		src = (u16*) ( (u8*) (src) + job->srcPitch );
		dst += job->dstPitch;
	}
}


/*!
*/
static void executeBlit_TextureCopy_24_to_32( const SBlitJob * job )
{
	void *src = (void*) job->src;
	u32 *dst = (u32*) job->dst;

	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		u8 * s = (u8*) src;

		for ( s32 dx = 0; dx != job->width; ++dx )
		{
			dst[dx] = 0xFF000000 | s[0] << 16 | s[1] << 8 | s[2];
			s += 3;
		}

		src = (void*) ( (u8*) (src) + job->srcPitch );
		dst = (u32*) ( (u8*) (dst) + job->dstPitch );
	}
}

static void executeBlit_TextureCopy_32_to_24( const SBlitJob * job )
{
	const u32 * src = (u32*) job->src;
	u8 * dst = (u8*) job->dst;

	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		for ( s32 dx = 0; dx != job->width; ++dx )
		{
			u8 * writeTo = &dst[dx * 3];
			*writeTo++ = (src[dx] >> 16)& 0xFF;
			*writeTo++ = (src[dx] >> 8) & 0xFF;
			*writeTo++ = src[dx] & 0xFF;
		}

		src = (u32*) ( (u8*) (src) + job->srcPitch );
		dst += job->dstPitch ;
	}

}


/*!
*/
static void executeBlit_TextureBlend_16_to_16( const SBlitJob * job )
{
	u32 dx;
	s32 dy;

	u32 *src = (u32*) job->src;
	u32 *dst = (u32*) job->dst;


	const u32 rdx = job->width >> 1;
	const u32 off = core::if_c_a_else_b( job->width & 1 ,job->width - 1, 0 );


	for ( dy = 0; dy != job->height; ++dy )
	{
		for ( dx = 0; dx != rdx; ++dx )
		{
			dst[dx] = PixelBlend16_simd( dst[dx], src[dx] );
		}

		if ( off )
		{
			((u16*) dst)[off] = PixelBlend16( ((u16*) dst)[off], ((u16*) src)[off] );
		}

		src = (u32*) ( (u8*) (src) + job->srcPitch );
		dst = (u32*) ( (u8*) (dst) + job->dstPitch );
	}
}

/*!
*/
static void executeBlit_TextureBlend_32_to_32( const SBlitJob * job )
{
	u32 *src = (u32*) job->src;
	u32 *dst = (u32*) job->dst;

	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		for ( s32 dx = 0; dx != job->width; ++dx )
		{
			dst[dx] = PixelBlend32( dst[dx], src[dx] );
		}
		src = (u32*) ( (u8*) (src) + job->srcPitch );
		dst = (u32*) ( (u8*) (dst) + job->dstPitch );
	}
}

/*!
*/
static void executeBlit_TextureBlendColor_16_to_16( const SBlitJob * job )
{
	u16 *src = (u16*) job->src;
	u16 *dst = (u16*) job->dst;

	u16 blend = video::A8R8G8B8toA1R5G5B5 ( job->argb );
	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		for ( s32 dx = 0; dx != job->width; ++dx )
		{
			if ( 0 == (src[dx] & 0x8000) )
				continue;

			dst[dx] = PixelMul16_2( src[dx], blend );
		}
		src = (u16*) ( (u8*) (src) + job->srcPitch );
		dst = (u16*) ( (u8*) (dst) + job->dstPitch );
	}
}


/*!
*/
static void executeBlit_TextureBlendColor_32_to_32( const SBlitJob * job )
{
	u32 *src = (u32*) job->src;
	u32 *dst = (u32*) job->dst;

	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		for ( s32 dx = 0; dx != job->width; ++dx )
		{
			dst[dx] = PixelBlend32( dst[dx], PixelMul32_2( src[dx], job->argb ) );
		}
		src = (u32*) ( (u8*) (src) + job->srcPitch );
		dst = (u32*) ( (u8*) (dst) + job->dstPitch );
	}
}

/*!
*/
static void executeBlit_Color_16_to_16( const SBlitJob * job )
{
	u16 *dst = (u16*) job->dst;

	u16 c0 = video::A8R8G8B8toA1R5G5B5( job->argb );
	u32 c = c0 | c0 << 16;

	if ( 0 == (job->srcPitch & 3 ) )
	{
		for ( s32 dy = 0; dy != job->height; ++dy )
		{
			memset32( dst, c, job->srcPitch );
			dst = (u16*) ( (u8*) (dst) + job->dstPitch );
		}
	}
	else
	{
		s32 dx = job->width - 1;

		for ( s32 dy = 0; dy != job->height; ++dy )
		{
			memset32( dst, c, job->srcPitch );
			dst[dx] = c0;
			dst = (u16*) ( (u8*) (dst) + job->dstPitch );
		}

	}
}

/*!
*/
static void executeBlit_Color_32_to_32( const SBlitJob * job )
{
	u32 *dst = (u32*) job->dst;

	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		memset32( dst, job->argb, job->srcPitch );
		dst = (u32*) ( (u8*) (dst) + job->dstPitch );
	}
}

/*!
*/
static void executeBlit_ColorAlpha_16_to_16( const SBlitJob * job )
{
	u16 *dst = (u16*) job->dst;

	const u16 alpha = extractAlpha( job->argb ) >> 3;
	if ( 0 == alpha )
		return;
	const u32 src = video::A8R8G8B8toA1R5G5B5( job->argb );

	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		for ( s32 dx = 0; dx != job->width; ++dx )
		{
			dst[dx] = 0x8000 | PixelBlend16( dst[dx], src, alpha );
		}
		dst = (u16*) ( (u8*) (dst) + job->dstPitch );
	}
}

/*!
*/
static void executeBlit_ColorAlpha_32_to_32( const SBlitJob * job )
{
	u32 *dst = (u32*) job->dst;

	const u32 alpha = extractAlpha( job->argb );
	const u32 src = job->argb;

	for ( s32 dy = 0; dy != job->height; ++dy )
	{
		for ( s32 dx = 0; dx != job->width; ++dx )
		{
			dst[dx] = (job->argb & 0xFF000000 ) | PixelBlend32( dst[dx], src, alpha );
		}
		dst = (u32*) ( (u8*) (dst) + job->dstPitch );
	}
}

// Blitter Operation
enum eBlitter
{
	BLITTER_INVALID = 0,
	BLITTER_COLOR,
	BLITTER_COLOR_ALPHA,
	BLITTER_TEXTURE,
	BLITTER_TEXTURE_ALPHA_BLEND,
	BLITTER_TEXTURE_ALPHA_COLOR_BLEND
};

typedef void (*tExecuteBlit) ( const SBlitJob * job );


/*!
*/
struct blitterTable
{
	eBlitter operation;
	s32 destFormat;
	s32 sourceFormat;
	tExecuteBlit func;
};

static const blitterTable blitTable[] =
{
	{ BLITTER_TEXTURE, -2, -2, executeBlit_TextureCopy_x_to_x },
	{ BLITTER_TEXTURE, video::ECF_A1R5G5B5, video::ECF_A8R8G8B8, executeBlit_TextureCopy_32_to_16 },
	{ BLITTER_TEXTURE, video::ECF_A1R5G5B5, video::ECF_R8G8B8, executeBlit_TextureCopy_24_to_16 },
	{ BLITTER_TEXTURE, video::ECF_A8R8G8B8, video::ECF_A1R5G5B5, executeBlit_TextureCopy_16_to_32 },
	{ BLITTER_TEXTURE, video::ECF_A8R8G8B8, video::ECF_R8G8B8, executeBlit_TextureCopy_24_to_32 },
	{ BLITTER_TEXTURE, video::ECF_R8G8B8, video::ECF_A1R5G5B5, executeBlit_TextureCopy_16_to_24 },
	{ BLITTER_TEXTURE, video::ECF_R8G8B8, video::ECF_A8R8G8B8, executeBlit_TextureCopy_32_to_24 },
	{ BLITTER_TEXTURE_ALPHA_BLEND, video::ECF_A1R5G5B5, video::ECF_A1R5G5B5, executeBlit_TextureBlend_16_to_16 },
	{ BLITTER_TEXTURE_ALPHA_BLEND, video::ECF_A8R8G8B8, video::ECF_A8R8G8B8, executeBlit_TextureBlend_32_to_32 },
	{ BLITTER_TEXTURE_ALPHA_COLOR_BLEND, video::ECF_A1R5G5B5, video::ECF_A1R5G5B5, executeBlit_TextureBlendColor_16_to_16 },
	{ BLITTER_TEXTURE_ALPHA_COLOR_BLEND, video::ECF_A8R8G8B8, video::ECF_A8R8G8B8, executeBlit_TextureBlendColor_32_to_32 },
	{ BLITTER_COLOR, video::ECF_A1R5G5B5, -1, executeBlit_Color_16_to_16 },
	{ BLITTER_COLOR, video::ECF_A8R8G8B8, -1, executeBlit_Color_32_to_32 },
	{ BLITTER_COLOR_ALPHA, video::ECF_A1R5G5B5, -1, executeBlit_ColorAlpha_16_to_16 },
	{ BLITTER_COLOR_ALPHA, video::ECF_A8R8G8B8, -1, executeBlit_ColorAlpha_32_to_32 },
	{ BLITTER_INVALID, -1, -1, 0 }
};


static inline tExecuteBlit getBlitter2( eBlitter operation,const video::IImage * dest,const video::IImage * source )
{
	video::ECOLOR_FORMAT sourceFormat = (video::ECOLOR_FORMAT) ( source ? source->getColorFormat() : -1 );
	video::ECOLOR_FORMAT destFormat = (video::ECOLOR_FORMAT) ( dest ? dest->getColorFormat() : -1 );

	const blitterTable * b = blitTable;

	while ( b->operation != BLITTER_INVALID )
	{
		if ( b->operation == operation )
		{
			if (( b->destFormat == -1 || b->destFormat == destFormat ) &&
				( b->sourceFormat == -1 || b->sourceFormat == sourceFormat ) )
					return b->func;
			else
			if ( b->destFormat == -2 && ( sourceFormat == destFormat ) )
					return b->func;
		}
		b += 1;
	}
	return 0;
}


// bounce clipping to texture
inline void setClip ( AbsRectangle &out, const core::rect<s32> *clip,
					 const video::IImage * tex, s32 passnative )
{
	if ( clip && 0 == tex && passnative )
	{
		out.x0 = clip->UpperLeftCorner.X;
		out.x1 = clip->LowerRightCorner.X;
		out.y0 = clip->UpperLeftCorner.Y;
		out.y1 = clip->LowerRightCorner.Y;
		return;
	}

	const s32 w = tex ? tex->getDimension().Width : 0;
	const s32 h = tex ? tex->getDimension().Height : 0;
	if ( clip )
	{
		out.x0 = core::s32_clamp ( clip->UpperLeftCorner.X, 0, w );
		out.x1 = core::s32_clamp ( clip->LowerRightCorner.X, out.x0, w );
		out.y0 = core::s32_clamp ( clip->UpperLeftCorner.Y, 0, h );
		out.y1 = core::s32_clamp ( clip->LowerRightCorner.Y, out.y0, h );
	}
	else
	{
		out.x0 = 0;
		out.y0 = 0;
		out.x1 = w;
		out.y1 = h;
	}

}

/*!
	a generic 2D Blitter
*/
static s32 Blit(eBlitter operation,
		video::IImage * dest,
		const core::rect<s32> *destClipping,
		const core::position2d<s32> *destPos,
		video::IImage * const source,
		const core::rect<s32> *sourceClipping,
		u32 argb)
{
	tExecuteBlit blitter = getBlitter2( operation, dest, source );
	if ( 0 == blitter )
	{
		return 0;
	}

	// Clipping
	AbsRectangle sourceClip;
	AbsRectangle destClip;
	AbsRectangle v;

	SBlitJob job;

	setClip ( sourceClip, sourceClipping, source, 1 );
	setClip ( destClip, destClipping, dest, 0 );

	v.x0 = destPos ? destPos->X : 0;
	v.y0 = destPos ? destPos->Y : 0;
	v.x1 = v.x0 + ( sourceClip.x1 - sourceClip.x0 );
	v.y1 = v.y0 + ( sourceClip.y1 - sourceClip.y0 );

	if ( !intersect( job.Dest, destClip, v ) )
		return 0;

	job.width = job.Dest.x1 - job.Dest.x0;
	job.height = job.Dest.y1 - job.Dest.y0;


	job.Source.x0 = sourceClip.x0 + ( job.Dest.x0 - v.x0 );
	job.Source.x1 = job.Source.x0 + job.width;

	job.Source.y0 = sourceClip.y0 + ( job.Dest.y0 - v.y0 );
	job.Source.y1 = job.Source.y0 + job.height;

	job.argb = argb;

	if ( source )
	{
		job.srcPitch = source->getPitch();
		job.srcPixelMul = source->getBytesPerPixel();
		job.src = (void*) ( (u8*) source->lock() + ( job.Source.y0 * job.srcPitch ) + ( job.Source.x0 * job.srcPixelMul ) );
	}
	else
	{
		// use srcPitch for color operation on dest
		job.srcPitch = job.width * dest->getBytesPerPixel();
	}

	job.dstPitch = dest->getPitch();
	job.dstPixelMul = dest->getBytesPerPixel();
	job.dst = (void*) ( (u8*) dest->lock() + ( job.Dest.y0 * job.dstPitch ) + ( job.Dest.x0 * job.dstPixelMul ) );

	blitter( &job );

	if ( source )
		source->unlock();

	if ( dest )
		dest->unlock();

	return 1;
}

}

#endif