2xsai.cpp

著名SFC模拟器Snes9x的源代码。

//                                       M|N O|P
		colorI = *(bP - Nextline - 1);
		colorE = *(bP - Nextline);
		colorF = *(bP - Nextline + 1);
		colorJ = *(bP - Nextline + 2);

		colorG = *(bP - 1);
		colorA = *(bP);
		colorB = *(bP + 1);
		colorK = *(bP + 2);

		colorH = *(bP + Nextline - 1);
		colorC = *(bP + Nextline);
		colorD = *(bP + Nextline + 1);
		colorL = *(bP + Nextline + 2);

		colorM = *(bP + Nextline + Nextline - 1);
		colorN = *(bP + Nextline + Nextline);
		colorO = *(bP + Nextline + Nextline + 1);
		colorP = *(bP + Nextline + Nextline + 2);

		if ((colorA == colorD) && (colorB != colorC))
		{
		    if (((colorA == colorE) && (colorB == colorL)) ||
			    ((colorA == colorC) && (colorA == colorF)
			     && (colorB != colorE) && (colorB == colorJ)))
		    {
			product = colorA;
		    }
		    else
		    {
			product = INTERPOLATE (colorA, colorB);
		    }

		    if (((colorA == colorG) && (colorC == colorO)) ||
			    ((colorA == colorB) && (colorA == colorH)
			     && (colorG != colorC) && (colorC == colorM)))
		    {
			product1 = colorA;
		    }
		    else
		    {
			product1 = INTERPOLATE (colorA, colorC);
		    }
		    product2 = colorA;
		}
		else if ((colorB == colorC) && (colorA != colorD))
		{
		    if (((colorB == colorF) && (colorA == colorH)) ||
			    ((colorB == colorE) && (colorB == colorD)
			     && (colorA != colorF) && (colorA == colorI)))
		    {
			product = colorB;
		    }
		    else
		    {
			product = INTERPOLATE (colorA, colorB);
		    }

		    if (((colorC == colorH) && (colorA == colorF)) ||
			    ((colorC == colorG) && (colorC == colorD)
			     && (colorA != colorH) && (colorA == colorI)))
		    {
			product1 = colorC;
		    }
		    else
		    {
			product1 = INTERPOLATE (colorA, colorC);
		    }
		    product2 = colorB;
		}
		else if ((colorA == colorD) && (colorB == colorC))
		{
		    if (colorA == colorB)
		    {
			product = colorA;
			product1 = colorA;
			product2 = colorA;
		    }
		    else
		    {
			register int r = 0;

			product1 = INTERPOLATE (colorA, colorC);
			product = INTERPOLATE (colorA, colorB);

			r +=
			    GetResult1 (colorA, colorB, colorG, colorE,
					colorI);
			r +=
			    GetResult2 (colorB, colorA, colorK, colorF,
					colorJ);
			r +=
			    GetResult2 (colorB, colorA, colorH, colorN,
					colorM);
			r +=
			    GetResult1 (colorA, colorB, colorL, colorO,
					colorP);

			if (r > 0)
			    product2 = colorA;
			else if (r < 0)
			    product2 = colorB;
			else
			{
			    product2 =
				Q_INTERPOLATE (colorA, colorB, colorC,
					       colorD);
			}
		    }
		}
		else
		{
		    product2 = Q_INTERPOLATE (colorA, colorB, colorC, colorD);

		    if ((colorA == colorC) && (colorA == colorF)
			    && (colorB != colorE) && (colorB == colorJ))
		    {
			product = colorA;
		    }
		    else
			if ((colorB == colorE) && (colorB == colorD)
			    && (colorA != colorF) && (colorA == colorI))
		    {
			product = colorB;
		    }
		    else
		    {
			product = INTERPOLATE (colorA, colorB);
		    }

		    if ((colorA == colorB) && (colorA == colorH)
			    && (colorG != colorC) && (colorC == colorM))
		    {
			product1 = colorA;
		    }
		    else
			if ((colorC == colorG) && (colorC == colorD)
			    && (colorA != colorH) && (colorA == colorI))
		    {
			product1 = colorC;
		    }
		    else
		    {
			product1 = INTERPOLATE (colorA, colorC);
		    }
		}

		product = colorA | (product << 16);
		product1 = product1 | (product2 << 16);
		*((int32 *) dP) = product;
		*((uint32 *) (dP + dstPitch)) = product1;

		bP += inc_bP;
		dP += sizeof (uint32);
	    }			// end of for ( finish= width etc..)

	    srcPtr += srcPitch;
	    dstPtr += dstPitch * 2;
	    deltaPtr += srcPitch;
	}			// endof: for (height; height; height--)
    }
}

#ifdef MMX
void Scale_2xSaI (uint8 *srcPtr, uint32 srcPitch, uint8 * /* deltaPtr */,
		  uint8 *dstPtr, uint32 dstPitch, 
		  uint32 dstWidth, uint32 dstHeight, int width, int height)
{
    uint8  *dP;
    uint16 *bP;
    uint32 w;
    uint32 h;
    uint32 dw;
    uint32 dh;
    uint32 hfinish;
    uint32 wfinish;
    uint32 Nextline;
    uint16 colorA[4];
    uint16 colorB[4];
    uint16 colorC[4];
    uint16 colorD[4];
    uint16 dx[4];
    uint16 dy[4];

    Nextline = srcPitch >> 1;

    wfinish = (width - 1) << 16;	// convert to fixed point
    hfinish = (height - 1) << 16;	// convert to fixed point
    dw = wfinish / (dstWidth - 1);
    dh = hfinish / (dstHeight - 1);

    for (h = 0; h < hfinish; h += dh)
    {
	uint32 y1, y2;

	y1 = h & 0xffff;	// fraction part of fixed point
	y2 = 0x10000 - y1;
	bP = (uint16 *) (srcPtr + ((h >> 16) * srcPitch));
	dP = dstPtr;

	for (w = 0; w < wfinish;)
	{
	    uint32 A, B, C, D;
	    uint32 E, F, G, H;
	    uint32 I, J, K, L;
	    uint32 x1, x2, a1, f1, f2;
	    uint32 position;

	    for (int c = 0; c < 4; c++)
	    {
		position = w >> 16;
		A = bP[position];	// current pixel
		B = bP[position + 1];	// next pixel
		C = bP[position + Nextline];
		D = bP[position + Nextline + 1];
		E = bP[position - Nextline];
		F = bP[position - Nextline + 1];
		G = bP[position - 1];
		H = bP[position + Nextline - 1];
		I = bP[position + 2];
		J = bP[position + Nextline + 2];
		K = bP[position + Nextline + Nextline];
		L = bP[position + Nextline + Nextline + 1];

		x1 = w & 0xffff;	// fraction part of fixed point
		x2 = 0x10000 - x1;

		/*1*/ 
		if (A == D && B != C)
		{
		    f1 = (x1 >> 1) + (0x10000 >> 2);
		    f2 = (y1 >> 1) + (0x10000 >> 2);
		    if (y1 <= f1 && A == J && A != E)	// close to B
		    {
			a1 = f1 - y1;
			colorA[c] = A;
			colorB[c] = B;
			colorC[c] = 0;
			colorD[c] = 0;
			dx[c] = a1;
			dy[c] = 0;
		    }
		    else if (y1 >= f1 && A == G && A != L)	// close to C
		    {
			a1 = y1 - f1;
			colorA[c] = A;
			colorB[c] = C;
			colorC[c] = 0;
			colorD[c] = 0;
			dx[c] = a1;
			dy[c] = 0;
		    }
		    else if (x1 >= f2 && A == E && A != J)	// close to B
		    {
			a1 = x1 - f2;
			colorA[c] = A;
			colorB[c] = B;
			colorC[c] = 0;
			colorD[c] = 0;
			dx[c] = a1;
			dy[c] = 0;
		    }
		    else if (x1 <= f2 && A == L && A != G)	// close to C
		    {
			a1 = f2 - x1;
			colorA[c] = A;
			colorB[c] = C;
			colorC[c] = 0;
			colorD[c] = 0;
			dx[c] = a1;
			dy[c] = 0;
		    }
		    else if (y1 >= x1)	// close to C
		    {
			a1 = y1 - x1;
			colorA[c] = A;
			colorB[c] = C;
			colorC[c] = 0;
			colorD[c] = 0;
			dx[c] = a1;
			dy[c] = 0;
		    }
		    else if (y1 <= x1)	// close to B
		    {
			a1 = x1 - y1;
			colorA[c] = A;
			colorB[c] = B;
			colorC[c] = 0;
			colorD[c] = 0;
			dx[c] = a1;
			dy[c] = 0;
		    }
		}
		else
		/*2*/ 
		if (B == C && A != D)
		{
		    f1 = (x1 >> 1) + (0x10000 >> 2);
		    f2 = (y1 >> 1) + (0x10000 >> 2);
		    if (y2 >= f1 && B == H && B != F)	// close to A
		    {
			a1 = y2 - f1;
			colorA[c] = B;
			colorB[c] = A;
			colorC[c] = 0;
			colorD[c] = 0;
			dx[c] = a1;
			dy[c] = 0;
		    }
		    else if (y2 <= f1 && B == I && B != K)	// close to D
		    {
			a1 = f1 - y2;
			colorA[c] = B;
			colorB[c] = D;
			colorC[c] = 0;
			colorD[c] = 0;
			dx[c] = a1;
			dy[c] = 0;
		    }
		    else if (x2 >= f2 && B == F && B != H)	// close to A
		    {
			a1 = x2 - f2;
			colorA[c] = B;
			colorB[c] = A;
			colorC[c] = 0;
			colorD[c] = 0;
			dx[c] = a1;
			dy[c] = 0;
		    }
		    else if (x2 <= f2 && B == K && B != I)	// close to D
		    {
			a1 = f2 - x2;
			colorA[c] = B;
			colorB[c] = D;
			colorC[c] = 0;
			colorD[c] = 0;
			dx[c] = a1;
			dy[c] = 0;
		    }
		    else if (y2 >= x1)	// close to A
		    {
			a1 = y2 - x1;
			colorA[c] = B;
			colorB[c] = A;
			colorC[c] = 0;
			colorD[c] = 0;
			dx[c] = a1;
			dy[c] = 0;
		    }
		    else if (y2 <= x1)	// close to D
		    {
			a1 = x1 - y2;
			colorA[c] = B;
			colorB[c] = D;
			colorC[c] = 0;
			colorD[c] = 0;
			dx[c] = a1;
			dy[c] = 0;
		    }
		}
		/*3*/
		else
		{
		    colorA[c] = A;
		    colorB[c] = B;
		    colorC[c] = C;
		    colorD[c] = D;
		    dx[c] = x1;
		    dy[c] = y1;
		}
		w += dw;
	    }
	    BilinearMMX (colorA, colorB, colorC, colorD, dx, dy, dP);
	    dP += 8;
	}
	dstPtr += dstPitch;
    };
    EndMMX ();

}

#else
static uint32 Bilinear (uint32 A, uint32 B, uint32 x)
{
    unsigned long areaA, areaB;
    unsigned long result;

    if (A == B)
	return A;

    areaB = (x >> 11) & 0x1f;	// reduce 16 bit fraction to 5 bits
    areaA = 0x20 - areaB;

    A = (A & redblueMask) | ((A & greenMask) << 16);
    B = (B & redblueMask) | ((B & greenMask) << 16);

    result = ((areaA * A) + (areaB * B)) >> 5;

    return (result & redblueMask) | ((result >> 16) & greenMask);

}

static uint32 Bilinear4 (uint32 A, uint32 B, uint32 C, uint32 D, uint32 x,
			 uint32 y)
{
    unsigned long areaA, areaB, areaC, areaD;
    unsigned long result, xy;

    x = (x >> 11) & 0x1f;
    y = (y >> 11) & 0x1f;
    xy = (x * y) >> 5;

    A = (A & redblueMask) | ((A & greenMask) << 16);
    B = (B & redblueMask) | ((B & greenMask) << 16);
    C = (C & redblueMask) | ((C & greenMask) << 16);
    D = (D & redblueMask) | ((D & greenMask) << 16);

    areaA = 0x20 + xy - x - y;
    areaB = x - xy;
    areaC = y - xy;
    areaD = xy;

    result = ((areaA * A) + (areaB * B) + (areaC * C) + (areaD * D)) >> 5;

    return (result & redblueMask) | ((result >> 16) & greenMask);
}

void Scale_2xSaI (uint8 *srcPtr, uint32 srcPitch, uint8 * /* deltaPtr */,
		  uint8 *dstPtr, uint32 dstPitch, 
		  uint32 dstWidth, uint32 dstHeight, int width, int height)
{
    uint8  *dP;
    uint16 *bP;

    uint32 w;
    uint32 h;
    uint32 dw;
    uint32 dh;
    uint32 hfinish;
    uint32 wfinish;

    uint32 Nextline = srcPitch >> 1;

    wfinish = (width - 1) << 16;	// convert to fixed point
    dw = wfinish / (dstWidth - 1);
    hfinish = (height - 1) << 16;	// convert to fixed point
    dh = hfinish / (dstHeight - 1);

    for (h = 0; h < hfinish; h += dh)
    {
	uint32 y1, y2;

	y1 = h & 0xffff;	// fraction part of fixed point
	bP = (uint16 *) (srcPtr + ((h >> 16) * srcPitch));
	dP = dstPtr;
	y2 = 0x10000 - y1;

	w = 0;

	for (; w < wfinish;)
	{
	    uint32 A, B, C, D;
	    uint32 E, F, G, H;
	    uint32 I, J, K, L;
	    uint32 x1, x2, a1, f1, f2;
	    uint32 position, product1;

	    position = w >> 16;
	    A = bP[position];	// current pixel
	    B = bP[position + 1];	// next pixel
	    C = bP[position + Nextline];
	    D = bP[position + Nextline + 1];
	    E = bP[position - Nextline];
	    F = bP[position - Nextline + 1];
	    G = bP[position - 1];
	    H = bP[position + Nextline - 1];
	    I = bP[position + 2];
	    J = bP[position + Nextline + 2];
	    K = bP[position + Nextline + Nextline];
	    L = bP[position + Nextline + Nextline + 1];

	    x1 = w & 0xffff;	// fraction part of fixed point
	    x2 = 0x10000 - x1;

	    /*0*/ 
	    if (A == B && C == D && A == C)
		product1 = A;
	    else
	    /*1*/ 
	    if (A == D && B != C)
	    {
		f1 = (x1 >> 1) + (0x10000 >> 2);
		f2 = (y1 >> 1) + (0x10000 >> 2);
		if (y1 <= f1 && A == J && A != E)	// close to B
		{
		    a1 = f1 - y1;
		    product1 = Bilinear (A, B, a1);
		}
		else if (y1 >= f1 && A == G && A != L)	// close to C
		{
		    a1 = y1 - f1;
		    product1 = Bilinear (A, C, a1);
		}
		else if (x1 >= f2 && A == E && A != J)	// close to B
		{
		    a1 = x1 - f2;
		    product1 = Bilinear (A, B, a1);
		}
		else if (x1 <= f2 && A == L && A != G)	// close to C
		{
		    a1 = f2 - x1;
		    product1 = Bilinear (A, C, a1);
		}
		else if (y1 >= x1)	// close to C
		{
		    a1 = y1 - x1;
		    product1 = Bilinear (A, C, a1);
		}
		else if (y1 <= x1)	// close to B
		{
		    a1 = x1 - y1;
		    product1 = Bilinear (A, B, a1);
		}
	    }
	    else
	    /*2*/ 
	    if (B == C && A != D)
	    {
		f1 = (x1 >> 1) + (0x10000 >> 2);
		f2 = (y1 >> 1) + (0x10000 >> 2);
		if (y2 >= f1 && B == H && B != F)	// close to A
		{
		    a1 = y2 - f1;
		    product1 = Bilinear (B, A, a1);
		}
		else if (y2 <= f1 && B == I && B != K)	// close to D
		{
		    a1 = f1 - y2;
		    product1 = Bilinear (B, D, a1);
		}
		else if (x2 >= f2 && B == F && B != H)	// close to A
		{
		    a1 = x2 - f2;
		    product1 = Bilinear (B, A, a1);
		}
		else if (x2 <= f2 && B == K && B != I)	// close to D
		{
		    a1 = f2 - x2;
		    product1 = Bilinear (B, D, a1);
		}
		else if (y2 >= x1)	// close to A
		{
		    a1 = y2 - x1;
		    product1 = Bilinear (B, A, a1);
		}
		else if (y2 <= x1)	// close to D
		{
		    a1 = x1 - y2;
		    product1 = Bilinear (B, D, a1);
		}
	    }
	    /*3*/
	    else
	    {
		product1 = Bilinear4 (A, B, C, D, x1, y1);
	    }

//end First Pixel
	    *(uint32 *) dP = product1;
	    dP += 2;
	    w += dw;
	}
	dstPtr += dstPitch;
    }
}

#endif