fbpict.c

按照官方的说法：Cairo is a vector graphics library with cross-device output support. 翻译过来

    CompositeFunc   func = NULL;
    Bool	    srcRepeat = pSrc->pDrawable && pSrc->repeat == RepeatNormal;
    Bool	    maskRepeat = FALSE;
    Bool	    srcTransform = pSrc->transform != 0;
    Bool	    maskTransform = FALSE;
    Bool	    srcAlphaMap = pSrc->alphaMap != 0;
    Bool	    maskAlphaMap = FALSE;
    Bool	    dstAlphaMap = pDst->alphaMap != 0;
    int		    x_msk, y_msk, x_src, y_src, x_dst, y_dst;
    int		    w, h, w_this, h_this;

#ifdef USE_MMX
    static Bool mmx_setup = FALSE;
    if (!mmx_setup) {
        fbComposeSetupMMX();
        mmx_setup = TRUE;
    }
#endif

    xDst += pDst->pDrawable->x;
    yDst += pDst->pDrawable->y;
    if (pSrc->pDrawable) {
        xSrc += pSrc->pDrawable->x;
        ySrc += pSrc->pDrawable->y;
    }

    if (srcRepeat && srcTransform &&
	pSrc->pDrawable->width == 1 &&
	pSrc->pDrawable->height == 1)
	srcTransform = FALSE;

    if (pMask && pMask->pDrawable)
    {
	xMask += pMask->pDrawable->x;
	yMask += pMask->pDrawable->y;
	maskRepeat = pMask->repeat == RepeatNormal;
	maskTransform = pMask->transform != 0;
#ifdef PIXMAN_CONVOLUTION
	if (pMask->filter == PictFilterConvolution)
	    maskTransform = TRUE;
#endif

	maskAlphaMap = pMask->alphaMap != 0;

	if (maskRepeat && maskTransform &&
	    pMask->pDrawable->width == 1 &&
	    pMask->pDrawable->height == 1)
	    maskTransform = FALSE;
    }

    if (pSrc->pDrawable && (!pMask || pMask->pDrawable)
        && !srcTransform && !maskTransform
        && !maskAlphaMap && !srcAlphaMap && !dstAlphaMap
#ifdef PIXMAN_CONVOLUTION
        && (pSrc->filter != PictFilterConvolution)
        && (!pMask || pMask->filter != PictFilterConvolution)
#endif
        )
    switch (op) {
    case PIXMAN_OPERATOR_OVER:
	if (pMask)
	{
	    if (srcRepeat &&
		pSrc->pDrawable->width == 1 &&
		pSrc->pDrawable->height == 1)
	    {
		if (PICT_FORMAT_COLOR(pSrc->format_code)) {
		    switch (pMask->format_code) {
		    case PICT_a8:
			switch (pDst->format_code) {
			case PICT_r5g6b5:
			case PICT_b5g6r5:
#ifdef USE_MMX
			    if (fbHaveMMX())
				func = fbCompositeSolidMask_nx8x0565mmx;
			    else
#endif
				func = fbCompositeSolidMask_nx8x0565;
			    break;
			case PICT_r8g8b8:
			case PICT_b8g8r8:
			    func = fbCompositeSolidMask_nx8x0888;
			    break;
			case PICT_a8r8g8b8:
			case PICT_x8r8g8b8:
			case PICT_a8b8g8r8:
			case PICT_x8b8g8r8:
#ifdef USE_MMX
			    if (fbHaveMMX())
				func = fbCompositeSolidMask_nx8x8888mmx;
			    else
#endif
				func = fbCompositeSolidMask_nx8x8888;
			    break;
			}
			break;
		    case PICT_a8r8g8b8:
			if (pMask->componentAlpha) {
			    switch (pDst->format_code) {
			    case PICT_a8r8g8b8:
			    case PICT_x8r8g8b8:
#ifdef USE_MMX
				if (fbHaveMMX())
				    func = fbCompositeSolidMask_nx8888x8888Cmmx;
				else
#endif
				    func = fbCompositeSolidMask_nx8888x8888C;
				break;
			    case PICT_r5g6b5:
#ifdef USE_MMX
				if (fbHaveMMX())
				    func = fbCompositeSolidMask_nx8888x0565Cmmx;
				else
#endif
				    func = fbCompositeSolidMask_nx8888x0565C;
				break;
			    }
			}
			else
			{
			    switch (pDst->format_code) {
			    case PICT_r5g6b5:
				func = fbCompositeSolidMask_nx8888x0565;
				break;
			    }
			}
			break;
		    case PICT_a8b8g8r8:
			if (pMask->componentAlpha) {
			    switch (pDst->format_code) {
			    case PICT_a8b8g8r8:
			    case PICT_x8b8g8r8:
#ifdef USE_MMX
				if (fbHaveMMX())
				    func = fbCompositeSolidMask_nx8888x8888Cmmx;
				else
#endif
				    func = fbCompositeSolidMask_nx8888x8888C;
				break;
			    case PICT_b5g6r5:
#ifdef USE_MMX
				if (fbHaveMMX())
				    func = fbCompositeSolidMask_nx8888x0565Cmmx;
				else
#endif
				    func = fbCompositeSolidMask_nx8888x0565C;
				break;
			    }
			}
			else
			{
			    switch (pDst->format_code) {
			    case PICT_b5g6r5:
				func = fbCompositeSolidMask_nx8888x0565;
				break;
			    }
			}
			break;
		    case PICT_a1:
			switch (pDst->format_code) {
			case PICT_r5g6b5:
			case PICT_b5g6r5:
			case PICT_r8g8b8:
			case PICT_b8g8r8:
			case PICT_a8r8g8b8:
			case PICT_x8r8g8b8:
			case PICT_a8b8g8r8:
			case PICT_x8b8g8r8:
			    func = fbCompositeSolidMask_nx1xn;
			    break;
			}
		    }
		}
		if (func != pixman_compositeGeneral)
		    srcRepeat = FALSE;
	    }
	    else /* has mask and non-repeating source */
	    {
		if (pSrc->pDrawable == pMask->pDrawable &&
		    xSrc == xMask && ySrc == yMask &&
		    !pMask->componentAlpha)
		{
		    /* source == mask: non-premultiplied data */
		    switch (pSrc->format_code) {
		    case PICT_x8b8g8r8:
			switch (pMask->format_code) {
			case PICT_a8r8g8b8:
			case PICT_a8b8g8r8:
			    switch (pDst->format_code) {
			    case PICT_a8r8g8b8:
			    case PICT_x8r8g8b8:
#ifdef USE_MMX
				if (fbHaveMMX())
				    func = fbCompositeSrc_8888RevNPx8888mmx;
#endif
				break;
			    case PICT_r5g6b5:
#ifdef USE_MMX
				if (fbHaveMMX())
				    func = fbCompositeSrc_8888RevNPx0565mmx;
#endif
				break;
			    }
			    break;
			}
			break;
		    case PICT_x8r8g8b8:
			switch (pMask->format_code) {
			case PICT_a8r8g8b8:
			case PICT_a8b8g8r8:
			    switch (pDst->format_code) {
			    case PICT_a8b8g8r8:
			    case PICT_x8b8g8r8:
#ifdef USE_MMX
				if (fbHaveMMX())
				    func = fbCompositeSrc_8888RevNPx8888mmx;
#endif
				break;
			    case PICT_r5g6b5:
#ifdef USE_MMX
				if (fbHaveMMX())
				    func = fbCompositeSrc_8888RevNPx0565mmx;
#endif
				break;
			    }
			    break;
			}
			break;
		    }
		    break;
		}
		else
		{
		    /* non-repeating source, repeating mask => translucent window */
		    if (maskRepeat &&
			pMask->pDrawable->width == 1 &&
			pMask->pDrawable->height == 1)
		    {
			switch (pSrc->format_code) {
			case PICT_r5g6b5:
			case PICT_b5g6r5:
			    if (pDst->format_code == pSrc->format_code)
				func = fbCompositeTrans_0565xnx0565;
			    break;
			case PICT_r8g8b8:
			case PICT_b8g8r8:
			    if (pDst->format_code == pSrc->format_code)
				func = fbCompositeTrans_0888xnx0888;
			    break;
#ifdef USE_MMX
			case PICT_x8r8g8b8:
			case PICT_x8b8g8r8:
			    if (pDst->format_code == pSrc->format_code &&
				pMask->format_code == PICT_a8 && fbHaveMMX())
				func = fbCompositeSrc_x888x8x8888mmx;
			    break;
#if 0 /* This case fails rendercheck for me */
			case PICT_a8r8g8b8:
			    if ((pDst->format == PICT_a8r8g8b8 ||
				 pDst->format == PICT_x8r8g8b8) &&
				pMask->format == PICT_a8 && fbHaveMMX())
				func = fbCompositeSrc_8888x8x8888mmx;
			    break;
#endif
			case PICT_a8b8g8r8:
			    if ((pDst->format_code == PICT_a8b8g8r8 ||
				 pDst->format_code == PICT_x8b8g8r8) &&
				pMask->format_code == PICT_a8 && fbHaveMMX())
				func = fbCompositeSrc_8888x8x8888mmx;
			    break;
#endif
			}

                        if (func != pixman_compositeGeneral)
			    maskRepeat = FALSE;
		    }
		}
	    }
	}
	else /* no mask */
	{
	    if (srcRepeat &&
		pSrc->pDrawable->width == 1 &&
		pSrc->pDrawable->height == 1)
	    {
		/* no mask and repeating source */
		switch (pSrc->format_code) {
		case PICT_a8r8g8b8:
		    switch (pDst->format_code) {
		    case PICT_a8r8g8b8:
		    case PICT_x8r8g8b8:
#ifdef USE_MMX
			if (fbHaveMMX())
			{
			    srcRepeat = FALSE;
			    func = fbCompositeSolid_nx8888mmx;
			}
#endif
			break;
		    case PICT_r5g6b5:
#ifdef USE_MMX
			if (fbHaveMMX())
			{
			    srcRepeat = FALSE;
			    func = fbCompositeSolid_nx0565mmx;
			}
#endif
			break;
		    }
		    break;
		}
	    }
	    else
	    {
		/*
		 * Formats without alpha bits are just Copy with Over
		 */
		if (pSrc->format_code == pDst->format_code && !PICT_FORMAT_A(pSrc->format_code))
		{
#ifdef USE_MMX
			if (fbHaveMMX() &&
			    (pSrc->format_code == PICT_x8r8g8b8 || pSrc->format_code == PICT_x8b8g8r8))
			    func = fbCompositeCopyAreammx;
			else
#endif
			    func = fbCompositeSrcSrc_nxn;
		}
		else switch (pSrc->format_code) {
		case PICT_a8r8g8b8:
		    switch (pDst->format_code) {
		    case PICT_a8r8g8b8:
		    case PICT_x8r8g8b8:
#ifdef USE_MMX
			if (fbHaveMMX())
			    func = fbCompositeSrc_8888x8888mmx;
			else
#endif
			    func = fbCompositeSrc_8888x8888;
			break;
		    case PICT_r8g8b8:
			func = fbCompositeSrc_8888x0888;
			break;
		    case PICT_r5g6b5:
			func = fbCompositeSrc_8888x0565;
			break;
		    }
		    break;
		case PICT_a8b8g8r8:
		    switch (pDst->format_code) {
		    case PICT_a8b8g8r8:
		    case PICT_x8b8g8r8:
#ifdef USE_MMX
			if (fbHaveMMX())
			    func = fbCompositeSrc_8888x8888mmx;
			else
#endif
			    func = fbCompositeSrc_8888x8888;
			break;
		    case PICT_b8g8r8:
			func = fbCompositeSrc_8888x0888;
			break;
		    case PICT_b5g6r5:
			func = fbCompositeSrc_8888x0565;
			break;
		    }
		    break;
		}
	    }
	}
	break;
    case PIXMAN_OPERATOR_ADD:
	if (pMask == 0)
	{
	    switch (pSrc->format_code) {
	    case PICT_a8r8g8b8:
		switch (pDst->format_code) {
		case PICT_a8r8g8b8:
#ifdef USE_MMX
		    if (fbHaveMMX())
			func = fbCompositeSrcAdd_8888x8888mmx;
		    else
#endif
			func = fbCompositeSrcAdd_8888x8888;
		    break;
		}
		break;
	    case PICT_a8b8g8r8:
		switch (pDst->format_code) {
		case PICT_a8b8g8r8:
#ifdef USE_MMX
		    if (fbHaveMMX())
			func = fbCompositeSrcAdd_8888x8888mmx;
		    else
#endif
			func = fbCompositeSrcAdd_8888x8888;
		    break;
		}
		break;
	    case PICT_a8:
		switch (pDst->format_code) {
		case PICT_a8:
#ifdef USE_MMX
		    if (fbHaveMMX())
			func = fbCompositeSrcAdd_8000x8000mmx;
		    else
#endif
			func = fbCompositeSrcAdd_8000x8000;
		    break;
		}
		break;
	    case PICT_a1:
		switch (pDst->format_code) {
		case PICT_a1:
		    func = fbCompositeSrcAdd_1000x1000;
		    break;
		}
		break;
	    }
	}
	break;
    case PIXMAN_OPERATOR_SRC:
	if (pMask)
	  {
#ifdef USE_MMX
	    if (srcRepeat &&
		pSrc->pDrawable->width == 1 &&
		pSrc->pDrawable->height == 1)
	    {
		if (pMask->format_code == PICT_a8)
		{
		    switch (pDst->format_code) {
		    case PICT_a8r8g8b8:
		    case PICT_x8r8g8b8:
		    case PICT_a8b8g8r8:
		    case PICT_x8b8g8r8:
			if (fbHaveMMX())
			    func = fbCompositeSolidMaskSrc_nx8x8888mmx;
			break;
		    }
		}
	    }
#endif
	  }
	else
	{
	    if (pSrc->format_code == pDst->format_code)
	    {
#ifdef USE_MMX
		if (pSrc->pDrawable != pDst->pDrawable &&
                    (PICT_FORMAT_BPP (pSrc->format_code) == 16 ||
                     PICT_FORMAT_BPP (pSrc->format_code) == 32))
		    func = fbCompositeCopyAreammx;
		else
#endif
		    func = fbCompositeSrcSrc_nxn;
	    }
	}
	break;
    default:
	/* For any operator not specifically handled above we default out to the general code. */
	func = NULL;
    }

    if (!func) {
        /* no fast path, use the general code */
        pixman_compositeGeneral(op, pSrc, pMask, pDst, xSrc, ySrc, xMask, yMask, xDst, yDst, width, height);
        return;
    }

    /* if we are transforming, we handle repeats in IcFetch[a]_transform */
    if (srcTransform)
	srcRepeat = 0;
    if (maskTransform)
	maskRepeat = 0;

    region = pixman_region_create();
    pixman_region_union_rect (region, region, xDst, yDst, width, height);

    if (!FbComputeCompositeRegion (region,
				   pSrc,
				   pMask,
				   pDst,
				   xSrc,
				   ySrc,
				   xMask,
				   yMask,
				   xDst,
				   yDst,
				   width,
				   height))
	return;

    n = pixman_region_num_rects (region);
    pbox = pixman_region_rects (region);
    while (n--)
    {
	h = pbox->y2 - pbox->y1;
	y_src = pbox->y1 - yDst + ySrc;
	y_msk = pbox->y1 - yDst + yMask;
	y_dst = pbox->y1;
	while (h)
	{
	    h_this = h;
	    w = pbox->x2 - pbox->x1;
	    x_src = pbox->x1 - xDst + xSrc;
	    x_msk = pbox->x1 - xDst + xMask;
	    x_dst = pbox->x1;
	    if (maskRepeat)
	    {
		y_msk = mod (y_msk, pMask->pDrawable->height);
		if (h_this > pMask->pDrawable->height - y_msk)
		    h_this = pMask->pDrawable->height - y_msk;
	    }
	    if (srcRepeat)
	    {
		y_src = mod (y_src, pSrc->pDrawable->height);
		if (h_this > pSrc->pDrawable->height - y_src)
		    h_this = pSrc->pDrawable->height - y_src;
	    }
	    while (w)
	    {
		w_this = w;
		if (maskRepeat)
		{
		    x_msk = mod (x_msk, pMask->pDrawable->width);
		    if (w_this > pMask->pDrawable->width - x_msk)
			w_this = pMask->pDrawable->width - x_msk;
		}
		if (srcRepeat)
		{
		    x_src = mod (x_src, pSrc->pDrawable->width);
		    if (w_this > pSrc->pDrawable->width - x_src)
			w_this = pSrc->pDrawable->width - x_src;
		}
		(*func) (op, pSrc, pMask, pDst,
			 x_src, y_src, x_msk, y_msk, x_dst, y_dst,
			 w_this, h_this);
		w -= w_this;
		x_src += w_this;
		x_msk += w_this;
		x_dst += w_this;
	    }
	    h -= h_this;
	    y_src += h_this;
	    y_msk += h_this;
	    y_dst += h_this;
	}
	pbox++;
    }
    pixman_region_destroy (region);
}
slim_hidden_def(pixman_composite);

/* The CPU detection code needs to be in a file not compiled with
 * "-mmmx -msse", as gcc would generate CMOV instructions otherwise
 * that would lead to SIGILL instructions on old CPUs that don't have
 * it.
 */
#if defined(USE_MMX) && !defined(__amd64__) && !defined(__x86_64__)

enum CPUFeatures {
    NoFeatures = 0,
    MMX = 0x1,
    MMX_Extensions = 0x2,
    SSE = 0x6,
    SSE2 = 0x8,
    CMOV = 0x10
};

static unsigned int detectCPUFeatures(void) {
    unsigned int result, features;
    char vendor[13];
    vendor[0] = 0;
    vendor[12] = 0;
    /* see p. 118 of amd64 instruction set manual Vol3 */
    /* We need to be careful about the handling of %ebx and
     * %esp here. We can't declare either one as clobbered
     * since they are special registers (%ebx is the "PIC
     * register" holding an offset to global data, %esp the
     * stack pointer), so we need to make sure they have their
     * original values when we access the output operands.
     */
    __asm__ ("pushf\n"
             "pop %%eax\n"
             "mov %%eax, %%ecx\n"
             "xor $0x00200000, %%eax\n"
             "push %%eax\n"
             "popf\n"
             "pushf\n"
             "pop %%eax\n"
             "mov $0x0, %%edx\n"
             "xor %%ecx, %%eax\n"
             "jz 1f\n"

             "mov $0x00000000, %%eax\n"
	     "push %%ebx\n"
             "cpuid\n"
             "mov %%ebx, %%eax\n"
	     "pop %%ebx\n"
             "mov %%eax, %1\n"
             "mov %%edx, %2\n"
             "mov %%ecx, %3\n"
             "mov $0x00000001, %%eax\n"
	     "push %%ebx\n"
             "cpuid\n"
	     "pop %%ebx\n"
             "1:\n"
             "mov %%edx, %0\n"
             : "=r" (result),
               "=m" (vendor[0]),
               "=m" (vendor[4]),
               "=m" (vendor[8])
             :
             : "%eax", "%ecx", "%edx"
        );

    features = 0;
    if (result) {
        /* result now contains the standard feature bits */
        if (result & (1 << 15))
            features |= CMOV;
        if (result & (1 << 23))
            features |= MMX;
        if (result & (1 << 25))
            features |= SSE;
        if (result & (1 << 26))
            features |= SSE2;
        if ((result & MMX) && !(result & SSE) && (strcmp(vendor, "AuthenticAMD") == 0)) {
            /* check for AMD MMX extensions */

            unsigned int result;
            __asm__("push %%ebx\n"
                    "mov $0x80000000, %%eax\n"
                    "cpuid\n"
                    "xor %%edx, %%edx\n"
                    "cmp $0x1, %%eax\n"
                    "jge 1f\n"
                    "mov $0x80000001, %%eax\n"
                    "cpuid\n"
                    "1:\n"
                    "pop %%ebx\n"
                    "mov %%edx, %0\n"
                    : "=r" (result)
                    :
                    : "%eax", "%ecx", "%edx"
                );
            if (result & (1<<22))
                features |= MMX_Extensions;
        }
    }
    return features;
}

Bool
fbHaveMMX (void)
{
    static Bool initialized = FALSE;
    static Bool mmx_present;

    if (!initialized)
    {
        unsigned int features = detectCPUFeatures();
	mmx_present = (features & (MMX|MMX_Extensions)) == (MMX|MMX_Extensions);
        initialized = TRUE;
    }

    return mmx_present;
}
#endif /* USE_MMX && !amd64 */
#endif /* RENDER */