The Tor Browser / file revision

 b=455513; add optional flag to allow converting a DDB to a DIB internally, if the surface is every used as a source; r=jmuizelaar

 If a DDB is used as a source for an operation that can't be handled

 natively by GDI, we end up needing to take a really slow path (creating a

 temporary surface for acquire_source) for each operation.  If we convert

 the DDB to a DIB, we then end up having a real image buffer and can hand

 things off to pixman directly.

 This isn't the default mode because I'm not sure if there are cases where a

 DDB is explicitly needed (e.g. for printing), and it would change

 current cairo behaviour.  It might become the default at some point in the

 future.

 diff --git a/gfx/cairo/cairo/src/cairo-win32-private.h b/gfx/cairo/cairo/src/cairo-win32-private.h

 --- a/gfx/cairo/cairo/src/cairo-win32-private.h

 +++ b/gfx/cairo/cairo/src/cairo-win32-private.h

 @@ -117,6 +117,9 @@

      /* Whether we can use the CHECKJPEGFORMAT escape function */

      CAIRO_WIN32_SURFACE_CAN_CHECK_PNG = (1<<8),

 +

 +    /* if this DDB surface can be converted to a DIB if necessary */

 +    CAIRO_WIN32_SURFACE_CAN_CONVERT_TO_DIB = (1<<9),

  };

  cairo_status_t

 diff --git a/gfx/cairo/cairo/src/cairo-win32-surface.c b/gfx/cairo/cairo/src/cairo-win32-surface.c

 --- a/gfx/cairo/cairo/src/cairo-win32-surface.c

 +++ b/gfx/cairo/cairo/src/cairo-win32-surface.c

 @@ -560,6 +560,56 @@

      return CAIRO_STATUS_SUCCESS;

  }

 +static void

 +_cairo_win32_convert_ddb_to_dib (cairo_win32_surface_t *surface)

 +{

 +    cairo_win32_surface_t *new_surface;

 +    int width = surface->extents.width;

 +    int height = surface->extents.height;

 +

 +    BOOL ok;

 +    HBITMAP oldbitmap;

 +

 +    new_surface = (cairo_win32_surface_t*)

 +	_cairo_win32_surface_create_for_dc (surface->dc,

 +					    surface->format,

 +					    width,

 +					    height);

 +

 +    if (new_surface->base.status)

 +	return;

 +

 +    /* DDB can't be 32bpp, so BitBlt is safe */

 +    ok = BitBlt (new_surface->dc,

 +		 0, 0, width, height,

 +		 surface->dc,

 +		 0, 0, SRCCOPY);

 +

 +    if (!ok)

 +	goto out;

 +

 +    /* Now swap around new_surface and surface's internal bitmap

 +     * pointers. */

 +    DeleteDC (new_surface->dc);

 +    new_surface->dc = NULL;

 +

 +    oldbitmap = SelectObject (surface->dc, new_surface->bitmap);

 +    DeleteObject (oldbitmap);

 +

 +    surface->image = new_surface->image;

 +    surface->is_dib = new_surface->is_dib;

 +    surface->bitmap = new_surface->bitmap;

 +

 +    new_surface->bitmap = NULL;

 +    new_surface->image = NULL;

 +

 +    /* Finally update flags */

 +    surface->flags = _cairo_win32_flags_for_dc (surface->dc);

 +

 +  out:

 +    cairo_surface_destroy ((cairo_surface_t*)new_surface);

 +}

 +

  static cairo_status_t

  _cairo_win32_surface_acquire_source_image (void                    *abstract_surface,

  					   cairo_image_surface_t  **image_out,

 @@ -568,6 +618,17 @@

      cairo_win32_surface_t *surface = abstract_surface;

      cairo_win32_surface_t *local = NULL;

      cairo_status_t status;

 +

 +    if (!surface->image && !surface->is_dib && surface->bitmap &&

 +	(surface->flags & CAIRO_WIN32_SURFACE_CAN_CONVERT_TO_DIB) != 0)

 +    {

 +	/* This is a DDB, and we're being asked to use it as a source for

 +	 * something that we couldn't support natively.  So turn it into

 +	 * a DIB, so that we have an equivalent image surface, as long

 +	 * as we're allowed to via flags.

 +	 */

 +	_cairo_win32_convert_ddb_to_dib (surface);

 +    }

      if (surface->image) {

  	*image_out = (cairo_image_surface_t *)surface->image;

 @@ -2133,3 +2194,61 @@

      free(rd);

      fflush (stderr);

  }

 +

 +/**

 + * cairo_win32_surface_set_can_convert_to_dib

 + * @surface: a #cairo_surface_t

 + * @can_convert: a #cairo_bool_t indicating whether this surface can

 + *               be coverted to a DIB if necessary

 + *

 + * A DDB surface with this flag set can be converted to a DIB if it's

 + * used as a source in a way that GDI can't natively handle; for

 + * example, drawing a RGB24 DDB onto an ARGB32 DIB.  Doing this

 + * conversion results in a significant speed optimization, because we

 + * can call on pixman to perform the operation natively, instead of

 + * reading the data from the DC each time.

 + *

 + * Return value: %CAIRO_STATUS_SUCCESS if the flag was successfully

 + * changed, or an error otherwise.

 + * 

 + */

 +cairo_status_t

 +cairo_win32_surface_set_can_convert_to_dib (cairo_surface_t *asurface, cairo_bool_t can_convert)

 +{

 +    cairo_win32_surface_t *surface = (cairo_win32_surface_t*) asurface;

 +    if (surface->base.type != CAIRO_SURFACE_TYPE_WIN32)

 +	return CAIRO_STATUS_SURFACE_TYPE_MISMATCH;

 +

 +    if (surface->bitmap) {

 +	if (can_convert)

 +	    surface->flags |= CAIRO_WIN32_SURFACE_CAN_CONVERT_TO_DIB;

 +	else

 +	    surface->flags &= ~CAIRO_WIN32_SURFACE_CAN_CONVERT_TO_DIB;

 +    }

 +

 +    return CAIRO_STATUS_SUCCESS;

 +}

 +

 +/**

 + * cairo_win32_surface_get_can_convert_to_dib

 + * @surface: a #cairo_surface_t

 + * @can_convert: a #cairo_bool_t* that receives the return value

 + *

 + * Returns the value of the flag indicating whether the surface can be

 + * converted to a DIB if necessary, as set by

 + * cairo_win32_surface_set_can_convert_to_dib.

 + *

 + * Return value: %CAIRO_STATUS_SUCCESS if the flag was successfully

 + * retreived, or an error otherwise.

 + * 

 + */

 +cairo_status_t

 +cairo_win32_surface_get_can_convert_to_dib (cairo_surface_t *asurface, cairo_bool_t *can_convert)

 +{

 +    cairo_win32_surface_t *surface = (cairo_win32_surface_t*) asurface;

 +    if (surface->base.type != CAIRO_SURFACE_TYPE_WIN32)

 +	return CAIRO_STATUS_SURFACE_TYPE_MISMATCH;

 +

 +    *can_convert = ((surface->flags & CAIRO_WIN32_SURFACE_CAN_CONVERT_TO_DIB) != 0);

 +    return CAIRO_STATUS_SUCCESS;

 +}

 diff --git a/gfx/cairo/cairo/src/cairo-win32.h b/gfx/cairo/cairo/src/cairo-win32.h

 --- a/gfx/cairo/cairo/src/cairo-win32.h

 +++ b/gfx/cairo/cairo/src/cairo-win32.h

 @@ -68,6 +68,12 @@ cairo_win32_surface_get_dc (cairo_surface_t *surface);

  cairo_public cairo_surface_t *

  cairo_win32_surface_get_image (cairo_surface_t *surface);

 +cairo_public cairo_status_t

 +cairo_win32_surface_set_can_convert_to_dib (cairo_surface_t *surface, cairo_bool_t can_convert);

 +

 +cairo_public cairo_status_t

 +cairo_win32_surface_get_can_convert_to_dib (cairo_surface_t *surface, cairo_bool_t *can_convert);

 +

  #if CAIRO_HAS_WIN32_FONT