static bool
_get_rectangular_clip (cairo_t *cr,
                       const nsIntRect& bounds,
                       bool *need_clip,
                       nsIntRect *rectangles, int max_rectangles,
                       int *num_rectangles)
{
    cairo_rectangle_list_t *cliplist;
    cairo_rectangle_t *clips;
    int i;
    bool retval = true;

    cliplist = cairo_copy_clip_rectangle_list (cr);
    if (cliplist->status != CAIRO_STATUS_SUCCESS) {
        retval = false;
        NATIVE_DRAWING_NOTE("FALLBACK: non-rectangular clip");
        goto FINISH;
    }

    /* the clip is always in surface backend coordinates (i.e. native backend coords) */
    clips = cliplist->rectangles;

    for (i = 0; i < cliplist->num_rectangles; ++i) {
        
        nsIntRect rect;
        if (!_convert_coord_to_int (clips[i].x, &rect.x) ||
            !_convert_coord_to_int (clips[i].y, &rect.y) ||
            !_convert_coord_to_int (clips[i].width, &rect.width) ||
            !_convert_coord_to_int (clips[i].height, &rect.height))
        {
            retval = false;
            NATIVE_DRAWING_NOTE("FALLBACK: non-integer clip");
            goto FINISH;
        }

        if (rect.IsEqualInterior(bounds)) {
            /* the bounds are entirely inside the clip region so we don't need to clip. */
            *need_clip = false;
            goto FINISH;
        }            

        NS_ASSERTION(bounds.Contains(rect),
                     "Was expecting to be clipped to bounds");

        if (i >= max_rectangles) {
            retval = false;
            NATIVE_DRAWING_NOTE("FALLBACK: unsupported clip rectangle count");
            goto FINISH;
        }

        rectangles[i] = rect;
    }
  
    *need_clip = true;
    *num_rectangles = cliplist->num_rectangles;

FINISH:
    cairo_rectangle_list_destroy (cliplist);

    return retval;
}
예제 #2
0
void
gfxImageSurface::MovePixels(const nsIntRect& aSourceRect,
                            const nsIntPoint& aDestTopLeft)
{
    const nsIntRect bounds(0, 0, mSize.width, mSize.height);
    nsIntPoint offset = aDestTopLeft - aSourceRect.TopLeft(); 
    nsIntRect clippedSource = aSourceRect;
    clippedSource.IntersectRect(clippedSource, bounds);
    nsIntRect clippedDest = clippedSource + offset;
    clippedDest.IntersectRect(clippedDest, bounds);
    const nsIntRect dest = clippedDest;
    const nsIntRect source = dest - offset;
    // NB: this relies on IntersectRect() and operator+/- preserving
    // x/y for empty rectangles
    NS_ABORT_IF_FALSE(bounds.Contains(dest) && bounds.Contains(source) &&
                      aSourceRect.Contains(source) &&
                      nsIntRect(aDestTopLeft, aSourceRect.Size()).Contains(dest) &&
                      source.Size() == dest.Size() &&
                      offset == (dest.TopLeft() - source.TopLeft()),
                      "Messed up clipping, crash or corruption will follow");
    if (source.IsEmpty() || source.IsEqualInterior(dest)) {
        return;
    }

    long naturalStride = ComputeStride(mSize, mFormat);
    if (mStride == naturalStride && dest.width == bounds.width) {
        // Fast path: this is a vertical shift of some rows in a
        // "normal" image surface.  We can directly memmove and
        // hopefully stay in SIMD land.
        unsigned char* dst = mData + dest.y * mStride;
        const unsigned char* src = mData + source.y * mStride;
        size_t nBytes = dest.height * mStride;
        memmove(dst, src, nBytes);
        return;
    }

    // Slow(er) path: have to move row-by-row.
    const int32_t bpp = BytePerPixelFromFormat(mFormat);
    const size_t nRowBytes = dest.width * bpp;
    // dstRow points at the first pixel within the current destination
    // row, and similarly for srcRow.  endSrcRow is one row beyond the
    // last row we need to copy.  stride is either +mStride or
    // -mStride, depending on which direction we're copying.
    unsigned char* dstRow;
    unsigned char* srcRow;
    unsigned char* endSrcRow;   // NB: this may point outside the image
    long stride;
    if (dest.y > source.y) {
        // We're copying down from source to dest, so walk backwards
        // starting from the last rows to avoid stomping pixels we
        // need.
        stride = -mStride;
        dstRow = mData + dest.x * bpp + (dest.YMost() - 1) * mStride;
        srcRow = mData + source.x * bpp + (source.YMost() - 1) * mStride;
        endSrcRow = mData + source.x * bpp + (source.y - 1) * mStride;
    } else {
        stride = mStride;
        dstRow = mData + dest.x * bpp + dest.y * mStride;
        srcRow = mData + source.x * bpp + source.y * mStride;
        endSrcRow = mData + source.x * bpp + source.YMost() * mStride;
    }

    for (; srcRow != endSrcRow; dstRow += stride, srcRow += stride) {
        memmove(dstRow, srcRow, nRowBytes);
    }
}