gxht_thresh_planes(gx_image_enum *penum, fixed xrun,
                   int dest_width, int dest_height,
                   byte *thresh_align, gx_device * dev, int offset_contone[],
                   int contone_stride)
{
    int thresh_width, thresh_height, dx;
    int left_rem_end, left_width, vdi;
    int num_full_tiles, right_tile_width;
    int k, jj, dy, j;
    byte *thresh_tile;
    int position;
    bool replicate_tile;
    image_posture posture = penum->posture;
    const int y_pos = penum->yci;
    int width = 0; /* Init to silence compiler warnings */
    byte *ptr_out, *row_ptr, *ptr_out_temp;
    byte *threshold;
    int init_tile, in_row_offset, ii, num_tiles, tile_remainder;
    int offset_bits = penum->ht_offset_bits;
    byte *halftone;
    int dithered_stride = penum->ht_stride;
    bool is_planar_dev = dev->is_planar;
    gx_color_index dev_white = gx_device_white(dev);
    gx_color_index dev_black = gx_device_black(dev);
    int spp_out = dev->color_info.num_components;
    byte *contone_align = NULL; /* Init to silence compiler warnings */

    /* Go ahead and fill the threshold line buffer with tiled threshold values.
       First just grab the row or column that we are going to tile with and
       then do memcpy into the buffer */

    /* Figure out the tile steps.  Left offset, Number of tiles, Right offset. */
    switch (posture) {
        case image_portrait:
            vdi = penum->hci;
            /*  Iterate over the vdi and fill up our threshold buffer.  We
                 also need to loop across the planes of data */
            for (j = 0; j < spp_out; j++) {
                bool threshold_inverted = penum->pgs->dev_ht->components[j].corder.threshold_inverted;

                thresh_width = penum->pgs->dev_ht->components[j].corder.width;
                thresh_height = penum->pgs->dev_ht->components[j].corder.full_height;
                halftone = penum->ht_buffer + j * vdi * dithered_stride;
                /* Compute the tiling positions with dest_width */
                dx = (fixed2int_var_rounded(xrun) + penum->pgs->screen_phase[0].x) % thresh_width;
                /* Left remainder part */
                left_rem_end = min(dx + dest_width, thresh_width);
                /* The left width of our tile part */
                left_width = left_rem_end - dx;
                /* Now the middle part */
                num_full_tiles =
                    (int)fastfloor((dest_width - left_width)/ (float) thresh_width);
                /* Now the right part */
                right_tile_width = dest_width -  num_full_tiles * thresh_width -
                                   left_width;
                /* Get the proper threshold for the colorant count */
                threshold = penum->pgs->dev_ht->components[j].corder.threshold;
                /* Point to the proper contone data */
                contone_align = penum->line + contone_stride * j +
                                offset_contone[j];
                for (k = 0; k < vdi; k++) {
                    /* Get a pointer to our tile row */
                    dy = (penum->yci + k + penum->dev->band_offset_y) % thresh_height;
                    if (dy < 0)
                        dy += thresh_height;
                    thresh_tile = threshold + thresh_width * dy;
                    /* Fill the buffer, can be multiple rows.  Make sure
                       to update with stride */
                    position = contone_stride * k;
                    /* Tile into the 128 bit aligned threshold strip */
                    fill_threshold_buffer(&(thresh_align[position]),
                                           thresh_tile, thresh_width, dx, left_width,
                                           num_full_tiles, right_tile_width);
                }
                /* Apply the threshold operation */
                if (offset_bits > dest_width)
                    offset_bits = dest_width;

                if (threshold_inverted ||
                    (dev->color_info.polarity == GX_CINFO_POLARITY_SUBTRACTIVE && is_planar_dev)) {
                    gx_ht_threshold_row_bit_sub(contone_align, thresh_align, contone_stride,
                                      halftone, dithered_stride, dest_width, vdi,
                                      offset_bits);
                } else {
                    gx_ht_threshold_row_bit(contone_align, thresh_align, contone_stride,
                          halftone, dithered_stride, dest_width, vdi,
                          offset_bits);
                }
            }
            /* FIXME: An improvement here would be to generate the initial
             * offset_bits at the correct offset within the byte so that they
             * align with the remainder of the line. This would mean not
             * always packing them into the first offset_bits (in MSB order)
             * of our 16 bit word, but rather into the last offset_bits
             * (in MSB order) (except when the entire run is small!).
             *
             * This would enable us to do just one aligned copy_mono call for
             * the entire scanline. */
            /* Now do the copy mono or copy plane operation */
            /* First the left remainder bits */
            if (offset_bits > 0) {
                int x_pos = fixed2int_var_rounded(xrun);
                if (!is_planar_dev) {
                    (*dev_proc(dev, copy_mono)) (dev, penum->ht_buffer, 0, dithered_stride,
                                                 gx_no_bitmap_id, x_pos, y_pos,
                                                 offset_bits, vdi, dev_white,
                                                 dev_black);
                } else {
                    (*dev_proc(dev, copy_planes)) (dev, penum->ht_buffer, 0, dithered_stride,
                                                 gx_no_bitmap_id, x_pos, y_pos,
                                                 offset_bits, vdi, vdi);
                }
            }
            if ((dest_width - offset_bits) > 0 ) {
                /* Now the primary aligned bytes */
                int curr_width = dest_width - offset_bits;
                int x_pos = fixed2int_var_rounded(xrun) + offset_bits;
                /* FIXME: This assumes the allowed offset_bits will always be <= 16 */
                int xoffs = offset_bits > 0 ? 16 : 0;

                if (!is_planar_dev) {
                    (*dev_proc(dev, copy_mono)) (dev, penum->ht_buffer, xoffs, dithered_stride,
                                                 gx_no_bitmap_id, x_pos, y_pos,
                                                 curr_width, vdi, dev_white,
                                                 dev_black);
                } else {
                    (*dev_proc(dev, copy_planes)) (dev, penum->ht_buffer, xoffs, dithered_stride,
                                                 gx_no_bitmap_id, x_pos, y_pos,
                                                 curr_width, vdi, vdi);
                }
            }

            break;
        case image_landscape:
            /* Go ahead and paint the chunk if we have LAND_BITS values or a
             * partial to get us in sync with the 1 bit devices 16 bit
             * positions. */
            vdi = penum->wci;
                /* Now do the haftoning into our buffer.  We basically check
                   first if we have enough data or are all done */
            while ( (penum->ht_landscape.count >= LAND_BITS ||
                   ((penum->ht_landscape.count >= offset_bits) &&
                    penum->ht_landscape.offset_set))) {
                /* Go ahead and 2D tile in the threshold buffer at this time */
                /* Always work the tiling from the upper left corner of our
                   LAND_BITS columns */
                for (j = 0; j < spp_out; j++) {
                    halftone = penum->ht_buffer +
                                   j * penum->ht_plane_height * (LAND_BITS>>3);
                    thresh_width = penum->pgs->dev_ht->components[j].corder.width;
                    thresh_height =
                          penum->pgs->dev_ht->components[j].corder.full_height;
                    /* Get the proper threshold for the colorant count */
                    threshold = penum->pgs->dev_ht->components[j].corder.threshold;
                    /* Point to the proper contone data */
                    contone_align = penum->line + offset_contone[j] +
                                      LAND_BITS * j * contone_stride;
                    if (penum->ht_landscape.offset_set) {
                        width = offset_bits;
                    } else {
                        width = LAND_BITS;
                    }
                    if (penum->y_extent.x < 0) {
                        dx = penum->ht_landscape.xstart - width + 1;
                    } else {
                        dx = penum->ht_landscape.xstart;
                    }
                    dx = (dx + penum->pgs->screen_phase[0].x) % thresh_width;
                    dy = (penum->ht_landscape.y_pos +
                              penum->dev->band_offset_y) % thresh_height;
                    if (dy < 0)
                        dy += thresh_height;
                    /* Left remainder part */
                    left_rem_end = min(dx + LAND_BITS, thresh_width);
                    left_width = left_rem_end - dx;
                    /* Now the middle part */
                    num_full_tiles = (LAND_BITS - left_width) / thresh_width;
                    /* Now the right part */
                    right_tile_width =
                        LAND_BITS - num_full_tiles * thresh_width - left_width;
                    /* Now loop over the y stuff */
                    ptr_out = thresh_align;
                    /* Do this in three parts.  We do a top part, followed by
                       larger mem copies followed by a bottom partial. After
                       a slower initial fill we are able to do larger faster
                       expansions */
                    if (dest_height <= 2 * thresh_height) {
                        init_tile = dest_height;
                        replicate_tile = false;
                    } else {
                        init_tile = thresh_height;
                        replicate_tile = true;
                    }
                    for (jj = 0; jj < init_tile; jj++) {
                        in_row_offset = (jj + dy) % thresh_height;
                        row_ptr = threshold + in_row_offset * thresh_width;
                        ptr_out_temp = ptr_out;
                        /* Left part */
                        memcpy(ptr_out_temp, row_ptr + dx, left_width);
                        ptr_out_temp += left_width;
                        /* Now the full tiles */
                        for (ii = 0; ii < num_full_tiles; ii++) {
                            memcpy(ptr_out_temp, row_ptr, thresh_width);
                            ptr_out_temp += thresh_width;
                        }
                        /* Now the remainder */
                        memcpy(ptr_out_temp, row_ptr, right_tile_width);
                        ptr_out += LAND_BITS;
                    }
                    if (replicate_tile) {
                        /* Find out how many we need to copy */
                        num_tiles =
                            (int)fastfloor((float) (dest_height - thresh_height)/ (float) thresh_height);
                        tile_remainder = dest_height - (num_tiles + 1) * thresh_height;
                        for (jj = 0; jj < num_tiles; jj ++) {
                            memcpy(ptr_out, thresh_align, LAND_BITS * thresh_height);
                            ptr_out += LAND_BITS * thresh_height;
                        }
                        /* Now fill in the remainder */
                        memcpy(ptr_out, thresh_align, LAND_BITS * tile_remainder);
                    }
                    /* Apply the threshold operation */
                    if (dev->color_info.polarity == GX_CINFO_POLARITY_SUBTRACTIVE
                        && is_planar_dev) {
                        gx_ht_threshold_landscape_sub(contone_align, thresh_align,
                                            &(penum->ht_landscape), halftone, dest_height);
                    } else {
                        gx_ht_threshold_landscape(contone_align, thresh_align,
                                            &(penum->ht_landscape), halftone, dest_height);
                    }
                    /* We may have a line left over that has to be maintained
                       due to line replication in the resolution conversion. */
                    if (width != penum->ht_landscape.count) {
                        /* move the line do not reset the stuff */
                        move_landscape_buffer(&(penum->ht_landscape),
                                              contone_align, dest_height);
                    }
                }
                /* Perform the copy mono */
                if (penum->ht_landscape.index < 0) {
                    if (!is_planar_dev) {
                        (*dev_proc(dev, copy_mono))
                                       (dev, penum->ht_buffer, 0, LAND_BITS>>3,
                                        gx_no_bitmap_id,
                                        penum->ht_landscape.xstart - width + 1,
                                        penum->ht_landscape.y_pos,
                                        width, dest_height,
                                        dev_white, dev_black);
                    } else {
                        (*dev_proc(dev, copy_planes))
                                       (dev, penum->ht_buffer, 0, LAND_BITS>>3,
                                        gx_no_bitmap_id,
                                        penum->ht_landscape.xstart - width + 1,
                                        penum->ht_landscape.y_pos,
                                        width, dest_height,
                                        penum->ht_plane_height);
                    }
                } else {
                    if (!is_planar_dev) {
                        (*dev_proc(dev, copy_mono)) (dev, penum->ht_buffer, 0, LAND_BITS>>3,
                                                     gx_no_bitmap_id,
                                                     penum->ht_landscape.xstart,
                                                     penum->ht_landscape.y_pos,
                                                     width, dest_height,
                                                     dev_white, dev_black);
                    } else {
                        (*dev_proc(dev, copy_planes)) (dev, penum->ht_buffer, 0, LAND_BITS>>3,
                                                     gx_no_bitmap_id,
                                                     penum->ht_landscape.xstart,
                                                     penum->ht_landscape.y_pos,
                                                     width, dest_height,
                                                     penum->ht_plane_height);
                    }
                }
                penum->ht_landscape.offset_set = false;
                if (width != penum->ht_landscape.count) {
                    reset_landscape_buffer(&(penum->ht_landscape),
                                           contone_align, dest_height,
                                           width);
                } else {
                    /* Reset the whole buffer */
                    penum->ht_landscape.count = 0;
                    if (penum->ht_landscape.index < 0) {
                        /* Going right to left */
                        penum->ht_landscape.curr_pos = LAND_BITS-1;
                    } else {
                        /* Going left to right */
                        penum->ht_landscape.curr_pos = 0;
                    }
                    penum->ht_landscape.num_contones = 0;
                    memset(&(penum->ht_landscape.widths[0]), 0, sizeof(int)*LAND_BITS);
                }
            }
            break;
        default:
            return gs_rethrow(-1, "Invalid orientation for thresholding");
    }
    return 0;
}