harvey/sys/src/cmd/gs/src/gxmclip.c

/* Copyright (C) 1998, 1999 Aladdin Enterprises.  All rights reserved.
  
  This file is part of AFPL Ghostscript.
  
  AFPL Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author or
  distributor accepts any responsibility for the consequences of using it, or
  for whether it serves any particular purpose or works at all, unless he or
  she says so in writing.  Refer to the Aladdin Free Public License (the
  "License") for full details.
  
  Every copy of AFPL Ghostscript must include a copy of the License, normally
  in a plain ASCII text file named PUBLIC.  The License grants you the right
  to copy, modify and redistribute AFPL Ghostscript, but only under certain
  conditions described in the License.  Among other things, the License
  requires that the copyright notice and this notice be preserved on all
  copies.
*/

/*$Id: gxmclip.c,v 1.2 2000/09/19 19:00:39 lpd Exp $ */
/* Mask clipping support */
#include "gx.h"
#include "gxdevice.h"
#include "gxdevmem.h"
#include "gxmclip.h"

/* Structure descriptor */
public_st_device_mask_clip();

/* GC procedures */
private ENUM_PTRS_WITH(device_mask_clip_enum_ptrs, gx_device_mask_clip *mcdev)
{
    if (index < st_gx_strip_bitmap_max_ptrs) {
	return ENUM_USING(st_gx_strip_bitmap, &mcdev->tiles,
			  sizeof(mcdev->tiles), index);
    }
    index -= st_gx_strip_bitmap_max_ptrs;
    if (index < st_device_memory_max_ptrs) {
	return ENUM_USING(st_device_memory, &mcdev->mdev,
			  sizeof(mcdev->mdev), index);
    }
    ENUM_PREFIX(st_device_forward, st_device_memory_max_ptrs);
}
ENUM_PTRS_END
private RELOC_PTRS_WITH(device_mask_clip_reloc_ptrs, gx_device_mask_clip *mcdev)
{
    RELOC_PREFIX(st_device_forward);
    RELOC_USING(st_gx_strip_bitmap, &mcdev->tiles, sizeof(mcdev->tiles));
    RELOC_USING(st_device_memory, &mcdev->mdev, sizeof(mcdev->mdev));
    if (mcdev->mdev.base != 0) {
	/*
	 * Update the line pointers specially, since they point into the
	 * buffer that is part of the mask clipping device itself.
	 */
	long diff = (char *)RELOC_OBJ(mcdev) - (char *)mcdev;
	int i;

	for (i = 0; i < mcdev->mdev.height; ++i)
	    mcdev->mdev.line_ptrs[i] += diff;
	mcdev->mdev.base = mcdev->mdev.line_ptrs[0];
	mcdev->mdev.line_ptrs =
	    (void *)((char *)(mcdev->mdev.line_ptrs) + diff);
    }
}
RELOC_PTRS_END

/* Initialize a mask clipping device. */
int
gx_mask_clip_initialize(gx_device_mask_clip * cdev,
			const gx_device_mask_clip * proto,
			const gx_bitmap * bits, gx_device * tdev,
			int tx, int ty, gs_memory_t *mem)
{
    int buffer_width = bits->size.x;
    int buffer_height =
	tile_clip_buffer_size / (bits->raster + sizeof(byte *));

    gx_device_init((gx_device *)cdev, (const gx_device *)proto,
		   mem, true);
    cdev->width = tdev->width;
    cdev->height = tdev->height;
    cdev->color_info = tdev->color_info;
    gx_device_set_target((gx_device_forward *)cdev, tdev);
    cdev->phase.x = -tx;
    cdev->phase.y = -ty;
    if (buffer_height > bits->size.y)
	buffer_height = bits->size.y;
    gs_make_mem_mono_device(&cdev->mdev, 0, 0);
    for (;;) {
	if (buffer_height <= 0) {
	    /*
	     * The tile is too wide to buffer even one scan line.
	     * We could do copy_mono in chunks, but for now, we punt.
	     */
	    cdev->mdev.base = 0;
	    return 0;
	}
	cdev->mdev.width = buffer_width;
	cdev->mdev.height = buffer_height;
	if (gdev_mem_bitmap_size(&cdev->mdev) <= tile_clip_buffer_size)
	    break;
	buffer_height--;
    }
    cdev->mdev.base = cdev->buffer.bytes;
    return (*dev_proc(&cdev->mdev, open_device))((gx_device *)&cdev->mdev);
}