path: root/gs/src/gxclipm.c

/* Copyright (C) 1998 Aladdin Enterprises.  All rights reserved.

   This file is part of Aladdin Ghostscript.

   Aladdin 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 Ghostscript Free Public
   License (the "License") for full details.

   Every copy of Aladdin 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 Aladdin 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.
 */


/* Mask clipping device */
#include "memory_.h"
#include "gx.h"
#include "gxdevice.h"
#include "gxdevmem.h"
#include "gxclipm.h"

public_st_device_mask_clip();

/* Device procedures */
private dev_proc_fill_rectangle(mask_clip_fill_rectangle);
private dev_proc_copy_mono(mask_clip_copy_mono);
private dev_proc_copy_color(mask_clip_copy_color);
private dev_proc_copy_alpha(mask_clip_copy_alpha);
private dev_proc_strip_copy_rop(mask_clip_strip_copy_rop);
private dev_proc_get_clipping_box(mask_clip_get_clipping_box);

/* The device descriptor. */
const gx_device_mask_clip gs_mask_clip_device =
{std_device_std_body_open(gx_device_mask_clip, 0, "mask clipper",
			  0, 0, 1, 1),
 {gx_default_open_device,
  gx_forward_get_initial_matrix,
  gx_default_sync_output,
  gx_default_output_page,
  gx_default_close_device,
  gx_forward_map_rgb_color,
  gx_forward_map_color_rgb,
  mask_clip_fill_rectangle,
  gx_default_tile_rectangle,
  mask_clip_copy_mono,
  mask_clip_copy_color,
  gx_default_draw_line,
  gx_forward_get_bits,
  gx_forward_get_params,
  gx_forward_put_params,
  gx_forward_map_cmyk_color,
  gx_forward_get_xfont_procs,
  gx_forward_get_xfont_device,
  gx_forward_map_rgb_alpha_color,
  gx_forward_get_page_device,
  gx_forward_get_alpha_bits,
  mask_clip_copy_alpha,
  gx_forward_get_band,
  gx_default_copy_rop,
  gx_default_fill_path,
  gx_default_stroke_path,
  gx_default_fill_mask,
  gx_default_fill_trapezoid,
  gx_default_fill_parallelogram,
  gx_default_fill_triangle,
  gx_default_draw_thin_line,
  gx_default_begin_image,
  gx_default_image_data,
  gx_default_end_image,
  gx_default_strip_tile_rectangle,
  mask_clip_strip_copy_rop,
  mask_clip_get_clipping_box,
  gx_default_begin_typed_image,
  gx_forward_get_bits_rectangle,
  gx_forward_map_color_rgb_alpha,
  gx_no_create_compositor,
  gx_forward_get_hardware_params,
  gx_default_text_begin
 }
};

/* Fill a rectangle by painting through the mask. */
private int
mask_clip_fill_rectangle(gx_device * dev, int x, int y, int w, int h,
			 gx_color_index color)
{
    gx_device_mask_clip *cdev = (gx_device_mask_clip *) dev;
    gx_device *tdev = cdev->target;

    /* Clip the rectangle to the region covered by the mask. */
    int mx0 = x + cdev->phase.x, my0 = y + cdev->phase.y;
    int mx1 = mx0 + w, my1 = my0 + h;

    if (mx0 < 0)
	mx0 = 0;
    if (my0 < 0)
	my0 = 0;
    if (mx1 > cdev->tiles.size.x)
	mx1 = cdev->tiles.size.x;
    if (my1 > cdev->tiles.size.y)
	my1 = cdev->tiles.size.y;
    return (*dev_proc(tdev, copy_mono))
	(tdev, cdev->tiles.data + my0 * cdev->tiles.raster, mx0,
	 cdev->tiles.raster, cdev->tiles.id,
	 mx0 - cdev->phase.x, my0 - cdev->phase.y,
	 mx1 - mx0, my1 - my0, gx_no_color_index, color);
}

/*
 * Clip the rectangle for a copy operation.
 * Sets m{x,y}{0,1} to the region in the mask coordinate system;
 * subtract cdev->phase.{x,y} to get target coordinates.
 * Sets sdata, sx to adjusted values of data, sourcex.
 * References cdev, data, sourcex, raster, x, y, w, h.
 */
#define DECLARE_MASK_COPY\
	const byte *sdata;\
	int sx, mx0, my0, mx1, my1
#define FIT_MASK_COPY(data, sourcex, raster, vx, vy, vw, vh)\
	BEGIN\
	  sdata = data, sx = sourcex;\
	  mx0 = vx + cdev->phase.x, my0 = vy + cdev->phase.y;\
	  mx1 = mx0 + vw, my1 = my0 + vh;\
	  if ( mx0 < 0 )\
	    sx -= mx0, mx0 = 0;\
	  if ( my0 < 0 )\
	    sdata -= my0 * raster, my0 = 0;\
	  if ( mx1 > cdev->tiles.size.x )\
	    mx1 = cdev->tiles.size.x;\
	  if ( my1 > cdev->tiles.size.y )\
	    my1 = cdev->tiles.size.y;\
	END

/* Copy a monochrome bitmap by playing Boolean games. */
private int
mask_clip_copy_mono(gx_device * dev,
		const byte * data, int sourcex, int raster, gx_bitmap_id id,
		    int x, int y, int w, int h,
		    gx_color_index color0, gx_color_index color1)
{
    gx_device_mask_clip *cdev = (gx_device_mask_clip *) dev;
    gx_device *tdev = cdev->target;
    gx_color_index color, mcolor0, mcolor1;

    DECLARE_MASK_COPY;
    int cy, ny;
    int code;

    setup_mask_copy_mono(cdev, color, mcolor0, mcolor1);
    FIT_MASK_COPY(data, sourcex, raster, x, y, w, h);
    for (cy = my0; cy < my1; cy += ny) {
	int ty = cy - cdev->phase.y;
	int cx, nx;

	ny = my1 - cy;
	if (ny > cdev->mdev.height)
	    ny = cdev->mdev.height;
	for (cx = mx0; cx < mx1; cx += nx) {
	    int tx = cx - cdev->phase.x;

	    nx = mx1 - cx;	/* also should be min */
	    /* Copy a tile slice to the memory device buffer. */
	    memcpy(cdev->buffer.bytes,
		   cdev->tiles.data + cy * cdev->tiles.raster,
		   cdev->tiles.raster * ny);
	    /* Intersect the tile with the source data. */
	    /* mcolor0 and mcolor1 invert the data if needed. */
	    /* This call can't fail. */
	    (*dev_proc(&cdev->mdev, copy_mono)) ((gx_device *) & cdev->mdev,
				     sdata + (ty - y) * raster, sx + tx - x,
						 raster, gx_no_bitmap_id,
					   cx, 0, nx, ny, mcolor0, mcolor1);
	    /* Now copy the color through the double mask. */
	    code = (*dev_proc(tdev, copy_mono)) (cdev->target,
				 cdev->buffer.bytes, cx, cdev->tiles.raster,
						 gx_no_bitmap_id,
				  tx, ty, nx, ny, gx_no_color_index, color);
	    if (code < 0)
		return code;
	}
    }
    return 0;
}

/*
 * Define the run enumerator for the other copying operations.  We can't use
 * the BitBlt tricks: we have to scan for runs of 1s.  There are obvious
 * ways to speed this up; we'll implement some if we need to.
 */
private int
clip_runs_enumerate(gx_device_mask_clip * cdev,
		    int (*process) (P5(clip_callback_data_t * pccd, int xc, int yc, int xec, int yec)),
		    clip_callback_data_t * pccd)
{
    DECLARE_MASK_COPY;
    int cy;
    const byte *tile_row;

    FIT_MASK_COPY(pccd->data, pccd->sourcex, pccd->raster,
		  pccd->x, pccd->y, pccd->w, pccd->h);
    tile_row = cdev->tiles.data + my0 * cdev->tiles.raster + (mx0 >> 3);
    for (cy = my0; cy < my1; cy++) {
	int cx = mx0;
	const byte *tp = tile_row;
	byte tbit = 0x80 >> (cx & 7);

	while (cx < mx1) {
	    int tx1, tx, ty;
	    int code;

	    /* Skip a run of 0s. */
	    while (cx < mx1 && (*tp & tbit) == 0) {
		if ((tbit >>= 1) == 0)
		    tp++, tbit = 0x80;
		++cx;
	    }
	    if (cx == mx1)
		break;
	    /* Scan a run of 1s. */
	    tx1 = cx - cdev->phase.x;
	    do {
		if ((tbit >>= 1) == 0)
		    tp++, tbit = 0x80;
		++cx;
	    } while (cx < mx1 && (*tp & tbit) != 0);
	    tx = cx - cdev->phase.x;
	    ty = cy - cdev->phase.y;
	    code = (*process) (pccd, tx1, ty, tx, ty + 1);
	    if (code < 0)
		return code;
	}
	tile_row += cdev->tiles.raster;
    }
    return 0;
}

/* Copy a color rectangle */
private int
mask_clip_copy_color(gx_device * dev,
		const byte * data, int sourcex, int raster, gx_bitmap_id id,
		     int x, int y, int w, int h)
{
    gx_device_mask_clip *cdev = (gx_device_mask_clip *) dev;
    clip_callback_data_t ccdata;

    ccdata.tdev = cdev->target;
    ccdata.data = data, ccdata.sourcex = sourcex, ccdata.raster = raster;
    ccdata.x = x, ccdata.y = y, ccdata.w = w, ccdata.h = h;
    return clip_runs_enumerate(cdev, clip_call_copy_color, &ccdata);
}

/* Copy a rectangle with alpha */
private int
mask_clip_copy_alpha(gx_device * dev,
		const byte * data, int sourcex, int raster, gx_bitmap_id id,
		int x, int y, int w, int h, gx_color_index color, int depth)
{
    gx_device_mask_clip *cdev = (gx_device_mask_clip *) dev;
    clip_callback_data_t ccdata;

    ccdata.tdev = cdev->target;
    ccdata.data = data, ccdata.sourcex = sourcex, ccdata.raster = raster;
    ccdata.x = x, ccdata.y = y, ccdata.w = w, ccdata.h = h;
    ccdata.color[0] = color, ccdata.depth = depth;
    return clip_runs_enumerate(cdev, clip_call_copy_alpha, &ccdata);
}

private int
mask_clip_strip_copy_rop(gx_device * dev,
	       const byte * data, int sourcex, uint raster, gx_bitmap_id id,
			 const gx_color_index * scolors,
	   const gx_strip_bitmap * textures, const gx_color_index * tcolors,
			 int x, int y, int w, int h,
		       int phase_x, int phase_y, gs_logical_operation_t lop)
{
    gx_device_mask_clip *cdev = (gx_device_mask_clip *) dev;
    clip_callback_data_t ccdata;

    ccdata.tdev = cdev->target;
    ccdata.x = x, ccdata.y = y, ccdata.w = w, ccdata.h = h;
    ccdata.data = data, ccdata.sourcex = sourcex, ccdata.raster = raster;
    ccdata.scolors = scolors, ccdata.textures = textures,
	ccdata.tcolors = tcolors;
    ccdata.phase.x = phase_x, ccdata.phase.y = phase_y, ccdata.lop = lop;
    return clip_runs_enumerate(cdev, clip_call_strip_copy_rop, &ccdata);
}

private void
mask_clip_get_clipping_box(gx_device * dev, gs_fixed_rect * pbox)
{
    gx_device_mask_clip *cdev = (gx_device_mask_clip *) dev;
    gx_device *tdev = cdev->target;
    gs_fixed_rect tbox;

    (*dev_proc(tdev, get_clipping_box)) (tdev, &tbox);
    pbox->p.x = tbox.p.x - cdev->phase.x;
    pbox->p.y = tbox.p.y - cdev->phase.y;
    pbox->q.x = tbox.q.x - cdev->phase.x;
    pbox->q.y = tbox.q.y - cdev->phase.y;
}