/* Copyright (C) 1995 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.
 */

/*$Id: gsdevmem.c $ */
/* Memory device creation for Ghostscript library */
#include "math_.h"		/* for fabs */
#include "memory_.h"
#include "gx.h"
#include "gserrors.h"
#include "gxarith.h"
#include "gxdevice.h"
#include "gxdevmem.h"

/* Make a memory (image) device. */
/* If colors_size = -16, -24, or -32, this is a true-color device; */
/* otherwise, colors_size is the size of the palette in bytes */
/* (2^N for gray scale, 3*2^N for RGB color). */
/* We separate device allocation and initialization at customer request. */
int
gs_initialize_wordimagedevice(gx_device_memory * new_dev, const gs_matrix * pmat,
	      uint width, uint height, const byte * colors, int colors_size,
		    bool word_oriented, bool page_device, gs_memory_t * mem)
{
    const gx_device_memory *proto_dev;
    int palette_count = colors_size;
    int num_components = 1;
    int pcount;
    int bits_per_pixel;
    float x_pixels_per_unit, y_pixels_per_unit;
    byte palette[256 * 3];
    byte *dev_palette;
    bool has_color;

    switch (colors_size) {
	case 3 * 2:
	    palette_count = 2;
	    num_components = 3;
	case 2:
	    bits_per_pixel = 1;
	    break;
	case 3 * 4:
	    palette_count = 4;
	    num_components = 3;
	case 4:
	    bits_per_pixel = 2;
	    break;
	case 3 * 16:
	    palette_count = 16;
	    num_components = 3;
	case 16:
	    bits_per_pixel = 4;
	    break;
	case 3 * 256:
	    palette_count = 256;
	    num_components = 3;
	case 256:
	    bits_per_pixel = 8;
	    break;
	case -16:
	    bits_per_pixel = 16;
	    palette_count = 0;
	    break;
	case -24:
	    bits_per_pixel = 24;
	    palette_count = 0;
	    break;
	case -32:
	    bits_per_pixel = 32;
	    palette_count = 0;
	    break;
	default:
	    return_error(gs_error_rangecheck);
    }
    proto_dev = (word_oriented ?
		 gdev_mem_word_device_for_bits(bits_per_pixel) :
		 gdev_mem_device_for_bits(bits_per_pixel));
    if (proto_dev == 0)		/* no suitable device */
	return_error(gs_error_rangecheck);
    pcount = palette_count * 3;
    /* Check to make sure the palette contains white and black, */
    /* and, if it has any colors, the six primaries. */
    if (bits_per_pixel <= 8) {
	const byte *p;
	byte *q;
	int primary_mask = 0;
	int i;

	has_color = false;
	for (i = 0, p = colors, q = palette;
	     i < palette_count; i++, q += 3
	    ) {
	    int mask = 1;

	    switch (num_components) {
		case 1:	/* gray */
		    q[0] = q[1] = q[2] = *p++;
		    break;
		default /* case 3 */ :		/* RGB */
		    q[0] = p[0], q[1] = p[1], q[2] = p[2];
		    p += 3;
	    }
#define shift_mask(b,n)\
  switch ( b ) { case 0xff: mask <<= n; case 0: break; default: mask = 0; }
	    shift_mask(q[0], 4);
	    shift_mask(q[1], 2);
	    shift_mask(q[2], 1);
#undef shift_mask
	    primary_mask |= mask;
	    if (q[0] != q[1] || q[0] != q[2])
		has_color = true;
	}
	switch (primary_mask) {
	    case 129:		/* just black and white */
		if (has_color)	/* color but no primaries */
		    return_error(gs_error_rangecheck);
	    case 255:		/* full color */
		break;
	    default:
		return_error(gs_error_rangecheck);
	}
    } else
	has_color = true;
    /*
     * The initial transformation matrix must map 1 user unit to
     * 1/72".  Let W and H be the width and height in pixels, and
     * assume the initial matrix is of the form [A 0 0 B X Y].
     * Then the size of the image in user units is (W/|A|,H/|B|),
     * hence the size in inches is ((W/|A|)/72,(H/|B|)/72), so
     * the number of pixels per inch is
     * (W/((W/|A|)/72),H/((H/|B|)/72)), or (|A|*72,|B|*72).
     * Similarly, if the initial matrix is [0 A B 0 X Y] for a 90
     * or 270 degree rotation, the size of the image in user
     * units is (W/|B|,H/|A|), so the pixels per inch are
     * (|B|*72,|A|*72).  We forbid non-orthogonal transformation
     * matrices.
     */
    if (is_fzero2(pmat->xy, pmat->yx))
	x_pixels_per_unit = pmat->xx, y_pixels_per_unit = pmat->yy;
    else if (is_fzero2(pmat->xx, pmat->yy))
	x_pixels_per_unit = pmat->yx, y_pixels_per_unit = pmat->xy;
    else
	return_error(gs_error_undefinedresult);
    /* All checks done, allocate the device. */
    if (bits_per_pixel != 1) {
	dev_palette = gs_alloc_string(mem, pcount,
				      "gs_makeimagedevice(palette)");
	if (dev_palette == 0)
	    return_error(gs_error_VMerror);
    }
    gs_make_mem_device(new_dev, proto_dev, mem,
		       (page_device ? 1 : -1), 0);
    if (!has_color) {
	new_dev->color_info.num_components = 1;
	new_dev->color_info.max_color = 0;
	new_dev->color_info.dither_colors = 0;
    }
    if (bits_per_pixel == 1) {	/* Determine the polarity from the palette. */
	/* This is somewhat bogus, but does the right thing */
	/* in the only cases we care about. */
	gdev_mem_mono_set_inverted(new_dev,
			       (palette[0] | palette[1] | palette[2]) != 0);
    } else {
	new_dev->palette.size = pcount;
	new_dev->palette.data = dev_palette;
	memcpy(dev_palette, palette, pcount);
    }
    new_dev->initial_matrix = *pmat;
    new_dev->MarginsHWResolution[0] = new_dev->HWResolution[0] =
	fabs(x_pixels_per_unit) * 72;
    new_dev->MarginsHWResolution[1] = new_dev->HWResolution[1] =
	fabs(y_pixels_per_unit) * 72;
    gx_device_set_width_height((gx_device *) new_dev, width, height);
    /* Set the ImagingBBox so we get a correct clipping region. */
    {
	gs_rect bbox;

	bbox.p.x = 0;
	bbox.p.y = 0;
	bbox.q.x = width;
	bbox.q.y = height;
	gs_bbox_transform_inverse(&bbox, pmat, &bbox);
	new_dev->ImagingBBox[0] = bbox.p.x;
	new_dev->ImagingBBox[1] = bbox.p.y;
	new_dev->ImagingBBox[2] = bbox.q.x;
	new_dev->ImagingBBox[3] = bbox.q.y;
	new_dev->ImagingBBox_set = true;
    }
    /* The bitmap will be allocated when the device is opened. */
    new_dev->is_open = false;
    new_dev->bitmap_memory = mem;
    return 0;
}

int
gs_makewordimagedevice(gx_device ** pnew_dev, const gs_matrix * pmat,
	       uint width, uint height, const byte * colors, int num_colors,
		    bool word_oriented, bool page_device, gs_memory_t * mem)
{
    int code;
    gx_device_memory *pnew =
    gs_alloc_struct(mem, gx_device_memory, &st_device_memory,
		    "gs_makeimagedevice(device)");

    if (pnew == 0)
	return_error(gs_error_VMerror);
    code = gs_initialize_wordimagedevice(pnew, pmat, width, height,
					 colors, num_colors, word_oriented,
					 page_device, mem);
    if (code < 0) {
	gs_free_object(mem, pnew, "gs_makeimagedevice(device)");
	return code;
    }
    *pnew_dev = (gx_device *) pnew;
    return 0;
}
