/* Copyright (C) 2001-2006 Artifex Software, Inc.
   All Rights Reserved.
  
   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied, modified
   or distributed except as expressly authorized under the terms of that
   license.  Refer to licensing information at http://www.artifex.com/
   or contact Artifex Software, Inc.,  7 Mt. Lassen Drive - Suite A-134,
   San Rafael, CA  94903, U.S.A., +1(415)492-9861, for further information.
*/

/* $Id: gsdevmem.c 8022 2007-06-05 22:23:38Z giles $ */
/* Memory device creation for Ghostscript library */
#include "math_.h"		/* for fabs */
#include "memory_.h"
#include "gx.h"
#include "gserrors.h"
#include "gsdevice.h"		/* for prototypes */
#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];
    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, initialize the device. */
    if (bits_per_pixel == 1) {
	/* Determine the polarity from the palette. */
	gs_make_mem_device(new_dev, proto_dev, mem,
			   (page_device ? 1 : -1), 0);
	/* 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 {
	byte *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);
	new_dev->palette.size = pcount;
	new_dev->palette.data = dev_palette;
	memcpy(dev_palette, palette, pcount);
	if (!has_color) {
	    new_dev->color_info.num_components = 1;
	    new_dev->color_info.max_color = 0;
	    new_dev->color_info.dither_colors = 0;
	    new_dev->color_info.gray_index = 0;
	}
    }
    /* Memory defice is always initialised as an internal device but */
    /* this is an external device */
    new_dev->retained = true;
    rc_init(new_dev, new_dev->memory, 1);

    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;
}
