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

/* Copyright (C) 2000 Aladdin Enterprises.  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 the license contained in the file LICENSE in this distribution.
  
  For more information about licensing, please refer to
  http://www.ghostscript.com/licensing/. For information on
  commercial licensing, go to http://www.artifex.com/licensing/ or
  contact Artifex Software, Inc., 101 Lucas Valley Road #110,
  San Rafael, CA  94903, U.S.A., +1(415)492-9861.
*/

/* $Id: gstrans.c,v 1.25 2005/08/30 16:49:34 igor Exp $ */
/* Implementation of transparency, other than rendering */
#include "math_.h"
#include "memory_.h"
#include "gx.h"
#include "gserrors.h"
#include "gstrans.h"
#include "gsutil.h"
#include "gzstate.h"
#include "gxdevcli.h"
#include "gdevp14.h"

#define PUSH_TS 0

/* ------ Transparency-related graphics state elements ------ */

int
gs_setblendmode(gs_state *pgs, gs_blend_mode_t mode)
{
#ifdef DEBUG
    if (gs_debug_c('v')) {
	static const char *const bm_names[] = { GS_BLEND_MODE_NAMES };

	dlprintf1("[v](0x%lx)blend_mode = ", (ulong)pgs);
	if (mode >= 0 && mode < countof(bm_names))
	    dprintf1("%s\n", bm_names[mode]);
	else
	    dprintf1("%d??\n", (int)mode);
    }
#endif
    if (mode < 0 || mode > MAX_BLEND_MODE)
	return_error(gs_error_rangecheck);
    pgs->blend_mode = mode;
    return 0;
}

gs_blend_mode_t
gs_currentblendmode(const gs_state *pgs)
{
    return pgs->blend_mode;
}

int
gs_setopacityalpha(gs_state *pgs, floatp alpha)
{
    if_debug2('v', "[v](0x%lx)opacity.alpha = %g\n", (ulong)pgs, alpha);
    pgs->opacity.alpha = (alpha < 0.0 ? 0.0 : alpha > 1.0 ? 1.0 : alpha);
    return 0;
}

float
gs_currentopacityalpha(const gs_state *pgs)
{
    return pgs->opacity.alpha;
}

int
gs_setshapealpha(gs_state *pgs, floatp alpha)
{
    if_debug2('v', "[v](0x%lx)shape.alpha = %g\n", (ulong)pgs, alpha);
    pgs->shape.alpha = (alpha < 0.0 ? 0.0 : alpha > 1.0 ? 1.0 : alpha);
    return 0;
}

float
gs_currentshapealpha(const gs_state *pgs)
{
    return pgs->shape.alpha;
}

int
gs_settextknockout(gs_state *pgs, bool knockout)
{
    if_debug2('v', "[v](0x%lx)text_knockout = %s\n", (ulong)pgs,
	      (knockout ? "true" : "false"));
    pgs->text_knockout = knockout;
    return 0;
}

bool
gs_currenttextknockout(const gs_state *pgs)
{
    return pgs->text_knockout;
}

/* ------ Transparency rendering stack ------ */

gs_transparency_state_type_t
gs_current_transparency_type(const gs_state *pgs)
{
    return (pgs->transparency_stack == 0 ? 0 :
	    pgs->transparency_stack->type);
}

/* Support for dummy implementation */
gs_private_st_ptrs1(st_transparency_state, gs_transparency_state_t,
		    "gs_transparency_state_t", transparency_state_enum_ptrs,
		    transparency_state_reloc_ptrs, saved);
#if PUSH_TS
private int
push_transparency_stack(gs_state *pgs, gs_transparency_state_type_t type,
			client_name_t cname)
{
    gs_transparency_state_t *pts =
	gs_alloc_struct(pgs->memory, gs_transparency_state_t,
			&st_transparency_state, cname);

    if (pts == 0)
	return_error(gs_error_VMerror);
    pts->saved = pgs->transparency_stack;
    pts->type = type;
    pgs->transparency_stack = pts;
    return 0;
}
#endif
private void
pop_transparency_stack(gs_state *pgs, client_name_t cname)
{
    gs_transparency_state_t *pts = pgs->transparency_stack; /* known non-0 */
    gs_transparency_state_t *saved = pts->saved;

    gs_free_object(pgs->memory, pts, cname);
    pgs->transparency_stack = saved;

}

/*
 * Push a PDF 1.4 transparency compositor onto the current device. Note that
 * if the current device already is a PDF 1.4 transparency compositor, the
 * create_compositor will update its parameters but not create a new
 * compositor device.
 */
private int
gs_state_update_pdf14trans(gs_state * pgs, gs_pdf14trans_params_t * pparams)
{
    gs_imager_state * pis = (gs_imager_state *)pgs;
    gx_device * dev = pgs->device;
    gx_device * pdf14dev;
    int code;

    /*
     * Send the PDF 1.4 create compositor action specified by the parameters.
     */
    code = send_pdf14trans(pis, dev, &pdf14dev, pparams, pgs->memory);
    /*
     * If we created a new PDF 1.4 compositor device then we need to install it
     * into the graphics state.
     */
    if (code >= 0 && pdf14dev != dev)
        gx_set_device_only(pgs, pdf14dev);

    return code;
}

void
gs_trans_group_params_init(gs_transparency_group_params_t *ptgp)
{
    ptgp->ColorSpace = 0;	/* bogus, but can't do better */
    ptgp->Isolated = false;
    ptgp->Knockout = false;
}

int
gs_begin_transparency_group(gs_state *pgs,
			    const gs_transparency_group_params_t *ptgp,
			    const gs_rect *pbbox)
{
    gs_pdf14trans_params_t params = { 0 };

#ifdef DEBUG
    if (gs_debug_c('v')) {
	static const char *const cs_names[] = {
	    GS_COLOR_SPACE_TYPE_NAMES
	};

	dlprintf5("[v](0x%lx)begin_transparency_group [%g %g %g %g]\n",
		  (ulong)pgs, pbbox->p.x, pbbox->p.y, pbbox->q.x, pbbox->q.y);
	if (ptgp->ColorSpace)
	    dprintf1("     CS = %s",
		cs_names[(int)gs_color_space_get_index(ptgp->ColorSpace)]);
	else
	    dputs("     (no CS)");
	dprintf2("  Isolated = %d  Knockout = %d\n",
		 ptgp->Isolated, ptgp->Knockout);
    }
#endif
    /*
     * Put parameters into a compositor parameter and then call the
     * create_compositor.  This will pass the data to the PDF 1.4
     * transparency device.
     */
    params.pdf14_op = PDF14_BEGIN_TRANS_GROUP;
    params.Isolated = ptgp->Isolated;
    params.Knockout = ptgp->Knockout;
    params.opacity = pgs->opacity;
    params.shape = pgs->shape;
    params.blend_mode = pgs->blend_mode;
    /*
     * We are currently doing nothing with the colorspace.  Currently
     * the blending colorspace is based upon the processs color model
     * of the output device.
     */
    params.bbox = *pbbox;
    return gs_state_update_pdf14trans(pgs, &params);
}

int
gx_begin_transparency_group(gs_imager_state * pis, gx_device * pdev,
				const gs_pdf14trans_params_t * pparams)
{
    gs_transparency_group_params_t tgp = {0};
    gs_rect bbox;

    if (pparams->Background_components != 0 && 
	pparams->Background_components != pdev->color_info.num_components)
	return_error(gs_error_rangecheck);
    tgp.Isolated = pparams->Isolated;
    tgp.Knockout = pparams->Knockout;
    pis->opacity.alpha = pparams->opacity.alpha;
    pis->shape.alpha = pparams->shape.alpha;
    pis->blend_mode = pparams->blend_mode;
    bbox = pparams->bbox;
#ifdef DEBUG
    if (gs_debug_c('v')) {
	static const char *const cs_names[] = {
	    GS_COLOR_SPACE_TYPE_NAMES
	};

	dlprintf5("[v](0x%lx)begin_transparency_group [%g %g %g %g]\n",
		  (ulong)pis, bbox.p.x, bbox.p.y, bbox.q.x, bbox.q.y);
	if (tgp.ColorSpace)
	    dprintf1("     CS = %s",
		cs_names[(int)gs_color_space_get_index(tgp.ColorSpace)]);
	else
	    dputs("     (no CS)");
	dprintf2("  Isolated = %d  Knockout = %d\n",
		 tgp.Isolated, tgp.Knockout);
    }
#endif
    if (dev_proc(pdev, begin_transparency_group) != 0)
	return (*dev_proc(pdev, begin_transparency_group)) (pdev, &tgp,
							&bbox, pis, NULL, NULL);
    else
	return 0;
}

int
gs_end_transparency_group(gs_state *pgs)
{
    gs_pdf14trans_params_t params = { 0 };

    params.pdf14_op = PDF14_END_TRANS_GROUP;  /* Other parameters not used */
    return gs_state_update_pdf14trans(pgs, &params);
}

int
gx_end_transparency_group(gs_imager_state * pis, gx_device * pdev)
{
    if (dev_proc(pdev, end_transparency_group) != 0)
	return (*dev_proc(pdev, end_transparency_group)) (pdev, pis, NULL);
    else
	return 0;
}

/*
 * Handler for identity mask transfer functions.
 */
private int
mask_transfer_identity(floatp in, float *out, void *proc_data)
{
    *out = (float) in;
    return 0;
}

void
gs_trans_mask_params_init(gs_transparency_mask_params_t *ptmp,
			  gs_transparency_mask_subtype_t subtype)
{
    ptmp->subtype = subtype;
    ptmp->Background_components = 0;
    ptmp->TransferFunction = mask_transfer_identity;
    ptmp->TransferFunction_data = 0;
}

int
gs_begin_transparency_mask(gs_state * pgs,
			   const gs_transparency_mask_params_t * ptmp,
			   const gs_rect * pbbox, bool mask_is_image)
{
    gs_pdf14trans_params_t params = { 0 };
    const int l = sizeof(params.Background[0]) * ptmp->Background_components;
    int i;

    if_debug8('v', "[v](0x%lx)begin_transparency_mask [%g %g %g %g]\n\
      subtype = %d  Background_components = %d  %s\n",
	      (ulong)pgs, pbbox->p.x, pbbox->p.y, pbbox->q.x, pbbox->q.y,
	      (int)ptmp->subtype, ptmp->Background_components,
	      (ptmp->TransferFunction == mask_transfer_identity ? "no TR" :
	       "has TR"));
    params.pdf14_op = PDF14_BEGIN_TRANS_MASK;
    params.bbox = *pbbox;
    params.subtype = ptmp->subtype;
    params.Background_components = ptmp->Background_components;
    memcpy(params.Background, ptmp->Background, l);
    params.GrayBackground = ptmp->GrayBackground;
    params.transfer_function = ptmp->TransferFunction_data;
    params.function_is_identity =
	    (ptmp->TransferFunction == mask_transfer_identity);
    params.mask_is_image = mask_is_image;
    /* Sample the transfer function */
    for (i = 0; i < MASK_TRANSFER_FUNCTION_SIZE; i++) {
	float in = (float)(i * (1.0 / (MASK_TRANSFER_FUNCTION_SIZE - 1)));
	float out;

	ptmp->TransferFunction(in, &out, ptmp->TransferFunction_data);
	params.transfer_fn[i] = (byte)floor((double)(out * 255 + 0.5));
    }
    return gs_state_update_pdf14trans(pgs, &params);
}

int
gx_begin_transparency_mask(gs_imager_state * pis, gx_device * pdev,
				const gs_pdf14trans_params_t * pparams)
{
    gx_transparency_mask_params_t tmp;
    const int l = sizeof(pparams->Background[0]) * pparams->Background_components;

    tmp.subtype = pparams->subtype;
    tmp.Background_components = pparams->Background_components;
    memcpy(tmp.Background, pparams->Background, l);
    tmp.GrayBackground = pparams->GrayBackground;
    tmp.function_is_identity = pparams->function_is_identity;
    memcpy(tmp.transfer_fn, pparams->transfer_fn, size_of(tmp.transfer_fn));
    if_debug8('v', "[v](0x%lx)begin_transparency_mask [%g %g %g %g]\n\
      subtype = %d  Background_components = %d  %s\n",
	      (ulong)pis, pparams->bbox.p.x, pparams->bbox.p.y,
	      pparams->bbox.q.x, pparams->bbox.q.y,
	      (int)tmp.subtype, tmp.Background_components,
	      (tmp.function_is_identity ? "no TR" :
	       "has TR"));
    if (dev_proc(pdev, begin_transparency_mask) != 0)
	return (*dev_proc(pdev, begin_transparency_mask))
	    		(pdev, &tmp, &(pparams->bbox), pis, NULL, NULL);
    else
	return 0;
}

int
gs_end_transparency_mask(gs_state *pgs,
			 gs_transparency_channel_selector_t csel)
{
    gs_pdf14trans_params_t params = { 0 };

    if_debug2('v', "[v](0x%lx)end_transparency_mask(%d)\n", (ulong)pgs,
	      (int)csel);

    params.pdf14_op = PDF14_END_TRANS_MASK;  /* Other parameters not used */
    params.csel = csel;
    return gs_state_update_pdf14trans(pgs, &params);
}

int
gx_end_transparency_mask(gs_imager_state * pis, gx_device * pdev,
				const gs_pdf14trans_params_t * pparams)
{
    if (dev_proc(pdev, end_transparency_mask) != 0)
	return (*dev_proc(pdev, end_transparency_mask)) (pdev, NULL);
    else
	return 0;
}

int
gs_discard_transparency_layer(gs_state *pgs)
{
    /****** NYI, DUMMY ******/
    gs_transparency_state_t *pts = pgs->transparency_stack;

    if_debug1('v', "[v](0x%lx)discard_transparency_layer\n", (ulong)pgs);
    if (!pts)
	return_error(gs_error_rangecheck);
    pop_transparency_stack(pgs, "gs_discard_transparency_layer");
    return 0;
}

int
gs_init_transparency_mask(gs_state *pgs,
			  gs_transparency_channel_selector_t csel)
{
    gs_pdf14trans_params_t params = { 0 };

    if_debug2('v', "[v](0x%lx)init_transparency_mask(%d)\n", (ulong)pgs,
	      (int)csel);

    params.pdf14_op = PDF14_INIT_TRANS_MASK;
    params.csel = csel;
    return gs_state_update_pdf14trans(pgs, &params);
}

int
gx_init_transparency_mask(gs_imager_state * pis,
				const gs_pdf14trans_params_t * pparams)
{
    gs_transparency_source_t *ptm;

    if_debug2('v', "[v](0x%lx)init_transparency_mask(%d)\n", (ulong)pis,
	      (int)pparams->csel);
    switch (pparams->csel) {
    case TRANSPARENCY_CHANNEL_Opacity: ptm = &pis->opacity; break;
    case TRANSPARENCY_CHANNEL_Shape: ptm = &pis->shape; break;
    default: return_error(gs_error_rangecheck);
    }
    rc_decrement_only(ptm->mask, "gs_init_transparency_mask");
    ptm->mask = 0;
    return 0;
}

int
gs_push_pdf14trans_device(gs_state * pgs)
{
    gs_pdf14trans_params_t params = { 0 };

    params.pdf14_op = PDF14_PUSH_DEVICE;  /* Other parameters not used */
    return gs_state_update_pdf14trans(pgs, &params);
}

int
gs_pop_pdf14trans_device(gs_state * pgs)
{
    gs_pdf14trans_params_t params = { 0 };

    params.pdf14_op = PDF14_POP_DEVICE;  /* Other parameters not used */
    return gs_state_update_pdf14trans(pgs, &params);
}