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/* Copyright (C) 2001-2006 Artifex Software, Inc.
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This software is provided AS-IS with no warranty, either express or
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This software is distributed under license and may not be copied, modified
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or distributed except as expressly authorized under the terms of that
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license. Refer to licensing information at http://www.artifex.com/
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or contact Artifex Software, Inc., 7 Mt. Lassen Drive - Suite A-134,
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San Rafael, CA 94903, U.S.A., +1(415)492-9861, for further information.
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/* $Id: gdevpdts.c 8518 2008-02-07 09:33:22Z ken $ */
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/* Text state management for pdfwrite */
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#include "gdevpdtf.h" /* for pdfont->FontType */
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/* ================ Types and structures ================ */
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* We accumulate text, and possibly horizontal or vertical moves (depending
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* on the font's writing direction), until forced to emit them. This
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* happens when changing text state parameters, when the buffer is full, or
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* when exiting text mode.
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* Note that movement distances are measured in unscaled text space.
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typedef struct pdf_text_move_s {
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int index; /* within buffer.chars */
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#define MAX_TEXT_BUFFER_CHARS 200 /* arbitrary, but overflow costs 5 chars */
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#define MAX_TEXT_BUFFER_MOVES 50 /* ibid. */
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typedef struct pdf_text_buffer_s {
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* count_moves <= MAX_TEXT_BUFFER_MOVES
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* count_chars <= MAX_TEXT_BUFFER_CHARS
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* 0 < moves[0].index < moves[1].index < ... moves[count_moves-1].index
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* moves[*].amount != 0
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pdf_text_move_t moves[MAX_TEXT_BUFFER_MOVES + 1];
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byte chars[MAX_TEXT_BUFFER_CHARS];
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#define TEXT_BUFFER_DEFAULT\
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{ { 0, 0 } }, /* moves */\
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* We maintain two sets of text state values (as defined in gdevpdts.h): the
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* "in" set reflects the current state as seen by the client, while the
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* "out" set reflects the current state as seen by an interpreter processing
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* the content stream emitted so far. We emit commands to make "out" the
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* same as "in" when necessary.
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/*typedef struct pdf_text_state_s pdf_text_state_t;*/ /* gdevpdts.h */
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struct pdf_text_state_s {
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/* State as seen by client */
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pdf_text_state_values_t in; /* see above */
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gs_point start; /* in.txy as of start of buffer */
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pdf_text_buffer_t buffer;
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int wmode; /* WMode of in.font */
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/* State relative to content stream */
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pdf_text_state_values_t out; /* see above */
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double leading; /* TL (not settable, only used internally) */
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bool use_leading; /* if true, use T* or ' */
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gs_point out_pos; /* output position */
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static const pdf_text_state_t ts_default = {
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/* State as seen by client */
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{ TEXT_STATE_VALUES_DEFAULT }, /* in */
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{ TEXT_BUFFER_DEFAULT }, /* buffer */
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/* State relative to content stream */
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{ TEXT_STATE_VALUES_DEFAULT }, /* out */
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0 /*false*/, /* use_leading */
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0 /*false*/, /* continue_line */
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{ 0, 0 }, /* line_start */
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{ 0, 0 } /* output position */
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gs_private_st_ptrs2(st_pdf_text_state, pdf_text_state_t, "pdf_text_state_t",
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pdf_text_state_enum_ptrs, pdf_text_state_reloc_ptrs,
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in.pdfont, out.pdfont);
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/* ================ Procedures ================ */
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/* ---------------- Private ---------------- */
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* Append a writing-direction movement to the text being accumulated. If
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* the buffer is full, or the requested movement is not in writing
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* direction, return <0 and do nothing. (This is different from
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* pdf_append_chars.) Requires pts->buffer.count_chars > 0.
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append_text_move(pdf_text_state_t *pts, floatp dw)
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int count = pts->buffer.count_moves;
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int pos = pts->buffer.count_chars;
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if (count > 0 && pts->buffer.moves[count - 1].index == pos) {
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/* Merge adjacent moves. */
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dw += pts->buffer.moves[--count].amount;
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/* Round dw if it's very close to an integer. */
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rounded = floor(dw + 0.5);
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if (fabs(dw - rounded) < 0.001)
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if (dw < -MAX_USER_COORD) {
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/* Acrobat reader 4.0c, 5.0 can't handle big offsets.
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Adobe Reader 6 can. */
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if (count == MAX_TEXT_BUFFER_MOVES)
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pts->buffer.moves[count].index = pos;
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pts->buffer.moves[count].amount = dw;
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pts->buffer.count_moves = count;
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* Set *pdist to the distance (dx,dy), in the space defined by *pmat.
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set_text_distance(gs_point *pdist, floatp dx, floatp dy, const gs_matrix *pmat)
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int code = gs_distance_transform_inverse(dx, dy, pmat, pdist);
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if (code == gs_error_undefinedresult) {
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/* The CTM is degenerate.
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Can't know the distance in user space.
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Set zero because we believe it is not important for rendering.
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We want to copy the text to PDF to make it searchable.
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pdist->x = pdist->y = 0;
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/* If the distance is very close to integers, round it. */
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if (fabs(pdist->x - (rounded = floor(pdist->x + 0.5))) < 0.0005)
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if (fabs(pdist->y - (rounded = floor(pdist->y + 0.5))) < 0.0005)
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* Test whether the transformation parts of two matrices are compatible.
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matrix_is_compatible(const gs_matrix *pmat1, const gs_matrix *pmat2)
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return (pmat2->xx == pmat1->xx && pmat2->xy == pmat1->xy &&
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pmat2->yx == pmat1->yx && pmat2->yy == pmat1->yy);
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* Try to handle a change of text position with TJ or a space
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* character. If successful, return >=0, if not, return <0.
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add_text_delta_move(gx_device_pdf *pdev, const gs_matrix *pmat)
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pdf_text_state_t *const pts = pdev->text->text_state;
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if (matrix_is_compatible(pmat, &pts->in.matrix)) {
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double dx = pmat->tx - pts->in.matrix.tx,
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dy = pmat->ty - pts->in.matrix.ty;
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double dw, dnotw, tdw;
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code = set_text_distance(&dist, dx, dy, pmat);
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dw = dist.y, dnotw = dist.x;
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dw = dist.x, dnotw = dist.y;
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if (dnotw == 0 && pts->buffer.count_chars > 0 &&
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* Acrobat Reader limits the magnitude of user-space
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* coordinates. Also, AR apparently doesn't handle large
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* positive movement values (negative X displacements), even
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* though the PDF Reference says this bug was fixed in AR3.
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* Old revisions used the upper threshold 1000 for tdw,
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* but it appears too big when a font sets a too big
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* character width in setcachedevice. Particularly this happens
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* with a Type 3 font generated by Aldus Freehand 4.0
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* to represent a texture - see bug #687051.
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* The problem is that when the Widths is multiplied
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* to the font size, the viewer represents the result
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* with insufficient fraction bits to represent the precise width.
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* We work around that problem here restricting tdw
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* with a smaller threshold 990. Our intention is to
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* disable Tj when the real glyph width appears smaller
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* than 1% of the width specified in setcachedevice.
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* A Td instruction will be generated instead.
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* Note that the value 990 is arbitrary and may need a
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* further adjustment.
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(tdw = dw * -1000.0 / pts->in.size,
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tdw >= -MAX_USER_COORD && tdw < 990)
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int code = append_text_move(pts, tdw);
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pts->in.matrix = *pmat;
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* Set the text matrix for writing text. The translation component of the
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* matrix is the text origin. If the non-translation components of the
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* matrix differ from the current ones, write a Tm command; if there is only
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* a Y translation, set use_leading so the next text string will be written
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* with ' rather than Tj; otherwise, write a Td command.
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pdf_set_text_matrix(gx_device_pdf * pdev)
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pdf_text_state_t *pts = pdev->text->text_state;
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stream *s = pdev->strm;
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pts->use_leading = false;
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if (matrix_is_compatible(&pts->out.matrix, &pts->in.matrix)) {
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code = set_text_distance(&dist, pts->start.x - pts->line_start.x,
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pts->start.y - pts->line_start.y, &pts->in.matrix);
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if (dist.x == 0 && dist.y < 0) {
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/* Use TL, if needed, and T* or '. */
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float dist_y = (float)-dist.y;
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if (fabs(pts->leading - dist_y) > 0.0005) {
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pprintg1(s, "%g TL\n", dist_y);
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pts->leading = dist_y;
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pts->use_leading = true;
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pprintg2(s, "%g %g Td\n", dist.x, dist.y);
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} else { /* Use Tm. */
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* See stream_to_text in gdevpdfu.c for why we need the following
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* matrix adjustments.
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double sx = 72.0 / pdev->HWResolution[0],
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sy = 72.0 / pdev->HWResolution[1];
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pprintg6(s, "%g %g %g %g %g %g Tm\n",
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pts->in.matrix.xx * sx, pts->in.matrix.xy * sy,
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pts->in.matrix.yx * sx, pts->in.matrix.yy * sy,
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pts->start.x * sx, pts->start.y * sy);
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pts->line_start.x = pts->start.x;
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pts->line_start.y = pts->start.y;
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pts->out.matrix = pts->in.matrix;
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/* ---------------- Public ---------------- */
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* Allocate and initialize text state bookkeeping.
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pdf_text_state_alloc(gs_memory_t *mem)
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pdf_text_state_t *pts =
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gs_alloc_struct(mem, pdf_text_state_t, &st_pdf_text_state,
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"pdf_text_state_alloc");
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* Set the text state to default values.
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pdf_set_text_state_default(pdf_text_state_t *pts)
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* Copy the text state.
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pdf_text_state_copy(pdf_text_state_t *pts_to, pdf_text_state_t *pts_from)
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* Reset the text state to its condition at the beginning of the page.
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pdf_reset_text_page(pdf_text_data_t *ptd)
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pdf_set_text_state_default(ptd->text_state);
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* Reset the text state after a grestore.
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pdf_reset_text_state(pdf_text_data_t *ptd)
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pdf_text_state_t *pts = ptd->text_state;
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pts->out = ts_default.out;
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* Transition from stream context to text context.
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pdf_from_stream_to_text(gx_device_pdf *pdev)
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pdf_text_state_t *pts = pdev->text->text_state;
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gs_make_identity(&pts->out.matrix);
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pts->line_start.x = pts->line_start.y = 0;
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pts->continue_line = false; /* Not sure, probably doesn't matter. */
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pts->buffer.count_chars = 0;
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pts->buffer.count_moves = 0;
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pdf_get_stoted_text_size(pdf_text_state_t *state)
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return state->buffer.count_chars;
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* Flush text from buffer.
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flush_text_buffer(gx_device_pdf *pdev)
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pdf_text_state_t *pts = pdev->text->text_state;
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stream *s = pdev->strm;
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if (pts->buffer.count_chars != 0) {
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pdf_font_resource_t *pdfont = pts->in.pdfont;
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int code = pdf_assign_font_object_id(pdev, pdfont);
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code = pdf_add_resource(pdev, pdev->substream_Resources, "/Font", (pdf_resource_t *)pdfont);
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if (pts->buffer.count_moves > 0) {
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if (pts->use_leading)
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stream_puts(s, "T*");
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for (i = 0; i < pts->buffer.count_moves; ++i) {
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int next = pts->buffer.moves[i].index;
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pdf_put_string(pdev, pts->buffer.chars + cur, next - cur);
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pprintg1(s, "%g", pts->buffer.moves[i].amount);
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if (pts->buffer.count_chars > cur)
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pdf_put_string(pdev, pts->buffer.chars + cur,
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pts->buffer.count_chars - cur);
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stream_puts(s, "]TJ\n");
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pdf_put_string(pdev, pts->buffer.chars, pts->buffer.count_chars);
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stream_puts(s, (pts->use_leading ? "'\n" : "Tj\n"));
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pts->buffer.count_chars = 0;
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pts->buffer.count_moves = 0;
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pts->use_leading = false;
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* Transition from string context to text context.
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sync_text_state(gx_device_pdf *pdev)
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pdf_text_state_t *pts = pdev->text->text_state;
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stream *s = pdev->strm;
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if (pts->buffer.count_chars == 0)
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return 0; /* nothing to output */
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if (pts->continue_line)
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return flush_text_buffer(pdev);
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/* Bring text state parameters up to date. */
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if (pts->out.character_spacing != pts->in.character_spacing) {
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pprintg1(s, "%g Tc\n", pts->in.character_spacing);
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pts->out.character_spacing = pts->in.character_spacing;
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if (pts->out.pdfont != pts->in.pdfont || pts->out.size != pts->in.size) {
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pdf_font_resource_t *pdfont = pts->in.pdfont;
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code = pdf_assign_font_object_id(pdev, pdfont);
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pprints1(s, "/%s ", pdfont->rname);
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pprintg1(s, "%g Tf\n", pts->in.size);
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pts->out.pdfont = pdfont;
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pts->out.size = pts->in.size;
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* In PDF, the only place to specify WMode is in the CMap
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* (a.k.a. Encoding) of a Type 0 font.
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(pdfont->FontType == ft_composite ?
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pdfont->u.type0.WMode : 0);
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code = pdf_used_charproc_resources(pdev, pdfont);
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if (memcmp(&pts->in.matrix, &pts->out.matrix, sizeof(pts->in.matrix)) ||
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((pts->start.x != pts->out_pos.x || pts->start.y != pts->out_pos.y) &&
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(pts->buffer.count_chars != 0 || pts->buffer.count_moves != 0))) {
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/* pdf_set_text_matrix sets out.matrix = in.matrix */
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code = pdf_set_text_matrix(pdev);
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if (pts->out.render_mode != pts->in.render_mode) {
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pprintg1(s, "%g Tr\n", pts->in.render_mode);
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pts->out.render_mode = pts->in.render_mode;
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if (pts->out.word_spacing != pts->in.word_spacing) {
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if (memchr(pts->buffer.chars, 32, pts->buffer.count_chars)) {
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pprintg1(s, "%g Tw\n", pts->in.word_spacing);
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pts->out.word_spacing = pts->in.word_spacing;
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return flush_text_buffer(pdev);
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pdf_from_string_to_text(gx_device_pdf *pdev)
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return sync_text_state(pdev);
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* Close the text aspect of the current contents part.
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pdf_close_text_contents(gx_device_pdf *pdev)
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* Clear the font pointer. This is probably left over from old code,
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* but it is appropriate in case we ever choose in the future to write
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* out and free font resources before the end of the document.
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pdf_text_state_t *pts = pdev->text->text_state;
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pts->in.pdfont = pts->out.pdfont = 0;
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pts->in.size = pts->out.size = 0;
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* Test whether a change in render_mode requires resetting the stroke
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pdf_render_mode_uses_stroke(const gx_device_pdf *pdev,
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const pdf_text_state_values_t *ptsv)
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return (pdev->text->text_state->in.render_mode != ptsv->render_mode &&
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ptsv->render_mode == 1 || ptsv->render_mode == 2 ||
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ptsv->render_mode == 5 || ptsv->render_mode == 6);
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* Read the stored client view of text state values.
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pdf_get_text_state_values(gx_device_pdf *pdev, pdf_text_state_values_t *ptsv)
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*ptsv = pdev->text->text_state->in;
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* Set wmode to text state.
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pdf_set_text_wmode(gx_device_pdf *pdev, int wmode)
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pdf_text_state_t *pts = pdev->text->text_state;
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* Set the stored client view of text state values.
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pdf_set_text_state_values(gx_device_pdf *pdev,
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const pdf_text_state_values_t *ptsv)
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pdf_text_state_t *pts = pdev->text->text_state;
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if (pts->buffer.count_chars > 0) {
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if (pts->in.character_spacing == ptsv->character_spacing &&
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pts->in.pdfont == ptsv->pdfont && pts->in.size == ptsv->size &&
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pts->in.render_mode == ptsv->render_mode &&
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pts->in.word_spacing == ptsv->word_spacing
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if (!memcmp(&pts->in.matrix, &ptsv->matrix,
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sizeof(pts->in.matrix)))
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/* add_text_delta_move sets pts->in.matrix if successful */
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code = add_text_delta_move(pdev, &ptsv->matrix);
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code = sync_text_state(pdev);
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pts->continue_line = false;
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* Transform a distance from unscaled text space (text space ignoring the
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* scaling implied by the font size) to device space.
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pdf_text_distance_transform(floatp wx, floatp wy, const pdf_text_state_t *pts,
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return gs_distance_transform(wx, wy, &pts->in.matrix, ppt);
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* Return the current (x,y) text position as seen by the client, in
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* unscaled text space.
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pdf_text_position(const gx_device_pdf *pdev, gs_point *ppt)
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pdf_text_state_t *pts = pdev->text->text_state;
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ppt->x = pts->in.matrix.tx;
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ppt->y = pts->in.matrix.ty;
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* Append characters to text being accumulated, giving their advance width
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pdf_append_chars(gx_device_pdf * pdev, const byte * str, uint size,
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floatp wx, floatp wy, bool nobreak)
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pdf_text_state_t *pts = pdev->text->text_state;
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if (pts->buffer.count_chars == 0 && pts->buffer.count_moves == 0) {
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pts->out_pos.x = pts->start.x = pts->in.matrix.tx;
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pts->out_pos.y = pts->start.y = pts->in.matrix.ty;
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if (pts->buffer.count_chars == MAX_TEXT_BUFFER_CHARS ||
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(nobreak && pts->buffer.count_chars + left > MAX_TEXT_BUFFER_CHARS)) {
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int code = sync_text_state(pdev);
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/* We'll keep a continuation of this line in the buffer,
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* but the current input parameters don't correspond to
632
* the current position, because the text was broken in a
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* middle with unknown current point.
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* Don't change the output text state parameters
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* until input parameters are changed.
636
* pdf_set_text_state_values will reset the 'continue_line' flag
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pts->continue_line = true;
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int code = pdf_open_page(pdev, PDF_IN_STRING);
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copy = min(MAX_TEXT_BUFFER_CHARS - pts->buffer.count_chars, left);
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memcpy(pts->buffer.chars + pts->buffer.count_chars, p, copy);
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pts->buffer.count_chars += copy;
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pts->in.matrix.tx += wx;
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pts->in.matrix.ty += wy;
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pts->out_pos.x += wx;
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pts->out_pos.y += wy;
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/* Check a new piece of charpath text to see if its safe to combine
660
* with a previous text operation using text rendering modes.
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bool pdf_compare_text_state_for_charpath(pdf_text_state_t *pts, gx_device_pdf *pdev,
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gs_imager_state *pis, gs_font *font,
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const gs_text_params_t *text)
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gs_matrix smat, tmat;
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struct pdf_font_resource_s *pdfont;
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/* check to ensure the new text has the same length as the saved text */
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if(text->size != pts->buffer.count_chars)
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if(font->FontType == ft_user_defined)
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/* check to ensure the new text has the same data as the saved text */
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if(memcmp(text->data.bytes, &pts->buffer.chars, text->size))
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/* See if the same font is in use by checking the attahced pdfont resource for
683
* the currrent font and comparing with the saved text state
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code = pdf_attached_font_resource(pdev, font, &pdfont, NULL, NULL, NULL, NULL);
689
if(!pdfont || pdfont != pts->in.pdfont)
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/* Check to see the new text starts at the same point as the saved text.
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* NB! only check 2 decimal places, allow some slack in the match. This
694
* still may prove to be too tight a requirement.
696
if((int)(pts->start.x * 100) != (int)(pis->current_point.x * 100) ||
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(int)(pts->start.y * 100) != (int)(pis->current_point.y * 100))
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size = pdf_calculate_text_size(pis, pdfont, &font->FontMatrix, &smat, &tmat, font, pdev);
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/* Finally, check the calculated size against the size stored in
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if(size != pts->in.size)
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/* Add a render mode to the rendering mode of the current text.
715
* If the modes are not compatible returns 0. NB currently only
716
* a stroke rendering mode is supported.
718
int pdf_modify_text_render_mode(pdf_text_state_t *pts, int render_mode)
720
switch (pts->in.render_mode) {
722
if (render_mode == 1) {
723
pts->in.render_mode = 2;
728
if (render_mode == 1)
732
if (render_mode == 1)
736
if (render_mode == 1) {
737
pts->in.render_mode = 1;
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if (render_mode == 1) {
743
pts->in.render_mode = 6;
748
if (render_mode == 1)
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if (render_mode == 1)
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if (render_mode == 1) {
757
pts->in.render_mode = 5;
added
removed
src/gdevpdts.c
