/* * wrap.c * * Text wrapping, hyphenation, justification and shaping * * Copyright © 2013 Thomas White * * This file is part of Colloquium. * * Colloquium is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . * */ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include #include #include "storycode.h" #include "wrap.h" #include "frame.h" #include "stylesheet.h" static void alloc_lines(struct frame *fr) { struct wrap_line *lines_new; lines_new = realloc(fr->lines, fr->max_lines * sizeof(struct wrap_line)); if ( lines_new == NULL ) { fprintf(stderr, "Couldn't allocate memory for lines!\n"); return; } fr->lines = lines_new; } static void alloc_boxes(struct wrap_line *l) { struct wrap_box *boxes_new; boxes_new = realloc(l->boxes, l->max_boxes * sizeof(struct wrap_box)); if ( boxes_new == NULL ) { fprintf(stderr, "Couldn't allocate memory for boxes!\n"); return; } l->boxes = boxes_new; } static void initialise_line(struct wrap_line *l) { l->n_boxes = 0; l->max_boxes = 32; l->boxes = NULL; l->width = 0; l->height = 0; l->ascent = 0; l->last_line = 0; l->overfull = 0; alloc_boxes(l); } void get_cursor_pos(struct frame *fr, size_t pos, double *xposd, double *yposd, double *line_height) { int line, box; signed int i; struct wrap_line *l; struct wrap_box *b; int p; int found = 0; *xposd = 0; *yposd = 0; line = 0; for ( i=0; in_lines; i++ ) { if ( fr->lines[i].sc_offset > pos ) { line = i-1; found = 1; break; } } if ( !found ) { /* Cursor is on the last line */ line = fr->n_lines-1; } assert(line >= 0); for ( i=0; ilines[i].height; } *line_height = pango_units_to_double(fr->lines[line].height); *yposd /= PANGO_SCALE; *yposd += fr->lop.pad_t; l = &fr->lines[line]; box = 0; for ( i=0; in_boxes-1; i++ ) { box = i; if ( l->boxes[i+1].type == WRAP_BOX_SENTINEL ) break; if ( l->boxes[i+1].sc_offset > pos ) break; *xposd += l->boxes[i].width; if ( i < l->n_boxes-2 ) { *xposd += l->boxes[i].sp; } } b = &l->boxes[box]; if ( b->type == WRAP_BOX_PANGO ) { pango_glyph_string_index_to_x(b->glyphs, b->text, strlen(b->text), &b->item->analysis, pos - b->sc_offset, FALSE, &p); //printf("offset %i in '%s' -> %i\n", // (int)pos-(int)b->sc_offset, b->text, p); *xposd += p; *xposd /= PANGO_SCALE; *xposd += fr->lop.pad_l; //printf("%i -> line %i, box %i -> %f, %f\n", // (int)pos, line, box, *xposd, *yposd); } else { } } #if 0 size_t find_cursor_pos(struct frame *fr, double xposd, double yposd) { int line, box; signed int i; struct wrap_line *l; struct wrap_box *b; int p; int found = 0; *xposd = 0; *yposd = 0; line = 0; for ( i=0; in_lines; i++ ) { if ( fr->lines[i].sc_offset > pos ) { line = i-1; found = 1; break; } } if ( !found ) { /* Cursor is on the last line */ line = fr->n_lines-1; } assert(line >= 0); for ( i=0; ilines[i].height; } *line_height = pango_units_to_double(fr->lines[line].height); *yposd /= PANGO_SCALE; *yposd += fr->lop.pad_t; l = &fr->lines[line]; box = 0; for ( i=0; in_boxes-1; i++ ) { box = i; if ( l->boxes[i+1].type == WRAP_BOX_SENTINEL ) break; if ( l->boxes[i+1].sc_offset > pos ) break; *xposd += l->boxes[i].width; if ( i < l->n_boxes-2 ) { *xposd += l->boxes[i].sp; } } b = &l->boxes[box]; if ( b->type == WRAP_BOX_PANGO ) { pango_glyph_string_index_to_x(b->glyphs, b->text, strlen(b->text), &b->item->analysis, pos - b->sc_offset, FALSE, &p); //printf("offset %i in '%s' -> %i\n", // (int)pos-(int)b->sc_offset, b->text, p); *xposd += p; *xposd /= PANGO_SCALE; *xposd += fr->lop.pad_l; //printf("%i -> line %i, box %i -> %f, %f\n", // (int)pos, line, box, *xposd, *yposd); } else { } } #endif static void shape_and_measure(gpointer data, gpointer user_data) { struct wrap_box *box = user_data; PangoItem *item = data; PangoRectangle rect; /* FIXME: Don't assume only one run per wrap box */ box->glyphs = pango_glyph_string_new(); box->item = item; pango_shape(box->text+item->offset, item->length, &item->analysis, box->glyphs); pango_glyph_string_extents(box->glyphs, box->font, NULL, &rect); box->width += rect.width; if ( rect.height > box->height ) { box->height = rect.height; } if ( PANGO_ASCENT(rect) > box->ascent ) { box->ascent = PANGO_ASCENT(rect); } } static void calc_line_geometry(struct wrap_line *line) { int i; line->width = 0; for ( i=0; in_boxes; i++ ) { struct wrap_box *box = &line->boxes[i]; line->width += box->width; line->width += box->sp; if ( box->height > line->height ) line->height = box->height; if ( box->ascent > line->ascent ) line->ascent = box->ascent; } } struct sc_font { PangoFontDescription *fontdesc; PangoFont *font; double col[4]; }; /* Add "text", followed by a space of type "space", to "line" */ static int add_wrap_box(struct wrap_line *line, char *text, size_t offset, enum wrap_box_space space, PangoContext *pc, struct sc_font *font) { GList *pango_items; struct wrap_box *box; PangoAttrList *attrs; PangoAttribute *attr; if ( line->n_boxes == line->max_boxes ) { line->max_boxes += 32; alloc_boxes(line); if ( line->n_boxes == line->max_boxes ) return 1; } box = &line->boxes[line->n_boxes]; box->sc_offset = offset; box->type = WRAP_BOX_PANGO; box->text = text; box->space = space; box->font = font->font; box->width = 0; box->ascent = 0; box->height = 0; box->col[0] = font->col[0]; /* Red */ box->col[1] = font->col[1]; /* Green */ box->col[2] = font->col[2]; /* Blue */ box->col[3] = font->col[3]; /* Alpha */ line->n_boxes++; if ( strlen(text) == 0 ) { box->type = WRAP_BOX_NOTHING; return 0; } attrs = pango_attr_list_new(); attr = pango_attr_font_desc_new(font->fontdesc); pango_attr_list_insert_before(attrs, attr); pango_items = pango_itemize(pc, text, 0, strlen(text), attrs, NULL); g_list_foreach(pango_items, shape_and_measure, box); g_list_free(pango_items); pango_attr_list_unref(attrs); return 0; } static int split_words(struct wrap_line *boxes, PangoContext *pc, char *sc, size_t sc_offset, PangoLanguage *lang, struct sc_font *font) { PangoLogAttr *log_attrs; size_t len; size_t i, start; /* Empty block? */ if ( sc == NULL ) return 1; len = strlen(sc); if ( len == 0 ) return 1; log_attrs = malloc((len+1)*sizeof(PangoLogAttr)); if ( log_attrs == NULL ) return 1; /* Create glyph string */ pango_get_log_attrs(sc, len, -1, lang, log_attrs, len+1); start = 0; for ( i=0; i0) && (sc[i-1] == '\n') ) len--; if ( (i>0) && (sc[i-1] == '\r') ) len--; } else if ( (i>0) && log_attrs[i-1].is_expandable_space ) { type = WRAP_SPACE_INTERWORD; len--; /* Not interested in spaces */ } else { type = WRAP_SPACE_NONE; } word = strndup(sc+start, len); if ( word == NULL ) { fprintf(stderr, "strndup() failed.\n"); free(log_attrs); return 1; } if ( add_wrap_box(boxes, word, start, type, pc, font) ) { fprintf(stderr, "Failed to add wrap box.\n"); } start = i; } } if ( i > start ) { char *word; word = strndup(sc+start, i-start); if ( word == NULL ) { fprintf(stderr, "strndup() failed.\n"); free(log_attrs); return 1; } if ( (word[i-start-1] == '\n') ) { /* There is a newline at the end of the SC */ char *word2; word2 = strndup(word, i-start-1); add_wrap_box(boxes, word2, start, WRAP_SPACE_EOP, pc, font); add_wrap_box(boxes, strdup(""), i, WRAP_SPACE_NONE, pc, font); } else { add_wrap_box(boxes, word, start, WRAP_SPACE_NONE, pc, font); } } free(log_attrs); return 0; } static void set_font(struct sc_font *scf, const char *font_name, PangoContext *pc) { scf->fontdesc = pango_font_description_from_string(font_name); if ( scf->fontdesc == NULL ) { fprintf(stderr, "Couldn't describe font.\n"); return; } scf->font = pango_font_map_load_font(pango_context_get_font_map(pc), pc, scf->fontdesc); if ( scf->font == NULL ) { fprintf(stderr, "Couldn't load font.\n"); return; } scf->col[0] = 0.0; scf->col[1] = 0.0; scf->col[2] = 0.0; scf->col[3] = 1.0; } static struct sc_font *push_font(struct sc_font *stack, const char *font_name, int *n_fonts, int *max_fonts, PangoContext *pc) { if ( *n_fonts == *max_fonts ) { struct sc_font *stack_new; stack_new = realloc(stack, sizeof(struct sc_font)*((*max_fonts)+8)); if ( stack_new == NULL ) { fprintf(stderr, "Failed to push font.\n"); return stack; } stack = stack_new; *max_fonts += 8; } set_font(&stack[*n_fonts], font_name, pc); (*n_fonts)++; return stack; } static void pop_font(struct sc_font *stack, int *n_fonts, int *max_fonts) { pango_font_description_free(stack[(*n_fonts)-1].fontdesc); (*n_fonts)--; } static void run_sc(const char *sc, struct sc_font *fonts, int *n_fonts, int *max_fonts, PangoContext *pc, struct wrap_line *boxes, PangoLanguage *lang) { SCBlockList *bl; SCBlockListIterator *iter; struct scblock *b; bl = sc_find_blocks(sc, NULL); if ( bl == NULL ) { printf("Failed to find blocks.\n"); return; } for ( b = sc_block_list_first(bl, &iter); b != NULL; b = sc_block_list_next(bl, iter) ) { if ( b->name == NULL ) { if ( split_words(boxes, pc, b->contents, b->offset, lang, &fonts[(*n_fonts)-1]) ) { fprintf(stderr, "Splitting failed.\n"); } } else if ( (strcmp(b->name, "font")==0) && (b->contents == NULL) ) { set_font(&fonts[(*n_fonts)-1], b->options, pc); } else if ( (strcmp(b->name, "font")==0) && (b->contents != NULL) ) { push_font(fonts, b->options, n_fonts, max_fonts, pc); run_sc(b->contents, fonts, n_fonts, max_fonts, pc, boxes, lang); pop_font(fonts, n_fonts, max_fonts); } /* FIXME: Handle images */ } sc_block_list_free(bl); } static struct wrap_line *sc_to_wrap_boxes(const char *sc, const char *prefix, PangoContext *pc) { struct wrap_line *boxes; PangoLanguage *lang; struct sc_font *fonts; int n_fonts, max_fonts; int i; boxes = malloc(sizeof(struct wrap_line)); if ( boxes == NULL ) { fprintf(stderr, "Failed to allocate boxes.\n"); return NULL; } initialise_line(boxes); fonts = NULL; n_fonts = 0; max_fonts = 0; /* FIXME: Determine proper language (somehow...) */ lang = pango_language_from_string("en_GB"); /* The "ultimate" default font */ fonts = push_font(fonts, "Sans 12", &n_fonts, &max_fonts, pc); if ( prefix != NULL ) { run_sc(prefix, fonts, &n_fonts, &max_fonts, pc, boxes, lang); } run_sc(sc, fonts, &n_fonts, &max_fonts, pc, boxes, lang); for ( i=0; i line_length ) { r = rho*(line_length - sigma_prime) / (sigma_prime - sigma_prime_min); } else { r = 0.0; } d = s[j] + pow(1.0 + 100.0 * pow(abs(r),3.0), 2.0); if ( d < *dprime ) { *dprime = d; *jprime = j; } } static double width(struct wrap_line *boxes, int i) { /* Indices in Knuth paper go from 1...n. Indices in array go * from 0...n-1 */ return boxes->boxes[i-1].width; } static enum wrap_box_space space(struct wrap_line *boxes, int i) { /* Indices in Knuth paper go from 1...n. Indices in array go * from 0...n-1 */ return boxes->boxes[i-1].space; } static void distribute_spaces(struct wrap_line *line, double l, double rho) { int i; double L, Y, Z, r; int overfull = 0; int underfull = 0; l = pango_units_from_double(l); L = 0.0; Y = 0.0; Z = 0.0; for ( i=0; in_boxes-1; i++ ) { L += line->boxes[i].width; L += sp_x(line->boxes[i].space); Y += sp_y(line->boxes[i].space); Z += sp_z(line->boxes[i].space); } L += line->boxes[line->n_boxes-1].width; if ( L < l ) { r = (l - L)/Y; } else if ( L > l ) { r = (l - L)/Z; } else { r = 0.0; } if ( r >= 0.0 ) { for ( i=0; in_boxes-1; i++ ) { line->boxes[i].sp = sp_x(line->boxes[i].space); line->boxes[i].sp += r*sp_y(line->boxes[i].space); } } else { for ( i=0; in_boxes-1; i++ ) { line->boxes[i].sp = sp_x(line->boxes[i].space); line->boxes[i].sp += r*sp_z(line->boxes[i].space); } } line->boxes[line->n_boxes-1].sp = 0.0; line->overfull = overfull; line->underfull = underfull; } static void output_line(int q, int s, struct frame *fr, struct wrap_line *boxes) { struct wrap_line *l; int j; l = &fr->lines[fr->n_lines]; fr->n_lines++; initialise_line(l); l->max_boxes = s-q; alloc_boxes(l); l->sc_offset = boxes->boxes[q].sc_offset; for ( j=q; jboxes[l->n_boxes++] = boxes->boxes[j]; } } static void output(int a, int i, int *p, struct frame *fr, struct wrap_line *boxes) { int q = i; int r; int s = 0; if ( fr->n_lines + (i-a) + 1 > fr->max_lines ) { fr->max_lines += 32; alloc_lines(fr); if ( fr->n_lines == fr->max_lines ) return; } while ( q != a ) { r = p[q]; p[q] = s; s = q; q = r; } while ( q != i ) { output_line(q, s, fr, boxes); q = s; s = p[q]; } } /* This is the "suboptimal fit" algorithm from Knuth and Plass, Software - * Practice and Experience 11 (1981) p1119-1184. Despite the name, it's * supposed to work as well as the full TeX algorithm in almost all of the cases * that we care about here. */ static void knuth_suboptimal_fit(struct wrap_line *boxes, double line_length, struct frame *fr, double rho) { int a = 0; int *p; double *s; struct wrap_box *box; int j; double sigma_prime, sigma_max_prime, sigma_min_prime; double dprime; int n; int reject; n = boxes->n_boxes; /* Set the space for the last box to be "end of paragraph" */ boxes->boxes[boxes->n_boxes-1].space = WRAP_SPACE_EOP; /* Add empty zero-width box at end */ if ( boxes->n_boxes == boxes->max_boxes ) { boxes->max_boxes += 32; alloc_boxes(boxes); if ( boxes->n_boxes == boxes->max_boxes ) return; } box = &boxes->boxes[boxes->n_boxes]; box->type = WRAP_BOX_SENTINEL; box->text = NULL; box->space = WRAP_SPACE_NONE; box->font = NULL; box->width = 0; box->ascent = 0; box->height = 0; boxes->n_boxes++; line_length *= PANGO_SCALE; reject = 0; for ( j=0; jn_boxes; j++ ) { if ( boxes->boxes[j].width > line_length ) { fprintf(stderr, "ERROR: Box %i too long (%i %f)\n", j, boxes->boxes[j].width, line_length); reject = 1; } } if ( reject ) return; p = malloc((n+2) * sizeof(int)); /* p[0]..p[n+1] inclusive */ if ( p == NULL ) { fprintf(stderr, "Failed to allocate p_k\n"); return; } s = malloc((n+2) * sizeof(double)); /* s[0]..s[n+1] inclusive */ if ( s == NULL ) { fprintf(stderr, "Failed to allocate s_k\n"); return; } do { int i = a; int k = i+1; double sigma = width(boxes, k); double sigma_min = sigma; double sigma_max = sigma; int m = 1; int jprime = 999; s[i] = 0; do { while ( sigma_min > line_length ) { /* Begin */ if ( s[i] < INFINITY ) m--; i++; sigma -= width(boxes, i); sigma -= sp_z(space(boxes, i)); sigma_max -= width(boxes, i); sigma_max -= sp_yp(space(boxes, i), rho); sigma_min -= width(boxes, i); sigma_min -= sp_zp(space(boxes, i)); /* End */ } /* Begin */ j = i; sigma_prime = sigma; sigma_max_prime = sigma_max; sigma_min_prime = sigma_min; dprime = INFINITY; while ( sigma_max_prime >= line_length ) { if ( s[j] < INFINITY ) { consider_break(sigma_prime, sigma_max_prime, sigma_min_prime, line_length, s, j, &dprime, &jprime, rho); } j++; sigma_prime -= width(boxes, j); sigma_prime -= sp_x(space(boxes, j)); sigma_max_prime -= width(boxes, j); sigma_max_prime -= sp_yp(space(boxes, j), rho); sigma_min_prime -= width(boxes, j); sigma_min_prime -= sp_zp(space(boxes, j)); } /* End */ s[k] = dprime; if ( dprime < INFINITY ) { m++; p[k] = jprime; } if ( (m == 0) || (k > n) ) break; sigma += width(boxes, k+1); sigma += sp_x(space(boxes, k)); sigma_max += width(boxes, k+1); sigma_max += sp_yp(space(boxes, k), rho); sigma_min += width(boxes, k+1); sigma_min += sp_zp(space(boxes, k)); k++; } while ( 1 ); if ( k > n ) { output(a, n+1, p, fr, boxes); break; } else { /* Begin */ do { sigma += width(boxes, i); sigma += sp_x(space(boxes, i)); sigma_max += width(boxes, i); sigma_max += sp_yp(space(boxes, i), rho); sigma_min += width(boxes, i); sigma_min += sp_zp(space(boxes, i)); i--; } while ( s[i] >= INFINITY ); output(a, i, p, fr, boxes); /* Begin */ jprime = 0; dprime = INFINITY; /* Test hyphenation points here */ /* End */ /* Begin */ output_line(i, k-1, fr, boxes); /* End */ /* End */ a = k-1; } } while ( 1 ); fr->lines[fr->n_lines-1].last_line = 1; free(p); free(s); } void wrap_line_free(struct wrap_line *l) { int i; for ( i=0; in_boxes; i++ ) { switch ( l->boxes[i].type ) { case WRAP_BOX_PANGO : pango_glyph_string_free(l->boxes[i].glyphs); pango_item_free(l->boxes[i].item); free(l->boxes[i].text); break; case WRAP_BOX_IMAGE : break; case WRAP_BOX_NOTHING : case WRAP_BOX_SENTINEL : break; } } free(l->boxes); } static struct wrap_line *split_paragraph(struct wrap_line *boxes, int *n) { int i; int start = *n; int end; if ( start >= boxes->n_boxes ) return NULL; for ( i=start; in_boxes; i++ ) { if ( boxes->boxes[i].space == WRAP_SPACE_EOP ) { break; } } end = i + 1; *n = end; if ( i == boxes->n_boxes ) end--; if ( end-start > 0 ) { struct wrap_line *para; para = malloc(sizeof(struct wrap_line)); para->boxes = NULL; para->max_boxes = end-start; para->n_boxes = end-start; alloc_boxes(para); for ( i=start; iboxes[i-start] = boxes->boxes[i]; } return para; } return NULL; } /* Wrap the StoryCode inside "fr->sc" so that it fits within width "fr->w", * and generate fr->lines */ int wrap_contents(struct frame *fr, PangoContext *pc) { struct wrap_line *boxes; struct wrap_line *para; int i; const double rho = 2.0; const double wrap_w = fr->w - fr->lop.pad_l - fr->lop.pad_r; char *prologue; if ( fr->style != NULL ) { prologue = fr->style->sc_prologue; } else { prologue = NULL; } /* Turn the StoryCode into wrap boxes, all on one line */ boxes = sc_to_wrap_boxes(fr->sc, prologue, pc); if ( boxes == NULL ) { fprintf(stderr, "Failed to create wrap boxes.\n"); return 1; } /* Clear lines */ fr->n_lines = 0; fr->max_lines = 32; fr->lines = NULL; alloc_lines(fr); /* Split text into paragraphs */ i = 0; do { para = split_paragraph(boxes, &i); /* Split paragraphs into lines */ if ( para != NULL ) { knuth_suboptimal_fit(para, wrap_w, fr, rho); free(para->boxes); free(para); } } while ( para != NULL ); free(boxes->boxes); free(boxes); for ( i=0; in_lines; i++ ) { distribute_spaces(&fr->lines[i], wrap_w, rho); calc_line_geometry(&fr->lines[i]); } return 0; }