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-rw-r--r--libass/ass_drawing.c495
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diff --git a/libass/ass_drawing.c b/libass/ass_drawing.c
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+/*
+ * Copyright (C) 2009 Grigori Goronzy <greg@geekmind.org>
+ *
+ * This file is part of libass.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <ft2build.h>
+#include FT_GLYPH_H
+#include FT_OUTLINE_H
+#include FT_BBOX_H
+#include <math.h>
+
+#include "ass_utils.h"
+#include "ass_font.h"
+#include "ass_drawing.h"
+
+#define CURVE_ACCURACY 64.0
+#define GLYPH_INITIAL_POINTS 100
+#define GLYPH_INITIAL_CONTOURS 5
+
+/*
+ * \brief Get and prepare a FreeType glyph
+ */
+static void drawing_make_glyph(ASS_Drawing *drawing, void *fontconfig_priv,
+ ASS_Font *font, ASS_Hinting hint)
+{
+ FT_OutlineGlyph glyph;
+
+ // This is hacky...
+ glyph = (FT_OutlineGlyph) ass_font_get_glyph(fontconfig_priv, font,
+ (uint32_t) ' ', hint, 0);
+ if (glyph) {
+ FT_Outline_Done(drawing->ftlibrary, &glyph->outline);
+ FT_Outline_New(drawing->ftlibrary, GLYPH_INITIAL_POINTS,
+ GLYPH_INITIAL_CONTOURS, &glyph->outline);
+
+ glyph->outline.n_contours = 0;
+ glyph->outline.n_points = 0;
+ glyph->root.advance.x = glyph->root.advance.y = 0;
+ }
+ drawing->glyph = glyph;
+}
+
+/*
+ * \brief Add a single point to a contour.
+ */
+static inline void drawing_add_point(ASS_Drawing *drawing,
+ FT_Vector *point)
+{
+ FT_Outline *ol = &drawing->glyph->outline;
+
+ if (ol->n_points >= drawing->max_points) {
+ drawing->max_points *= 2;
+ ol->points = realloc(ol->points, sizeof(FT_Vector) *
+ drawing->max_points);
+ ol->tags = realloc(ol->tags, drawing->max_points);
+ }
+
+ ol->points[ol->n_points].x = point->x;
+ ol->points[ol->n_points].y = point->y;
+ ol->tags[ol->n_points] = 1;
+ ol->n_points++;
+}
+
+/*
+ * \brief Close a contour and check glyph size overflow.
+ */
+static inline void drawing_close_shape(ASS_Drawing *drawing)
+{
+ FT_Outline *ol = &drawing->glyph->outline;
+
+ if (ol->n_contours >= drawing->max_contours) {
+ drawing->max_contours *= 2;
+ ol->contours = realloc(ol->contours, sizeof(short) *
+ drawing->max_contours);
+ }
+
+ if (ol->n_points) {
+ ol->contours[ol->n_contours] = ol->n_points - 1;
+ ol->n_contours++;
+ }
+}
+
+/*
+ * \brief Prepare drawing for parsing. This just sets a few parameters.
+ */
+static void drawing_prepare(ASS_Drawing *drawing)
+{
+ // Scaling parameters
+ drawing->point_scale_x = drawing->scale_x *
+ 64.0 / (1 << (drawing->scale - 1));
+ drawing->point_scale_y = drawing->scale_y *
+ 64.0 / (1 << (drawing->scale - 1));
+}
+
+/*
+ * \brief Finish a drawing. This only sets the horizontal advance according
+ * to the glyph's bbox at the moment.
+ */
+static void drawing_finish(ASS_Drawing *drawing, int raw_mode)
+{
+ int i, offset;
+ FT_BBox bbox;
+ FT_Outline *ol = &drawing->glyph->outline;
+
+ // Close the last contour
+ drawing_close_shape(drawing);
+
+#if 0
+ // Dump points
+ for (i = 0; i < ol->n_points; i++) {
+ printf("point (%d, %d)\n", (int) ol->points[i].x,
+ (int) ol->points[i].y);
+ }
+
+ // Dump contours
+ for (i = 0; i < ol->n_contours; i++)
+ printf("contour %d\n", ol->contours[i]);
+#endif
+
+ ass_msg(drawing->library, MSGL_V,
+ "Parsed drawing with %d points and %d contours", ol->n_points,
+ ol->n_contours);
+
+ if (raw_mode)
+ return;
+
+ FT_Outline_Get_CBox(&drawing->glyph->outline, &bbox);
+ drawing->glyph->root.advance.x = d6_to_d16(bbox.xMax - bbox.xMin);
+
+ drawing->desc = double_to_d6(-drawing->pbo * drawing->scale_y);
+ drawing->asc = bbox.yMax - bbox.yMin + drawing->desc;
+
+ // Place it onto the baseline
+ offset = (bbox.yMax - bbox.yMin) + double_to_d6(-drawing->pbo *
+ drawing->scale_y);
+ for (i = 0; i < ol->n_points; i++)
+ ol->points[i].y += offset;
+}
+
+/*
+ * \brief Check whether a number of items on the list is available
+ */
+static int token_check_values(ASS_DrawingToken *token, int i, int type)
+{
+ int j;
+ for (j = 0; j < i; j++) {
+ if (!token || token->type != type) return 0;
+ token = token->next;
+ }
+
+ return 1;
+}
+
+/*
+ * \brief Tokenize a drawing string into a list of ASS_DrawingToken
+ * This also expands points for closing b-splines
+ */
+static ASS_DrawingToken *drawing_tokenize(char *str)
+{
+ char *p = str;
+ int i, val, type = -1, is_set = 0;
+ FT_Vector point = {0, 0};
+
+ ASS_DrawingToken *root = NULL, *tail = NULL, *spline_start = NULL;
+
+ while (*p) {
+ if (*p == 'c' && spline_start) {
+ // Close b-splines: add the first three points of the b-spline
+ // back to the end
+ if (token_check_values(spline_start->next, 2, TOKEN_B_SPLINE)) {
+ for (i = 0; i < 3; i++) {
+ tail->next = calloc(1, sizeof(ASS_DrawingToken));
+ tail->next->prev = tail;
+ tail = tail->next;
+ tail->type = TOKEN_B_SPLINE;
+ tail->point = spline_start->point;
+ spline_start = spline_start->next;
+ }
+ spline_start = NULL;
+ }
+ } else if (!is_set && mystrtoi(&p, &val)) {
+ point.x = val;
+ is_set = 1;
+ p--;
+ } else if (is_set == 1 && mystrtoi(&p, &val)) {
+ point.y = val;
+ is_set = 2;
+ p--;
+ } else if (*p == 'm')
+ type = TOKEN_MOVE;
+ else if (*p == 'n')
+ type = TOKEN_MOVE_NC;
+ else if (*p == 'l')
+ type = TOKEN_LINE;
+ else if (*p == 'b')
+ type = TOKEN_CUBIC_BEZIER;
+ else if (*p == 'q')
+ type = TOKEN_CONIC_BEZIER;
+ else if (*p == 's')
+ type = TOKEN_B_SPLINE;
+ // We're simply ignoring TOKEN_EXTEND_B_SPLINE here.
+ // This is not harmful at all, since it can be ommitted with
+ // similar result (the spline is extended anyway).
+
+ if (type != -1 && is_set == 2) {
+ if (root) {
+ tail->next = calloc(1, sizeof(ASS_DrawingToken));
+ tail->next->prev = tail;
+ tail = tail->next;
+ } else
+ root = tail = calloc(1, sizeof(ASS_DrawingToken));
+ tail->type = type;
+ tail->point = point;
+ is_set = 0;
+ if (type == TOKEN_B_SPLINE && !spline_start)
+ spline_start = tail->prev;
+ }
+ p++;
+ }
+
+#if 0
+ // Check tokens
+ ASS_DrawingToken *t = root;
+ while(t) {
+ printf("token %d point (%d, %d)\n", t->type, t->point.x, t->point.y);
+ t = t->next;
+ }
+#endif
+
+ return root;
+}
+
+/*
+ * \brief Free a list of tokens
+ */
+static void drawing_free_tokens(ASS_DrawingToken *token)
+{
+ while (token) {
+ ASS_DrawingToken *at = token;
+ token = token->next;
+ free(at);
+ }
+}
+
+/*
+ * \brief Translate and scale a point coordinate according to baseline
+ * offset and scale.
+ */
+static inline void translate_point(ASS_Drawing *drawing, FT_Vector *point)
+{
+ point->x = drawing->point_scale_x * point->x;
+ point->y = drawing->point_scale_y * -point->y;
+}
+
+/*
+ * \brief Evaluate a curve into lines
+ * This curve evaluator is also used in VSFilter (RTS.cpp); it's a simple
+ * implementation of the De Casteljau algorithm.
+ */
+static void drawing_evaluate_curve(ASS_Drawing *drawing,
+ ASS_DrawingToken *token, char spline,
+ int started)
+{
+ double cx3, cx2, cx1, cx0, cy3, cy2, cy1, cy0;
+ double t, h, max_accel, max_accel1, max_accel2;
+ FT_Vector cur = {0, 0};
+
+ cur = token->point;
+ translate_point(drawing, &cur);
+ int x0 = cur.x;
+ int y0 = cur.y;
+ token = token->next;
+ cur = token->point;
+ translate_point(drawing, &cur);
+ int x1 = cur.x;
+ int y1 = cur.y;
+ token = token->next;
+ cur = token->point;
+ translate_point(drawing, &cur);
+ int x2 = cur.x;
+ int y2 = cur.y;
+ token = token->next;
+ cur = token->point;
+ translate_point(drawing, &cur);
+ int x3 = cur.x;
+ int y3 = cur.y;
+
+ if (spline) {
+ // 1 [-1 +3 -3 +1]
+ // - * [+3 -6 +3 0]
+ // 6 [-3 0 +3 0]
+ // [+1 +4 +1 0]
+
+ double div6 = 1.0/6.0;
+
+ cx3 = div6*(- x0+3*x1-3*x2+x3);
+ cx2 = div6*( 3*x0-6*x1+3*x2);
+ cx1 = div6*(-3*x0 +3*x2);
+ cx0 = div6*( x0+4*x1+1*x2);
+
+ cy3 = div6*(- y0+3*y1-3*y2+y3);
+ cy2 = div6*( 3*y0-6*y1+3*y2);
+ cy1 = div6*(-3*y0 +3*y2);
+ cy0 = div6*( y0+4*y1+1*y2);
+ } else {
+ // [-1 +3 -3 +1]
+ // [+3 -6 +3 0]
+ // [-3 +3 0 0]
+ // [+1 0 0 0]
+
+ cx3 = - x0+3*x1-3*x2+x3;
+ cx2 = 3*x0-6*x1+3*x2;
+ cx1 = -3*x0+3*x1;
+ cx0 = x0;
+
+ cy3 = - y0+3*y1-3*y2+y3;
+ cy2 = 3*y0-6*y1+3*y2;
+ cy1 = -3*y0+3*y1;
+ cy0 = y0;
+ }
+
+ max_accel1 = fabs(2 * cy2) + fabs(6 * cy3);
+ max_accel2 = fabs(2 * cx2) + fabs(6 * cx3);
+
+ max_accel = FFMAX(max_accel1, max_accel2);
+ h = 1.0;
+
+ if (max_accel > CURVE_ACCURACY)
+ h = sqrt(CURVE_ACCURACY / max_accel);
+
+ if (!started) {
+ cur.x = cx0;
+ cur.y = cy0;
+ drawing_add_point(drawing, &cur);
+ }
+
+ for (t = 0; t < 1.0; t += h) {
+ cur.x = cx0 + t * (cx1 + t * (cx2 + t * cx3));
+ cur.y = cy0 + t * (cy1 + t * (cy2 + t * cy3));
+ drawing_add_point(drawing, &cur);
+ }
+
+ cur.x = cx0 + cx1 + cx2 + cx3;
+ cur.y = cy0 + cy1 + cy2 + cy3;
+ drawing_add_point(drawing, &cur);
+}
+
+/*
+ * \brief Create and initialize a new drawing and return it
+ */
+ASS_Drawing *ass_drawing_new(void *fontconfig_priv, ASS_Font *font,
+ ASS_Hinting hint, FT_Library lib)
+{
+ ASS_Drawing *drawing;
+
+ drawing = calloc(1, sizeof(*drawing));
+ drawing->text = calloc(1, DRAWING_INITIAL_SIZE);
+ drawing->size = DRAWING_INITIAL_SIZE;
+
+ drawing->ftlibrary = lib;
+ if (font) {
+ drawing->library = font->library;
+ drawing_make_glyph(drawing, fontconfig_priv, font, hint);
+ }
+
+ drawing->scale_x = 1.;
+ drawing->scale_y = 1.;
+ drawing->max_contours = GLYPH_INITIAL_CONTOURS;
+ drawing->max_points = GLYPH_INITIAL_POINTS;
+
+ return drawing;
+}
+
+/*
+ * \brief Free a drawing
+ */
+void ass_drawing_free(ASS_Drawing* drawing)
+{
+ if (drawing) {
+ if (drawing->glyph)
+ FT_Done_Glyph((FT_Glyph) drawing->glyph);
+ free(drawing->text);
+ }
+ free(drawing);
+}
+
+/*
+ * \brief Add one ASCII character to the drawing text buffer
+ */
+void ass_drawing_add_char(ASS_Drawing* drawing, char symbol)
+{
+ drawing->text[drawing->i++] = symbol;
+ drawing->text[drawing->i] = 0;
+
+ if (drawing->i + 1 >= drawing->size) {
+ drawing->size *= 2;
+ drawing->text = realloc(drawing->text, drawing->size);
+ }
+}
+
+/*
+ * \brief Create a hashcode for the drawing
+ * XXX: To avoid collisions a better hash algorithm might be useful.
+ */
+void ass_drawing_hash(ASS_Drawing* drawing)
+{
+ drawing->hash = fnv_32a_str(drawing->text, FNV1_32A_INIT);
+}
+
+/*
+ * \brief Convert token list to outline. Calls the line and curve evaluators.
+ */
+FT_OutlineGlyph *ass_drawing_parse(ASS_Drawing *drawing, int raw_mode)
+{
+ int started = 0;
+ ASS_DrawingToken *token;
+ FT_Vector pen = {0, 0};
+
+ if (!drawing->glyph)
+ return NULL;
+
+ drawing->tokens = drawing_tokenize(drawing->text);
+ drawing_prepare(drawing);
+
+ token = drawing->tokens;
+ while (token) {
+ // Draw something according to current command
+ switch (token->type) {
+ case TOKEN_MOVE_NC:
+ pen = token->point;
+ translate_point(drawing, &pen);
+ token = token->next;
+ break;
+ case TOKEN_MOVE:
+ pen = token->point;
+ translate_point(drawing, &pen);
+ if (started) {
+ drawing_close_shape(drawing);
+ started = 0;
+ }
+ token = token->next;
+ break;
+ case TOKEN_LINE: {
+ FT_Vector to;
+ to = token->point;
+ translate_point(drawing, &to);
+ if (!started) drawing_add_point(drawing, &pen);
+ drawing_add_point(drawing, &to);
+ started = 1;
+ token = token->next;
+ break;
+ }
+ case TOKEN_CUBIC_BEZIER:
+ if (token_check_values(token, 3, TOKEN_CUBIC_BEZIER) &&
+ token->prev) {
+ drawing_evaluate_curve(drawing, token->prev, 0, started);
+ token = token->next;
+ token = token->next;
+ token = token->next;
+ started = 1;
+ } else
+ token = token->next;
+ break;
+ case TOKEN_B_SPLINE:
+ if (token_check_values(token, 3, TOKEN_B_SPLINE) &&
+ token->prev) {
+ drawing_evaluate_curve(drawing, token->prev, 1, started);
+ token = token->next;
+ started = 1;
+ } else
+ token = token->next;
+ break;
+ default:
+ token = token->next;
+ break;
+ }
+ }
+
+ drawing_finish(drawing, raw_mode);
+ drawing_free_tokens(drawing->tokens);
+ return &drawing->glyph;
+}
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