1 files changed, 78 insertions, 5 deletions

diff --git a/libass/ass_shaper.c b/libass/ass_shaper.c
index 6efc177..911732c 100644
--- a/libass/ass_shaper.c
+++ b/libass/ass_shaper.c
@@ -17,17 +17,20 @@
  */
 
 #include <fribidi/fribidi.h>
+#include <hb-ft.h>
 
 #include "ass_render.h"
 #include "ass_shaper.h"
 
+#define MAX_RUNS 30
+
 /**
  * \brief Print version information
  */
 void ass_shaper_info(ASS_Library *lib)
 {
     ass_msg(lib, MSGL_V, "Complex text layout enabled, using FriBidi "
-            FRIBIDI_VERSION);
+            FRIBIDI_VERSION " HarfBuzz-ng %s", hb_version_string());
 }
 
 /**
@@ -39,11 +42,18 @@ void ass_shaper_info(ASS_Library *lib)
 void ass_shaper_shape(TextInfo *text_info, FriBidiCharType *ctypes,
                       FriBidiLevel *emblevels)
 {
-    int i, last_break;
+    int i, j, last_break;
     FriBidiParType dir;
     FriBidiChar *event_text = calloc(sizeof(*event_text), text_info->length);
     FriBidiJoiningType *joins = calloc(sizeof(*joins), text_info->length);
     GlyphInfo *glyphs = text_info->glyphs;
+    // XXX: dynamically allocate
+    struct {
+        int offset;
+        int end;
+        hb_buffer_t *buf;
+        hb_font_t *font;
+    } runs[MAX_RUNS];
 
     // Get bidi character types and embedding levels
     last_break = 0;
@@ -61,26 +71,89 @@ void ass_shaper_shape(TextInfo *text_info, FriBidiCharType *ctypes,
         }
     }
 
+    // add embedding levels to shape runs for final runs
+    for (i = 0; i < text_info->length; i++) {
+        glyphs[i].shape_run_id += emblevels[i];
+    }
+
 #if 0
     printf("levels ");
     for (i = 0; i < text_info->length; i++) {
-        printf("%d:%d ", ctypes[i], emblevels[i]);
+        printf("%d ", glyphs[i].shape_run_id);
     }
     printf("\n");
 #endif
 
+#if 0
     // Use FriBidi's shaper for mirroring and simple Arabic shaping
     fribidi_get_joining_types(event_text, text_info->length, joins);
     fribidi_join_arabic(ctypes, text_info->length, emblevels, joins);
     fribidi_shape(FRIBIDI_FLAGS_DEFAULT | FRIBIDI_FLAGS_ARABIC, emblevels,
             text_info->length, joins, event_text);
+#endif
+
+    // Shape runs with HarfBuzz-ng
+    int run = 0;
+    for (i = 0; i < text_info->length && run < MAX_RUNS; i++, run++) {
+        // get length and level of the current run
+        int k = i;
+        int level = glyphs[i].shape_run_id;
+        while (i < (text_info->length - 1) && level == glyphs[i+1].shape_run_id)
+            i++;
+        //printf("run %d from %d to %d with level %d\n", run, k, i, level);
+        FT_Face run_font = glyphs[k].font->faces[glyphs[k].face_index];
+        runs[run].offset = k;
+        runs[run].end    = i;
+        runs[run].buf    = hb_buffer_create(i - k + 1);
+        runs[run].font   = hb_ft_font_create(run_font, NULL);
+        hb_buffer_set_direction(runs[run].buf, (level % 2) ? HB_DIRECTION_RTL :
+                HB_DIRECTION_LTR);
+        hb_buffer_add_utf32(runs[run].buf, event_text + k, i - k + 1,
+                0, i - k + 1);
+        hb_shape(runs[run].font, runs[run].buf, NULL, 0);
+    }
+    //printf("shaped %d runs\n", run);
 
-    // XXX: insert HarfBuzz shaper here
+    // Initialize: skip all glyphs, this is undone later as needed
+    for (i = 0; i < text_info->length; i++)
+        glyphs[i].skip = 1;
+
+    // Update glyph indexes, positions and advances from the shaped runs
+    for (i = 0; i < run; i++) {
+        int num_glyphs = hb_buffer_get_length(runs[i].buf);
+        hb_glyph_info_t *glyph_info = hb_buffer_get_glyph_infos(runs[i].buf, NULL);
+        hb_glyph_position_t *pos    = hb_buffer_get_glyph_positions(runs[i].buf, NULL);
+        //printf("run text len %d num_glyphs %d\n", runs[i].end - runs[i].offset + 1,
+        //        num_glyphs);
+        // Update glyphs
+        for (j = 0; j < num_glyphs; j++) {
+            int idx = glyph_info[j].cluster + runs[i].offset;
+#if 0
+            printf("run %d cluster %d codepoint %d -> '%c'\n", i, idx,
+                    glyph_info[j].codepoint, event_text[idx]);
+            printf("position %d %d advance %d %d\n",
+                    pos[j].x_offset, pos[j].y_offset,
+                    pos[j].x_advance, pos[j].y_advance);
+#endif
+            glyphs[idx].skip = 0;
+            glyphs[idx].glyph_index = glyph_info[j].codepoint;
+            glyphs[idx].offset.x    = pos[j].x_offset * glyphs[idx].scale_x;
+            glyphs[idx].offset.y    = pos[j].y_offset * glyphs[idx].scale_y;
+            glyphs[idx].advance.x   = pos[j].x_advance * glyphs[idx].scale_x;
+            glyphs[idx].advance.y   = pos[j].y_advance * glyphs[idx].scale_y;
+        }
+    }
+
+    // Free runs and associated data
+    for (i = 0; i < run; i++) {
+        hb_buffer_destroy(runs[i].buf);
+        hb_font_destroy(runs[i].font);
+    }
 
     // Update glyphs
     for (i = 0; i < text_info->length; i++) {
         glyphs[i].symbol = event_text[i];
-        // Skip direction override characters
+        // Skip direction override control characters
         // NOTE: Behdad said HarfBuzz is supposed to remove these, but this hasn't
         // been implemented yet
         if (glyphs[i].symbol <= 0x202F && glyphs[i].symbol >= 0x202a) {