support threading with Imager's Freetype 1.x driver

This creates a new engine for each perl thread, which is meant to be
enough to be thread safe.

diff --git a/Imager.xs b/Imager.xs
index 58775f4a657ac53c7e1f60ad0e606ba43b51ee0b..81918e8e888ffa79dab99fc31fd8687ae648914c 100644 (file)
--- a/Imager.xs
+++ b/Imager.xs
@@ -4082,3 +4082,6 @@ BOOT:
 #endif
        start_context(aTHX);
        im_get_context = perl_get_context;
+#ifdef HAVE_LIBTT
+        i_tt_start();
+#endif

diff --git a/fontft1.c b/fontft1.c
index 7febeede9287dc6a7cae37104ae83a736f73d150..e0332f1262aa5a4c003971387d25322c7951022f 100644 (file)
--- a/fontft1.c
+++ b/fontft1.c
@@ -66,9 +66,16 @@ Some of these functions are internal.
 #define TT_MS_LANGID_ENGLISH_GENERAL 0x0409
 #endif
 
+static im_slot_t slot = -1;
+
 /* convert a code point into an index in the glyph cache */
 #define TT_HASH(x) ((x) & 0xFF)
 
+typedef struct {
+  int initialized;
+  TT_Engine engine;
+} i_tt_engine;
+
 typedef struct i_glyph_entry_ {
   TT_Glyph glyph;
   unsigned long ch;
@@ -105,6 +112,7 @@ struct TT_Fonthandle_ {
 #define TT_VALID( handle )  ( ( handle ).z != NULL )
 
 static void i_tt_push_error(TT_Error rc);
+static void i_tt_uninit(void *);
 
 /* Prototypes */
 
@@ -132,8 +140,6 @@ static undef_int i_tt_bbox_inst( TT_Fonthandle *handle, int inst ,const char *tx
 
 /* static globals needed */
 
-static int TT_initialized = 0;
-static TT_Engine    engine;
 static int  LTT_dpi    = 72; /* FIXME: this ought to be a part of the call interface */
 static int  LTT_hinted = 1;  /* FIXME: this too */
 
@@ -142,58 +148,91 @@ static int  LTT_hinted = 1;  /* FIXME: this too */
  * FreeType interface
  */
 
+void
+i_tt_start(void) {
+  im_context_t ctx = im_get_context();
+  if (slot == -1)
+    slot = im_context_slot_new(i_tt_uninit);
+}
+
 
 /*
 =item init_tt()
 
-Initializes the freetype font rendering engine
+Initializes the freetype font rendering engine (if needed)
 
 =cut
 */
 
-static undef_int
+static i_tt_engine *
 i_init_tt(void) {
   TT_Error  error;
+  im_context_t ctx = im_get_context();
   TT_Byte palette[] = { 0, 64, 127, 191, 255 };
+  i_tt_engine *result = im_context_slot_get(ctx, slot);
 
   i_clear_error();
 
+  if (result == NULL) {
+    result = mymalloc(sizeof(i_tt_engine));
+    memset(result, 0, sizeof(*result));
+    im_context_slot_set(ctx, slot, result);
+    mm_log((1, "allocated FT1 state %p\n", result));
+  }
+
   mm_log((1,"init_tt()\n"));
-  error = TT_Init_FreeType( &engine );
+
+  if (result->initialized)
+    return result;
+
+  error = TT_Init_FreeType( &result->engine );
   if ( error ){
     mm_log((1,"Initialization of freetype failed, code = 0x%x\n",
            (unsigned)error));
     i_tt_push_error(error);
     i_push_error(0, "Could not initialize freetype 1.x");
-    return(1);
+    return NULL;
   }
 
 #ifdef FTXPOST
-  error = TT_Init_Post_Extension( engine );
+  error = TT_Init_Post_Extension( result->engine );
   if (error) {
     mm_log((1, "Initialization of Post extension failed = 0x%x\n",
            (unsigned)error));
     
     i_tt_push_error(error);
     i_push_error(0, "Could not initialize FT 1.x POST extension");
-    return 1;
+    return NULL;
   }
 #endif
 
-  error = TT_Set_Raster_Gray_Palette(engine, palette);
+  error = TT_Set_Raster_Gray_Palette(result->engine, palette);
   if (error) {
     mm_log((1, "Initialization of gray levels failed = 0x%x\n",
            (unsigned)error));
     i_tt_push_error(error);
     i_push_error(0, "Could not initialize FT 1.x POST extension");
-    return 1;
+    return NULL;
   }
 
-  TT_initialized = 1;
+  mm_log((1, "initialized FT1 state %p\n", result));
+
+  result->initialized = 1;
 
-  return(0);
+  return result;
 }
 
+static void
+i_tt_uninit(void *p) {
+  i_tt_engine *tteng = p;
+
+  if (tteng->initialized) {
+    mm_log((1, "finalizing FT1 state %p\n", tteng));
+    TT_Done_FreeType(tteng->engine);
+  }
+  mm_log((1, "freeing FT1 state %p\n", tteng));
+  myfree(tteng);
+}
 
 /* 
 =item i_tt_get_instance(handle, points, smooth)
@@ -315,8 +354,9 @@ i_tt_new(const char *fontname) {
   TT_Fonthandle *handle;
   unsigned short i,n;
   unsigned short platform,encoding;
+  i_tt_engine *tteng;
 
-  if (!TT_initialized && i_init_tt()) {
+  if ((tteng = i_init_tt()) == NULL) {
     i_push_error(0, "Could not initialize FT1 engine");
     return NULL;
   }
@@ -330,7 +370,7 @@ i_tt_new(const char *fontname) {
   handle = mymalloc( sizeof(TT_Fonthandle) ); /* checked 5Nov05 tonyc */
 
   /* load the typeface */
-  error = TT_Open_Face( engine, fontname, &handle->face );
+  error = TT_Open_Face( tteng->engine, fontname, &handle->face );
   if ( error ) {
     if ( error == TT_Err_Could_Not_Open_File ) {
       mm_log((1, "Could not find/open %s.\n", fontname ));

diff --git a/imager.h b/imager.h
index f305fb13138b398c50889b738571a338b0560d64..087a0e9a3981a4be4b11d21f57c1bdef7d4b3eb6 100644 (file)
--- a/imager.h
+++ b/imager.h
@@ -184,10 +184,10 @@ int i_img_samef(i_img *im1,i_img *im2, double epsilon, const char *what);
 
 /* font routines */
 
-undef_int i_init_fonts( int t1log );
-
 #ifdef HAVE_LIBTT
 
+extern void i_tt_start(void);
+
 TT_Fonthandle* i_tt_new(const char *fontname);
 void i_tt_destroy( TT_Fonthandle *handle );
 undef_int i_tt_cp( TT_Fonthandle *handle,i_img *im,i_img_dim xb,i_img_dim yb,int channel,double points,char const* txt,size_t len,int smooth, int utf8, int align);