add a sample.py script

README.md

@@ -0,0 +1,46 @@
+## uharfbuzz
+
+Streamlined Cython bindings for the [HarfBuzz][hb] shaping engine.
+
+
+### Example
+
+```python
+import uharfbuzz as hb
+import sys
+
+
+with open(sys.argv[1], 'rb') as fontfile:
+    fontdata = fontfile.read()
+
+text = sys.argv[2]
+
+face = hb.Face.create(fontdata)
+font = hb.Font.create(face)
+upem = face.upem
+
+font.scale = (upem, upem)
+hb.ot_font_set_funcs(font)
+
+buf = hb.Buffer.create()
+
+buf.add_str(text)
+buf.guess_segment_properties()
+
+features = {"kern": True, "liga": True}
+hb.shape(font, buf, features)
+
+infos = buf.glyph_infos
+positions = buf.glyph_positions
+
+for info, pos in zip(infos, positions):
+    gid = info.codepoint
+    cluster = info.cluster
+    x_advance = pos.x_advance
+    x_offset = pos.x_offset
+    y_offset = pos.y_offset
+    print(f"gid{gid}={cluster}@{x_advance},{x_offset}+{y_offset}")
+```
+
+
+[hb]: https://github.com/harfbuzz/harfbuzz

setup.py

@@ -1,12 +1,22 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 from skbuild import setup
+import os
+from io import open
 
 
+here = os.path.abspath(os.path.dirname(__file__))
+
+# Get the long description from the README file
+with open(os.path.join(here, 'README.md'), encoding='utf-8') as f:
+    long_description = f.read()
+
 setup(
     name="uharfbuzz",
     version="0.1.0.dev0",
     description="Streamlined Cython bindings for the harfbuzz shaping engine",
+    long_description=long_description,
+    long_description_content_type='text/markdown',
     author="Adrien Tétar",
     author_email="adri-from-59@hotmail.fr",
     url="https://github.com/trufont/uharfbuzz",

src/uharfbuzz/_harfbuzz.pyx

@@ -55,6 +55,7 @@ cdef class GlyphPosition:
 
 cdef class Buffer:
     cdef hb_buffer_t* _hb_buffer
+    cdef object _message_func
 
     def __cinit__(self):
         self._hb_buffer = NULL
@@ -111,7 +112,6 @@ cdef class Buffer:
             positions.append(position)
         return positions
 
-
     @property
     def language(self) -> str:
         cdef const_char* cstr = hb_language_to_string(
@@ -178,6 +178,23 @@ cdef class Buffer:
     def guess_segment_properties(self) -> None:
         hb_buffer_guess_segment_properties(self._hb_buffer)
 
+    def set_message_func(self, func: Callable[[str], bool]) -> None:
+        # XXX I'm passing the python callback as user_data and recovering it
+        # from the C-API func below. Is there a better way?
+        # Also, the callback is only taking a message argument, no buffer,
+        # nor font or its own user_data. Not sure whether/how to pass them on
+        hb_buffer_set_message_func(
+            self._hb_buffer, _buffer_message_func, <void*>func, NULL)
+        self._message_func = func
+
+
+cdef hb_bool_t _buffer_message_func(hb_buffer_t* buffer, hb_font_t* font,
+                                    const char* message, void* user_data):
+    cdef object py_func = <object>user_data
+    cdef str py_message = (<bytes>message).decode("utf-8")
+    return bool(py_func(py_message))
+
+
 cdef hb_user_data_key_t k
 
 
@@ -209,13 +226,13 @@ cdef class Face:
         if self._hb_face is not NULL:
             hb_face_destroy(self._hb_face)
 
-    """ use bytes/bytearray, not Blob
     @classmethod
-    def create(self, blob: Blob, index: int):
+    def create(cls, bytes blob, int index=0):
         cdef Face inst = cls()
-        inst._hb_face = hb_face_create(blob, index)
+        cdef hb_blob_t* cblob = hb_blob_create(
+            blob, len(blob), HB_MEMORY_MODE_READONLY, NULL, NULL)
+        inst._hb_face = hb_face_create(cblob, index)
         return inst
-    """
 
     @classmethod
     def create_for_tables(cls,
@@ -451,3 +468,7 @@ def ot_layout_table_get_script_tags(face: Face, tag: str) -> List[str]:
         packed = cstr
         tags.append(packed.decode())
     return tags
+
+
+def void ot_font_set_funcs(Font font):
+    hb_ot_font_set_funcs(font._hb_font)

src/uharfbuzz/charfbuzz.pxd

@@ -100,6 +100,12 @@ cdef extern from "hb.h":
     hb_language_t hb_buffer_get_language(hb_buffer_t* buffer)
     void hb_buffer_set_language(hb_buffer_t* buffer, hb_language_t language)
     void hb_buffer_destroy(hb_buffer_t* buffer)
+    ctypedef hb_bool_t(*hb_buffer_message_func_t) (
+        hb_buffer_t* buffer, hb_font_t* font, const char* message,
+        void* user_data)
+    void hb_buffer_set_message_func(
+        hb_buffer_t* buffer, hb_buffer_message_func_t func,
+        void* user_data, hb_destroy_func_t destroy)
 
     # hb-face.h
     ctypedef struct hb_face_t:
@@ -197,3 +203,6 @@ cdef extern from "hb-ot.h":
         unsigned int start_offset,
         unsigned int* script_count,  # in/out
         hb_tag_t* script_tags)  # out
+
+    # hb-ot-font.h
+    void hb_ot_font_set_funcs(hb_font_t* font)