Initial commit of the TextureCreator

TextureCreator/lib/FontFaceCreator.py

@@ -0,0 +1,89 @@
+'''
+This script is part of the FURWARE texture creator, a texture
+generation script for the FURWARE text text-on-prim script
+for Second Life(R).
+
+Please see the included README and LICENSE files in the root
+directory for more information.
+'''
+
+'''
+This script loads a font file using the FreeType library
+for usage with (py)cairo. This is merely a workaround because
+the python binding to cairo currently doesn't support loading
+of fonts from a file. The function is based on the code from
+http://www.cairographics.org/freetypepython/
+'''
+
+import cairo
+import ctypes
+import ctypes.util
+
+_freetypeInitialized = False
+
+class PycairoContext(ctypes.Structure):
+    _fields_ = [
+        ("PyObject_HEAD", ctypes.c_byte * object.__basicsize__),
+        ("ctx", ctypes.c_void_p),
+        ("base", ctypes.c_void_p)
+    ]
+
+def fontFaceFromFile(filename):
+    global _freetypeInitialized
+    global _freetype_so
+    global _cairo_so
+    global _ft_lib
+    global _surface
+
+    CAIRO_STATUS_SUCCESS = 0
+    FT_Err_Ok = 0
+
+    if not _freetypeInitialized:
+        # Find shared libraries.
+        freetypeLibName = ctypes.util.find_library("freetype")
+        if not freetypeLibName:
+            raise Exception("FreeType library not found.")
+        
+        cairoLibName = ctypes.util.find_library("cairo")
+        if not cairoLibName:
+            raise Exception("Cairo library not found.")
+        
+        _freetype_so = ctypes.CDLL(freetypeLibName)
+        _cairo_so = ctypes.CDLL(cairoLibName)
+
+        _cairo_so.cairo_ft_font_face_create_for_ft_face.restype  =  ctypes.c_void_p
+        _cairo_so.cairo_ft_font_face_create_for_ft_face.argtypes = [ctypes.c_void_p, ctypes.c_int]
+        _cairo_so.cairo_set_font_face.argtypes                   = [ctypes.c_void_p, ctypes.c_void_p]
+        _cairo_so.cairo_font_face_status.argtypes                = [ctypes.c_void_p]
+        _cairo_so.cairo_status.argtypes                          = [ctypes.c_void_p]
+
+        # Initialize FreeType.
+        _ft_lib = ctypes.c_void_p()
+        
+        if _freetype_so.FT_Init_FreeType(ctypes.byref(_ft_lib)) != FT_Err_Ok:
+            raise Exception("Error initialising FreeType library.")
+
+        _surface = cairo.ImageSurface(cairo.FORMAT_A8, 0, 0)
+
+        _freetypeInitialized = True
+
+    # Create FreeType face.
+    ftFace = ctypes.c_void_p()
+    cairo_ctx = cairo.Context(_surface)
+    cairo_t = PycairoContext.from_address(id(cairo_ctx)).ctx
+
+    if _freetype_so.FT_New_Face(_ft_lib, filename.encode("utf-8"), 0, ctypes.byref(ftFace)) != FT_Err_Ok:
+        raise Exception("Error creating FreeType font face for " + filename)
+
+    # Create Cairo font face for FreeType face.
+    cr_face = _cairo_so.cairo_ft_font_face_create_for_ft_face(ftFace, 0)
+    if CAIRO_STATUS_SUCCESS != _cairo_so.cairo_font_face_status(cr_face):
+        raise Exception("Error creating cairo font face for " + filename)
+
+    _cairo_so.cairo_set_font_face(cairo_t, cr_face)
+    if CAIRO_STATUS_SUCCESS != _cairo_so.cairo_status(cairo_t):
+        raise Exception("Error creating cairo font face for " + filename)
+
+    face = cairo_ctx.get_font_face()
+
+    return face