Add custom LCD filter weights

Author: mdboom

doc/source/api.rst

@@ -134,6 +134,15 @@ TrueType information
    TT_WEIGHT_CLASS
    TT_FS_SELECTION
 
+LCD Filtering
+-------------
+
+.. autosummary::
+   :toctree: _generated
+
+   set_lcd_filter
+   set_lcd_filter_weights
+
 Basic Types
 -----------
 

docstrings/lcd.py

@@ -41,11 +41,10 @@
 Parameters
 ----------
 
-filter : `RENDER_MODE` constant
+filter : `LCD_FILTER` constant
 
 Notes
 -----
-
 This feature is always disabled by default. Clients must make an
 explicit call to this function with a `filter` value other than
 `LCD_FILTER.NONE` in order to enable it.
@@ -57,6 +56,23 @@
 FreeType.
 """
 
+set_lcd_filter_weights = """
+Enable LCD filter with custom weights.
+
+Parameters
+----------
+a, b, c, d, e : int
+    The filter weights
+
+Notes
+-----
+Due to PATENTS covering subpixel rendering, this function doesn't do
+anything except raising `NotImplementedError` if the configuration
+macro ``FT_CONFIG_OPTION_SUBPIXEL_RENDERING`` is not defined in your
+build of the library, which should correspond to all default builds of
+FreeType.
+"""
+
 
 LCD_FILTER = """
 Identifies various types of LCD filters.

src/freetypy.c

@@ -91,8 +91,30 @@ py_set_lcd_filter(PyObject *self, PyObject *args, PyObject *kwargs)
 }
 
 
+PyObject *
+py_set_lcd_filter_weights(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+    char filters[5];
+
+    static char *kwlist[] = {"filter", NULL};
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "bbbbb:set_lcd_filter_weights", kwlist,
+                                     &filters[0], &filters[1], &filters[2],
+                                     &filters[3], &filters[4])) {
+        return NULL;
+    }
+
+    if (ftpy_exc(FT_Library_SetLcdFilterWeights(get_ft_library(), filters))) {
+        return NULL;
+    }
+
+    Py_RETURN_NONE;
+}
+
+
 static PyMethodDef module_methods[] = {
     {"set_lcd_filter", (PyCFunction)py_set_lcd_filter, METH_VARARGS|METH_KEYWORDS, doc_set_lcd_filter},
+    {"set_lcd_filter_weights", (PyCFunction)py_set_lcd_filter_weights, METH_VARARGS|METH_KEYWORDS, doc_set_lcd_filter_weights},
     {NULL}  /* Sentinel */
 };