Added variation font support (#3802)

Added variation font support

Tests/fonts/LICENSE.txt

@@ -1,12 +1,12 @@
 
 NotoNastaliqUrdu-Regular.ttf, from https://github.com/googlei18n/noto-fonts
 NotoSansJP-Thin.otf, from https://www.google.com/get/noto/help/cjk/
+AdobeVFPrototype.ttf, from https://github.com/adobe-fonts/adobe-variable-font-prototype
+TINY5x3GX.ttf, from http://velvetyne.fr/fonts/tiny
 
-All Noto fonts are published under the SIL Open Font License (OFL) v1.1 (http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=OFL), which allows you to copy, modify, and redistribute them if you need to.
+All of the above fonts are published under the SIL Open Font License (OFL) v1.1 (http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=OFL), which allows you to copy, modify, and redistribute them if you need to.
 
 
-10x20-ISO8859-1.pcf
-
-(from https://packages.ubuntu.com/xenial/xfonts-base)
+10x20-ISO8859-1.pcf, from https://packages.ubuntu.com/xenial/xfonts-base
 
 "Public domain font.  Share and enjoy."

Tests/test_imagefont.py

@@ -570,6 +570,91 @@ class TestImageFont(PillowTestCase):
             self.assertRaises(KeyError, t.getmask, 'абвг', features=['-kern'])
             self.assertRaises(KeyError, t.getmask, 'абвг', language='sr')
 
+    def test_variation_get(self):
+        font = self.get_font()
+
+        freetype = distutils.version.StrictVersion(ImageFont.core.freetype2_version)
+        if freetype < '2.9.1':
+            self.assertRaises(NotImplementedError, font.get_variation_names)
+            self.assertRaises(NotImplementedError, font.get_variation_axes)
+            return
+
+        self.assertRaises(IOError, font.get_variation_names)
+        self.assertRaises(IOError, font.get_variation_axes)
+
+        font = ImageFont.truetype("Tests/fonts/AdobeVFPrototype.ttf")
+        self.assertEqual(
+            font.get_variation_names(),
+            [b'ExtraLight', b'Light', b'Regular', b'Semibold', b'Bold',
+             b'Black', b'Black Medium Contrast', b'Black High Contrast', b'Default'])
+        self.assertEqual(
+            font.get_variation_axes(),
+            [{'name': b'Weight', 'minimum': 200, 'maximum': 900, 'default': 389},
+             {'name': b'Contrast', 'minimum': 0, 'maximum': 100, 'default': 0}])
+
+        font = ImageFont.truetype("Tests/fonts/TINY5x3GX.ttf")
+        self.assertEqual(
+            font.get_variation_names(),
+            [b'20', b'40', b'60', b'80', b'100', b'120', b'140', b'160', b'180',
+             b'200', b'220', b'240', b'260', b'280', b'300', b'Regular'])
+        self.assertEqual(
+            font.get_variation_axes(),
+            [{'name': b'Size', 'minimum': 0, 'maximum': 300, 'default': 0}])
+
+    def test_variation_set_by_name(self):
+        font = self.get_font()
+
+        freetype = distutils.version.StrictVersion(ImageFont.core.freetype2_version)
+        if freetype < '2.9.1':
+            self.assertRaises(NotImplementedError, font.set_variation_by_name, "Bold")
+            return
+
+        self.assertRaises(IOError, font.set_variation_by_name, "Bold")
+
+        def _check_text(font, path, epsilon):
+            im = Image.new("RGB", (100, 75), "white")
+            d = ImageDraw.Draw(im)
+            d.text((10, 10), "Text", font=font, fill="black")
+
+            expected = Image.open(path)
+            self.assert_image_similar(im, expected, epsilon)
+        font = ImageFont.truetype("Tests/fonts/AdobeVFPrototype.ttf", 36)
+        _check_text(font, "Tests/images/variation_adobe.png", 11)
+        for name in ["Bold", b"Bold"]:
+            font.set_variation_by_name(name)
+        _check_text(font, "Tests/images/variation_adobe_name.png", 11)
+
+        font = ImageFont.truetype("Tests/fonts/TINY5x3GX.ttf", 36)
+        _check_text(font, "Tests/images/variation_tiny.png", 40)
+        for name in ["200", b"200"]:
+            font.set_variation_by_name(name)
+        _check_text(font, "Tests/images/variation_tiny_name.png", 40)
+
+    def test_variation_set_by_axes(self):
+        font = self.get_font()
+
+        freetype = distutils.version.StrictVersion(ImageFont.core.freetype2_version)
+        if freetype < '2.9.1':
+            self.assertRaises(NotImplementedError, font.set_variation_by_axes, [100])
+            return
+
+        self.assertRaises(IOError, font.set_variation_by_axes, [500, 50])
+
+        def _check_text(font, path, epsilon):
+            im = Image.new("RGB", (100, 75), "white")
+            d = ImageDraw.Draw(im)
+            d.text((10, 10), "Text", font=font, fill="black")
+
+            expected = Image.open(path)
+            self.assert_image_similar(im, expected, epsilon)
+        font = ImageFont.truetype("Tests/fonts/AdobeVFPrototype.ttf", 36)
+        font.set_variation_by_axes([500, 50])
+        _check_text(font, "Tests/images/variation_adobe_axes.png", 5.1)
+
+        font = ImageFont.truetype("Tests/fonts/TINY5x3GX.ttf", 36)
+        font.set_variation_by_axes([100])
+        _check_text(font, "Tests/images/variation_tiny_axes.png", 32.5)
+
 
 @unittest.skipUnless(HAS_RAQM, "Raqm not Available")
 class TestImageFont_RaqmLayout(TestImageFont):

src/PIL/ImageFont.py

@@ -417,6 +417,59 @@ class FreeTypeFont(object):
             layout_engine=layout_engine or self.layout_engine,
         )
 
+    def get_variation_names(self):
+        """
+        :returns: A list of the named styles in a variation font.
+        :exception IOError: If the font is not a variation font.
+        """
+        try:
+            names = self.font.getvarnames()
+        except AttributeError:
+            raise NotImplementedError("FreeType 2.9.1 or greater is required")
+        return [name.replace(b"\x00", b"") for name in names]
+
+    def set_variation_by_name(self, name):
+        """
+        :param name: The name of the style.
+        :exception IOError: If the font is not a variation font.
+        """
+        names = self.get_variation_names()
+        if not isinstance(name, bytes):
+            name = name.encode()
+        index = names.index(name)
+
+        if index == getattr(self, "_last_variation_index", None):
+            # When the same name is set twice in a row,
+            # there is an 'unknown freetype error'
+            # https://savannah.nongnu.org/bugs/?56186
+            return
+        self._last_variation_index = index
+
+        self.font.setvarname(index)
+
+    def get_variation_axes(self):
+        """
+        :returns: A list of the axes in a variation font.
+        :exception IOError: If the font is not a variation font.
+        """
+        try:
+            axes = self.font.getvaraxes()
+        except AttributeError:
+            raise NotImplementedError("FreeType 2.9.1 or greater is required")
+        for axis in axes:
+            axis["name"] = axis["name"].replace(b"\x00", b"")
+        return axes
+
+    def set_variation_by_axes(self, axes):
+        """
+        :param axes: A list of values for each axis.
+        :exception IOError: If the font is not a variation font.
+        """
+        try:
+            self.font.setvaraxes(axes)
+        except AttributeError:
+            raise NotImplementedError("FreeType 2.9.1 or greater is required")
+
 
 class TransposedFont(object):
     "Wrapper for writing rotated or mirrored text"

src/_imagingft.c

@@ -25,6 +25,8 @@
 #include <ft2build.h>
 #include FT_FREETYPE_H
 #include FT_GLYPH_H
+#include FT_MULTIPLE_MASTERS_H
+#include FT_SFNT_NAMES_H
 
 #define KEEP_PY_UNICODE
 #include "py3.h"
@@ -877,6 +879,158 @@ font_render(FontObject* self, PyObject* args)
     Py_RETURN_NONE;
 }
 
+#if FREETYPE_MAJOR > 2 ||\
+    (FREETYPE_MAJOR == 2 && FREETYPE_MINOR > 9) ||\
+    (FREETYPE_MAJOR == 2 && FREETYPE_MINOR == 9 && FREETYPE_PATCH == 1)
+    static PyObject*
+    font_getvarnames(FontObject* self, PyObject* args)
+    {
+        int error;
+        FT_UInt i, j, num_namedstyles, name_count;
+        FT_MM_Var *master;
+        FT_SfntName name;
+        PyObject *list_names, *list_name;
+
+        error = FT_Get_MM_Var(self->face, &master);
+        if (error)
+            return geterror(error);
+
+        num_namedstyles = master->num_namedstyles;
+        list_names = PyList_New(num_namedstyles);
+
+        name_count = FT_Get_Sfnt_Name_Count(self->face);
+        for (i = 0; i < name_count; i++) {
+            error = FT_Get_Sfnt_Name(self->face, i, &name);
+            if (error)
+                return geterror(error);
+
+            for (j = 0; j < num_namedstyles; j++) {
+                if (PyList_GetItem(list_names, j) != NULL)
+                    continue;
+
+                if (master->namedstyle[j].strid == name.name_id) {
+                    list_name = Py_BuildValue(PY_ARG_BYTES_LENGTH,
+                                              name.string, name.string_len);
+                    PyList_SetItem(list_names, j, list_name);
+                    break;
+                }
+            }
+        }
+
+        FT_Done_MM_Var(library, master);
+
+        return list_names;
+    }
+
+    static PyObject*
+    font_getvaraxes(FontObject* self, PyObject* args)
+    {
+        int error;
+        FT_UInt i, j, num_axis, name_count;
+        FT_MM_Var* master;
+        FT_Var_Axis axis;
+        FT_SfntName name;
+        PyObject *list_axes, *list_axis, *axis_name;
+        error = FT_Get_MM_Var(self->face, &master);
+        if (error)
+            return geterror(error);
+
+        num_axis = master->num_axis;
+        name_count = FT_Get_Sfnt_Name_Count(self->face);
+
+        list_axes = PyList_New(num_axis);
+        for (i = 0; i < num_axis; i++) {
+            axis = master->axis[i];
+
+            list_axis = PyDict_New();
+            PyDict_SetItemString(list_axis, "minimum",
+                                 PyInt_FromLong(axis.minimum / 65536));
+            PyDict_SetItemString(list_axis, "default",
+                                 PyInt_FromLong(axis.def / 65536));
+            PyDict_SetItemString(list_axis, "maximum",
+                                 PyInt_FromLong(axis.maximum / 65536));
+
+            for (j = 0; j < name_count; j++) {
+                error = FT_Get_Sfnt_Name(self->face, j, &name);
+                if (error)
+                    return geterror(error);
+
+                if (name.name_id == axis.strid) {
+                    axis_name = Py_BuildValue(PY_ARG_BYTES_LENGTH,
+                                              name.string, name.string_len);
+                    PyDict_SetItemString(list_axis, "name", axis_name);
+                    break;
+                }
+            }
+
+            PyList_SetItem(list_axes, i, list_axis);
+        }
+
+        FT_Done_MM_Var(library, master);
+
+        return list_axes;
+    }
+
+    static PyObject*
+    font_setvarname(FontObject* self, PyObject* args)
+    {
+        int error;
+
+        int instance_index;
+        if (!PyArg_ParseTuple(args, "i", &instance_index))
+            return NULL;
+
+        error = FT_Set_Named_Instance(self->face, instance_index);
+        if (error)
+            return geterror(error);
+
+        Py_INCREF(Py_None);
+        return Py_None;
+    }
+
+    static PyObject*
+    font_setvaraxes(FontObject* self, PyObject* args)
+    {
+        int error;
+
+        PyObject *axes, *item;
+        Py_ssize_t i, num_coords;
+        FT_Fixed *coords;
+        FT_Fixed coord;
+        if (!PyArg_ParseTuple(args, "O", &axes))
+            return NULL;
+
+        if (!PyList_Check(axes)) {
+            PyErr_SetString(PyExc_TypeError, "argument must be a list");
+            return NULL;
+        }
+
+        num_coords = PyObject_Length(axes);
+        coords = malloc(2 * sizeof(coords));
+        for (i = 0; i < num_coords; i++) {
+            item = PyList_GET_ITEM(axes, i);
+            if (PyFloat_Check(item))
+                coord = PyFloat_AS_DOUBLE(item);
+            else if (PyInt_Check(item))
+                coord = (float) PyInt_AS_LONG(item);
+            else if (PyNumber_Check(item))
+                coord = PyFloat_AsDouble(item);
+            else {
+                PyErr_SetString(PyExc_TypeError, "list must contain numbers");
+                return NULL;
+            }
+            coords[i] = coord * 65536;
+        }
+
+        error = FT_Set_Var_Design_Coordinates(self->face, num_coords, coords);
+        if (error)
+            return geterror(error);
+
+        Py_INCREF(Py_None);
+        return Py_None;
+    }
+#endif
+
 static void
 font_dealloc(FontObject* self)
 {
@@ -892,6 +1046,14 @@ font_dealloc(FontObject* self)
 static PyMethodDef font_methods[] = {
     {"render", (PyCFunction) font_render, METH_VARARGS},
     {"getsize", (PyCFunction) font_getsize, METH_VARARGS},
+#if FREETYPE_MAJOR > 2 ||\
+    (FREETYPE_MAJOR == 2 && FREETYPE_MINOR > 9) ||\
+    (FREETYPE_MAJOR == 2 && FREETYPE_MINOR == 9 && FREETYPE_PATCH == 1)
+    {"getvarnames", (PyCFunction) font_getvarnames, METH_VARARGS },
+    {"getvaraxes", (PyCFunction) font_getvaraxes, METH_VARARGS },
+    {"setvarname", (PyCFunction) font_setvarname, METH_VARARGS},
+    {"setvaraxes", (PyCFunction) font_setvaraxes, METH_VARARGS},
+#endif
     {NULL, NULL}
 };