Prefer single transform matrix over offset/scale

Lib/fontTools/pens/freetypePen.py

@@ -20,6 +20,7 @@ from freetype.ft_errors import FT_Exception
 
 from fontTools.pens.basePen import BasePen
 from fontTools.misc.roundTools import otRound
+from fontTools.misc.transform import Transform
 
 Contour   = collections.namedtuple('Contour', ('points', 'tags'))
 LINE      = 0b00000001
@@ -48,13 +49,14 @@ class FreeTypePen(BasePen):
 
             from fontTools.ttLib import TTFont
             from fontTools.pens.freetypePen import FreeTypePen
+            from fontTools.misc.transform import Offset
             pen = FreeTypePen(None)
             font = TTFont('SourceSansPro-Regular.otf')
             glyph = font.getGlyphSet()['fi']
             glyph.draw(pen)
             width, ascender, descender = glyph.width, font['OS/2'].usWinAscent, -font['OS/2'].usWinDescent
             height = ascender - descender
-            pen.show(offset=(0, -descender), width=width, height=height)
+            pen.show(width=width, height=height, transform=Offset(0, -descender))
 
         Combining with `uharfbuzz`, you can typeset a chunk of glyphs in a pen::
 
@@ -98,7 +100,7 @@ class FreeTypePen(BasePen):
                     offset = (-vhea_descender, -y)
                     width  = vhea_ascender - vhea_descender
                     height = -y
-                pen.show(offset=offset, width=width, height=height, contain=contain)
+                pen.show(width=width, height=height, transform=Offset(*offset), contain=contain)
 
         For Jupyter Notebook, the rendered image will be displayed in a cell if
         you replace ``show()`` with ``image()`` in the examples.
@@ -108,22 +110,25 @@ class FreeTypePen(BasePen):
         BasePen.__init__(self, glyphSet)
         self.contours = []
 
-    def outline(self, offset=None, scale=None, evenOdd=False):
+    def outline(self, transform=None, evenOdd=False):
         """Converts the current contours to ``FT_Outline``.
 
         Args:
-            offset: A optional tuple of ``(x, y)`` used for translation.
+            transform: A optional 6-tuple containing an affine transformation,
-            scale:  A optional tuple of ``(scale_x, scale_y)`` used for scaling.
+                or a ``Transform`` object from the ``fontTools.misc.transform``
+                module.
             evenOdd: Pass ``True`` for even-odd fill instead of non-zero.
         """
-        offset = offset or (0, 0)
+        transform = transform or Transform()
-        scale  = scale  or (1.0, 1.0)
+        if not hasattr(transform, 'transformPoint'):
+            transform = Transform(*transform)
         nContours = len(self.contours)
-        n_points   = sum((len(contour.points) for contour in self.contours))
+        n_points  = sum((len(contour.points) for contour in self.contours))
         points = []
         for contour in self.contours:
             for point in contour.points:
-                points.append(FT_Vector(FT_Pos(otRound((point[0] + offset[0]) * scale[0] * 64)), FT_Pos(otRound((point[1] + offset[1]) * scale[1] * 64))))
+                point = transform.transformPoint(point)
+                points.append(FT_Vector(FT_Pos(otRound(point[0] * 64)), FT_Pos(otRound(point[1] * 64))))
         tags = []
         for contour in self.contours:
             for tag in contour.tags:
@@ -143,16 +148,15 @@ class FreeTypePen(BasePen):
             (ctypes.c_int)(flags)
         )
 
-    def buffer(self, offset=None, width=1000, height=1000, evenOdd=False, scale=None, contain=False):
+    def buffer(self, width=1000, height=1000, transform=None, evenOdd=False, contain=False):
         """Renders the current contours within a bitmap buffer.
 
         Args:
-            offset: A optional tuple of ``(x, y)`` used for translation.
-                Typically ``(0, -descender)`` can be passed so that the glyph
-                image would not been clipped.
             width:  Image width of the bitmap in pixels.
             height:  Image height of the bitmap in pixels.
-            scale:  A optional tuple of ``(scale_x, scale_y)`` used for scaling.
+            transform: A optional 6-tuple containing an affine transformation,
+                or a ``Transform`` object from the ``fontTools.misc.transform``
+                module. The bitmap size is not affected by this matrix.
             evenOdd: Pass ``True`` for even-odd fill instead of non-zero.
             contain: If ``True``, the image size will be automatically expanded
                 so that it fits to the bounding box of the paths. Useful for
@@ -170,17 +174,20 @@ class FreeTypePen(BasePen):
             >> type(buf), len(buf), size
             (<class 'bytes'>, 500000, (500, 1000))
         """
-        offset_x, offset_y = offset or (0, 0)
+        transform = transform or Transform()
+        if not hasattr(transform, 'transformPoint'):
+            transform = Transform(*transform)
         if contain:
-            bbox      = self.bbox
+            bbox = self.bbox
+            bbox = transform.transformPoints((bbox[0:2], bbox[2:4]))
+            bbox = (*bbox[0], *bbox[1])
             bbox_size = bbox[2] - bbox[0], bbox[3] - bbox[1]
-            offset_x  = min(offset_x, bbox[0]) * -1
+            dx = min(-transform.dx, bbox[0]) * -1.0
-            width     = max(width,  bbox_size[0])
+            dy = min(-transform.dy, bbox[1]) * -1.0
-            offset_y  = min(offset_y, bbox[1]) * -1
+            width  = max(width,  bbox_size[0])
-            height    = max(height, bbox_size[1])
+            height = max(height, bbox_size[1])
-        scale  = scale or (1.0, 1.0)
+            transform = Transform(*transform[:4], dx, dy)
-        width  = math.ceil(width  * scale[0])
+        width, height = math.ceil(width), math.ceil(height)
-        height = math.ceil(height * scale[1])
         buf = ctypes.create_string_buffer(width * height)
         bitmap = FT_Bitmap(
             (ctypes.c_int)(height),
@@ -192,22 +199,21 @@ class FreeTypePen(BasePen):
             (ctypes.c_char)(0),
             (ctypes.c_void_p)(None)
         )
-        outline = self.outline(offset=(offset_x, offset_y), evenOdd=evenOdd, scale=scale)
+        outline = self.outline(transform=transform, evenOdd=evenOdd)
         err = FT_Outline_Get_Bitmap(freetype.get_handle(), ctypes.byref(outline), ctypes.byref(bitmap))
         if err != 0:
             raise FT_Exception(err)
         return buf.raw, (width, height)
 
-    def array(self, offset=None, width=1000, height=1000, evenOdd=False, scale=None, contain=False):
+    def array(self, width=1000, height=1000, transform=None, evenOdd=False, contain=False):
         """Returns the rendered contours as a numpy array. Requires `numpy`.
 
         Args:
-            offset: A optional tuple of ``(x, y)`` used for translation.
-                Typically ``(0, -descender)`` can be passed so that the glyph
-                image would not been clipped.
             width:  Image width of the bitmap in pixels.
             height:  Image height of the bitmap in pixels.
-            scale:  A optional tuple of ``(scale_x, scale_y)`` used for scaling.
+            transform: A optional 6-tuple containing an affine transformation,
+                or a ``Transform`` object from the ``fontTools.misc.transform``
+                module. The bitmap size is not affected by this matrix.
             evenOdd: Pass ``True`` for even-odd fill instead of non-zero.
             contain: If ``True``, the image size will be automatically expanded
                 so that it fits to the bounding box of the paths. Useful for
@@ -225,20 +231,19 @@ class FreeTypePen(BasePen):
             (<class 'numpy.ndarray'>, (1000, 500))
         """
         import numpy as np
-        buf, size = self.buffer(offset=offset, width=width, height=height, evenOdd=evenOdd, scale=scale, contain=contain)
+        buf, size = self.buffer(width=width, height=height, transform=transform, evenOdd=evenOdd, contain=contain)
         return np.frombuffer(buf, 'B').reshape((size[1], size[0])) / 255.0
 
-    def show(self, offset=None, width=1000, height=1000, evenOdd=False, scale=None, contain=False):
+    def show(self, width=1000, height=1000, transform=None, evenOdd=False, contain=False):
         """Plots the rendered contours with `pyplot`. Requires `numpy` and
         `matplotlib`.
 
         Args:
-            offset: A optional tuple of ``(x, y)`` used for translation.
-                Typically ``(0, -descender)`` can be passed so that the glyph
-                image would not been clipped.
             width:  Image width of the bitmap in pixels.
             height:  Image height of the bitmap in pixels.
-            scale:  A optional tuple of ``(scale_x, scale_y)`` used for scaling.
+            transform: A optional 6-tuple containing an affine transformation,
+                or a ``Transform`` object from the ``fontTools.misc.transform``
+                module. The bitmap size is not affected by this matrix.
             evenOdd: Pass ``True`` for even-odd fill instead of non-zero.
             contain: If ``True``, the image size will be automatically expanded
                 so that it fits to the bounding box of the paths. Useful for
@@ -250,21 +255,20 @@ class FreeTypePen(BasePen):
             >> pen.show(width=500, height=1000)
         """
         from matplotlib import pyplot as plt
-        a = self.array(offset=offset, width=width, height=height, evenOdd=evenOdd, scale=scale, contain=contain)
+        a = self.array(width=width, height=height, transform=transform, evenOdd=evenOdd, contain=contain)
         plt.imshow(a, cmap='gray_r', vmin=0, vmax=1)
         plt.show()
 
-    def image(self, offset=None, width=1000, height=1000, evenOdd=False, scale=None, contain=False):
+    def image(self, width=1000, height=1000, transform=None, evenOdd=False, contain=False):
         """Returns the rendered contours as a PIL image. Requires `Pillow`.
         Can be used to display a glyph image in Jupyter Notebook.
 
         Args:
-            offset: A optional tuple of ``(x, y)`` used for translation.
-                Typically ``(0, -descender)`` can be passed so that the glyph
-                image would not been clipped.
             width:  Image width of the bitmap in pixels.
             height:  Image height of the bitmap in pixels.
-            scale:  A optional tuple of ``(scale_x, scale_y)`` used for scaling.
+            transform: A optional 6-tuple containing an affine transformation,
+                or a ``Transform`` object from the ``fontTools.misc.transform``
+                module. The bitmap size is not affected by this matrix.
             evenOdd: Pass ``True`` for even-odd fill instead of non-zero.
             contain: If ``True``, the image size will be automatically expanded
                 so that it fits to the bounding box of the paths. Useful for
@@ -282,7 +286,7 @@ class FreeTypePen(BasePen):
             (<class 'PIL.Image.Image'>, (500, 1000))
         """
         from PIL import Image
-        buf, size = self.buffer(offset=offset, width=width, height=height, evenOdd=evenOdd, scale=scale, contain=contain)
+        buf, size = self.buffer(width=width, height=height, transform=transform, evenOdd=evenOdd, contain=contain)
         img = Image.new('L', size, 0)
         img.putalpha(Image.frombuffer('L', size, buf))
         return img

Tests/pens/freetypePen_test.py

@@ -6,6 +6,8 @@ try:
 except ImportError:
     FREETYPE_PY_AVAILABLE = False
 
+from fontTools.misc.transform import Scale
+
 def draw_cubic(pen):
     pen.moveTo((50, 0))
     pen.lineTo((50, 500))
@@ -47,8 +49,8 @@ class FreeTypePenTest(unittest.TestCase):
         ZLIB_B64_BIN = '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'
         pen = FreeTypePen(None)
         draw_cubic(pen)
-        offset, width, height = (0, 0), 500, 500
+        width, height = 500, 500
-        buf1, _ = pen.buffer(offset=offset, width=width, height=height)
+        buf1, _ = pen.buffer(width=width, height=height)
         buf2 = zlib.decompress(base64.b64decode(ZLIB_B64_BIN))
         self.assertEqual(len(buf1), len(buf2))
         self.assertGreater(psnr(buf1, buf2), PSNR_THRESHOLD)
@@ -58,16 +60,17 @@ class FreeTypePenTest(unittest.TestCase):
         ZLIB_B64_BIN = 'eJy91r8NgkAUx/FLMHECCLMQC5gGK3UB4gJEXABhAbTAJXAJ7GkoBIornrQif/w2vvo+yXH37vFTqi/5rKYs8jhwDDVdMlp15ttM9NVFE2ZSiLShCYVI5VIhekeFSLKmQhIsZLixZaFdKqQyqZAQi9amQiIsOpsK8bHIsKgNKsTBIsAixiLHosCixKLB4vWHXfEv56fLb5B3Ce5E3u1XRQV+tXwy4OnDJxyeopUFhfYUFHsFRaqgSOGfUx+G65cSgPcNZlPGyRoBM0nmjJJMfdv+mpaa5+N+OW5W44vfouHQiw=='
         pen = FreeTypePen(None)
         draw_cubic(pen)
-        offset, width, height = (0, 0), 500, 500
+        t = Scale(0.1, 0.1)
-        buf1, size = pen.buffer(offset=offset, width=width, height=height, scale=(0.1, 0.1))
+        width, height = t.transformPoint((500, 500))
+        buf1, size = pen.buffer(width=width, height=height, transform=t)
         buf2 = zlib.decompress(base64.b64decode(ZLIB_B64_BIN))
         self.assertEqual(size, (50, 50))
         self.assertGreater(psnr(buf1, buf2), PSNR_THRESHOLD)
 
     def test_empty(self):
         pen = FreeTypePen(None)
-        offset, width, height = (0, 0), 500, 500
+        width, height = 500, 500
-        buf, size = pen.buffer(offset=offset, width=width, height=height)
+        buf, size = pen.buffer(width=width, height=height)
         self.assertEqual(b'\0' * size[0] * size[1], buf)
 
     def test_bbox_and_cbox(self):
@@ -81,8 +84,10 @@ class FreeTypePenTest(unittest.TestCase):
         ZLIB_B64_BIN = 'eJzt2L0NglAUhmESTZxA4yzGAqfRSl3AuABRF/BnAbTAJXAJ7GkoBAqKo4WNhbk3OZ4vknzvAk/g/nC5QcAYY4wxxhhrRfJZmaXJfjXqWBrving6tDZe1dufKV8NkSrqmxsieWhvSDO3N0SOPXtDjgBD9K/LbTShvSG5dgp7GBIBjEq54n0M2QKMWvcgXoZMAUYMMArVR8vPkBHAWAGMPcBIAEYKMDKAUQKMB8BAvCvEmCPmLmINIvYSwJ6I2NvPGuJ/vrWIMwPg7IM4wwHOovnA3GgmSsLDWGgJt3FSE07jZP7P2Sz1gusOQD3cLqPaaCety6h3xncyxWVmd7dU3m/Xw3rc/R3AGGOMsbb3BMrP0Is='
         pen = FreeTypePen(None)
         draw_cubic(pen)
-        offset, width, height = (0, 200), 1000, 1000
+        t = Scale(0.1, 0.1)
-        buf1, size = pen.buffer(offset=offset, width=width, height=height, scale=(0.1, 0.1), evenOdd=False)
+        width, height = t.transformPoint((1000, 1000))
+        t = t.translate(0, 200)
+        buf1, size = pen.buffer(width=width, height=height, transform=t, evenOdd=False)
         buf2 = zlib.decompress(base64.b64decode(ZLIB_B64_BIN))
         self.assertEqual(len(buf1), len(buf2))
         self.assertGreater(psnr(buf1, buf2), PSNR_THRESHOLD)
@@ -92,8 +97,10 @@ class FreeTypePenTest(unittest.TestCase):
         ZLIB_B64_BIN = 'eJzt2L0NglAUhmESTZxA4yzGAqfRSl3AuABRF/BnAbTAJXAJ7GkoBAqKo4WNhbk3OZ4vknzvAk/g/nC5QcAYY4wxxhhrRfJZmaXJfjXqWBrving6tDZe1dufKV8NkSrqmxsieWhvSDO3N0SOPXtDjgBD9K/LbTShvSG5dgp7GBIBjEq54n0M2QKMWvcgXoZMAUYMMArVR8vPkBHAWAGMPcBIAEYKMDKAUQKMB8BAvCvEmCPmLmINIvYSwJ6I2NvPGuJ/vrWIMwPg7IM4wwHOovnA3GgmSsLDWGgJt3FSE07jZP7P2Sz1gusOQD3cLqPaaCety6h3xncyxWVmd7dU3m/Xw3rc/R3AGGOMsbb3BMrP0Is='
         pen = FreeTypePen(None)
         draw_cubic(pen)
-        offset, width, height = (0, 200), 1000, 1000
+        t = Scale(0.1, 0.1)
-        buf1, size = pen.buffer(offset=offset, width=width, height=height, scale=(0.1, 0.1), evenOdd=True)
+        width, height = t.transformPoint((1000, 1000))
+        t = t.translate(0, 200)
+        buf1, size = pen.buffer(width=width, height=height, transform=t, evenOdd=True)
         buf2 = zlib.decompress(base64.b64decode(ZLIB_B64_BIN))
         self.assertEqual(len(buf1), len(buf2))
         self.assertGreater(psnr(buf1, buf2), PSNR_THRESHOLD)
@@ -102,9 +109,9 @@ class FreeTypePenTest(unittest.TestCase):
         pen1, pen2 = FreeTypePen(None), FreeTypePen(None)
         draw_cubic(pen1)
         draw_quadratic(pen2)
-        offset, width, height = (0, 0), 500, 500
+        width, height = 500, 500
-        buf1, _ = pen1.buffer(offset=offset, width=width, height=height)
+        buf1, _ = pen1.buffer(width=width, height=height)
-        buf2, _ = pen2.buffer(offset=offset, width=width, height=height)
+        buf2, _ = pen2.buffer(width=width, height=height)
         self.assertEqual(len(buf1), len(buf2))
         self.assertGreater(psnr(buf1, buf2), PSNR_THRESHOLD)
 
@@ -113,8 +120,9 @@ class FreeTypePenTest(unittest.TestCase):
         ZLIB_B64_BIN = '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'
         pen = FreeTypePen(None)
         star(pen)
-        offset, width, height = (0, 0), 0, 0
+        t = Scale(0.05, 0.05)
-        buf1, size = pen.buffer(offset=offset, width=width, height=height, scale=(0.05, 0.05), contain=True)
+        width, height = 0, 0
+        buf1, size = pen.buffer(width=width, height=height, transform=t, contain=True)
         buf2 = zlib.decompress(base64.b64decode(ZLIB_B64_BIN))
         self.assertEqual(len(buf1), len(buf2))
         self.assertGreater(psnr(buf1, buf2), PSNR_THRESHOLD)