Add ability to scale cursor images

In ImageMagick 7, the semantics of the opacity channel is flipped.

.github/workflows/build.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [ 3.6, 3.7, 3.8, 3.9 ]
+        python-version: [ 3.7, 3.8, 3.9, '3.10' ]
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python ${{ matrix.python-version }}
@@ -32,6 +32,7 @@ jobs:
       - name: Lint with flake8
         run: flake8 .
       - name: Typecheck with mypy
+        if: matrix.python-version != 3.7
         run: mypy .
       - name: Test packages
         run: python setup.py sdist bdist_wheel

README.md

@@ -1,4 +1,4 @@
-# `win2xcur` and `x2wincur` [![Build Status](https://img.shields.io/github/workflow/status/quantum5/win2xcur/Python%20package)](https://github.com/quantum5/win2xcur/actions) [![PyPI](https://img.shields.io/pypi/v/win2xcur.svg)](https://pypi.org/project/win2xcur/) [![PyPI - Format](https://img.shields.io/pypi/format/win2xcur.svg)](https://pypi.org/project/win2xcur/) [![PyPI - Python Version](https://img.shields.io/pypi/pyversions/win2xcur.svg)](https://pypi.org/project/win2xcur/)
+# `win2xcur` and `x2wincur` [![Build Status](https://img.shields.io/github/actions/workflow/status/quantum5/win2xcur/build.yml)](https://github.com/quantum5/win2xcur/actions) [![PyPI](https://img.shields.io/pypi/v/win2xcur.svg)](https://pypi.org/project/win2xcur/) [![PyPI - Format](https://img.shields.io/pypi/format/win2xcur.svg)](https://pypi.org/project/win2xcur/) [![PyPI - Python Version](https://img.shields.io/pypi/pyversions/win2xcur.svg)](https://pypi.org/project/win2xcur/)
 
 `win2xcur` is a tool that converts cursors from Windows format (`*.cur`,
 `*.ani`) to Xcursor format. This allows Windows cursor themes to be used on
@@ -44,3 +44,11 @@ For example, if you want to convert DMZ-White to Windows:
 
     mkdir dmz-white/
     x2wincur /usr/share/icons/DMZ-White/cursors/* -o dmz-white/
+
+## Troubleshooting
+
+`win2xcur` and `x2wincur` should work out of the box on most systems. If you
+are using unconventional distros (e.g. Alpine) and are getting errors related
+to `wand`, please see the [Wand documentation on installation][wand-install].
+
+  [wand-install]: https://docs.wand-py.org/en/0.6.7/guide/install.html

mypy.ini

@@ -1,3 +1,4 @@
 [mypy]
 ignore_missing_imports = True
 strict = true
+plugins = numpy.typing.mypy_plugin

setup.py

@@ -7,7 +7,7 @@ with open(os.path.join(os.path.dirname(__file__), 'README.md')) as f:
 
 setup(
     name='win2xcur',
-    version='0.1.0',
+    version='0.1.2',
     packages=find_packages(),
     install_requires=['numpy', 'Wand'],
 

win2xcur/main/win2xcur.py

@@ -7,7 +7,7 @@ from multiprocessing.pool import ThreadPool
 from threading import Lock
 from typing import BinaryIO
 
-from win2xcur import shadow
+from win2xcur import scale, shadow
 from win2xcur.parser import open_blob
 from win2xcur.writer import to_x11
 
@@ -29,9 +29,11 @@ def main() -> None:
     parser.add_argument('-x', '--shadow-x', type=float, default=0.05,
                         help='x-offset of shadow (as fraction of width)')
     parser.add_argument('-y', '--shadow-y', type=float, default=0.05,
-                        help='x-offset of shadow (as fraction of height)')
+                        help='y-offset of shadow (as fraction of height)')
     parser.add_argument('-c', '--shadow-color', default='#000000',
                         help='color of the shadow')
+    parser.add_argument('--scale', default=None, type=float,
+                        help='Scale the cursor by the specified factor.')
 
     args = parser.parse_args()
     print_lock = Lock()
@@ -46,6 +48,8 @@ def main() -> None:
                 print(f'Error occurred while processing {name}:', file=sys.stderr)
                 traceback.print_exc()
         else:
+            if args.scale:
+                scale.apply_to_frames(cursor.frames, scale=args.scale)
             if args.shadow:
                 shadow.apply_to_frames(cursor.frames, color=args.shadow_color, radius=args.shadow_radius,
                                        sigma=args.shadow_sigma, xoffset=args.shadow_x, yoffset=args.shadow_y)

win2xcur/main/x2wincur.py

@@ -7,6 +7,7 @@ from multiprocessing.pool import ThreadPool
 from threading import Lock
 from typing import BinaryIO
 
+from win2xcur import scale
 from win2xcur.parser import open_blob
 from win2xcur.writer import to_smart
 
@@ -17,6 +18,8 @@ def main() -> None:
                         help='X11 cursor files to convert (no extension)')
     parser.add_argument('-o', '--output', '--output-dir', default=os.curdir,
                         help='Directory to store converted cursor files.')
+    parser.add_argument('-S', '--scale', default=None, type=float,
+                        help='Scale the cursor by the specified factor.')
 
     args = parser.parse_args()
     print_lock = Lock()
@@ -31,6 +34,8 @@ def main() -> None:
                 print(f'Error occurred while processing {name}:', file=sys.stderr)
                 traceback.print_exc()
         else:
+            if args.scale:
+                scale.apply_to_frames(cursor.frames, scale=args.scale)
             ext, result = to_smart(cursor.frames)
             output = os.path.join(args.output, os.path.basename(name) + ext)
             with open(output, 'wb') as f:

win2xcur/parser/xcursor.py

@@ -49,6 +49,7 @@ class XCursorParser(BaseParser):
 
             size, actual_type, nominal_size, version, width, height, x_offset, y_offset, delay = \
                 self._unpack(self.IMAGE_HEADER, position)
+            delay /= 1000
 
             if size != self.IMAGE_HEADER.size:
                 raise ValueError(f'Unexpected size: {size}, expected {self.IMAGE_HEADER.size}')

win2xcur/scale.py

@@ -0,0 +1,12 @@
+from typing import List
+
+from win2xcur.cursor import CursorFrame
+
+
+def apply_to_frames(frames: List[CursorFrame], *, scale: float) -> None:
+    for frame in frames:
+        for cursor in frame:
+            cursor.image.scale(
+                int(round(cursor.image.width * scale)),
+                int(round(cursor.image.height) * scale),
+            )

win2xcur/shadow.py

@@ -1,10 +1,17 @@
 from typing import List
 
 from wand.color import Color
-from wand.image import BaseImage, Image
+from wand.image import BaseImage, COMPOSITE_OPERATORS, Image
 
 from win2xcur.cursor import CursorFrame
 
+if 'copy_opacity' in COMPOSITE_OPERATORS:
+    COPY_ALPHA = 'copy_opacity'  # ImageMagick 6 name
+    NEEDS_NEGATE = False
+else:
+    COPY_ALPHA = 'copy_alpha'  # ImageMagick 7 name
+    NEEDS_NEGATE = True
+
 
 def apply_to_image(image: BaseImage, *, color: str, radius: float, sigma: float, xoffset: float,
                    yoffset: float) -> Image:
@@ -13,18 +20,24 @@ def apply_to_image(image: BaseImage, *, color: str, radius: float, sigma: float,
     new_width = image.width + 3 * xoffset
     new_height = image.height + 3 * yoffset
 
+    if NEEDS_NEGATE:
+        channel = image.channel_images['opacity'].clone()
+        channel.negate()
+    else:
+        channel = image.channel_images['opacity']
+
     opacity = Image(width=new_width, height=new_height, pseudo='xc:white')
-    opacity.composite(image.channel_images['opacity'], left=xoffset, top=yoffset)
+    opacity.composite(channel, left=xoffset, top=yoffset)
     opacity.gaussian_blur(radius * image.width, sigma * image.width)
     opacity.negate()
     opacity.modulate(50)
 
     shadow = Image(width=new_width, height=new_height, pseudo='xc:' + color)
-    shadow.composite(opacity, operator='copy_opacity')
+    shadow.composite(opacity, operator=COPY_ALPHA)
 
     result = Image(width=new_width, height=new_height, pseudo='xc:transparent')
+    result.composite(shadow)
     result.composite(image)
-    result.composite(shadow, operator='difference')
 
     trimmed = result.clone()
     trimmed.trim(color=Color('transparent'))

win2xcur/utils.py

@@ -1,12 +1,12 @@
-from typing import cast
+from typing import Any
 
-import numpy
+import numpy as np
 
 
 def premultiply_alpha(source: bytes) -> bytes:
-    buffer = numpy.frombuffer(source, dtype=numpy.uint8).astype(numpy.double)
+    buffer: np.ndarray[Any, np.dtype[np.double]] = np.frombuffer(source, dtype=np.uint8).astype(np.double)
     alpha = buffer[3::4] / 255.0
     buffer[0::4] *= alpha
     buffer[1::4] *= alpha
     buffer[2::4] *= alpha
-    return cast(bytes, buffer.astype(numpy.uint8).tobytes())
+    return buffer.astype(np.uint8).tobytes()