added cone option (#24)

src/ttmask/__init__.py

@@ -14,5 +14,6 @@
 from .cylinder import cylinder
 from .cuboid import cuboid
 from .cube import cube
+from .cone import cone
 
 

src/ttmask/cone.py

@@ -0,0 +1,67 @@
+import numpy as np
+import einops
+import typer
+from scipy.ndimage import distance_transform_edt
+import mrcfile
+from ._cli import cli
+
+
+@cli.command(name='cone')
+def cone(
+    sidelength: int = typer.Option(...),
+    cone_height: float = typer.Option(...),
+    cone_base_diameter: float = typer.Option(...),
+    soft_edge_width: int = typer.Option(0),
+    mrc_voxel_size: float = typer.Option(...),
+    output: str = typer.Option("cone.mrc")
+):
+    c = sidelength // 2
+    center = np.array([c, c, c])
+    mask = np.zeros(shape=(sidelength, sidelength, sidelength), dtype=np.float32)
+
+    # 3d positions of all voxels
+    positions = np.indices([sidelength, sidelength, sidelength])
+    positions = einops.rearrange(positions, 'zyx d h w -> d h w zyx')
+
+    centered = positions - center  #pixels relative to center point
+    magnitudes = np.linalg.norm(centered, axis=-1)
+
+    magnitudes = einops.rearrange(magnitudes, 'd h w -> d h w 1')
+
+    # Check for zeros in magnitudes and replace them with a small value to avoid Nan warning
+    near_zero = 1e-8
+    magnitudes = np.where(magnitudes == 0, near_zero, magnitudes)
+    normalised = centered / magnitudes
+
+    principal_axis = np.array([1, 0, 0])
+    dot_product = np.dot(normalised, principal_axis)
+    angles_radians = np.arccos(dot_product)
+    angles = np.rad2deg(angles_radians)
+
+    z_distance = centered[:, :, :, 0]  # (100, 100, 100)
+
+    # Calculate the angle from the tip of the cone to the edge of the base
+    cone_base_radius = cone_base_diameter / 2
+    cone_angle = np.rad2deg(np.arctan(cone_base_radius / cone_height))
+
+    within_cone_height = z_distance < cone_height
+    within_cone_angle = angles < cone_angle
+
+    # mask[within_cone_height] = 1
+    mask[np.logical_and(within_cone_height, within_cone_angle)] = 1
+
+    # Shift the mask in the z-axis by cone_height / 2
+    z_shift = -int(cone_height / 2)
+    mask = np.roll(mask, z_shift, axis=0)
+
+
+    distance_from_edge = distance_transform_edt(mask == 0)
+    boundary_pixels = (distance_from_edge <= soft_edge_width) & (distance_from_edge != 0)
+    normalised_distance_from_edge = (distance_from_edge[boundary_pixels] / soft_edge_width) * np.pi
+
+    mask[boundary_pixels] = (0.5 * np.cos(normalised_distance_from_edge) + 0.5)
+
+
+    mrcfile.write(output, mask, voxel_size= mrc_voxel_size, overwrite=True)
+
+