2
0
Files
font/py/arch_cut.py
2026-04-03 12:01:46 +09:00

129 lines
3.8 KiB
Python

#!/usr/bin/env fontforge
"""
Apply arch cut to uppercase A-Z and digit 2-9.
Arch = planet rising from below. The arc curves UPWARD into the bottom of the glyph.
The cut area is removed (transparent), not filled.
"""
import fontforge
import os
import math
SRC_DIR = "/tmp/aifont_meslo"
DST_DIR = "/tmp/aifont_arch"
os.makedirs(DST_DIR, exist_ok=True)
chars = []
for c in range(ord('A'), ord('Z')+1):
chars.append(chr(c))
for c in range(ord('0'), ord('9')+1):
chars.append(chr(c))
# Skip arch for round-bottom characters
skip_arch = set()
WIDTH = 602 # Meslo monospace width
workfont = fontforge.font()
workfont.em = 1000
workfont.encoding = "UnicodeFull"
for g in chars:
cp = ord(g)
src = os.path.join(SRC_DIR, g + ".svg")
if not os.path.exists(src):
continue
glyph = workfont.createChar(cp, g)
glyph.importOutlines(src)
glyph.width = WIDTH
if g not in skip_arch:
bb = glyph.boundingBox()
xmin, ymin, xmax, ymax = bb
h = ymax - ymin
w = xmax - xmin
# How much of the glyph bottom to cut (15%)
cut_depth = h * 0.07
# Large arc radius - the "planet" rising from below
# Larger radius = gentler curve
radius = w * 2.5
# The arc center is below the glyph
cx = (xmin + xmax) / 2.0
# Position so the top of the arc reaches cut_depth into the glyph
cy = ymin - radius + cut_depth
# We need to intersect the glyph with the area ABOVE the arc.
# Strategy: create a large clockwise (additive) shape representing
# "everything above the arc line", then intersect with the glyph.
# Step 1: Clear glyph, we'll rebuild via intersection
# Save current contours by using a temp approach
# Better strategy using fontforge:
# 1. Create a second glyph with a huge filled area that has the arc as its bottom edge
# 2. Use intersect to keep only where glyph and mask overlap
# Create mask glyph: a large rectangle with arc-shaped bottom
mask_cp = 0xE900
mask = workfont.createChar(mask_cp, "mask")
mask.clear()
margin = 200
left = xmin - margin
right = xmax + margin
top = ymax + margin
# The arc: we need points along the arc from left to right
# Arc equation: (x - cx)^2 + (y - cy)^2 = radius^2
# y = cy + sqrt(radius^2 - (x-cx)^2) (upper half of circle)
# Calculate arc endpoints
def arc_y(x):
dx = x - cx
if abs(dx) > radius:
return ymin
return cy + math.sqrt(radius * radius - dx * dx)
# Generate points along the arc
n_points = 40
arc_points = []
for idx in range(n_points + 1):
x = left + (right - left) * idx / n_points
y = arc_y(x)
arc_points.append((x, y))
pen = mask.glyphPen()
# Draw clockwise: top-left -> top-right -> arc from right to left -> close
pen.moveTo((left, top))
pen.lineTo((right, top))
# Go down right side to arc start
pen.lineTo((right, arc_points[-1][1]))
# Follow arc from right to left (reverse order)
for idx in range(n_points - 1, -1, -1):
pen.lineTo(arc_points[idx])
pen.closePath()
pen = None
# Now intersect: keep only the part of glyph inside the mask
glyph.correctDirection()
mask.correctDirection()
# Copy mask into glyph's layer and intersect
workfont.selection.select(mask_cp)
workfont.copy()
workfont.selection.select(cp)
workfont.pasteInto()
glyph.intersect()
# Clean up mask
mask.clear()
dst = os.path.join(DST_DIR, g + ".svg")
glyph.export(dst)
print("Done: " + g)
print("\nAll done! Results: " + DST_DIR)