Rewrite generate_svg skeleton around arc geometry (body/rim/pivot only)

web/app.py

@@ -52,18 +52,40 @@ def _load_fonts():
 _FONTS = _load_fonts()
 _DEFAULT_FONT = 'alte-din-1451-mittelschrift.regular'
 
-# SVG absolute coordinate constants (1 user unit = 1 mm)
+# SVG absolute coordinate constants (1 user unit = 1 mm), pre-layer-translate
-ZERO_X    = 60.844130
+# local frame — the <g> wrapper applies translate(-60.717741,-107.14126).
-MAX_X     = 180.251230
+PIVOT_X, PIVOT_Y = 107.42845, 162.62819
-BAR_Y     = 107.54670
+R0 = 43.842751          # rim / inner-tick radius
-SCALE_LEN = MAX_X - ZERO_X   # 119.4071 mm
+ANGLE_MIN, ANGLE_MAX = -45.667193, 45.667193   # degrees from vertical, clockwise-positive
 
-BIG_H   = 5.0895
+MAJOR_LEN,  MAJOR_W  = 4.7839203, 0.79658329
-SMALL_H = 2.6683
+MEDIUM_LEN, MEDIUM_W = 3.1215858, 0.37985462
+SMALL_LEN,  SMALL_W  = 1.8121802, 0.27478597
 
-_UNIT_AREA_WIDTH = 18.445
+LABEL_RADIUS = 49.862
-_UNIT_SCALE_X    = 0.96486402
+
-_UNIT_MAX_FS     = 18.7981
+UNIT_X, UNIT_Y = 107.03512, 136.64594
+
+LEFT_X, LEFT_Y0   = 73.432251, 145.16051
+RIGHT_X, RIGHT_Y0 = 142.4485, 145.32773
+CORNER_LINE_SPACING = 4.4586
+CORNER_FONT_SIZE = 3.56685
+
+PIVOT_CIRCLE_R = 1.7287594
+
+BODY_D = (
+    "m 62.162097,107.14126 c -0.800087,0 -1.444356,0.64428 -1.444356,1.44436 v 45.44839 "
+    "c 0,0.80008 0.644269,1.44436 1.444356,1.44436 h 7.345288 c 0.902634,0 1.233517,1.12706 "
+    "1.233517,1.12706 l 0.09043,3.03909 21.903573,-0.0904 2.226221,-5.98775 c 8.352594,-2.8884 "
+    "16.624974,-2.8884 24.817094,0 l 2.22674,5.98775 21.90357,0.0904 0.0904,-3.03909 c 0,0 "
+    "0.33088,-1.12706 1.23352,-1.12706 h 7.86567 c 0.80009,0 1.44384,-0.64428 1.44384,-1.44436 "
+    "v -45.44839 c 0,-0.80008 -0.64375,-1.44436 -1.44384,-1.44436 z m 29.619898,45.85354 "
+    "a 1.3990685,1.3990685 0 0 1 1.398881,1.39939 1.3990685,1.3990685 0 0 1 -1.398881,1.39888 "
+    "1.3990685,1.3990685 0 0 1 -1.399398,-1.39888 1.3990685,1.3990685 0 0 1 1.399398,-1.39939 "
+    "z m 31.220835,0 a 1.3990685,1.3990685 0 0 1 1.39888,1.39939 1.3990685,1.3990685 0 0 1 "
+    "-1.39888,1.39888 1.3990685,1.3990685 0 0 1 -1.3994,-1.39888 1.3990685,1.3990685 0 0 1 "
+    "1.3994,-1.39939 z"
+)
 
 # --- Inline markup for the unit label -------------------------------------
 _SUP_SCALE = 0.62
@@ -74,9 +96,15 @@ _FRAC_AXIS  = 0.32
 _FRAC_GAP   = 0.14
 _FRAC_SIDE  = 0.12
 
-_UNIT_BOX_X0, _UNIT_BOX_X1 = 39.6, 57.4
+_UNIT_BOX_X0, _UNIT_BOX_X1 = UNIT_X - 15.0, UNIT_X + 15.0
-_UNIT_BOX_Y0, _UNIT_BOX_Y1 = 92.8, 114.8
+_UNIT_BOX_Y0, _UNIT_BOX_Y1 = UNIT_Y - 6.0, UNIT_Y + 6.0
-_UNIT_BOX_HALF_Y0 = (_UNIT_BOX_Y0 + _UNIT_BOX_Y1) / 2  # 103.8 — bottom half starts here
+_UNIT_MAX_FS = 9.46938021
+_UNIT_SCALE_X = 1.0
+
+
+def _point_at(radius: float, angle_deg: float):
+    th = math.radians(angle_deg)
+    return PIVOT_X + radius * math.sin(th), PIVOT_Y - radius * math.cos(th)
 
 
 def _glyph_svg(ch: str, x: float, y: float, fs: float, fill: str, fd: _FontData):
@@ -247,11 +275,10 @@ def _has_markup(s: str) -> bool:
     return any(c in s for c in '^_') or ('{' in s and '}' in s)
 
 
-def _markup_unit_svg(unit: str, fd: _FontData, fill='#1a1a1a', box_y0=None, box_y1=None) -> str:
+def _markup_unit_svg(unit: str, fd: _FontData, fill='#1a1a1a') -> str:
     nodes = _parse_markup(unit)
     x0, x1 = _UNIT_BOX_X0, _UNIT_BOX_X1
-    y0 = box_y0 if box_y0 is not None else _UNIT_BOX_Y0
+    y0, y1 = _UNIT_BOX_Y0, _UNIT_BOX_Y1
-    y1 = box_y1 if box_y1 is not None else _UNIT_BOX_Y1
     xc, yc = (x0 + x1) / 2, (y0 + y1) / 2
 
     w1 = _measure(nodes, 1.0, fd)
@@ -270,13 +297,6 @@ def _markup_unit_svg(unit: str, fd: _FontData, fill='#1a1a1a', box_y0=None, box_
     return f'<g transform="{cond}">\n{chr(10).join(parts)}\n</g>'
 
 
-def _unit_font_size(unit: str, fd: _FontData) -> float:
-    em_w = _measure(_parse_markup(unit), 1.0, fd)
-    if em_w <= 0:
-        return _UNIT_MAX_FS
-    return min(_UNIT_MAX_FS, _UNIT_AREA_WIDTH / (em_w * _UNIT_SCALE_X))
-
-
 def _text_to_paths(text, x, y, font_size, fd: _FontData, anchor='start', fill='#1a1a1a', wrap_transform=None):
     s = font_size / fd.upm
 
@@ -319,90 +339,10 @@ def _fmt(v: float) -> str:
     return s.rstrip('0').rstrip('.') if '.' in s else s
 
 
-def generate_svg(unit, min_val, max_val, range_label, big_ticks, small_ticks, label_count,
+def generate_svg(unit, min_val, max_val, left_label, right_label, big_ticks, small_ticks,
-                 use_paths=True, scale_type='linear', custom_labels=None, label_size=9,
+                 label_count, use_paths=True, scale_type='linear', custom_labels=None,
-                 font_key=None, half_height_unit=False):
+                 label_size=5.1126, font_key=None):
     fd = _FONTS.get(font_key) or _FONTS.get(_DEFAULT_FONT) or next(iter(_FONTS.values()))
-    unit_box_y0 = _UNIT_BOX_HALF_Y0 if half_height_unit else None
-
-    if scale_type == 'log':
-        if min_val <= 0 or max_val <= 0:
-            raise ValueError("Logarithmic scale requires min and max values greater than 0.")
-        lmin, lmax = math.log(min_val), math.log(max_val)
-        lspan = lmax - lmin
-        if lspan == 0:
-            raise ValueError("Logarithmic scale requires min and max values to differ.")
-
-        def value_to_x(v):
-            return ZERO_X + SCALE_LEN * (math.log(v) - lmin) / lspan
-
-        def major_value(i):
-            return min_val * (max_val / min_val) ** (i / big_ticks)
-
-    elif scale_type == 'sqrt':
-        if min_val < 0:
-            raise ValueError("Square-root scale requires min value ≥ 0.")
-        span = max_val - min_val
-        if span <= 0:
-            raise ValueError("Square-root scale requires max value greater than min.")
-
-        def value_to_x(v):
-            return ZERO_X + SCALE_LEN * math.sqrt((v - min_val) / span)
-
-        def major_value(i):
-            return min_val + span * (i / big_ticks) ** 2
-
-    elif scale_type == 'reciprocal':
-        if min_val <= 0:
-            raise ValueError("Reciprocal scale requires min and max values greater than 0.")
-        if not math.isinf(max_val) and max_val <= min_val:
-            raise ValueError("Reciprocal scale requires max value greater than min.")
-        if math.isinf(max_val):
-            def value_to_x(v):
-                if math.isinf(v):
-                    return ZERO_X
-                return ZERO_X + SCALE_LEN * min_val / v
-
-            def major_value(i):
-                if i == 0:
-                    return math.inf
-                return min_val * big_ticks / i
-        else:
-            if max_val <= 0:
-                raise ValueError("Reciprocal scale requires min and max values greater than 0.")
-            k = 1.0 / min_val - 1.0 / max_val
-
-            def value_to_x(v):
-                return ZERO_X + SCALE_LEN * (1.0 / v - 1.0 / max_val) / k
-
-            def major_value(i):
-                return 1.0 / (1.0 / max_val + i / big_ticks * k)
-
-    else:
-        span = max_val - min_val
-
-        def value_to_x(v):
-            if span == 0:
-                return ZERO_X
-            return ZERO_X + SCALE_LEN * (v - min_val) / span
-
-        def major_value(i):
-            return min_val + span * i / big_ticks
-
-    big_interval = SCALE_LEN / big_ticks
-    big_xs = [ZERO_X + i * big_interval for i in range(big_ticks + 1)]
-    big_vals = [major_value(i) for i in range(big_ticks + 1)]
-
-    if custom_labels:
-        label_count = max(1, min(len(custom_labels), big_ticks + 1))
-        custom_labels = custom_labels[:label_count]
-    else:
-        label_count = max(2, min(label_count, big_ticks + 1))
-
-    if label_count == 1:
-        label_indices = [0]
-    else:
-        label_indices = [round(k * big_ticks / (label_count - 1)) for k in range(label_count)]
 
     font_face = (
         '<defs><style>'
@@ -413,77 +353,35 @@ def generate_svg(unit, min_val, max_val, range_label, big_ticks, small_ticks, la
 
     parts = [
         '<?xml version="1.0" encoding="UTF-8" standalone="no"?>',
-        '<svg width="157.18373mm" height="26.683672mm"'
+        '<svg width="93.824249mm" height="57.215687mm"'
-        ' viewBox="0 0 157.18373 26.683672" version="1.1"'
+        ' viewBox="0 0 93.824249 57.215687" version="1.1"'
         ' xmlns="http://www.w3.org/2000/svg">',
     ]
 
     if use_paths:
-        parts.append('  <g transform="translate(-37.352226,-90.454928)">')
+        parts.append('  <g transform="translate(-60.717741,-107.14126)">')
     else:
-        parts += [font_face, '  <g transform="translate(-37.352226,-90.454928)">']
+        parts += [font_face, '  <g transform="translate(-60.717741,-107.14126)">']
 
     parts.append(
-        '    <path style="fill:#ffffff;stroke:#1a1a1a;stroke-width:0.184;'
+        f'    <path style="fill:#f9f9f9;stroke:#1a1a1a;stroke-width:0.184;'
-        'stroke-linecap:round;stroke-miterlimit:10"'
+        f'stroke-linecap:round;stroke-miterlimit:10" d="{BODY_D}" />'
-        ' d="M 37.444226,90.546928 V 117.0466 H 194.44395 V 90.546928 Z'
-        ' M 58.443978,107.54692 H 183.64409 v 6.19963 H 58.443978 Z" />'
     )
 
-    # Paths mode and any unit needing special handling (markup, half-height):
+    p0 = _point_at(R0, ANGLE_MIN)
-    # use _markup_unit_svg which fits actual ink bounds to the box, giving
+    pmid = _point_at(R0, 0.0)
-    # correct sizing for all fonts. Text mode for plain normal-height units
+    p1 = _point_at(R0, ANGLE_MAX)
-    # keeps live <text> nodes; half-height always uses paths for correct centering.
-    if use_paths or _has_markup(unit) or half_height_unit:
-        unit_svg = '    ' + _markup_unit_svg(unit, fd, box_y0=unit_box_y0)
-    else:
-        fs = _unit_font_size(unit, fd)
-        unit_svg = (
-            f'    <text style="font-size:{fs:.4f}px;font-family:\'{fd.label}\',monospace;fill:#1a1a1a"'
-            f' x="41.455711" y="109.03796"'
-            f' transform="scale({_UNIT_SCALE_X},1.0364155)">{escape(unit)}</text>'
-        )
-
-    if use_paths:
-        parts += [unit_svg, '    ' + _text_to_paths(range_label, 184.79707, 113.6755, 3.60539, fd)]
-    else:
-        parts += [
-            unit_svg,
-            f'    <text style="font-size:3.60539px;font-family:\'{fd.label}\',monospace;fill:#1a1a1a"'
-            f' x="184.79707" y="113.6755">{escape(range_label)}</text>',
-        ]
-
-    for x in big_xs:
     parts.append(
-            f'    <line x1="{x:.5f}" y1="{BAR_Y}" x2="{x:.5f}" y2="{BAR_Y - BIG_H:.5f}"'
+        f'    <path style="fill:none;stroke:#000000;stroke-width:0.484;'
-            f' style="stroke:#1a1a1a;stroke-width:0.555;stroke-linecap:butt" />'
+        f'stroke-linecap:round;stroke-miterlimit:10"'
+        f' d="M {p0[0]:.5f},{p0[1]:.5f} A {R0},{R0} 0 0 1 {pmid[0]:.5f},{pmid[1]:.5f}'
+        f' A {R0},{R0} 0 0 1 {p1[0]:.5f},{p1[1]:.5f}" />'
     )
 
-    if small_ticks > 0:
-        sub = small_ticks + 1
-        for i in range(big_ticks):
-            for j in range(1, small_ticks + 1):
-                if scale_type == 'sqrt':
-                    x = big_xs[i] + (j / sub) ** 2 * (big_xs[i + 1] - big_xs[i])
-                elif scale_type == 'reciprocal' or math.isinf(big_vals[i]):
-                    x = big_xs[i] + (j / sub) * (big_xs[i + 1] - big_xs[i])
-                else:
-                    v = big_vals[i] + j * (big_vals[i + 1] - big_vals[i]) / sub
-                    x = value_to_x(v)
     parts.append(
-                    f'    <line x1="{x:.5f}" y1="{BAR_Y}" x2="{x:.5f}" y2="{BAR_Y - SMALL_H:.5f}"'
+        f'    <circle style="fill:none;stroke:#b3b3b3;stroke-width:0.184;'
-                    f' style="stroke:#1a1a1a;stroke-width:0.302;stroke-linecap:butt" />'
+        f'stroke-linecap:round;stroke-miterlimit:10"'
-                )
+        f' cx="{PIVOT_X:.5f}" cy="{PIVOT_Y:.5f}" r="{PIVOT_CIRCLE_R}" />'
-
-    for k, idx in enumerate(label_indices):
-        x = big_xs[idx]
-        label = custom_labels[k] if custom_labels else _fmt(big_vals[idx])
-        if use_paths:
-            parts.append('    ' + _text_to_paths(label, x, 101.49598, label_size, fd, anchor='middle'))
-        else:
-            parts.append(
-                f'    <text style="font-size:{label_size:.5f}px;font-family:\'{fd.label}\',monospace;fill:#1a1a1a"'
-                f' text-anchor="middle" x="{x:.5f}" y="101.49598">{escape(label)}</text>'
     )
 
     parts += ['  </g>', '</svg>']
@@ -502,24 +400,24 @@ def generate():
     unit        = request.form.get('unit', '%')
     min_val     = float(request.form.get('min', 0))
     max_val     = float(request.form.get('max', 100))
-    range_label = request.form.get('range_label', '5mA')
+    left_label  = request.form.get('left_label', '')
+    right_label = request.form.get('right_label', '')
     big_ticks   = max(1, min(50, int(request.form.get('big_ticks', 10))))
     small_ticks = max(0, min(20, int(request.form.get('small_ticks', 4))))
     label_count = max(2, int(request.form.get('label_count', 6)))
     use_paths   = request.form.get('output_mode', 'paths') == 'paths'
     scale_type  = request.form.get('scale_type', 'linear')
     font_key    = request.form.get('font', _DEFAULT_FONT)
-    half_height_unit = request.form.get('half_height_unit') == '1'
     if request.form.get('max_is_inf') == '1':
         max_val = math.inf
 
     custom_labels = [s.strip() for s in request.form.get('labels', '').split(',') if s.strip()] or None
-    label_size    = max(0.5, min(25.0, float(request.form.get('label_size', 9))))
+    label_size    = max(0.5, min(25.0, float(request.form.get('label_size', 5.1126))))
 
     try:
-        svg = generate_svg(unit, min_val, max_val, range_label, big_ticks, small_ticks,
+        svg = generate_svg(unit, min_val, max_val, left_label, right_label, big_ticks,
-                           label_count, use_paths, scale_type, custom_labels, label_size,
+                           small_ticks, label_count, use_paths, scale_type, custom_labels,
-                           font_key, half_height_unit)
+                           label_size, font_key)
     except ValueError as err:
         return Response(str(err), status=400, mimetype='text/plain')
     return Response(svg, mimetype='image/svg+xml')