from fontTools.ttLib import newTable from fontTools.ttLib.tables._f_v_a_r import Axis as fvarAxis from fontTools.pens.areaPen import AreaPen from fontTools.pens.basePen import NullPen from fontTools.pens.statisticsPen import StatisticsPen from fontTools.varLib.models import piecewiseLinearMap, normalizeValue from fontTools.misc.cliTools import makeOutputFileName import math import logging from pprint import pformat __all__ = [ "planWeightAxis", "planWidthAxis", "planSlantAxis", "planOpticalSizeAxis", "planAxis", "sanitizeWeight", "sanitizeWidth", "sanitizeSlant", "measureWeight", "measureWidth", "measureSlant", "interpolateLinear", "interpolateLog", "makeDesignspaceSnippet", "addEmptyAvar", "main", ] log = logging.getLogger("fontTools.varLib.avarPlanner") WEIGHTS = [ 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, ] WIDTHS = [ 25.0, 37.5, 50.0, 62.5, 75.0, 87.5, 100.0, 112.5, 125.0, 137.5, 150.0, 162.5, 175.0, 187.5, 200.0, ] SLANTS = list(math.degrees(math.atan(d / 20.0)) for d in range(-20, 21)) SIZES = [ 8, 9, 10, 11, 12, 14, 18, 24, 30, 36, 48, 60, 72, 96, ] SAMPLES = 8 def interpolateLinear(t, a, b): """Linear interpolation between a and b, with t typically in [0, 1].""" return a + t * (b - a) def interpolateLog(t, a, b): """Logarithmic interpolation between a and b, with t typically in [0, 1].""" logA = math.log(a) logB = math.log(b) return math.exp(logA + t * (logB - logA)) def measureWeight(glyphset, glyphs=None): """Measure the perceptual average weight of the given glyphs.""" if isinstance(glyphs, dict): frequencies = glyphs else: frequencies = {g: 1 for g in glyphs} wght_sum = wdth_sum = 0 for glyph_name in glyphs: if frequencies is not None: frequency = frequencies.get(glyph_name, 0) if frequency == 0: continue else: frequency = 1 glyph = glyphset[glyph_name] pen = AreaPen(glyphset=glyphset) glyph.draw(pen) mult = glyph.width * frequency wght_sum += mult * abs(pen.value) wdth_sum += mult return wght_sum / wdth_sum def measureWidth(glyphset, glyphs=None): """Measure the average width of the given glyphs.""" if isinstance(glyphs, dict): frequencies = glyphs else: frequencies = {g: 1 for g in glyphs} wdth_sum = 0 freq_sum = 0 for glyph_name in glyphs: if frequencies is not None: frequency = frequencies.get(glyph_name, 0) if frequency == 0: continue else: frequency = 1 glyph = glyphset[glyph_name] pen = NullPen() glyph.draw(pen) wdth_sum += glyph.width * frequency freq_sum += frequency return wdth_sum / freq_sum def measureSlant(glyphset, glyphs=None): """Measure the perceptual average slant angle of the given glyphs.""" if isinstance(glyphs, dict): frequencies = glyphs else: frequencies = {g: 1 for g in glyphs} slnt_sum = 0 freq_sum = 0 for glyph_name in glyphs: if frequencies is not None: frequency = frequencies.get(glyph_name, 0) if frequency == 0: continue else: frequency = 1 glyph = glyphset[glyph_name] pen = StatisticsPen(glyphset=glyphset) glyph.draw(pen) mult = glyph.width * frequency slnt_sum += mult * pen.slant freq_sum += mult return -math.degrees(math.atan(slnt_sum / freq_sum)) def sanitizeWidth(userTriple, designTriple, pins, measurements): """Sanitize the width axis limits.""" minVal, defaultVal, maxVal = ( measurements[designTriple[0]], measurements[designTriple[1]], measurements[designTriple[2]], ) calculatedMinVal = userTriple[1] * (minVal / defaultVal) calculatedMaxVal = userTriple[1] * (maxVal / defaultVal) log.info("Original width axis limits: %g:%g:%g", *userTriple) log.info( "Calculated width axis limits: %g:%g:%g", calculatedMinVal, userTriple[1], calculatedMaxVal, ) if ( abs(calculatedMinVal - userTriple[0]) / userTriple[1] > 0.05 or abs(calculatedMaxVal - userTriple[2]) / userTriple[1] > 0.05 ): log.warning("Calculated width axis min/max do not match user input.") log.warning( " Current width axis limits: %g:%g:%g", *userTriple, ) log.warning( " Suggested width axis limits: %g:%g:%g", calculatedMinVal, userTriple[1], calculatedMaxVal, ) return False return True def sanitizeWeight(userTriple, designTriple, pins, measurements): """Sanitize the weight axis limits.""" if len(set(userTriple)) < 3: return True minVal, defaultVal, maxVal = ( measurements[designTriple[0]], measurements[designTriple[1]], measurements[designTriple[2]], ) logMin = math.log(minVal) logDefault = math.log(defaultVal) logMax = math.log(maxVal) t = (userTriple[1] - userTriple[0]) / (userTriple[2] - userTriple[0]) y = math.exp(logMin + t * (logMax - logMin)) t = (y - minVal) / (maxVal - minVal) calculatedDefaultVal = userTriple[0] + t * (userTriple[2] - userTriple[0]) log.info("Original weight axis limits: %g:%g:%g", *userTriple) log.info( "Calculated weight axis limits: %g:%g:%g", userTriple[0], calculatedDefaultVal, userTriple[2], ) if abs(calculatedDefaultVal - userTriple[1]) / userTriple[1] > 0.05: log.warning("Calculated weight axis default does not match user input.") log.warning( " Current weight axis limits: %g:%g:%g", *userTriple, ) log.warning( " Suggested weight axis limits, changing default: %g:%g:%g", userTriple[0], calculatedDefaultVal, userTriple[2], ) t = (userTriple[2] - userTriple[0]) / (userTriple[1] - userTriple[0]) y = math.exp(logMin + t * (logDefault - logMin)) t = (y - minVal) / (defaultVal - minVal) calculatedMaxVal = userTriple[0] + t * (userTriple[1] - userTriple[0]) log.warning( " Suggested weight axis limits, changing maximum: %g:%g:%g", userTriple[0], userTriple[1], calculatedMaxVal, ) t = (userTriple[0] - userTriple[2]) / (userTriple[1] - userTriple[2]) y = math.exp(logMax + t * (logDefault - logMax)) t = (y - maxVal) / (defaultVal - maxVal) calculatedMinVal = userTriple[2] + t * (userTriple[1] - userTriple[2]) log.warning( " Suggested weight axis limits, changing minimum: %g:%g:%g", calculatedMinVal, userTriple[1], userTriple[2], ) return False return True def sanitizeSlant(userTriple, designTriple, pins, measurements): """Sanitize the slant axis limits.""" log.info("Original slant axis limits: %g:%g:%g", *userTriple) log.info( "Calculated slant axis limits: %g:%g:%g", measurements[designTriple[0]], measurements[designTriple[1]], measurements[designTriple[2]], ) if ( abs(measurements[designTriple[0]] - userTriple[0]) > 1 or abs(measurements[designTriple[1]] - userTriple[1]) > 1 or abs(measurements[designTriple[2]] - userTriple[2]) > 1 ): log.warning("Calculated slant axis min/default/max do not match user input.") log.warning( " Current slant axis limits: %g:%g:%g", *userTriple, ) log.warning( " Suggested slant axis limits: %g:%g:%g", measurements[designTriple[0]], measurements[designTriple[1]], measurements[designTriple[2]], ) return False return True def planAxis( axisTag, measureFunc, interpolateFunc, glyphSetFunc, axisLimits, values=None, samples=None, glyphs=None, designLimits=None, pins=None, sanitizeFunc=None, ): """Plan an axis.""" if isinstance(axisLimits, fvarAxis): axisLimits = (axisLimits.minValue, axisLimits.defaultValue, axisLimits.maxValue) minValue, defaultValue, maxValue = axisLimits if samples is None: samples = SAMPLES if glyphs is None: glyphs = glyphSetFunc({}).keys() if pins is None: pins = {} else: pins = pins.copy() log.info("Value min %g / default %g / max %g", minValue, defaultValue, maxValue) triple = (minValue, defaultValue, maxValue) if designLimits is not None: log.info("Value design-limits min %g / default %g / max %g", *designLimits) else: designLimits = triple # if "avar" in font: # log.debug("Checking that font doesn't have axis mapping already.") # existingMapping = font["avar"].segments[axisTag] # if existingMapping and existingMapping != {-1: -1, 0: 0, +1: +1}: # log.error("Font already has a `avar` value mapping. Remove it.") if pins: log.info("Pins %s", sorted(pins.items())) pins.update( { minValue: designLimits[0], defaultValue: designLimits[1], maxValue: designLimits[2], } ) out = {} outNormalized = {} axisMeasurements = {} for value in sorted({minValue, defaultValue, maxValue} | set(pins.keys())): glyphset = glyphSetFunc(location={axisTag: value}) designValue = pins[value] axisMeasurements[designValue] = measureFunc(glyphset, glyphs) if sanitizeFunc is not None: log.info("Sanitizing axis limit values for the `%s` axis.", axisTag) sanitizeFunc(triple, designLimits, pins, axisMeasurements) log.debug("Calculated average value:\n%s", pformat(axisMeasurements)) for (rangeMin, targetMin), (rangeMax, targetMax) in zip( list(sorted(pins.items()))[:-1], list(sorted(pins.items()))[1:], ): targetValues = {w for w in values if rangeMin < w < rangeMax} if not targetValues: continue normalizedMin = normalizeValue(rangeMin, triple) normalizedMax = normalizeValue(rangeMax, triple) normalizedTargetMin = normalizeValue(targetMin, designLimits) normalizedTargetMax = normalizeValue(targetMax, designLimits) log.info("Planning target values %s.", sorted(targetValues)) log.info("Sampling %u points in range %g,%g.", samples, rangeMin, rangeMax) valueMeasurements = axisMeasurements.copy() for sample in range(1, samples + 1): value = rangeMin + (rangeMax - rangeMin) * sample / (samples + 1) log.debug("Sampling value %g.", value) glyphset = glyphSetFunc(location={axisTag: value}) designValue = piecewiseLinearMap(value, pins) valueMeasurements[designValue] = measureFunc(glyphset, glyphs) log.debug("Sampled average value:\n%s", pformat(valueMeasurements)) measurementValue = {} for value in sorted(valueMeasurements): measurementValue[valueMeasurements[value]] = value out[rangeMin] = targetMin outNormalized[normalizedMin] = normalizedTargetMin for value in sorted(targetValues): t = (value - rangeMin) / (rangeMax - rangeMin) targetMeasurement = interpolateFunc( t, valueMeasurements[targetMin], valueMeasurements[targetMax] ) targetValue = piecewiseLinearMap(targetMeasurement, measurementValue) log.debug("Planned mapping value %g to %g." % (value, targetValue)) out[value] = targetValue outNormalized[ normalizedMin + t * (normalizedMax - normalizedMin) ] = normalizedTargetMin + (targetValue - targetMin) / ( targetMax - targetMin ) * ( normalizedTargetMax - normalizedTargetMin ) out[rangeMax] = targetMax outNormalized[normalizedMax] = normalizedTargetMax log.info("Planned mapping for the `%s` axis:\n%s", axisTag, pformat(out)) log.info( "Planned normalized mapping for the `%s` axis:\n%s", axisTag, pformat(outNormalized), ) if all(abs(k - v) < 0.02 for k, v in outNormalized.items()): log.info("Detected identity mapping for the `%s` axis. Dropping.", axisTag) out = {} outNormalized = {} return out, outNormalized def planWeightAxis( glyphSetFunc, axisLimits, weights=None, samples=None, glyphs=None, designLimits=None, pins=None, sanitize=False, ): """Plan a weight axis.""" if weights is None: weights = WEIGHTS return planAxis( "wght", measureWeight, interpolateLog, glyphSetFunc, axisLimits, values=weights, samples=samples, glyphs=glyphs, designLimits=designLimits, pins=pins, sanitizeFunc=sanitizeWeight if sanitize else None, ) def planWidthAxis( glyphSetFunc, axisLimits, widths=None, samples=None, glyphs=None, designLimits=None, pins=None, sanitize=False, ): """Plan a width axis.""" if widths is None: widths = WIDTHS return planAxis( "wdth", measureWidth, interpolateLinear, glyphSetFunc, axisLimits, values=widths, samples=samples, glyphs=glyphs, designLimits=designLimits, pins=pins, sanitizeFunc=sanitizeWidth if sanitize else None, ) def planSlantAxis( glyphSetFunc, axisLimits, slants=None, samples=None, glyphs=None, designLimits=None, pins=None, sanitize=False, ): """Plan a slant axis.""" if slants is None: slants = SLANTS return planAxis( "slnt", measureSlant, interpolateLinear, glyphSetFunc, axisLimits, values=slants, samples=samples, glyphs=glyphs, designLimits=designLimits, pins=pins, sanitizeFunc=sanitizeSlant if sanitize else None, ) def planOpticalSizeAxis( glyphSetFunc, axisLimits, sizes=None, samples=None, glyphs=None, designLimits=None, pins=None, sanitize=False, ): """Plan a slant axis.""" if sizes is None: sizes = SIZES return planAxis( "opsz", measureWeight, interpolateLog, glyphSetFunc, axisLimits, values=sizes, samples=samples, glyphs=glyphs, designLimits=designLimits, pins=pins, sanitizeFunc=sanitizeSlant if sanitize else None, ) def makeDesignspaceSnippet(axisTag, axisName, axisLimit, mapping): """Make a designspace snippet for a single axis.""" designspaceSnippet = ( '