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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 | import { jsPDF } from 'jspdf' import { NextResponse } from 'next/server' import { clefExtent, clefGlyph, fitStaff, halfSpaceForWidth, ledgerHalfWidth, noteExtent, placeClef, placeNotehead, positionY, STAFF_EXTENT, type StaffMetrics, stemRect, traceGlyph, unionExtents, } from '@/components/music/glyphPath' import { SMUFL_GLYPHS } from '@/components/music/smuflGlyphs' import { withAuth } from '@/lib/auth/withAuth' interface MusicFlashcardRequest { clef: 'treble' | 'bass' | 'both' lowNote: number // position relative to bottom line (0 = E for treble, G for bass) highNote: number layout: '1-up' | '4-up' | '6-up' showNoteNames: boolean } // Note names for treble clef (position 0 = E) const TREBLE_NOTES = ['E', 'F', 'G', 'A', 'B', 'C', 'D'] // Note names for bass clef (position 0 = G) const BASS_NOTES = ['G', 'A', 'B', 'C', 'D', 'E', 'F'] // Get note name from position function getNoteName(position: number, clef: 'treble' | 'bass'): string { const notes = clef === 'treble' ? TREBLE_NOTES : BASS_NOTES // Handle negative positions (below staff) const adjustedPos = ((position % 7) + 7) % 7 const noteName = notes[adjustedPos] // Special naming for certain positions if (clef === 'treble') { if (position === -2) return 'C' // Middle C if (position === 10) return 'A' // High A } if (clef === 'bass') { if (position === 10) return 'C' // Middle C } return noteName } /** mm of card reserved at the top for the clef label, and at the bottom for the note name. */ const LABEL_BAND = 9 /** * Ceiling on `lineGap` as a fraction of card height, so a staff never grows * taller than it is wide — at that point it stops reading as notation. */ const MAX_LINE_GAP_RATIO = 0.08 /** Fraction of the card width the staff spans. */ const STAFF_WIDTH_RATIO = 0.85 /** * How the staff is scaled and placed inside a card. * * Positions are counted in half-spaces from the bottom staff line, so the five * lines sit at 0/2/4/6/8 and everything outside that needs ledger lines. The * card therefore has to be sized for the DECK's full range, not for the staff: * a "G below the staff" card (position -5) reaches five half-spaces past the * bottom line, and the old fixed `height * 0.08` scale put it below the card * border entirely. Computing this once per deck also keeps every card's staff * identical, which matters when a learner compares two cards side by side. */ /** * Scale and placement for every card in a deck, measured from the card's own * top-left corner. `staffTop` is therefore an offset, not an absolute y. */ function computeStaffGeometry( width: number, height: number, positions: number[], clefs: Array<'treble' | 'bass'> ): StaffMetrics { // Everything drawn has to fit, and the notes are not the tallest thing on the // card. A real G clef reaches from roughly position -3 to +11, almost twice // the staff's own height, and a stem adds three and a half spaces past its // notehead. Sizing to the staff and note range alone — which is what this did // while the clef was a Helvetica letter — pushes the clef off the card. return fitStaff({ top: LABEL_BAND, availableHeight: height - LABEL_BAND * 2, extent: unionExtents(STAFF_EXTENT, ...clefs.map(clefExtent), ...positions.map(noteExtent)), maxHalfSpace: [ halfSpaceForWidth(width * STAFF_WIDTH_RATIO), // leave the note room beside the clef height * MAX_LINE_GAP_RATIO, ], }) } // Draw a music staff with a note function drawMusicCard( doc: jsPDF, x: number, y: number, width: number, height: number, position: number, clef: 'treble' | 'bass', showNoteName: boolean, geometry: StaffMetrics ) { const lineGap = geometry.halfSpace const staffWidth = width * STAFF_WIDTH_RATIO const staffLeft = x + (width - staffWidth) / 2 // The deck geometry is relative to a card's top-left corner; place it. const metrics: StaffMetrics = { ...geometry, staffTop: y + geometry.staffTop } const staffTop = metrics.staffTop // Draw card border doc.setDrawColor(180) doc.setLineWidth(0.3) doc.roundedRect(x, y, width, height, 3, 3, 'S') // Draw 5 staff lines doc.setDrawColor(0) doc.setLineWidth(0.3) for (let i = 0; i < 5; i++) { const lineY = staffTop + i * lineGap * 2 doc.line(staffLeft, lineY, staffLeft + staffWidth, lineY) } // Draw the clef from its Bravura outline. One fill across every subpath keeps // the counters (the eye of the G clef) hollow via nonzero winding. doc.setFillColor(0, 0, 0) const clefAt = placeClef(metrics, clef, staffLeft + lineGap) traceGlyph(clefGlyph(clef).commands, clefAt, doc) doc.fill() // Centre the note in what the clef leaves of the staff. A fixed fraction of // the staff width (this was 0.55) put the note underneath the clef as soon as // the clef became a real glyph rather than a letter. const glyph = clefGlyph(clef) const clefRight = clefAt.x + glyph.bbox.right * clefAt.scale const noteX = (clefRight + lineGap * 2 + staffLeft + staffWidth) / 2 const ledgerHalf = ledgerHalfWidth(metrics) // Draw ledger lines if needed doc.setLineWidth(0.3) if (position < 0) { // Ledger lines below let ledgerPos = -2 while (ledgerPos >= position) { const ledgerY = positionY(metrics, ledgerPos) doc.line(noteX - ledgerHalf, ledgerY, noteX + ledgerHalf, ledgerY) ledgerPos -= 2 } } if (position > 8) { // Ledger lines above let ledgerPos = 10 while (ledgerPos <= position) { const ledgerY = positionY(metrics, ledgerPos) doc.line(noteX - ledgerHalf, ledgerY, noteX + ledgerHalf, ledgerY) ledgerPos += 2 } } // Draw the note. This was an upright filled ellipse with no stem, which is // not a note of any duration; it is now Bravura's quarter-note head (already // carrying the correct tilt) with a stem attached at the font's own anchor. doc.setFillColor(0, 0, 0) const headAt = placeNotehead(metrics, position, noteX) traceGlyph(SMUFL_GLYPHS.noteheadBlack.commands, headAt, doc) doc.fill() const stem = stemRect(metrics, position, headAt) doc.rect(stem.x, stem.y, stem.width, stem.height, 'F') // Draw note name in corner if requested if (showNoteName) { const noteName = getNoteName(position, clef) doc.setFontSize(8) doc.setFont('helvetica', 'normal') doc.setTextColor(150) doc.text(noteName, x + width - 8, y + height - 5) doc.setTextColor(0) } // Draw clef label at top doc.setFontSize(7) doc.setTextColor(120) doc.text(clef.toUpperCase(), x + 5, y + 8) doc.setTextColor(0) } export const POST = withAuth(async (request) => { try { const body: MusicFlashcardRequest = await request.json() const { clef, lowNote, highNote, layout, showNoteNames } = body // Generate list of notes const notes: Array<{ position: number; clef: 'treble' | 'bass' }> = [] const addNotesForClef = (c: 'treble' | 'bass') => { for (let pos = lowNote; pos <= highNote; pos++) { notes.push({ position: pos, clef: c }) } } if (clef === 'both') { addNotesForClef('treble') addNotesForClef('bass') } else { addNotesForClef(clef) } // An inverted range would otherwise produce a zero-card PDF with NaN // geometry rather than telling the caller what was wrong. if (notes.length === 0) { return NextResponse.json( { error: `Empty note range: lowNote (${lowNote}) is above highNote (${highNote}).` }, { status: 400 } ) } // Create PDF const doc = new jsPDF({ orientation: 'portrait', unit: 'mm', format: 'letter', }) const pageWidth = 215.9 // Letter width in mm const pageHeight = 279.4 // Letter height in mm const margin = 12 // Layout configuration let cols: number, rows: number, cardWidth: number, cardHeight: number switch (layout) { case '1-up': cols = 1 rows = 1 cardWidth = pageWidth - margin * 2 cardHeight = pageHeight * 0.4 break case '6-up': cols = 2 rows = 3 cardWidth = (pageWidth - margin * 3) / 2 cardHeight = (pageHeight - margin * 4) / 3 break case '4-up': default: cols = 2 rows = 2 cardWidth = (pageWidth - margin * 3) / 2 cardHeight = (pageHeight - margin * 3) / 2 break } const cardsPerPage = cols * rows let cardIndex = 0 // One geometry for the whole deck: every card is the same card size, and a // staff that changed scale per note would make the deck unreadable. const geometry = computeStaffGeometry( cardWidth, cardHeight, notes.map((n) => n.position), [...new Set(notes.map((n) => n.clef))] ) for (const note of notes) { // New page if needed if (cardIndex > 0 && cardIndex % cardsPerPage === 0) { doc.addPage() } const pageCardIndex = cardIndex % cardsPerPage const col = pageCardIndex % cols const row = Math.floor(pageCardIndex / cols) const x = margin + col * (cardWidth + margin) const y = margin + row * (cardHeight + margin) drawMusicCard( doc, x, y, cardWidth, cardHeight, note.position, note.clef, showNoteNames, geometry ) cardIndex++ } // Generate PDF buffer const pdfBuffer = Buffer.from(doc.output('arraybuffer')) return new NextResponse(pdfBuffer, { headers: { 'Content-Type': 'application/pdf', 'Content-Disposition': `attachment; filename="music-flashcards-${clef}.pdf"`, }, }) } catch (error) { console.error('Music flashcard generation error:', error) return NextResponse.json( { error: error instanceof Error ? error.message : 'Generation failed' }, { status: 500 } ) } }) |