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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 | import type { CoordinatePlaneState, CoordinatePlaneOverlay } from './types' import type { EquationProbeState } from './ruler/types' import type { TickMark } from '../number-line/types' import { DEFAULT_TICK_THRESHOLDS } from '../number-line/types' import type { CollisionFadeMap } from '../shared/collisionDetection' import { computeCollisionOpacity } from '../shared/collisionDetection' import { computeAxisTicks } from './coordinatePlaneTicks' import { worldToScreen } from '../shared/coordinateConversions' import { smoothstep, getTickHeight, getTickLineWidth, getTickAlpha, getTickFontSize, getTickFontWeight, formatTickLabel, LIGHT_COLORS, DARK_COLORS, COLLISION_FADE_MS, SYSTEM_FONT, } from '../shared/tickMath' // How many px from the viewport edge the label flip transition starts const LABEL_FLIP_ZONE = 40 // ── Label collision detection ─────────────────────────────────────── interface LabelInfo { tick: TickMark screenPos: number label: string fontSize: number fontWeight: number labelWidth: number /** Horizontal extent: [min, max] on the canvas */ extentMin: number extentMax: number } const LABEL_PAD = 6 function computeLabelCollisions(labelInfos: LabelInfo[]): Set<LabelInfo> { // Sort by prominence descending so higher-prominence labels take priority const sorted = [...labelInfos].sort((a, b) => b.tick.prominence - a.tick.prominence) const visible = new Set<LabelInfo>() const occupied: { min: number; max: number }[] = [] for (const info of sorted) { const pad = LABEL_PAD / 2 let overlaps = false for (const occ of occupied) { if (info.extentMin - pad < occ.max && info.extentMax + pad > occ.min) { overlaps = true break } } if (!overlaps) { visible.add(info) occupied.push({ min: info.extentMin, max: info.extentMax }) } } return visible } // ── Main render function ──────────────────────────────────────────── /** * Render the coordinate plane onto a canvas context. * Assumes ctx.scale(dpr, dpr) has already been called. * * Returns true if animations are in progress (label fading). */ export function renderCoordinatePlane( ctx: CanvasRenderingContext2D, state: CoordinatePlaneState, cssWidth: number, cssHeight: number, isDark: boolean, zoomVelocity = 0, zoomHue = 0, zoomFocalX = 0.5, zoomFocalY = 0.5, xCollisionFadeMap?: CollisionFadeMap, yCollisionFadeMap?: CollisionFadeMap, overlays?: CoordinatePlaneOverlay[], probeState?: EquationProbeState ): boolean { const colors = isDark ? DARK_COLORS : LIGHT_COLORS let animating = false // ── Pass 1: Clear ────────────────────────────────────────────── ctx.clearRect(0, 0, cssWidth, cssHeight) // ── Pass 2: Zoom velocity wash ───────────────────────────────── if (Math.abs(zoomVelocity) > 0.001) { const intensity = Math.min(Math.abs(zoomVelocity) * 3, 0.35) const sat = 80 const lum = isDark ? 30 : 70 const focalPxX = zoomFocalX * cssWidth const focalPxY = zoomFocalY * cssHeight const radius = Math.max(cssWidth, cssHeight) * 0.7 const gradient = ctx.createRadialGradient(focalPxX, focalPxY, 0, focalPxX, focalPxY, radius) gradient.addColorStop(0, `hsla(${zoomHue}, ${sat}%, ${lum}%, ${intensity})`) gradient.addColorStop(1, `hsla(${zoomHue}, ${sat}%, ${lum}%, 0)`) ctx.fillStyle = gradient ctx.fillRect(0, 0, cssWidth, cssHeight) } // ── Pass 3: Behind-grid overlays ─────────────────────────────── if (overlays) { for (const overlay of overlays) { if (overlay.layer === 'behind-grid') { overlay.render(ctx, state, cssWidth, cssHeight, isDark) } } } // ── Compute ticks for both axes ──────────────────────────────── const xTicks = computeAxisTicks(state, 'x', cssWidth, DEFAULT_TICK_THRESHOLDS) const yTicks = computeAxisTicks(state, 'y', cssHeight, DEFAULT_TICK_THRESHOLDS) // ── Pass 4: Grid lines ───────────────────────────────────────── // Vertical grid lines from X ticks for (const tick of xTicks) { const sx = worldToScreen(tick.value, state.center.x, state.pixelsPerUnit.x, cssWidth) if (sx < -1 || sx > cssWidth + 1) continue const tickAlpha = getTickAlpha(tick.prominence) const gridAlpha = tickAlpha * 0.3 * tick.opacity if (gridAlpha < 0.005) continue ctx.beginPath() ctx.moveTo(sx, 0) ctx.lineTo(sx, cssHeight) ctx.strokeStyle = `rgba(${colors.tickRgb}, ${gridAlpha})` ctx.lineWidth = Math.max(0.5, getTickLineWidth(tick.prominence) * 0.6) ctx.stroke() } // Horizontal grid lines from Y ticks for (const tick of yTicks) { // Y-axis inversion: positive Y goes up const sy = cssHeight / 2 - (tick.value - state.center.y) * state.pixelsPerUnit.y if (sy < -1 || sy > cssHeight + 1) continue const tickAlpha = getTickAlpha(tick.prominence) const gridAlpha = tickAlpha * 0.3 * tick.opacity if (gridAlpha < 0.005) continue ctx.beginPath() ctx.moveTo(0, sy) ctx.lineTo(cssWidth, sy) ctx.strokeStyle = `rgba(${colors.tickRgb}, ${gridAlpha})` ctx.lineWidth = Math.max(0.5, getTickLineWidth(tick.prominence) * 0.6) ctx.stroke() } // ── Pass 4.5: Probe grid line glow ──────────────────────────── if (probeState?.active) { const glowRGB = isDark ? '129, 140, 248' : '79, 70, 229' // indigo if (probeState.nearX != null) { // Vertical glow at nearX grid line const sx = worldToScreen(probeState.nearX, state.center.x, state.pixelsPerUnit.x, cssWidth) const distX = Math.abs(probeState.worldX - probeState.nearX) const alpha = 1 - distX / 0.15 // 0.15 is snap threshold if (alpha > 0) { // Soft glow (wide) const glowWidth = 12 const grad = ctx.createLinearGradient(sx - glowWidth, 0, sx + glowWidth, 0) grad.addColorStop(0, `rgba(${glowRGB}, 0)`) grad.addColorStop(0.5, `rgba(${glowRGB}, ${0.2 * alpha})`) grad.addColorStop(1, `rgba(${glowRGB}, 0)`) ctx.fillStyle = grad ctx.fillRect(sx - glowWidth, 0, glowWidth * 2, cssHeight) // Bright center line ctx.beginPath() ctx.moveTo(sx, 0) ctx.lineTo(sx, cssHeight) ctx.strokeStyle = `rgba(${glowRGB}, ${0.7 * alpha})` ctx.lineWidth = 1.5 ctx.stroke() } } if (probeState.nearY != null) { // Horizontal glow at nearY grid line const sy = cssHeight / 2 - (probeState.nearY - state.center.y) * state.pixelsPerUnit.y const distY = Math.abs(probeState.worldY - probeState.nearY) const alpha = 1 - distY / 0.15 if (alpha > 0) { const glowWidth = 12 const grad = ctx.createLinearGradient(0, sy - glowWidth, 0, sy + glowWidth) grad.addColorStop(0, `rgba(${glowRGB}, 0)`) grad.addColorStop(0.5, `rgba(${glowRGB}, ${0.2 * alpha})`) grad.addColorStop(1, `rgba(${glowRGB}, 0)`) ctx.fillStyle = grad ctx.fillRect(0, sy - glowWidth, cssWidth, glowWidth * 2) ctx.beginPath() ctx.moveTo(0, sy) ctx.lineTo(cssWidth, sy) ctx.strokeStyle = `rgba(${glowRGB}, ${0.7 * alpha})` ctx.lineWidth = 1.5 ctx.stroke() } } } // ── Pass 5: Axis lines ───────────────────────────────────────── // X-axis (horizontal line at y=0) const xAxisScreenY = cssHeight / 2 - (0 - state.center.y) * state.pixelsPerUnit.y const xAxisPinnedTop = xAxisScreenY < 0 const xAxisPinnedBottom = xAxisScreenY > cssHeight const xAxisPinned = xAxisPinnedTop || xAxisPinnedBottom const xAxisDrawY = Math.max(0, Math.min(cssHeight, xAxisScreenY)) const xAxisAlpha = xAxisPinned ? 0.3 : 0.8 ctx.beginPath() ctx.moveTo(0, xAxisDrawY) ctx.lineTo(cssWidth, xAxisDrawY) ctx.strokeStyle = isDark ? `rgba(209, 213, 219, ${xAxisAlpha})` : `rgba(55, 65, 81, ${xAxisAlpha})` ctx.lineWidth = 2 ctx.stroke() // Y-axis (vertical line at x=0) const yAxisScreenX = worldToScreen(0, state.center.x, state.pixelsPerUnit.x, cssWidth) const yAxisPinnedLeft = yAxisScreenX < 0 const yAxisPinnedRight = yAxisScreenX > cssWidth const yAxisPinned = yAxisPinnedLeft || yAxisPinnedRight const yAxisDrawX = Math.max(0, Math.min(cssWidth, yAxisScreenX)) const yAxisAlpha = yAxisPinned ? 0.3 : 0.8 ctx.beginPath() ctx.moveTo(yAxisDrawX, 0) ctx.lineTo(yAxisDrawX, cssHeight) ctx.strokeStyle = isDark ? `rgba(209, 213, 219, ${yAxisAlpha})` : `rgba(55, 65, 81, ${yAxisAlpha})` ctx.lineWidth = 2 ctx.stroke() // Compute smooth label flip factors (0 = default side, 1 = flipped side). // X labels: default below axis, flip above when axis near bottom edge. // Y labels: default left of axis, flip right when axis near left edge. const xSpaceBelow = cssHeight - xAxisDrawY const xLabelFlip = xSpaceBelow < LABEL_FLIP_ZONE ? smoothstep(1 - xSpaceBelow / LABEL_FLIP_ZONE) : 0 const ySpaceLeft = yAxisDrawX const yLabelFlip = ySpaceLeft < LABEL_FLIP_ZONE ? smoothstep(1 - ySpaceLeft / LABEL_FLIP_ZONE) : 0 // ── Pass 6: On-grid overlays ─────────────────────────────────── if (overlays) { for (const overlay of overlays) { if (overlay.layer === 'on-grid') { overlay.render(ctx, state, cssWidth, cssHeight, isDark) } } } // ── Pass 7: Tick marks ───────────────────────────────────────── // X-axis tick marks (short vertical lines perpendicular to x-axis) const xTickLength = 6 for (const tick of xTicks) { const sx = worldToScreen(tick.value, state.center.x, state.pixelsPerUnit.x, cssWidth) if (sx < -50 || sx > cssWidth + 50) continue const tickAlpha = getTickAlpha(tick.prominence) const lineWidth = getTickLineWidth(tick.prominence) // Scale tick length by prominence const halfLen = xTickLength * (0.5 + 0.5 * tick.prominence) ctx.globalAlpha = tick.opacity ctx.beginPath() ctx.moveTo(sx, xAxisDrawY - halfLen) ctx.lineTo(sx, xAxisDrawY + halfLen) ctx.strokeStyle = `rgba(${colors.tickRgb}, ${tickAlpha})` ctx.lineWidth = lineWidth ctx.stroke() } ctx.globalAlpha = 1 // Y-axis tick marks (short horizontal lines perpendicular to y-axis) const yTickLength = 6 for (const tick of yTicks) { const sy = cssHeight / 2 - (tick.value - state.center.y) * state.pixelsPerUnit.y if (sy < -50 || sy > cssHeight + 50) continue const tickAlpha = getTickAlpha(tick.prominence) const lineWidth = getTickLineWidth(tick.prominence) const halfLen = yTickLength * (0.5 + 0.5 * tick.prominence) ctx.globalAlpha = tick.opacity ctx.beginPath() ctx.moveTo(yAxisDrawX - halfLen, sy) ctx.lineTo(yAxisDrawX + halfLen, sy) ctx.strokeStyle = `rgba(${colors.tickRgb}, ${tickAlpha})` ctx.lineWidth = lineWidth ctx.stroke() } ctx.globalAlpha = 1 // ── Pass 8: Labels ───────────────────────────────────────────── const now = performance.now() // X-axis labels (below x-axis) { const labelInfos: LabelInfo[] = [] for (const tick of xTicks) { const sx = worldToScreen(tick.value, state.center.x, state.pixelsPerUnit.x, cssWidth) if (sx < -50 || sx > cssWidth + 50) continue if (tick.opacity <= 0) continue const label = formatTickLabel(tick.value, tick.power) const fontSize = getTickFontSize(tick.prominence) const fontWeight = getTickFontWeight(tick.prominence) ctx.font = `${fontWeight} ${fontSize}px ${SYSTEM_FONT}` const labelWidth = ctx.measureText(label).width labelInfos.push({ tick, screenPos: sx, label, fontSize, fontWeight, labelWidth, extentMin: sx - labelWidth / 2, extentMax: sx + labelWidth / 2, }) } const visibleLabels = computeLabelCollisions(labelInfos) const seenValues = new Set<number>() for (const info of labelInfos) { const { tick, screenPos, label, fontSize, fontWeight, labelWidth } = info seenValues.add(tick.value) const isVisible = visibleLabels.has(info) let collisionOpacity = isVisible ? 1 : 0 if (xCollisionFadeMap) { const result = computeCollisionOpacity( tick.value, isVisible, xCollisionFadeMap, now, COLLISION_FADE_MS ) collisionOpacity = result.opacity if (result.animating) animating = true } if (collisionOpacity <= 0.01) continue const tickAlpha = getTickAlpha(tick.prominence) ctx.font = `${fontWeight} ${fontSize}px ${SYSTEM_FONT}` ctx.globalAlpha = tick.opacity * collisionOpacity ctx.fillStyle = `rgba(${colors.labelRgb}, ${tickAlpha})` ctx.textAlign = 'center' ctx.textBaseline = 'top' // Smoothly interpolate label Y between below-axis and above-axis positions const gap = 10 const belowY = xAxisDrawY + gap const aboveY = xAxisDrawY - gap - fontSize const labelY = belowY + (aboveY - belowY) * xLabelFlip ctx.fillText(label, screenPos, labelY) } // Clean up stale entries if (xCollisionFadeMap) { for (const key of xCollisionFadeMap.keys()) { if (!seenValues.has(key)) xCollisionFadeMap.delete(key) } } } ctx.globalAlpha = 1 // Y-axis labels (left of y-axis) { const labelInfos: LabelInfo[] = [] for (const tick of yTicks) { if (tick.value === 0) continue // skip origin label on Y (X has it) const sy = cssHeight / 2 - (tick.value - state.center.y) * state.pixelsPerUnit.y if (sy < -50 || sy > cssHeight + 50) continue if (tick.opacity <= 0) continue const label = formatTickLabel(tick.value, tick.power) const fontSize = getTickFontSize(tick.prominence) const fontWeight = getTickFontWeight(tick.prominence) ctx.font = `${fontWeight} ${fontSize}px ${SYSTEM_FONT}` const labelWidth = ctx.measureText(label).width // For Y labels, "extent" is vertical (use font size as height) labelInfos.push({ tick, screenPos: sy, label, fontSize, fontWeight, labelWidth, extentMin: sy - fontSize / 2, extentMax: sy + fontSize / 2, }) } const visibleLabels = computeLabelCollisions(labelInfos) const seenValues = new Set<number>() for (const info of labelInfos) { const { tick, screenPos, label, fontSize, fontWeight } = info seenValues.add(tick.value) const isVisible = visibleLabels.has(info) let collisionOpacity = isVisible ? 1 : 0 if (yCollisionFadeMap) { const result = computeCollisionOpacity( tick.value, isVisible, yCollisionFadeMap, now, COLLISION_FADE_MS ) collisionOpacity = result.opacity if (result.animating) animating = true } if (collisionOpacity <= 0.01) continue const tickAlpha = getTickAlpha(tick.prominence) ctx.font = `${fontWeight} ${fontSize}px ${SYSTEM_FONT}` ctx.globalAlpha = tick.opacity * collisionOpacity ctx.fillStyle = `rgba(${colors.labelRgb}, ${tickAlpha})` ctx.textBaseline = 'middle' // Smoothly interpolate label X between left-of-axis and right-of-axis const gap = 10 const leftCenterX = yAxisDrawX - gap - info.labelWidth / 2 const rightCenterX = yAxisDrawX + gap + info.labelWidth / 2 const labelX = leftCenterX + (rightCenterX - leftCenterX) * yLabelFlip ctx.textAlign = 'center' ctx.fillText(label, labelX, screenPos) } // Clean up stale entries if (yCollisionFadeMap) { for (const key of yCollisionFadeMap.keys()) { if (!seenValues.has(key)) yCollisionFadeMap.delete(key) } } } ctx.globalAlpha = 1 // ── Pass 9: Origin marker ────────────────────────────────────── if (!xAxisPinned && !yAxisPinned) { const ox = yAxisDrawX const oy = xAxisDrawY // Subtle glow const glowRadius = 12 const glow = ctx.createRadialGradient(ox, oy, 0, ox, oy, glowRadius) const glowColor = isDark ? '129, 140, 248' : '79, 70, 229' // indigo glow.addColorStop(0, `rgba(${glowColor}, 0.3)`) glow.addColorStop(1, `rgba(${glowColor}, 0)`) ctx.fillStyle = glow ctx.fillRect(ox - glowRadius, oy - glowRadius, glowRadius * 2, glowRadius * 2) // Filled circle ctx.beginPath() ctx.arc(ox, oy, 4, 0, Math.PI * 2) ctx.fillStyle = isDark ? 'rgba(129, 140, 248, 0.9)' : 'rgba(79, 70, 229, 0.9)' ctx.fill() // Outer ring ctx.beginPath() ctx.arc(ox, oy, 6, 0, Math.PI * 2) ctx.strokeStyle = isDark ? 'rgba(129, 140, 248, 0.4)' : 'rgba(79, 70, 229, 0.4)' ctx.lineWidth = 1 ctx.stroke() } // ── Pass 10: Above-grid overlays ─────────────────────────────── if (overlays) { for (const overlay of overlays) { if (overlay.layer === 'above-grid') { overlay.render(ctx, state, cssWidth, cssHeight, isDark) } } } return animating } |