fastchart

Native C PHP extension. 26 chart types behind a modern OO API with fluent setters and final classes. Line, area, bar, scatter, bubble, pie, radar, polar, surface, contour, gauge, gantt, box-plot, treemap, funnel, waterfall, heatmap, linear meter, plus a deep StockChart (seven candle styles, SMA / EMA / WMA overlays, volume + indicator panes).

SVG is the canonical render format. PNG / JPG / WebP outputs flatten text to glyph paths, run plutovg over the resulting SVG, and encode the RGBA buffer with libpng / libjpeg-turbo / libwebp. The same chart object serves a sharp <svg> for dashboards or a PNG for emails without rebuilding state. renderToFile() picks the encoder from the extension; renderPng() / renderJpeg() / renderWebp() / renderSvg() return bytes in-process.

Live gallery →. Side-by-side SVG / PNG / JPG / WebP renders for every chart family, with the source PHP shown above each row.

Status

v1.1: confidence-band area charts, cone-style funnels, smooth polar curves with overlay vectors, log-scale bubble plots, HTML image-map hot-spots on Bar / Pie / Scatter (setImageMap + getImageMap). v1.0 dropped libgd as a runtime dependency, rebuilt rasterization around vendored plutovg, and replaced draw($canvas) with renderSvg/Png/Jpeg/Webp + renderToFile. 26 chart types, 2-class Symbol family, 127 phpt tests. See CHANGELOG.md for the full breaking-change list.

Install

Via PIE (recommended)

PIE handles the configure / make / install cycle for you against your active PHP install:

pie install iliaal/fastchart

PIE picks up the latest tagged release from Packagist and respects your platform's pkg-config for the FreeType / libpng / libjpeg-turbo / libwebp probes. After install, enable the extension via your distribution's mechanism (e.g. docker-php-ext-enable fastchart on the official PHP images, or add extension=fastchart to php.ini).

From source

Build manually against the PHP install you want to extend:

phpize
./configure --enable-fastchart
make -j
make test

Strict-warnings dev build (recommended for contributors):

./configure --enable-fastchart --enable-fastchart-dev

Runtime check:

php -d extension=./modules/fastchart.so \
  -r 'echo FastChart\Chart::version(), PHP_EOL;'

Requirements

• PHP 8.3 or later (NTS or ZTS).
• FreeType development headers (libfreetype-dev / freetype-devel). Required, since text rendering depends on FreeType.
• libpng / libjpeg-turbo / libwebp development headers. Each is optional; config.m4 probes them independently via pkg-config and the corresponding renderPng() / renderJpeg() / renderWebp() is wired up only for libs that resolve at build time. A missing lib turns the matching method into a "format not compiled in" Error at call time; SVG output stays available regardless. phpinfo() reports the resolved version of each lib (or (not compiled in)) so you can audit a build.
• plutovg + plutosvg are vendored under vendor/; no separate install required.

Quick start

The shortest path is the renderToFile() helper, which picks the encoder from the file extension:

(new FastChart\LineChart(640, 320))
    ->setTitle('Daily active users')
    ->setSeries([['data' => [820, 940, 870, 1020, 1180, 1250, 1340]]])
    ->setCategoryLabels(['Mon','Tue','Wed','Thu','Fri','Sat','Sun'])
    ->renderToFile('/tmp/dau.png');

renderPng(), renderJpeg(), and renderWebp() return the encoded bytes if you need them in memory. Raster compression knobs:

$chart->setJpegQuality(75);              // sticks on the chart instance;
$chart->renderJpeg();                    // ...used by every render call
$chart->renderJpeg(95);                  // per-call override (1..100)

$chart->renderWebp();                    // default quality 90
$chart->renderWebp(60);                  // smaller, lossier (1..100)

$chart->renderToFile('/tmp/out.webp');   // setJpegQuality only affects
                                         // .jpg; renderToFile uses the
                                         // built-in WebP default

PNG is always lossless; there's no quality knob. The encoder is libpng with default filter selection.

WebP has four encoder modes selectable via setWebpMode(). The default WEBP_DRAWING is tuned for chart-shaped content (flat fills, sharp edges); see the table in docs/examples/50_webp_modes.php for the speed/size trade-offs each mode picks.

$chart->setWebpMode(FastChart\Chart::WEBP_LOSSLESS);  // archival
$chart->setWebpMode(FastChart\Chart::WEBP_FAST);      // preview pipelines
$chart->setWebpMode(FastChart\Chart::WEBP_PHOTO);     // photo backgrounds
$chart->setWebpMode(FastChart\Chart::WEBP_DRAWING);   // back to default

Call renderSvg() on the same chart object for vector output: dashboards, print, anywhere infinite-zoom matters.

$chart = (new FastChart\LineChart(640, 320))
    ->setTitle('Daily active users')
    ->setSeries([['data' => [820, 940, 870, 1020, 1180, 1250, 1340]]])
    ->setCategoryLabels(['Mon','Tue','Wed','Thu','Fri','Sat','Sun']);

$svg = $chart->renderSvg();              // full <?xml ?><svg>...</svg>
$chart->renderToFile('/tmp/dau.svg');    // same, written to disk

// Stitch several charts into one outer SVG document:
$fragment = $chart->drawSvgFragment();   // <g class="fastchart">...</g>

Construction is identical for every output format; only the final render call differs. By default, SVG text is flattened to glyph outline paths (SVG_TEXT_PATHS mode). The resulting SVG is self- contained and renders identically in any viewer or rasterizer. For smaller files with selectable text, switch to native <text> mode:

$chart->setSvgTextMode(FastChart\Chart::SVG_TEXT_NATIVE);
$svg = $chart->renderSvg();  // ~30% smaller; needs consumer text support

Raster outputs (PNG/JPG/WebP) always use the PATHS mode internally; plutovg has no text support of its own, so glyph flattening is what makes labels appear in the rasterized output.

Three static methods on FastChart\Chart rasterize caller-supplied SVG bytes through the same plutovg + libpng / libjpeg-turbo / libwebp pipeline. Useful for round-tripping renderSvg() output, or for stitching multiple drawSvgFragment() calls into one outer SVG and rasterizing the result, all in-process:

$png  = FastChart\Chart::svgToPng($svg);
$jpg  = FastChart\Chart::svgToJpeg($svg, 88, 0xFFFFFF);  // bg + quality
$webp = FastChart\Chart::svgToWebp($svg, 90, FastChart\Chart::WEBP_LOSSLESS);

Output dimensions come from the SVG's width / height / viewBox. SVG <text> elements render blank — plutovg has no text engine, so text must be path-flattened first (fastchart's own SVG builder does this automatically). See docs/examples/51_svg_to_raster.php for a runnable demo and docs/specs/svg-to-raster.md for the full contract.

📊 Performance

Median in-memory render time at 1920×1080 on a single core (Intel i9-13950HX, PHP 8.4 debug build, default font + DPI). SVG is the canonical output; PNG / WebP / JPG go through the same SVG build, then plutosvg + plutovg rasterize, then the format encoder (libpng / libwebp / libjpeg-turbo). The raster columns therefore add the rasterize cost on top of the SVG-only number.

Chart	SVG ms	PNG ms	WebP ms	JPG ms
AreaChart	5.7	71.7	54.4	34.5
BarChart	11.0	75.8	57.0	38.8
BoxPlot	4.4	65.0	47.5	31.6
BubbleChart	2.6	90.9	62.7	38.6
ContourChart	3.0	79.1	60.0	35.3
Funnel	4.2	62.6	47.4	30.9
GanttChart	5.7	65.9	48.8	30.8
GaugeChart	1.2	69.4	49.7	29.1
Heatmap	1.7	69.3	52.1	34.5
LineChart	5.4	74.2	55.5	34.3
LinearMeter	1.4	62.7	40.7	25.2
PieChart	2.8	71.6	51.9	33.0
PolarChart	1.2	73.7	51.7	31.8
RadarChart	3.7	75.3	56.2	36.5
ScatterChart	5.0	72.6	51.1	34.6
StockChart	8.4	80.8	63.3	41.0
SurfaceChart	2.3	64.7	46.4	28.3
Treemap	4.8	65.0	48.5	31.5
Waterfall	5.2	65.2	48.3	31.1

SVG is in the single-digit-ms range across the board because there's no rasterization; the backend appends strings into a smart_str. The raster encoders split into three bands: JPG fastest (25-41 ms, libjpeg-turbo with 4:2:0 subsampling), WebP middle (40-63 ms, libwebp with WEBP_PRESET_DRAWING + method=2 + multi-thread), PNG slowest (62-91 ms, libpng's deflate dominates). All four formats stay under 95 ms at 1080p on one thread.

Repro the numbers locally:

php -d extension=./modules/fastchart.so docs/bench/bench.php

Iteration count via FC_BENCH_ITERS (default 50). Bench source at docs/bench/bench.php.

What you can render

26 chart classes plus a 2-class symbology family, all under the FastChart\ namespace. Each name links to its rendered example image:

• Cartesian: LineChart, AreaChart, BarChart (vertical, horizontal, stacked, grouped, floating, layered), ScatterChart, BubbleChart.
• Financial: StockChart with seven candle styles (STYLE_CANDLE, STYLE_BAR, STYLE_DIAMOND, STYLE_I_CAP, STYLE_HOLLOW, STYLE_VOLUME, STYLE_VECTOR), SMA / EMA / WMA overlays, optional volume pane and custom indicator panes (RSI, MACD, Bollinger, OBV, stochastic, PSAR).
• Non-Cartesian: RadarChart, PolarChart, SurfaceChart, ContourChart.
• Specialised: PieChart (with optional donut hole + leader lines), GaugeChart, LinearMeter, GanttChart, BoxPlot, Treemap, Funnel, Waterfall, Heatmap, BulletChart, ParetoChart, CalendarHeatmap.
• Hierarchical / flow: SunburstChart, SankeyChart, MarimekkoChart, VectorChart.
• Symbology: Code128 (1D barcode, ISO/IEC 15417, auto-switching A/B/C subsets, optional human-readable text), QrCode (2D matrix code, ISO/IEC 18004, ECC L/M/Q/H, versions 1..40).

Cross-cutting features available on most chart types:

• TrueType / OpenType labels via setFontPath() (and per-role setTitleFont(), setAxisFont(), setLabelFont()).
• Light and dark themes (THEME_LIGHT, THEME_DARK); per-series colors via setSeriesColors(); full custom palettes via setPalette().
• Legend positioning (LEGEND_TOP_RIGHT, _TOP_LEFT, _BOTTOM_RIGHT, _BOTTOM_LEFT, _NONE).
• Annotations: plot bands, vertical bands, horizontal / vertical lines, text labels, icon plots, error bars, zones.
• Strict-mode input validation (setStrict(true) rejects malformed series with a TypeError instead of silently coercing to NaN).
• Background images, drop shadows, anti-aliased lines and markers.
• Image map output (getImageMap() returns category-aligned rectangles for HTML overlay).

Examples

A gallery of code + rendered chart pairs lives in docs/README.md. Forty-two runnable scripts in docs/examples/ regenerate the images and exercise every public method on the API surface.

Public classes

All under the FastChart\ namespace:

• Chart: abstract base. Carries shared geometry / theme / font / legend / annotation setters, the version() static, and the chart- family enums (themes, candle styles, legend positions, line styles, marker styles, MA kinds).
• LineChart, AreaChart, BarChart, ScatterChart, BubbleChart: series-based plots.
• PieChart: slice-based, with optional donut hole.
• StockChart: OHLC(V) candlesticks, moving-average overlays, volume + indicator panes.
• RadarChart, PolarChart, SurfaceChart, ContourChart: non-Cartesian plots.
• GaugeChart, LinearMeter: single-value readouts with zoned ranges.
• GanttChart: time-axis task bars with dependency links and milestones.
• BoxPlot: five-number summaries with per-category outliers.
• Treemap, Funnel, Waterfall: value-encoded layouts (rectangle packing, stage drop-off, signed-delta running totals). Funnel supports a triangle-with-bands layout via setStyle(STYLE_PYRAMID) for callers who want the classic pyramid shape.
• Heatmap: 2D grid with linear color-ramp interpolation.

Every setter returns static, so a single fluent expression configures and emits a chart.

The Symbol family lives parallel to Chart (no shared base, since axes / palettes / plot rect have no meaning for a barcode):

• Symbol: abstract base for all 1D + 2D codes. Carries shared setters: setSize(), setData(), setQuietZone(), setForeground(), setBackground(), setTransparentBackground(), setDpi(), setSvgTextMode(), setJpegQuality(), plus the same renderPng() / renderJpeg() / renderWebp() / renderSvg() / drawSvgFragment() / renderToFile() helpers as Chart. Reload via imagecreatefromstring() to composite onto an existing canvas.
• Barcode: abstract 1D linear-barcode base.
• Code128 (extends Barcode): ISO/IEC 15417, alphanumeric, three subsets (A: control + uppercase, B: full ASCII printable, C: digit pairs). Auto-switches between subsets to minimise encoded length; mod-103 checksum appended automatically. setShowText(true) renders the human-readable payload below the bars using the auto-detected default font.
• QrCode (extends Symbol): ISO/IEC 18004, four error-correction levels (ECC_L ~7%, ECC_M ~15%, ECC_Q ~25%, ECC_H ~30%), versions 1..40. Encoder is the vendored nayuki/QR-Code-generator C library. setMinVersion() / setMaxVersion() pin the symbol size; the encoder picks the smallest version that fits within the range. Input must be valid UTF-8.

🔗 PHP Performance Toolkit

Companion native PHP extensions for high-throughput PHP workloads:

• php_excel: native Excel I/O. 7-10× faster than PhpSpreadsheet, full XLS/XLSX with formulas, formatting, and styling. Powered by LibXL.
• mdparser: native CommonMark + GFM parser. 15-30× faster than pure-PHP alternatives, full CommonMark 0.31 compliance.
• php_clickhouse: native ClickHouse client speaking the wire protocol directly. Picks up where SeasClick left off.

License

BSD 3-Clause for the extension itself; see LICENSE. Vendored third-party code (all MIT):

• vendor/plutovg/: Samuel Ugochukwu's plutovg 2D rasterizer. See vendor/plutovg/LICENSE.
• vendor/plutosvg/: Samuel Ugochukwu's plutosvg SVG document parser. See vendor/plutosvg/LICENSE.
• vendor/qrcodegen/: nayuki's QR-Code-generator (C variant). See vendor/qrcodegen/LICENSE.

SPDX: (BSD-3-Clause AND MIT).

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