silx.gui.plot: Added pygfx/WGPU rendering backend for 2D plotting

.github/actions/setup-system/action.yml

@@ -10,13 +10,14 @@ runs:
     # libegl1-mesa: Required by Qt xcb platform plugin
     # libgl1-mesa-glx: For OpenGL
     # xserver-xorg-video-dummy: For OpenGL
+    # mesa-vulkan-drivers (lavapipe), libgl1-mesa-dri (llvmpipe): software rendering for pygfx/wgpu
     # libxkbcommon-x11-0, ..: needed for Qt plugins
     - name: Install system packages
       if: runner.os == 'Linux'
       shell: bash
       run: |
         sudo apt-get update
-        sudo apt-get install ocl-icd-opencl-dev xvfb libegl1 libglx-mesa0 xserver-xorg-video-dummy libxkbcommon-x11-0 libxkbcommon0 libxkbcommon-dev libxcb-icccm4 libxcb-image0 libxcb-shm0 libxcb-keysyms1 libxcb-randr0 libxcb-render-util0 libxcb-render0 libxcb-shape0 libxcb-sync1 libxcb-xfixes0 libxcb-xinerama0 libxcb-xkb1 libxcb-cursor0 libxcb1
+        sudo apt-get install ocl-icd-opencl-dev xvfb libegl1 libglx-mesa0 mesa-vulkan-drivers libgl1-mesa-dri xserver-xorg-video-dummy libxkbcommon-x11-0 libxkbcommon0 libxkbcommon-dev libxcb-icccm4 libxcb-image0 libxcb-shm0 libxcb-keysyms1 libxcb-randr0 libxcb-render-util0 libxcb-render0 libxcb-shape0 libxcb-sync1 libxcb-xfixes0 libxcb-xinerama0 libxcb-xkb1 libxcb-cursor0 libxcb1
 
     - name: Setup Intel OpenCL ICD
       if: runner.os == 'Linux'

.github/workflows/ci.yml

@@ -43,18 +43,21 @@ jobs:
             QT_API: PySide6
             with_opencl: true
             with_gl_test: true
+            with_pygfx_test: true
 
           - os: macos-latest
             python-version: "3.14"
             QT_API: PyQt6
             with_opencl: false
             with_gl_test: false
+            with_pygfx_test: true
 
           - os: windows-latest
             python-version: "3.10"
             QT_API: PyQt5
             with_opencl: false
             with_gl_test: true
+            with_pygfx_test: false  # No Vulkan/DX12 software driver on Windows CI
 
     steps:
       - uses: actions/checkout@v5
@@ -87,5 +90,14 @@ jobs:
           QT_API: ${{ matrix.QT_API }}
           SILX_OPENCL: ${{ matrix.with_opencl && 'True' || 'False' }}
           WITH_GL_TEST: ${{ matrix.with_gl_test && 'True' || 'False' }}
+          WITH_PYGFX_TEST: ${{ matrix.with_pygfx_test && 'True' || 'False' }}
+          # run_tests() runs pytest against the installed silx, so the source
+          # pyproject.toml is not the pytest configfile and its ini options are
+          # ignored. Pass the xvfb color depth as a pytest ini override here so
+          # it actually reaches the run: pytest-xvfb defaults to a 16-bit
+          # display, on which lavapipe advertises no Vulkan surface formats and
+          # the pygfx/wgpu swapchain aborts (wgpuSurfaceConfigure fatal panic).
+          # 24-bit (like real desktops / the macOS runner) exposes BGRA8.
+          PYTEST_ADDOPTS: "-o xvfb_colordepth=24"
         run: |
           python -c "import silx.test, sys; sys.exit(silx.test.run_tests(verbosity=3, args=['--qt-binding=${{ matrix.QT_API }}']))"

examples/pygfx_backend/01_basic_curves.py

@@ -0,0 +1,51 @@
+"""Basic curve plotting with pygfx backend.
+
+Demonstrates: multiple curves, colors, line widths, symbols, fill, legend.
+"""
+
+import numpy
+from silx.gui import qt
+from silx.gui.plot import Plot1D
+
+
+def main():
+    app = qt.QApplication([])
+
+    plot = Plot1D(backend="pygfx")
+    plot.setWindowTitle("pygfx - Basic Curves")
+    plot.setGraphTitle("Trigonometric Functions")
+    plot.setGraphXLabel("X")
+    plot.setGraphYLabel("Y")
+
+    x = numpy.linspace(0, 4 * numpy.pi, 500)
+
+    # Solid line
+    plot.addCurve(x, numpy.sin(x), legend="sin(x)", color="blue", linewidth=2)
+    # Dashed line with symbols
+    plot.addCurve(
+        x[::20],
+        numpy.cos(x[::20]),
+        legend="cos(x)",
+        color="red",
+        linewidth=1.5,
+        linestyle="--",
+        symbol="o",
+    )
+    # Filled curve
+    plot.addCurve(
+        x,
+        0.5 * numpy.sin(2 * x),
+        legend="0.5*sin(2x)",
+        color="green",
+        linewidth=1,
+        fill=True,
+    )
+
+    plot.setActiveCurveHandling(False)
+    plot.resetZoom()
+    plot.show()
+    app.exec()
+
+
+if __name__ == "__main__":
+    main()

examples/pygfx_backend/02_image_display.py

@@ -0,0 +1,52 @@
+"""Image display with pygfx backend.
+
+Demonstrates: 2D image with colormap, RGBA image, origin/scale, colorbar.
+"""
+
+import numpy
+from silx.gui import qt
+from silx.gui.plot import Plot2D
+
+
+def main():
+    app = qt.QApplication([])
+
+    # --- Plot2D with colormap image ---
+    plot = Plot2D(backend="pygfx")
+    plot.setWindowTitle("pygfx - Image Display")
+    plot.setGraphTitle("2D Gaussian + Noise")
+    plot.setGraphXLabel("X")
+    plot.setGraphYLabel("Y")
+
+    # Generate a 2D Gaussian
+    size = 256
+    x = numpy.linspace(-3, 3, size)
+    y = numpy.linspace(-3, 3, size)
+    xx, yy = numpy.meshgrid(x, y)
+    image = numpy.exp(-(xx**2 + yy**2)) + 0.1 * numpy.random.random((size, size))
+
+    plot.getDefaultColormap().setName("viridis")
+    plot.addImage(image, origin=(-3, -3), scale=(6 / size, 6 / size))
+    plot.setKeepDataAspectRatio(True)
+    plot.resetZoom()
+    plot.show()
+
+    # --- RGBA image window ---
+    plot2 = Plot2D(backend="pygfx")
+    plot2.setWindowTitle("pygfx - RGBA Image")
+    plot2.setGraphTitle("RGBA Gradient")
+
+    rgba = numpy.zeros((200, 300, 4), dtype=numpy.uint8)
+    rgba[:, :, 0] = numpy.linspace(0, 255, 300)[numpy.newaxis, :]  # R gradient
+    rgba[:, :, 1] = numpy.linspace(0, 255, 200)[:, numpy.newaxis]  # G gradient
+    rgba[:, :, 2] = 128
+    rgba[:, :, 3] = 255
+    plot2.addImage(rgba)
+    plot2.resetZoom()
+    plot2.show()
+
+    app.exec()
+
+
+if __name__ == "__main__":
+    main()

examples/pygfx_backend/03_scatter_plot.py

@@ -0,0 +1,35 @@
+"""Scatter plot with pygfx backend.
+
+Demonstrates: scatter points with colormap values, symbol sizes.
+"""
+
+import numpy
+from silx.gui import qt
+from silx.gui.plot import Plot1D
+
+
+def main():
+    app = qt.QApplication([])
+
+    plot = Plot1D(backend="pygfx")
+    plot.setWindowTitle("pygfx - Scatter Plot")
+    plot.setGraphTitle("Random Scatter with Colormap")
+    plot.setGraphXLabel("X")
+    plot.setGraphYLabel("Y")
+    plot.getDefaultColormap().setName("plasma")
+
+    numpy.random.seed(42)
+    n = 200
+    x = numpy.random.randn(n)
+    y = numpy.random.randn(n)
+    value = numpy.sqrt(x**2 + y**2)  # distance from origin
+
+    plot.addScatter(x, y, value, legend="distance", symbol="o")
+    plot.setKeepDataAspectRatio(True)
+    plot.resetZoom()
+    plot.show()
+    app.exec()
+
+
+if __name__ == "__main__":
+    main()

examples/pygfx_backend/04_line_styles.py

@@ -0,0 +1,67 @@
+"""Line styles and symbols with pygfx backend.
+
+Demonstrates: all line styles (solid, dashed, dash-dot, dotted),
+various symbols, line widths, gap colors.
+"""
+
+import numpy
+from silx.gui import qt
+from silx.gui.plot import PlotWidget
+
+
+def main():
+    app = qt.QApplication([])
+
+    plot = PlotWidget(backend="pygfx")
+    plot.setWindowTitle("pygfx - Line Styles & Symbols")
+    plot.setGraphTitle("Line Styles and Symbols")
+    plot.setGraphXLabel("X")
+    plot.setGraphYLabel("Y")
+
+    x = numpy.linspace(0, 10, 100)
+
+    # Line styles
+    styles = [
+        ("-", "solid"),
+        ("--", "dashed"),
+        ("-.", "dash-dot"),
+        (":", "dotted"),
+    ]
+    for i, (style, name) in enumerate(styles):
+        y = numpy.sin(x) + i * 2.5
+        plot.addCurve(x, y, legend=name, linestyle=style, linewidth=2, symbol="")
+
+    # Gap color example
+    y = numpy.sin(x) + 10
+    plot.addCurve(
+        x,
+        y,
+        legend="dashed+gapcolor",
+        linestyle="--",
+        linewidth=2,
+        symbol="",
+        color="blue",
+    )
+
+    # Symbols (only those supported by silx SymbolMixIn)
+    symbols = ["o", ".", "+", "x", "d", "s", ",", "|", "_"]
+    x_sym = numpy.linspace(0, 10, 30)
+    for i, sym in enumerate(symbols):
+        y_sym = numpy.cos(x_sym) + 15 + i * 1.5
+        plot.addCurve(
+            x_sym,
+            y_sym,
+            legend=f"sym '{sym}'",
+            symbol=sym,
+            linestyle=" ",
+            color=f"C{i % 10}",
+        )
+
+    plot.setActiveCurveHandling(False)
+    plot.resetZoom()
+    plot.show()
+    app.exec()
+
+
+if __name__ == "__main__":
+    main()

examples/pygfx_backend/05_markers_shapes.py

@@ -0,0 +1,57 @@
+"""Markers and shapes with pygfx backend.
+
+Demonstrates: point markers with text, x/y markers, shapes (rectangle, polyline).
+"""
+
+import numpy
+from silx.gui import qt
+from silx.gui.plot import PlotWidget
+from silx.gui.plot import items
+
+
+def main():
+    app = qt.QApplication([])
+
+    plot = PlotWidget(backend="pygfx")
+    plot.setWindowTitle("pygfx - Markers & Shapes")
+    plot.setGraphTitle("Markers, Text Labels and Shapes")
+
+    # Background image for visual reference
+    size = 100
+    xx, yy = numpy.meshgrid(numpy.linspace(0, 1, size), numpy.linspace(0, 1, size))
+    image = numpy.sin(10 * xx) * numpy.cos(10 * yy)
+    plot.addImage(image, origin=(0, 0), scale=(100 / size, 100 / size))
+    plot.getDefaultColormap().setName("gray")
+
+    # Point markers with text
+    plot.addMarker(20, 80, legend="marker1", text="Point A", color="red", symbol="o")
+    plot.addMarker(50, 60, legend="marker2", text="Point B", color="blue", symbol="d")
+    plot.addMarker(80, 80, legend="marker3", text="Point C", color="green", symbol="s")
+
+    # Horizontal and vertical markers
+    plot.addXMarker(30, legend="x_marker", text="X=30", color="yellow")
+    plot.addYMarker(40, legend="y_marker", text="Y=40", color="cyan")
+
+    # Rectangle shape
+    rect = items.Shape("rectangle")
+    rect.setPoints(numpy.array([(10, 10), (45, 45)]))
+    rect.setColor("red")
+    rect.setLineWidth(2)
+    plot.addItem(rect)
+
+    # Polyline shape
+    poly = items.Shape("polylines")
+    poly.setPoints(numpy.array([(55, 10), (70, 40), (85, 15), (95, 35)]))
+    poly.setColor("green")
+    poly.setLineWidth(2)
+    plot.addItem(poly)
+
+    plot.setGraphXLimits(-5, 105)
+    plot.setGraphYLimits(-5, 105)
+    plot.resetZoom()
+    plot.show()
+    app.exec()
+
+
+if __name__ == "__main__":
+    main()

examples/pygfx_backend/06_error_bars.py

@@ -0,0 +1,63 @@
+"""Error bars with pygfx backend.
+
+Demonstrates: curves with x and y error bars.
+"""
+
+import numpy
+from silx.gui import qt
+from silx.gui.plot import Plot1D
+
+
+def main():
+    app = qt.QApplication([])
+
+    plot = Plot1D(backend="pygfx")
+    plot.setWindowTitle("pygfx - Error Bars")
+    plot.setGraphTitle("Curves with Error Bars")
+    plot.setGraphXLabel("X")
+    plot.setGraphYLabel("Y")
+
+    x = numpy.linspace(0, 10, 30)
+
+    # Symmetric Y errors
+    y1 = numpy.sin(x)
+    yerr1 = 0.1 + 0.1 * numpy.abs(numpy.sin(x))
+    plot.addCurve(
+        x,
+        y1,
+        legend="sym Y error",
+        color="blue",
+        symbol="o",
+        yerror=yerr1,
+        linewidth=1.5,
+    )
+
+    # Asymmetric Y errors
+    y2 = numpy.cos(x) + 3
+    yerr_low = 0.2 * numpy.ones_like(x)
+    yerr_high = 0.5 * numpy.abs(numpy.cos(x))
+    plot.addCurve(
+        x,
+        y2,
+        legend="asym Y error",
+        color="red",
+        symbol="s",
+        yerror=numpy.array([yerr_low, yerr_high]),
+        linewidth=1.5,
+    )
+
+    # X errors
+    y3 = 0.5 * x - 1.5
+    xerr = 0.3 * numpy.ones_like(x)
+    plot.addCurve(
+        x, y3, legend="X error", color="green", symbol="d", xerror=xerr, linewidth=1.5
+    )
+
+    plot.setActiveCurveHandling(False)
+    plot.resetZoom()
+    plot.show()
+    app.exec()
+
+
+if __name__ == "__main__":
+    main()