Pointer events in the pixel-centre convention; bold and outlined text markers

AGENTS.md

@@ -115,7 +115,7 @@ grep -nE '^\s*(function|const|let) [A-Za-z_]' anyplotlib/figure_esm.js
 ```
 
 and reconcile against the two numbered tables (the section map near the top and
-the 2-D function table). Both were last verified at 12,349 lines.
+the 2-D function table). Both were last verified at 12,386 lines.
 
 Changelog entries: add a fragment file to `upcoming_changes/` (e.g.
 `123.new_feature.rst`) — towncrier assembles `CHANGELOG.rst` at release time.

anyplotlib/FIGURE_ESM.md

@@ -50,31 +50,31 @@ Rule 5 – Text never clips.  Optional gutters earn real layout space:
 | Shared plot-area padding (`PAD_*`) | 9 |
 | Theme (dark/light detection) | 26 |
 | Shared math helpers | 64 |
-| b64 array decode helpers | 109 |
-| **Rich-text (mini-TeX) engine**: `_texRuns` / `_texLayout` / `_drawTex` | 175 / 242 / 264 |
-| **2D gutter geometry**: `_cbLabelW` / `_cbValueChars` / `_cbTickW` / `_cbWidth` / `_cbGap` / `_padT` / `_titlePx` | 313 / 324 / 342 / 354 / 364 / 374 / 384 |
-| **Layout engine** `applyLayout` | 875 |
-| `_buildCanvasStack` | 958 |
-| `_createPanelDOM` | 1100 |
-| `_createInsetDOM` / `_applyAllInsetStates` | 1241 / 1635 |
-| `_resizePanelDOM` | 2348 |
-| **2D drawing**: `_imgFitRect` | 2519 |
-| `draw2d` | 2863 |
-| `drawScaleBar2d` / `drawColorbar2d` | 3058 / 3338 |
-| **Floating keys**: `_keyEnsure` / `_keyRect` / `drawKeys` | 3157 / 3180 / 3193 |
-| `_drawAxes2d` (ticks, labels, title) | 3450 |
-| `drawOverlay2d` / `drawMarkers2d` | 3603 / 3767 |
-| **Image layers**: `_layerBytes` / `_layerBitmap` / `_drawLayers2d` | 2683 / 2707 / 2768 |
-| Binary-bytes splice: `_spliceBinaryBytes` / `_registerBinaryPixelListeners` | 831 / 862 |
-| **Hover readout**: `_pixelValue2d` / `_readoutInfo2d` | 4611 / 4693 |
-| `_notifyReadout` / `_updateStatus2d` / `_armValueProbe` | 4733 / 4748 / 4769 |
-| **3D drawing**: `draw3d` | 5745 |
-| Event emission `_emitEvent` | 6582 |
-| 3D event handlers `_attachEvents3d` | 6639 |
-| **1D drawing**: `draw1d` | 6863 |
-| `_drawLine` (1D series + markers) | 7016 |
-| `drawOverlay1d` / `drawMarkers1d` | 7309 / 7393 |
-| Marker hit-test `_markerHitTest2d` | 7661 |
+| b64 array decode helpers | 141 |
+| **Rich-text (mini-TeX) engine**: `_texRuns` / `_texLayout` / `_drawTex` | 193 / 260 / 282 |
+| **2D gutter geometry**: `_cbLabelW` / `_cbValueChars` / `_cbTickW` / `_cbWidth` / `_cbGap` / `_padT` / `_titlePx` | 331 / 342 / 360 / 372 / 382 / 392 / 402 |
+| **Layout engine** `applyLayout` | 893 |
+| `_buildCanvasStack` | 976 |
+| `_createPanelDOM` | 1118 |
+| `_createInsetDOM` / `_applyAllInsetStates` | 1259 / 1653 |
+| `_resizePanelDOM` | 2366 |
+| **2D drawing**: `_imgFitRect` | 2537 |
+| `draw2d` | 2881 |
+| `drawScaleBar2d` / `drawColorbar2d` | 3076 / 3356 |
+| **Floating keys**: `_keyEnsure` / `_keyRect` / `drawKeys` | 3175 / 3198 / 3211 |
+| `_drawAxes2d` (ticks, labels, title) | 3468 |
+| `drawOverlay2d` / `drawMarkers2d` | 3621 / 3785 |
+| **Image layers**: `_layerBytes` / `_layerBitmap` / `_drawLayers2d` | 2701 / 2725 / 2786 |
+| Binary-bytes splice: `_spliceBinaryBytes` / `_registerBinaryPixelListeners` | 849 / 880 |
+| **Hover readout**: `_pixelValue2d` / `_readoutInfo2d` | 4629 / 4714 |
+| `_notifyReadout` / `_updateStatus2d` / `_armValueProbe` | 4753 / 4768 / 4789 |
+| **3D drawing**: `draw3d` | 5765 |
+| Event emission `_emitEvent` | 6602 |
+| 3D event handlers `_attachEvents3d` | 6659 |
+| **1D drawing**: `draw1d` | 6883 |
+| `_drawLine` (1D series + markers) | 7036 |
+| `drawOverlay1d` / `drawMarkers1d` | 7329 / 7413 |
+| Marker hit-test `_markerHitTest2d` | 7680 |
 
 > **`raster` marker (1D/PlotXY)** — `drawMarkers1d` has a `type==='raster'`
 > branch that blits a single RGBA image across data-coord `extent` (the fast
@@ -83,22 +83,22 @@ Rule 5 – Text never clips.  Optional gutters earn real layout space:
 > redraws never re-transmit them; the decoded `OffscreenCanvas` is cached on
 > the marker set (`ms._rasterBmp`/`_rasterKey`). The shared `clip_path` block
 > clips it to a curved sector.
-| Panel event dispatch `_attachPanelEvents` | 7918 |
-| 2D events `_attachEvents2d` | 7960 |
-| 1D events `_attachEvents1d` | 8353 |
-| 2D widget drag `_ovHitTest2d` / `_doDrag2d` | 8628 / 8907 |
-| **Brush strokes**: `_brushLiveBegin` / `_brushCommit` / `_brushErase` / `_brushPaintAt` | 8820 / 8834 / 8863 / 8898 |
-| 1D widget drag `_canvasXToFrac1d` … / snapping `_snapVal` | 9032 / 9105 |
-| Shared-axis propagation `_getShareGroups` | 9176 |
-| Figure resize `_applyFigResizeDOM` | 9240 |
-| **Bar chart**: `_barGeom` / `drawBar` / `_attachEventsBar` | 9434 / 9497 / 9873 |
-| Generic redraw `_redrawPanel` | 10063 |
-| **PNG export**: `_compositeCanvas` / `exportCanvas` / `exportPNG` | 10226 / 10422 / 10481 |
-| Native-resolution render `_withNativeSize` | 10202 |
-| **Export UI**: `_toast` / `_downloadCanvas` / `_openMenu` | 10515 / 10624 / 10803 |
-| Export registry `registerExportAction` | 10680 |
-| **Embedding API**: `createLocalModel` / `mount` | 11194 / 11250 |
-| **Navigated embed**: `decodeBlocks` / `mountNavigated` | 11505 / 11892 |
+| Panel event dispatch `_attachPanelEvents` | 7937 |
+| 2D events `_attachEvents2d` | 8004 |
+| 1D events `_attachEvents1d` | 8390 |
+| 2D widget drag `_ovHitTest2d` / `_doDrag2d` | 8665 / 8944 |
+| **Brush strokes**: `_brushLiveBegin` / `_brushCommit` / `_brushErase` / `_brushPaintAt` | 8857 / 8871 / 8900 / 8935 |
+| 1D widget drag `_canvasXToFrac1d` … / snapping `_snapVal` | 9069 / 9142 |
+| Shared-axis propagation `_getShareGroups` | 9213 |
+| Figure resize `_applyFigResizeDOM` | 9277 |
+| **Bar chart**: `_barGeom` / `drawBar` / `_attachEventsBar` | 9471 / 9534 / 9910 |
+| Generic redraw `_redrawPanel` | 10100 |
+| **PNG export**: `_compositeCanvas` / `exportCanvas` / `exportPNG` | 10263 / 10459 / 10518 |
+| Native-resolution render `_withNativeSize` | 10239 |
+| **Export UI**: `_toast` / `_downloadCanvas` / `_openMenu` | 10552 / 10661 / 10840 |
+| Export registry `registerExportAction` | 10717 |
+| **Embedding API**: `createLocalModel` / `mount` | 11231 / 11287 |
+| **Navigated embed**: `decodeBlocks` / `mountNavigated` | 11542 / 11929 |
 
 > **`brush` widget (2-D)** — the one widget whose drag is *modal*, and the one
 > that must NOT write the model per tick. `_ovHitTest2d` takes an extra `mods`
@@ -282,17 +282,28 @@ st.colorbar_label_size            (label font sizes; optional)
 
 | Function | Line | Purpose |
 |----------|------|---------|
-| **`_imgFitRect(iw,ih,cw,ch)`** / `_cbFitRect(st,imgW,imgH)` | **2519 / 2528** | Largest rect of aspect `iw:ih` centred in `cw×ch`; all 2-D coordinate functions derive from this.  `_cbFitRect` is its vertical extent in whole px — the colorbar strip spans the letterboxed IMAGE, not the whole image area (`p._cbH`) |
-| `draw2d(p)` | 2863 | Main render: `_resizePanelDOM` → decode → LUT → ImageBitmap → blit; then mask, axes, scale bar, colorbar, overlay, markers |
-| `drawScaleBar2d(p)` | 3058 | Physical scale bar |
-| `_rawBand(st)` / `_displayFrac(st, val)` / `_buildLut32(st)` | 2578 / 2588 / 2596 | The quantisation band the u8 bytes were encoded over, the ONE rule mapping a value through the display window and scale mode to a colormap fraction (shared by the LUT and the colorbar strip, so the strip's colours are the image's), then the 256-entry LUT built from both. `_rawBand` mirrors Python `_tile_quant_clim`: a DEGENERATE band (`raw_max <= raw_min`) is UNSET and falls back to `display_min/max`. Both render paths and the colorbar go through it — honouring a `(0, 0)` band paints solid black |
-| `drawColorbar2d(p)` | 3338 | Gradient strip coloured through the display window (`_displayFrac` — saturated beyond it, like the image) + min/max marks (band-relative, via `_rawBand`) + the two values written beside them (`fmtRange`; kept inside the strip by the glyphs' measured extent, held apart on a tiny range, the maximum alone at its own place on a strip too short for both; omitted when the layout dropped the gutter, `p._cbTickW == 0`) + rotated label centred right after the values' measured width (never past the reserved gutter) |
-| `_drawAxes2d(p)` | 3450 | Ticks (edge labels nudged inward both axes), axis labels + title via `_drawTex` |
-| `drawOverlay2d(p)` / `drawMarkers2d(p)` | 3603 / 3767 | Widgets / marker groups |
+| **`_imgFitRect(iw,ih,cw,ch)`** / `_cbFitRect(st,imgW,imgH)` | **2537 / 2546** | Largest rect of aspect `iw:ih` centred in `cw×ch`; all 2-D coordinate functions derive from this.  `_cbFitRect` is its vertical extent in whole px — the colorbar strip spans the letterboxed IMAGE, not the whole image area (`p._cbH`) |
+| `draw2d(p)` | 2881 | Main render: `_resizePanelDOM` → decode → LUT → ImageBitmap → blit; then mask, axes, scale bar, colorbar, overlay, markers |
+| `drawScaleBar2d(p)` | 3076 | Physical scale bar |
+| `_rawBand(st)` / `_displayFrac(st, val)` / `_buildLut32(st)` | 2596 / 2606 / 2614 | The quantisation band the u8 bytes were encoded over, the ONE rule mapping a value through the display window and scale mode to a colormap fraction (shared by the LUT and the colorbar strip, so the strip's colours are the image's), then the 256-entry LUT built from both. `_rawBand` mirrors Python `_tile_quant_clim`: a DEGENERATE band (`raw_max <= raw_min`) is UNSET and falls back to `display_min/max`. Both render paths and the colorbar go through it — honouring a `(0, 0)` band paints solid black |
+| `drawColorbar2d(p)` | 3356 | Gradient strip coloured through the display window (`_displayFrac` — saturated beyond it, like the image) + min/max marks (band-relative, via `_rawBand`) + the two values written beside them (`fmtRange`; kept inside the strip by the glyphs' measured extent, held apart on a tiny range, the maximum alone at its own place on a strip too short for both; omitted when the layout dropped the gutter, `p._cbTickW == 0`) + rotated label centred right after the values' measured width (never past the reserved gutter) |
+| `_drawAxes2d(p)` | 3468 | Ticks (edge labels nudged inward both axes), axis labels + title via `_drawTex` |
+| `drawOverlay2d(p)` / `drawMarkers2d(p)` | 3621 / 3785 | Widgets / marker groups |
 
 Zoom model: at `zoom=1` the whole image fills the fit-rect; at `zoom=Z>1` a
 `1/Z` region fills it.  `_imgToCanvas2d` / `_canvasToImg2d` must stay exact
-inverses of the blit geometry.
+inverses of the blit geometry — and of each other.  Both use the pixel-CENTRE
+convention (integer *i* is the centre of pixel *i*, which spans
+`[i − 0.5, i + 0.5)`), the same as marker offsets, widget positions and Python's
+`data_to_display` / `display_to_data`; `_imgPix2d` / `_inImgAxis2d` name the
+pixel under a coordinate and bound it.  Pointer events and the readout map a
+coordinate to `xdata`/`ydata` through `_imgToAxisVal2d` (imshow axes are
+per-pixel centres, pcolormesh axes cell edges).  Code that addresses texels or
+the detail region by pixel EDGE (`_pixelValue2d`) adds the `0.5` back itself.
+
+`texts` markers (1-D and 2-D) set their font and optional outline through
+`_markerTextStyle(ctx, ms)` (`fontweight`, `outline_color`, `outline_width`)
+and draw via `_drawMarkerText`, which strokes the halo under the fill.
 
 ### Hover readout
 
@@ -641,13 +652,13 @@ exportCanvas(same opts) → {canvas, width, height}   // synchronous, throws
 
 | Function | Line | Purpose |
 |----------|------|---------|
-| `_cssScale` | 10098 | inverse of `_applyScale`'s `transform:scale()` |
-| `_panelBox` | 10109 | the element whose rect bounds one panel |
-| `_neutralizeView` / `_restoreView` | 10118 / 10143 | transient whole-extent view |
-| `_nativeGeom` / `_nativeGuard` | 10158 / 10177 | native size + why-not message |
-| `_withNativeSize` | 10202 | resize → redraw → run → restore |
-| `_compositeCanvas` | 10226 | the compositor (`_drawEl` / `_drawPanel` …) |
-| `exportCanvas` / `exportPNG` | 10422 / 10481 | orchestrator / data-URL wrapper |
+| `_cssScale` | 10135 | inverse of `_applyScale`'s `transform:scale()` |
+| `_panelBox` | 10146 | the element whose rect bounds one panel |
+| `_neutralizeView` / `_restoreView` | 10155 / 10180 | transient whole-extent view |
+| `_nativeGeom` / `_nativeGuard` | 10195 / 10214 | native size + why-not message |
+| `_withNativeSize` | 10239 | resize → redraw → run → restore |
+| `_compositeCanvas` | 10263 | the compositor (`_drawEl` / `_drawPanel` …) |
+| `exportCanvas` / `exportPNG` | 10459 / 10518 | orchestrator / data-URL wrapper |
 
 **The whole pipeline is ONE synchronous task** — theme swap, view reset, native
 resize, composite, restore — so the browser never paints an intermediate state
@@ -743,13 +754,13 @@ leaders that cross into the panel included. Pinned by
 
 | Function | Line | Purpose |
 |----------|------|---------|
-| `_toast` | 10515 | transient bottom-centre message |
-| `_copyCanvas` | 10550 | clipboard write + feature detection |
-| `_showPngPreview` | 10574 | framed-document download fallback |
-| `_downloadCanvas` | 10624 | `<a download>` or the preview |
-| `registerExportAction` | 10680 | downstream extension point |
-| `_menuRows` / `_openMenu` | 10734 / 10803 | menu model / DOM |
-| `_panelAtPoint` | 10915 | hit test (insets first — they sit on top) |
+| `_toast` | 10552 | transient bottom-centre message |
+| `_copyCanvas` | 10587 | clipboard write + feature detection |
+| `_showPngPreview` | 10611 | framed-document download fallback |
+| `_downloadCanvas` | 10661 | `<a download>` or the preview |
+| `registerExportAction` | 10717 | downstream extension point |
+| `_menuRows` / `_openMenu` | 10771 / 10840 | menu model / DOM |
+| `_panelAtPoint` | 10952 | hit test (insets first — they sit on top) |
 
 - **An `exportBtn` badge (⤓, beside the help badge) opens the same menu on an
   ordinary left click.** It is a `role="button"` with `tabIndex=0` and
@@ -833,16 +844,16 @@ bindings, let it dispatch", rather than a hand-written program per result kind.
 
 | Function | Line | Purpose |
 |----------|------|---------|
-| `decodeBlocks` | 11505 | one base64 `fetch` → one ArrayBuffer → a typed-array view per manifest entry |
-| `dense` | 11531 | `at` / `gather` / `reduce` over a block whose leading axes are the nav axes |
-| `ragged` | 11596 | the same three, over a row-pointer block (`offsets` + one array per column) |
-| `maskFromWidget` | 11679 | rectangle / circle / annulus widget dict → `Uint8Array` (carries `width`/`height`) |
-| `rasterDisks` | 11719 | splat `{x, y, intensity}` rows as filled disks — the base image of a vectors panel |
-| `robustLevels` / `toU8` | 11748 / 11789 | the percentile window and the 8-bit code map, one implementation |
-| `panelAxis` | 11867 | a 1-D panel's decoded x axis (`_1dXArr`, else `x_axis_b64`) |
-| `installTouchShim` / `reportEmbedHeight` | 11804 / 11823 | page chrome: touch → mouse, `postMessage({aplEmbedHeight})` |
-| `encodeBase64` / `typedArrayBytes` | 11843 / 11851 | a 3-D cloud's geometry channel is base64, not the binary side table |
-| `mountNavigated` | 11892 | mount + bind + dispatch; resolves to the mount handle plus `dispatch`/`index`/`blocks` |
+| `decodeBlocks` | 11542 | one base64 `fetch` → one ArrayBuffer → a typed-array view per manifest entry |
+| `dense` | 11568 | `at` / `gather` / `reduce` over a block whose leading axes are the nav axes |
+| `ragged` | 11633 | the same three, over a row-pointer block (`offsets` + one array per column) |
+| `maskFromWidget` | 11716 | rectangle / circle / annulus widget dict → `Uint8Array` (carries `width`/`height`) |
+| `rasterDisks` | 11756 | splat `{x, y, intensity}` rows as filled disks — the base image of a vectors panel |
+| `robustLevels` / `toU8` | 11785 / 11826 | the percentile window and the 8-bit code map, one implementation |
+| `panelAxis` | 11904 | a 1-D panel's decoded x axis (`_1dXArr`, else `x_axis_b64`) |
+| `installTouchShim` / `reportEmbedHeight` | 11841 / 11860 | page chrome: touch → mouse, `postMessage({aplEmbedHeight})` |
+| `encodeBase64` / `typedArrayBytes` | 11880 / 11888 | a 3-D cloud's geometry channel is base64, not the binary side table |
+| `mountNavigated` | 11929 | mount + bind + dispatch; resolves to the mount handle plus `dispatch`/`index`/`blocks` |
 
 `mountNavigated(el, page, opts)` is **async** — the blob decode is a `fetch` of
 a `data:` URL — so a host `await`s it.  `page` is `{state, blocks, bindings,

anyplotlib/_base_plot.py

@@ -719,7 +719,8 @@ def add_text(self, x, y, s, name=None, *, color="#ff0000",
         transform : str, optional
             Coordinate system for ``(x, y)``.  Default ``"data"``.
         **kwargs : dict
-            Forwarded to :meth:`add_texts` (e.g. ``clip_display``).
+            Forwarded to :meth:`add_texts` (e.g. ``clip_display``,
+            ``fontweight``, ``outline_color``).
 
         Returns
         -------

anyplotlib/callbacks.py

@@ -43,7 +43,7 @@ class Event:
         button         — 0=left 1=middle 2=right; None on move/enter/leave/settled
         buttons        — bitmask of currently held buttons
         xdata, ydata   — data-space coordinates (None for Plot3D)
-        img_x, img_y   — Plot2D/PlotMesh: position in IMAGE PIXELS (column, row; row 0 at the top, origin already applied), so a handler can index the source array directly. None on other plot types.
+        img_x, img_y   — Plot2D/PlotMesh: position in IMAGE PIXELS (column, row; row 0 at the top, origin already applied), so a handler can index the source array directly. Integer i is the CENTRE of pixel i (as for markers and widgets), so round() names the pixel. None on other plot types.
         ray            — Plot3D only: {"origin": [...], "direction": [...]}
         line_id        — Plot1D only: set when pointer is over a line
         dwell_ms       — pointer_settled only: actual dwell time