Support SGR-Pixels mouse reporting (DECSET 1016), bump to 2.0.4

[tomlm]

Summary

• CSI ? 1016 h/l selects/resets a new MouseEncoding.SGRPixels: SGR-format reports (CSI < b ; x ; y M/m) with 1-based pixel coordinates, matching xterm (EmitMousePosition adds 1 in both 1006 and 1016 modes). It's mutually exclusive with 1005/1006/1015.
• DECRQM now answers set/reset for 1016 instead of "not recognised" (Ps=0), so apps that probe before switching see it as supported.
• New Terminal.GenerateMouseEvent(button, x, y, pixelX, pixelY, eventType, modifiers) overload for hosts that know the pointer's pixel position. Other encodings ignore the pixels and still report cells.
• The existing cell-only overload still works under 1016: it reports the clicked cell's top-left corner from CellWidthPixels/CellHeightPixels, so dividing by the CSI 16 t cell size lands back on that cell.
• Bumps version to 2.0.4.

Tests

• 1016 moved from the "not recognised" DECRQM theory to "untouched mode reports reset"; added a test for 1016 and 1006 replacing each other.
• New encoding tests: pixel reports (press and release), the cell-only fallback, and the pixel overload under plain 1006.
• Full suite: 2229 passed, 1 skipped.

Host follow-up (Avalonia.Terminal)

TerminalView.Mouse.cs should call the pixel overload. Its once-per-cell motion dedupe also needs to compare pixel positions when MouseEncoding == SGRPixels.

🤖 Generated with Claude Code

[Copilot]

Copilot review overview

🟡 Changes recommended

The new tests embed raw ESC control bytes that should be replaced with escaped source representations.

Review effort: Balanced
Findings: 1

Open (1)

• Use escaped ESC representation instead of raw control bytes · New

What changed in this PR

Adds DECSET 1016 SGR-Pixels mouse reporting and releases it as version 2.0.4.

Changes:

• Adds pixel-coordinate SGR event generation with a cell-based fallback.
• Implements mode selection, reset, and DECRQM reporting.
• Adds coverage for pixel reporting and encoding transitions.

File	Description
src/​XTerm.NET/​XTerm.NET.csproj	Bumps version to 2.0.4.
src/​XTerm.NET/​Terminal.cs	Exposes the pixel-coordinate mouse overload.
src/​XTerm.NET/​InputHandler.Modes.cs	Adds 1016 query/reset handling.
src/​XTerm.NET/​InputHandler.cs	Enables SGR-Pixels mode.
src/​XTerm.NET/​Input/​MouseTracker.cs	Generates pixel-coordinate reports and fallback coordinates.
src/​XTerm.NET/​Input/​MouseInput.cs	Adds the SGR-Pixels encoding value.
src/​XTerm.NET.Tests/​RequestModeTests.cs	Tests 1016 mode reporting and exclusivity.
src/​XTerm.NET.Tests/​MouseTrackingTests.cs	Tests pixel reports and fallback behavior.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[github-actions]

Perf comparison — this change, against its base

3 run(s) of each side, alternating on one machine. Allocation is a count and is gated exactly. Time is a measurement, so its gate is derived from the spread this job just observed in itself rather than fixed in advance.

corpus	bytes/char	gen0/Mchar	ns/char	Δ time	noise	gate
scroll-ascii	0.00 → 0.00	0.00 → 0.00	3.54 → 3.54	-0.2%	±1%	4%
sgr-churn	0.00 → 0.00	0.00 → 0.00	8.91 → 8.90	-0.1%	±5%	15%
truecolor	0.00 → 0.00	0.00 → 0.00	9.16 → 9.10	-0.6%	±1%	4%
alt-redraw	0.00 → 0.00	0.00 → 0.00	13.57 → 13.60	+0.2%	±5%	16%
unicode	7.66 → 7.66	0.30 → 0.30	32.80 → 32.85	+0.2%	±4%	13%
flood	0.00 → 0.00	0.00 → 0.00	104.58 → 103.77	-0.8%	±2%	6%

Each corpus is gated at max(4%, 3 × its own noise). A wide noise column means this runner was busy and the timing half of the table should be read as advisory; the allocation half is exact either way.

assemblies measured

• base: XTerm.NET 2.0.3.0 mvid:49f84c34-f27d-4cac-b5ec-43bdd387e050
• head: XTerm.NET 2.0.4.0 mvid:f2608658-7693-4306-9a40-b279ada246b1

---

Perf comparison — cumulative, everything since 2.0.3

3 run(s) of each side, alternating on one machine. Allocation is a count and is gated exactly. Time is a measurement, so its gate is derived from the spread this job just observed in itself rather than fixed in advance.

corpus	bytes/char	gen0/Mchar	ns/char	Δ time	noise	gate
scroll-ascii	0.00 → 0.00	0.00 → 0.00	3.58 → 3.54	-1.1%	±2%	7%
sgr-churn	0.00 → 0.00	0.00 → 0.00	8.89 → 8.90	+0.2%	±3%	10%
truecolor	0.00 → 0.00	0.00 → 0.00	9.01 → 9.10	+1.1%	±6%	19%
alt-redraw	0.00 → 0.00	0.00 → 0.00	13.59 → 13.60	+0.0%	±4%	11%
unicode	7.66 → 7.66	0.30 → 0.30	33.89 → 32.85	-3.1%	±5%	15%
flood	0.00 → 0.00	0.00 → 0.00	104.82 → 103.77	-1.0%	±1%	5%

Each corpus is gated at max(5%, 3 × its own noise). A wide noise column means this runner was busy and the timing half of the table should be read as advisory; the allocation half is exact either way.

assemblies measured

• base: XTerm.NET 2.0.3.0 mvid:9ba0ce98-0d1e-4424-8aa1-9ab012cdc07a
• head: XTerm.NET 2.0.4.0 mvid:f2608658-7693-4306-9a40-b279ada246b1