ultraviolet 0.6.0

Core cell/buffer/style types for terminal rendering.

Changelog

0.6.0

• Require Dart SDK 3.13.0 or newer.
• Skip terminal-graphics parsing when measuring ordinary styled text bounds.
• Expose RenderMetrics.isIdle for diagnostic displays without changing the numeric FPS behavior for idle applications.
• Compare canonical cell style identifiers while rendering buffer lines, avoiding repeated style hashing and equality checks.
• Skip building the tile-density map when packed dirty bits already show that a frame is too dense for sparse tile traversal.
• Allocate cell finalizer detach tokens lazily, avoiding two auxiliary objects for cells without pooled graphemes or hyperlinks.
• Reuse dirty-line metadata for touches already covered by a dirty span, avoiding redundant allocations while preserving per-cell dirty bits.
• Added clipAnsiByCells for exact-column overlay composition. Partial wide glyphs and graphics payloads become styled spaces without snapping or moving neighboring layers; existing whole-grapheme slicing behavior is unchanged.
• Added the native-only raster.dart software UV renderer. It accepts caller-supplied TrueType glyf fonts and produces package:image pixels; no system font discovery or browser/Flutter engine is used. Blink is deterministic (visible), unsupported glyphs and font variants are diagnostics and fail in strict mode.
• Added UvPaintPolicy, shared by native raster, web canvas, and Flutter painting, so terminal defaults, palettes, reverse/faint/conceal, and underline colors resolve consistently across non-ANSI backends.
• Expanded hyperlink registry identities to 20-bit slots and 32-bit generations, preventing frequent slot reuse from hitting the former 8-bit generation limit. Arithmetic encoding preserves exact identities on native and web targets; exhausted generations retire safely rather than aliasing stale IDs.
• Release hyperlink URLs and parameters when the last cell reference is released, retaining only identity bookkeeping in reusable registry slots.
• Added explicit disposal for owned lines, buffers, canvases, and renderer frame state. Resizing and compositing now release discarded cells promptly. setCellOwned consumes its input on every path, including rejected or unchanged writes; callers must not read a cell after transferring ownership.

0.5.1

Changed

• Made the raw Kitty, iTerm2, and Sixel image encoders available from the public rendering entrypoints so protocol encoding has one package-owned implementation. Raw Kitty encoding preserves normal cursor movement by default, while retained drawables suppress it explicitly.
• Added focused, browser-safe core.dart, input.dart, rendering.dart, terminal.dart, and unicode.dart entrypoints for consumers that do not need the full package surface.
• Added uv.dart as the complete low-level UV surface used by compatibility consumers.
• Removed the unused direct meta dependency and excluded generated DevTools profiler sessions from the published package archive.

Fixed

• Taught the ANSI cell slicer device-control strings (Kitty APC, Sixel DCS, plus PM/SOS, 7-bit and C1 forms): payloads tokenize whole with display widths matching Ansi.visibleLength (Kitty transmit/put occupies c columns, Sixel one), so cuts never split base64/sixel data into visible-text garbage. Partially covered images are excluded whole rather than fragmented.
• Exported truncateLeftAnsiByCells alongside cutAnsiByCells.
• Kept the main ultraviolet.dart entrypoint browser-compatible by loading the Windows native console reader only on dart:io platforms.
• Preserved SGR attributes, underline variants and colors (including explicit color-space slots), and complete grapheme widths across ANSI-aware wrapped lines; oversized graphemes now make progress at narrower wrap widths.
• Prevented style-cache fingerprint collisions from leaking underline and other decorations into later text with the same foreground color.
• Prevented malformed OSC 8 hyperlinks containing control characters from crashing cell-buffer rendering; unsafe links are now discarded.

0.5.0

Added

• Added per-cell diff policies for always-redrawn cells, externally owned skipped cells, and content with an explicitly forced terminal width.

Changed

• Added row-level routing for cells that require explicit diff semantics while preserving the tile-based fast path for ordinary dirty rows.

Performance

• Reused dirty-span and dirty-tracking storage, consolidated renderer Sixel and stale-cell scans, cached attribute-rich SGR transitions, and removed per-frame renderer metrics timing allocations.
• Replaced CSI parameter substring/split parsing with direct byte parsing and a compact flattened parameter representation.
• Added repeatable JIT/AOT benchmarks with named DevTools CPU/memory regions.
• Added DevTools-backed allocation bytes and instances per operation to the benchmark JSON report.
• Retained exact truecolor style-transition pairs to eliminate repeated SGR construction during dense styled rendering.
• Combined adjacent truecolor foreground/background changes into one SGR emission for dense RGB rendering.

Fixed

• Fixed wide-cell trailing cleanup in the line-oriented diff traversal, including styled wide-glyph shrink handling.
• Prevented cursor movement optimizations from overwriting cells marked as externally owned or crossing the trailing region of a wide glyph.

0.4.0

Performance

• Renderer hot path: added per-buffer sixel display cache to avoid re-scanning every cell for terminal graphics on every frame. Added ASCII-only fast-path to mayContainTerminalGraphics for short cell content (≤3 chars). Combined improvement: 23.9% → 5.4% self time (4.4× reduction on this hotspot). Overall renderer throughput up 2.1× for full-buffer writes.
• styleToSgr / styleDiff: replaced List<String> + join() with StringBuffer to eliminate intermediate list allocations. Added 64-entry LRU cache keyed by style.packedKey for repeated style emission.
• Event decoder: replaced buf.sublist() allocations with index-based access via parseUtf8At() and decodeOneRuneAt(). Optimized _to7Bit with pre-allocated output list. Event throughput improved 33-57% across all input types.
• Alpha compositing (sourceOver): replaced (x + 127) ~/ 255 with (x + 127) * 257 >> 16 to eliminate slow integer division. sourceOver throughput improved +61%.
• Float32x4 SIMD color ops: added batchTransformRgba() that processes 4 RGBA pixels in parallel using SoA (Structure of Arrays) Float32x4 layout with pre-splatted matrix coefficients. Single-pixel path _transformRgbaF64 uses shuffle-based horizontal sum for dot products. Color matrix ops improved +37%, rgbToHsl +100%.
• consumeEscapeSequence converted from linear if/else cascade to switch-on-int (Dart VM jump table dispatch).
• String width cache refactored into _cachedStringWidth / _cacheStringWidth helpers with same eviction strategy (no regression).

Added

• Comprehensive benchmark suite (benchmark/) with 6 focused benchmarks stress-testing renderer diff, string width, style ops, event decoder, color ops, and full-stack end-to-end scenarios.
• Profiler baseline and optimized session artifacts in benchmark/profiles/.

Changed

• All optimizations are internal refactors with zero public API changes.

0.3.0

Added

• New terminal_graphics.dart module exposes shared helpers for Kitty APC and Sixel DCS protocols: TerminalGraphicsControl, TerminalGraphicsFrame, TerminalGraphicsProtocol, parseTerminalGraphicsControls, mayContainTerminalGraphics, containsRetainedTerminalGraphics, containsSixelDisplay, suppressOverflowingTerminalGraphics, deleteAllRetainedGraphics, and deleteRetainedGraphic.
• OwnedCellScreen interface with setCellOwned allows callers to transfer ownership of freshly created cells without an extra clone.
• Buffer.create and ScreenBuffer accept tracksDirty: false for offscreen composition buffers that do not need per-frame dirty-tracking bookkeeping.
• Canvas now opts out of dirty tracking in its internal ScreenBuffer.
• KittyImage.encode / encodePng accept suppressCursorMovement (default true), emitting C=1 so retained-mode renderers control cursor state.
• KittyImageDrawable accepts clearBeforeDraw: true to emit a Kitty delete-placement sequence before drawing, preventing stale placements after a resize or move.
• SixelImageDrawable accepts allowUpscale: false to cap the Sixel raster at its native resolution instead of stretching to fill the cell area.
• SixelImage.encode prefixes a raster-attributes header to declare a 1:1 pixel aspect ratio and encoded dimensions for correct rendering in foot and similar terminals.
• clampRgbChannel in color_utils.dart clamps a color component to [0, 255].
• Added CanvasTerminalRenderer for browser/wasm rendering on an HTML canvas.
• Added a web canvas example and demo page for exercising UV rendering outside native terminals.

Changed

• UvTerminalRenderer defers retained-graphics cells (Kitty C=1) and Sixel display payloads to end-of-frame to avoid cursor-position conflicts with normal cell output. Retained cells are repositioned via cursor-movement sequences; Sixel payloads use absolute cursor positioning.
• UvTerminalRenderer wraps graphics payloads in a tmux DCS passthrough when TMUX is set or TERM starts with tmux, allowing Kitty and Sixel sequences to pass through a tmux multiplexer.
• UvTerminalRenderer calls erase() before rendering any frame that contains a Sixel display to prevent stale data from bleeding through.
• StyledString.draw now treats Kitty APC (ESC _ G ... ESC \) and Sixel DCS (ESC P q ... ESC \) control strings as terminal-graphics payload cells with the correct display-column width derived from the c= parameter.
• Ansi.visibleLength now accounts for Kitty (c=) and Sixel (1 cell) display width instead of stripping them to zero.
• Ansi.expandTabs and CRLF normalization use early-exit fast paths when the input contains no tab or CR characters.
• Truecolor SGR parameters are now clamped to [0, 255] across style_ops, styled_string, ansi_slice, wrap, and terminal_renderer to prevent invalid CSI sequences from oversized or 16-bit color components.
• emojiPresentationWidth is now a settable property; updates also clear the unicode string-width cache to keep cached values consistent.
• Unicode string widths are cached (up to 2048 entries, strings up to 4096 chars) to reduce repeated grapheme-cluster traversal on the same strings.
• Rectangle.isEmpty now checks precomputed edges directly in hot render paths.
• Split terminal, stdin, and window-size helpers across IO, web, and stub implementations so UV can be used from browser targets.
• Extracted the common terminal renderer abstraction from UvTerminalRenderer for reuse by native and canvas-backed renderers.

Performance

• Optimized packed cell construction for styled text and printable ASCII cells.
• Cached repeated style ids and ASCII scalar strings so Markdown-heavy render paths avoid repeated packed-style encoding and String.fromCharCode churn.
• Reduced offscreen composition overhead by using non-dirty-tracked buffers and updating line cells in place.

Fixed

• Cell._setStyle short-circuits immediately for the zero style, skipping a redundant packed-key encode.
• _LinkRegistry.intern caches the last interned link to avoid a map lookup on repeated calls with the same Link value.
• _containsControl now iterates code units instead of runes.
• _widthBits widened from 3 to 16 to support large terminal-graphics cell widths (e.g. an 80-column Kitty image) without overflow in pooled ids.
• Buffer.setCell skips compositing when the new cell is fully opaque.
• Buffer.fillArea clips to the buffer bounds before iterating, preventing out-of-bounds dirty touches.
• Buffer.replaceWithClone copies in-place via copyFrom and updates the render hash incrementally.
• Ansi.requestPrimaryDeviceAttributes corrected from ESC[?c to ESC[c.
• Fixed web canvas background inheritance so selected rows, dominant backgrounds, default-background rows, and non-background cells bridge consistently during canvas rendering.

0.2.0

Changed

• Terminal startup capability probing now queries DA2 as well as DA1, kitty keyboard, colors, and kitty graphics.
• Terminal startup capability probing now queries DA3 and terminal-version reports alongside the existing DA1/DA2, kitty keyboard, color, and kitty-graphics probes.
• Terminal startup capability probing now queries the terminal light/dark color-scheme report alongside the existing device, keyboard, graphics, and color probes.
• TerminalCapabilities now tracks exact kitty keyboard enhancement flags plus foreground, background, cursor, and palette color reports with idempotent updates.
• TerminalCapabilities now tracks ModifyOtherKeys mode reports and terminal dark/light color-scheme state instead of treating those reports as transient decode-only events.
• Terminal startup capability probing now queries foreground and cursor colors in addition to the existing background, keyboard, device-attribute, and kitty-graphics probes.
• TerminalCapabilities now infers Kitty and iTerm2 image-protocol support from terminal-version replies in addition to the existing environment and device-attribute hints.

Fixed

• Terminal is now explicitly single-use after stop(), repeated mode toggles are idempotent, and changing kitty keyboard enhancement flags now resets the old mode before applying the new one.
• Added lifecycle coverage for kitty keyboard enhancement enable/disable behavior and shutdown cleanup in Terminal.
• Fixed capability state tracking so primary device attribute changes are detected even when Sixel support does not change, and repeated identical color/capability reports no longer churn state.
• TerminalCapabilities now stores and de-duplicates secondary device attributes instead of discarding DA2 reports after decode.
• TerminalCapabilities now stores and de-duplicates DA3 tertiary attributes and terminal-version reports instead of discarding them after decode.
• Added direct Terminal coverage for focus/blur events, bracketed paste events, and startup foreground/cursor color capability updates.
• Added direct Terminal coverage for mouse click, release, motion, and wheel events plus standard and in-band resize report handling.
• Added direct Terminal coverage for cursor-position, ModifyOtherKeys, and primary/secondary/tertiary device-attribute reports, including capability-state updates from DA1.
• Added direct Terminal coverage for clipboard, terminal-version, XTGETTCAP, background-color, and palette report handling.
• Fixed UvTerminalRenderer leading-blank overwrite fallback so it only emits blanks for truly blank old-line regions instead of using spaces to move across existing content.

0.1.1+1

• fix documentation + missing assets

0.1.1

Fixed

• Updated package screenshots/readme media setup for pub.dev rendering.
• Added pubspec.yaml screenshot metadata (assets/layout.png) for package page preview.

0.1.0

Added

• Initial release of ultraviolet.
• Core terminal rendering primitives: cells, buffers, styles, ANSI handling, and terminal renderer.
• Layout/rendering helpers and example suite for advanced terminal graphics.

Fixed

• Synchronized-output skipped-frame behavior in UvTerminalRenderer dirty-line handling.