v2.3 - September 2019

Notable User Changes:

• Added formulaic XYZ gates, which can have their rotation angle set to a custom constant or equation
• Added parity controls, which are satisfied as a group if an odd number of them are individually satisfied
• Removed the Sampling Display, the Mystery Gate, and the XYZ^1/8 gates from the toolbox
• Holding "alt" while dragging will now replace gates with their alternates (the alternate is often the inverse)
• Moved the 'Silly' section to the bottom toolbox, renamed it to 'Scalar', and expanded to include i, -i, sqrt(i), sqrt(-i)
• X and Y axis post-selection gates now use symbols that match the input state symbols
• Middle-clicking the initial state of a wire now clears it to |0>
• All display state tooltips now include the decimal equivalent of the state's binary string
• Fixed amplitude displays not normalizing incoherent conditioned results
• Fixed amplitude displays not showing "assuming deferred measurement" warning
• Fixed column dragging not working on OSX

Notable Dev Changes:

• Fixed a Travis-CI breakage due to export DISPLAY being deprecated

v2.2 - March 2019

Notable User Changes:

• Added Detector gates, which perform collapsing measurements
• Qubit initial states can now be cycled between 0/1/+/-/i/-i by clicking on wires' initial state labels
• Qubit wires can now be re-ordered by control-clicking the wire's initial state label and dragging
• The export menu can now export simulation data, including the data from displays
• Gate columns and rows can now be control-dragged out of the circuit to delete them
• Added another example circuit: magic state distillation
• Added the imaginary gate (global phase by i)
• Fixed density matrix display showing transposed contents
• Fixed the custom matrix gate "ensure unitary" option incorrectly permuting the matrix
• Fixed quantum-controlled permutation gates being allowed on measured qubits

Notable Dev Changes:

• Dropped Code Climate
• Travis-ci now runs some of the WebGL tests
• Fixed precision issues in modular multiplication gates and phase gradient gates
• Rewrote amplitude displays to be more resilient to floating point error

v2.1 - September 2017

Notable User Changes:

• Added the dynamic phase gradient gate "Grad^t"
• Worked around a Chrome bug causing shader compilation to fail
• The NOT gate is now drawn as a circled plus even when uncontrolled or in the toolbox.
• Fixed permutation gates with coherent controls not being disabled when applied to measured qubits.
• Added a "clear circuit" button that doesn't remove custom gates
• Location-independent gates (e.g. set-input gates and global phase gates) are now drawn as octagons
• Set-input gates are now considered "non-local" and show a vertical dashed line
• Removed reversed-input gates from toolbox
• Fixed gates not being removed when middle-clicking through their resize tab
• Change the phase gradient gate's symbol to "Grad^1/2"
• Entering a single value when defining a custom matrix gate now produces a global phase gate
• X/Y post-selection gates symbols now use circled characters
• Fixed a precision-loss bug in the shader used by phase gradient gates

Notable Dev Changes:

• Renamed the template folder to html
• Added hidden modular-multiply-accumulate and pivot-flip gates
• Added license headers (Quirk's copyright is now owned by Google)
• Added utility testing methods for gates that only perform phasing
• Test pages now include a progress indicator
• Worked around travis-ci adding enough webgl support to run circuit tests, but not enough to pass all of them
• ketShaderPhase now works with angles instead of complex unit values.

v2.0 - April 2017

Breaking changes from v1 to v2:

• Changed spherical coordinate system to match physics conventions
  • Off is upward, On is downward
  • Z up/down, Y left/right, X toward/away
  • Theta ranges from 0 (up) to 180 (down)
  • Phi=0 points toward user, Phi=90 points rightward
• Swapped the Off/On symbols for both the X-controls and Y-controls
  • X-On is a circled plus (matches the NOT gate, since they interchange)
  • X-Off is a circled-minus
  • Y-On is a circled cross
  • Y-Off is a circled slash
  • Serialized ids did not change; old circuits will load correctly

Notable User Changes:

• Bug fixes:
  • Fixed reversed-input gates not reversing
  • Fixed input gates not drawing control lines into custom circuit gates
  • Fixed drawing control lines to custom identity operations
  • Fixed permute-wire drawings not fully erasing covered wires
  • Fixed bad URLs being created for custom gates with '%' or '&' in their names
• Toolbox changes
  • Hid exp(iUt) gates
  • Hid 16'th-root gates
  • Hid shift-cycling gates
  • Moved all X/Y/Z gates to top
  • Added parametrized X/Y/Z gates
  • Added comparison gates
  • Added multiplication gates
  • Added 'set default input' gates
  • Added modular arithmetic gates and Input R
  • Added interleave gates
• Appearance:
  • Bottom toolbox has a fourth row
  • Input gates shaded gray
  • Bit-rotate gates show a rearranged-wire symbol
  • Bit-permutating gates show the wire re-arranging even when controlled
  • Increment/Decrement gates now show "+1" and "-1" instead of "++" and "--"
  • Sample gate shows an extra decimal ket in its tooltip text
  • Added 'Shor Period Finding' example
  • Added version indicator
  • Gates no longer show a 'resizable' symbol
  • Phase gradient gates now show "e^iπ%" instead of incorrect "Z^#"

Notable Dev Changes:

• Improved startup time
  • Added mutation-based GateBuilder and used it instead of replacement-based Gate.with methods
  • All resizable gates now give matrix functions instead of spending time making matrices
  • Avoided creating webgl context twice
  • Switched shaderFromBitPermutation from Seq to a raw loop
• Support for multi-line gate symbols
• Support for clickable gate buttons
• Separated gate effect properties into 'actual' (for simulating) and 'known' (for drawing/testing)
• Commented the Gate class
• Extracted unit-tested methods from control-line-drawing code
• Added 'knownPermutation' gate effect, and added tests for validating actual effect against permutation
• Added ketInputGateShaderCode/ketInputGateArgs, unifying how gates get inputs
• Added serialized 'param' property to gates

v1.9b - February 2017

Notable user changes:

• Fixed extra digit in output-superposition column labels in odd-sized circuits
• Removed 8-wire height limit on counting gates
• Added more example circuits

Notable dev changes:

• Added hidden ±=A² gates

v1.9 - February 2017

Notable User Changes:

• Added an intro menu w/ tutorial video, github link, example circuits
• Kets are now big-endian
• Showing per-gate-column loss%/gain% due to non-unitary operations such as post-selection
• No longer drawing 'control wire' from input gates to non-input-taking gates
• Shift gates now drawn as a wire-rearrangement
• Reverse and Shift gates now allowed on wires that are a mix of measured and coherent
• Small performance boost from cached drawing of output superposition labels

Notable Dev Changes:

• Added hidden "±1s(A)" bitcount gates
• Added hidden "⊕A" xor gates
• Full react-simulate-redraw integration test
• Fixed columns not dragging downward when 16 wires visible
• Fixed column drag error on macs
• Lint fixes

v1.8 - October 2016

Notable user changes:

• iPhone compatibility
• Performance improvements
• Drag columns up and down with ctrl+drag
• 'Use controls' tutorial hint

Notable dev changes:

• Added perf tests
• Tests now pass on iPhone and on Android
• 'ketShader' utility for writing gate shaders easily (order of magnitude fewer lines per shader)
• Introduced ShaderCoder/ShaderParts to allow transparent fallback to byte textures
• Refactored every single shader to use ShaderCoder / ketShader
• Test circuit diagrams can now select from a gate family by adding hole characters below a gate character
• Lots of Seq stuff turned into loops for performance reasons
• No more caching of circuits containing dynamic gates
• webGlTests now run once with float textures allowed and once with the byte texture fallback forced
• All texture alloc management is now done via WglTexturePool and WglTextureTrader, creating a more imperative style
• Texture sizes now commonly specified by the power-of-2 exponent of their area
• Cached toolbox painting
• Skipping unit tests that require float textures when running on a device without support for that.
• Debugged some seriously challenging shader precision issues

v1.7b - Bug Fixed September 2016

Fixes a bug where controlled display gates were conditioning on the Z axis, even for X and Y controls.

v1.7 - September 2016

Notable user changes:

• Ability to make custom rotation/matrix/circuit gates
• Input gates
• Arithmetic gates now use the Input gates
• Shift gates now use up/down arrow symbols
• Silly Ne-Gate
• 'Clear ALL' button
• Dynamic gates have yellow highlight in toolbox
• Removed default density matrix displays at right of circuit

Notable dev changes:

• Improved startup time
• Added meta tags
• Fixed disabled controls starting a control line
• Added hidden 'anti-cross' (/) and |/></| gates
• Reworked circuit inspection code to work on inner circuits within a gate in an outer circuit
• Gates specify custom disable reason finders and texture->texture transformations
• Optimized final amplitude display drawing (200ms -> 20ms for 16 qubit circuit)
• Optimized redraw scheduling
• Unit testing utilities to compare a circuit operation against a matrix
• Serializing custom gates
• Parsing formulas

v1.6 - June 2016

Notable user changes:

• Export menu
• Undo/redo buttons
• A second toolbox below the circuit
• Showing 'discard rate' when post-selection is present
• New gates (Inverse QFT, reverse, zero, shifts [<<, >>, <<t, >>t], multiply-accumulates [c+=ab, c-=ab], X/Y-axis control/post-selection [⊕, ⊖, ⊗, |X⟩⟨X|, |+⟩⟨+|, |-⟩⟨-|])

Notable dev changes:

• Build output is now a single html file
• Testing that gate shaders correspond to their claimed matrices
• Testing backwards/forwards serializer compatibility w.r.t. known gate ids
• Support for saving an offline copy (including all code and current circuit)
• Support for transformed controls (via pre/post shaders)
• 'sans-serif' instead of 'helvetica'
• Hidden tiny-Z gates ("Z^⅟₁₂₈", "Z^⅟₆₄", and "Z^⅟₃₂")
• Fixed double-draw when grabbing things
• Fixed not showing "Scripts disabled" in some cases
• Some untangling in main.js