Release 0.8.8 "Voice" - Power usage reduction

This release focuses on reducing power usage and improving reactivity, notably while running on battery.

Features

• Cache rendered graphics and text on the stack to reduce the time spent redrawing the stack.

• Limit the size of objects being rendered on the stack. Objects that are too large will simply render as something like Large bignum (399 bytes) on the stack. This is configured by two new settings, TextRenderingSizeLimit and GraphRenderingSizeLimit.

• Limit the size spent rendering graphical objects. There are four settings controlling the maximum time spent rendering objects graphically. ResultGraphingSizeLimits controls the display for the first level on the stack, StackGraphingSizeLimit controls the display for the other levels on the stack, ShowTimeLimit controls the display for the Show command, and GraphingTimeLimit controls other graphical rendering.

• Blink the battery icon when in a low-battery situation.

• Add configurable MinimumBatteryVoltage to adjust the threshold for low-battery detection and automatic power-off.

• Power-related commands: The BatteryVoltage and PowerVoltage read the battery and power voltage respectively. The USBPowered commands detects if the calculator is running on USB power. The LowBattery command detects if the calculator is running low on battery.

• Detect and reject Unicode characters that look like mathematical characters, and are produced by auto-correction on Windows, notably the- and * signs that look like - and *. This is notably useful when copy-pasting in the simulator on Windows.

Bug fixes

• Fix NDupN again. While the previous release fixed what NDupN does, it did not fix the detection of the number of arguments, meaning that NDupN would incorrectly complain about missing arguments if the stack was not deep enough.

• Fix the precedence of unary - when in front of a parenthesized expression. For example, -(X)^2 now parses correctly.

• Disable keyboard repeat timer when no key is pressed. It was possible to trigger a condition where the keyboard repeat timer would trigger continuously if two keys had been pressed in rapid succession, keeping the CPU in a busy loop and depleting the battery unnecessarily rapidly until another key was pressed. This could also trigger incorrect long-press detections, e.g. the shift key triggering alpha mode instead of a simple shift.

• Disable all timers when switching the calculator off. In some situations, the display refresh timer could still remain active
  after the calculator had been switched off.

• RclΣ now returns the statistics data even when the ΣData variable contains the name of a variable or file.

• The Off command can now be used while editing and no longer causes immediate command-line evaluation.

• Return to the first page of the catalog menus when updating it, to avoid scenarios where the catalog appeared empty

• Return to the first page of the cartalog menu when changing directories, to avoid showing an empty variables menu in a non-empty directory.

• Do not leave garbage on the stack after failed array arithmetic.

• Avoid occasional test crashes due to concurrent pixmap updates in the simulator.

• Avoid occasional spurious error on Primitive test due to long execution time.

• Switch to kg as the base unit for UBASE instead of g, following the SI standard.

Improvements

• Reduce animations more drastically while on battery power. Notably, the cursor does not blink, and menu animations are entirely disabled.

• Rework the animation and screen refresh system to make it easier to maintain and more power-efficient while on battery.

• Refresh the display using hardware-accelerated background refresh routines provided by the DMCP platform. This can be disabled using the SoftwareDisplayRefresh flag.

• Redraw the battery immediately on power change, i.e. plugging or unplugging the USB cable.

• Updated built-in constants with latets CODATA values(contributed by Jean Wilson)