mandelbtot set: better controls

[nanderer]

Pleaae improve the controles of the Mandelbrot set app, zoom in/out in the middle of the screeen, not into the top left corner, keep moving when holding down direction buttons and dont freeze when zoomed in to far.
Thanks in advance

[DefinetlyNotAI]

Also make it consistant... Its too inconsistant

[mishamyte]

Implemented in Mandelbrot Set 1.4 (#241). All three of your points, plus zoom out:

• Zoom into the middle of the screen. The centre is now fixed and only the span around it changes. Previously the span shrank while the top-left edge stayed pinned, which is why everything contracted into the corner.
• Keep moving when holding a direction button. Arrows now react to press, long and repeat events, so holding one keeps panning. The step is a fixed fraction of the screen, so it scales automatically with how far in you are.
• Don't freeze when zoomed in too far. Same fix as "Mandelbrot Set" hangs after a dozen button presses #160: the picture is computed off the GUI thread and can be interrupted between scanlines. Zooming also now halves or doubles the span per step rather than subtracting a fixed amount, which used to drive the span through zero and mirror the picture after roughly two dozen presses.
• Zoom out, which the app could not do at all: hold Ok, and it repeats while held. Zoom in stops at 16384x, where single precision floats run out of precision, and the current zoom factor is shown briefly after each step so hitting either limit is visible instead of looking like the app stopped responding.