UXFrameHud

UXFrameHud is a small panel that shows how fast the app’s turn is running: the frames in the last whole second, and the fastest, average and slowest frame in that same second. It is a view like any other, so it travels to every backend. That matters because the developer’s machine is fast and the target device may not be.

#use <UXKit>

Overview

UXFrameHud* hud = new UXFrameHud();
hud.setEnabled(true);
canvas.addSubview(hud, UXGeom.make(8, 8, hud.preferredWidth(), hud.preferredHeight()));
app.everyTurn(&tick, 0);   // and in tick(): hud.tick();

Call tick() once per turn from the app’s turn function. Each call is one frame boundary. Every whole second the panel publishes that second, and all four numbers come from the same frames:

shown	meaning
`fps`	the frames in the second
`min`	the fastest frame in it, in milliseconds
`avg`	the second’s length divided by its frames, so `1000 / fps`
`max`	the slowest frame in it

So it always reads min ≤ avg ≤ max, and avg agrees with fps. The latest single frame is not shown, because the turn that repaints the panel tends to be a long one, which makes the reading misleading. Code that wants it can call framePrev.

The panel asks for its own surface, so where the backend has GL it draws over the GL view rather than under it.

Topics

Showing · setEnabled / isEnabled / toggle · preferredWidth / preferredHeight Sampling · tick · reset Reading · frameFps / frameMin / frameAvg / frameMax · framePrev

setEnabled / isEnabled / toggle

void setEnabled(bool e)
bool isEnabled(void)
void toggle(void)

Shows the panel and starts sampling, or hides it. Turning it on restarts the clock, so the first second after that is a fresh one.

preferredWidth / preferredHeight

i32 preferredWidth(void)
i32 preferredHeight(void)

The size the readout needs. The width is measured on the backend’s own font for the widest text the panel can show (a three-digit frame rate, frame times up to 999.99 ms), so the app does not have to guess. The panel fills whatever frame it is given.

tick

void tick(void)

One frame boundary. The first call only starts the clock; each later one is a frame.

reset

void reset(void)

Drops the numbers and starts a fresh second.

frameFps / frameMin / frameAvg / frameMax

i32 frameFps(void)
i32 frameMin(void)
i32 frameAvg(void)
i32 frameMax(void)

The last whole second: its frame count, and its fastest, average and slowest frame in microseconds. They are 0 until a second has passed.

framePrev

i32 framePrev(void)

The latest single frame, in microseconds.