ui_plot.c File Reference

The multi-series plot on one time base. See ui_plot.h. More...

#include "ui_plot.h"
#include <math.h>
#include <stdio.h>
#include <string.h>
#include "ui_text.h"
#include "ui_theme.h"
#include "ui_widgets.h"

Macros
#define	SHRINK_HOLD   60
#define	HEADROOM   1.12f
#define	RAIL_W   6
#define	RAIL_PITCH   10
#define	TICKS   8

Functions
float	ui_plot_nice_ceil (float v)
	Round v up to 1, 1.2, 1.5, 2, 2.5, 3, 4, 5, 6, 8 or 10 times a power of ten.
static int	leader_of (const ui_plot_t *p, int k)
void	ui_plot_init (ui_plot_t *p, const ui_plot_series_t *series, int count, float span_s)
	An empty, running plot of series.
void	ui_plot_push (ui_plot_t *p, const float *values)
	Push one sample per series, newest last.
void	ui_plot_set_running (ui_plot_t *p, bool running)
	Start or stop the trace. Stopping holds it; starting does not clear it.
void	ui_plot_clear (ui_plot_t *p)
	Drop every sample and return each scale to its floor. Keeps the series, the time base, the focus and what is hidden.
float	ui_plot_sample (const ui_plot_t *p, int series, int back)
	A sample of a series.
void	ui_plot_update_scales (ui_plot_t *p, int visible_samples)
	Recompute the scales.
void	ui_plot_touch_series (ui_plot_t *p, int series)
	Tap a legend chip: focus it, or hide it if it was already focused.
int	ui_plot_map_y (const ui_plot_t *p, int series, float value, int y0, int h)
	Where value lands inside a plot h tall.
void	ui_plot_render_legend (const ui_plot_t *p, gfx_canvas_t *c, gfx_rect_t r)
	A row of swatch + name + full scale, one entry per series.
void	ui_plot_render (const ui_plot_t *p, gfx_canvas_t *c, gfx_rect_t r)
	The plot body: grid, traces, the focused series' scale. One sample a pixel column, in the first UI_PLOT_HISTORY columns from the left edge, the newest in the last of them.

Detailed Description

The multi-series plot on one time base. See ui_plot.h.

SPDX-License-Identifier: MIT

Function Documentation

ui_plot_clear()

void ui_plot_clear

(

ui_plot_t *

p

)

Drop every sample and return each scale to its floor. Keeps the series, the time base, the focus and what is hidden.

Parameters

p

The plot.

ui_plot_init()

void ui_plot_init	(	ui_plot_t *	p,
		const ui_plot_series_t *	series,
		int	count,
		float	span_s )

An empty, running plot of series.

Parameters

p	The plot.
series	The series, copied.
count	How many, at most UI_PLOT_MAX_SERIES.
span_s	The width of the time base, for the axis label.

ui_plot_map_y()

int ui_plot_map_y	(	const ui_plot_t *	p,
		int	series,
		float	value,
		int	y0,
		int	h )

Where value lands inside a plot h tall.

Parameters

p	The plot.
series	The series whose scale it is on.
value	The value.
y0	The plot's top.
h	The plot's height.

Returns

The row, clamped to the box.

ui_plot_nice_ceil()

float ui_plot_nice_ceil

(

float

v

)

Round v up to 1, 1.2, 1.5, 2, 2.5, 3, 4, 5, 6, 8 or 10 times a power of ten.

The finer steps keep a 6S pack (25.2V) on a 0 to 30V scale rather than the 0 to 50V a 1/2/5 ladder gives.

Parameters

v	The value.

Returns

The step at or above it.

ui_plot_push()

void ui_plot_push	(	ui_plot_t *	p,
		const float *	values )

Push one sample per series, newest last.

A non-finite value is a gap: not drawn and not in the autorange. A stopped plot counts the call and drops the sample.

Parameters

p	The plot.
values	One value per series: count of them.

ui_plot_render()

void ui_plot_render	(	const ui_plot_t *	p,
		gfx_canvas_t *	c,
		gfx_rect_t	r )

The plot body: grid, traces, the focused series' scale. One sample a pixel column, in the first UI_PLOT_HISTORY columns from the left edge, the newest in the last of them.

Parameters

p	The plot.
c	Canvas.
r	The plot's box.

ui_plot_render_legend()

void ui_plot_render_legend	(	const ui_plot_t *	p,
		gfx_canvas_t *	c,
		gfx_rect_t	r )

A row of swatch + name + full scale, one entry per series.

Parameters

p	The plot.
c	Canvas.
r	The legend's row.

ui_plot_sample()

float ui_plot_sample	(	const ui_plot_t *	p,
		int	series,
		int	back )

A sample of a series.

Parameters

p	The plot.
series	The series.
back	How far back: the newest is 0.

Returns

The sample; 0 for one that has not arrived or out of range, and not-a-number for a gap pushed as a non-finite value.

ui_plot_set_running()

void ui_plot_set_running	(	ui_plot_t *	p,
		bool	running )

Start or stop the trace. Stopping holds it; starting does not clear it.

Two calls rather than one setter that also empties the ring: this widget has no idea what a run is, and a start that silently wiped the samples would be a trap for the next caller that wanted to resume one.

Parameters

p	The plot.
running	Whether the trace advances.

ui_plot_touch_series()

void ui_plot_touch_series	(	ui_plot_t *	p,
		int	series )

Tap a legend chip: focus it, or hide it if it was already focused.

Parameters

p	The plot.
series	The series of the chip.

ui_plot_update_scales()

void ui_plot_update_scales	(	ui_plot_t *	p,
		int	visible_samples )

Recompute the scales.

A scale grows immediately and shrinks only after 60 consecutive samples (3s at 20Hz) below it, so a brief spike does not rescale the plot twice.

Parameters

p	The plot.
visible_samples	The newest samples the plot shows.