Meshtastic-Android/app/src/main/java/com/geeksville/mesh/util/GraphUtil.kt
2025-10-08 18:20:09 +00:00

122 lines
4.5 KiB
Kotlin

/*
* Copyright (c) 2025 Meshtastic LLC
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
package com.geeksville.mesh.util
import android.content.res.Resources
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.Brush
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.Path
import androidx.compose.ui.graphics.StrokeCap
import androidx.compose.ui.graphics.asAndroidPath
import androidx.compose.ui.graphics.asComposePath
import androidx.compose.ui.graphics.drawscope.DrawContext
import androidx.compose.ui.graphics.drawscope.DrawScope
import androidx.compose.ui.graphics.drawscope.Stroke
import androidx.compose.ui.unit.dp
import org.meshtastic.proto.TelemetryProtos.Telemetry
object GraphUtil {
val RADIUS = Resources.getSystem().displayMetrics.density * 2
/**
* @param value Must be zero-scaled before passing.
* @param divisor The range for the data set.
*/
fun plotPoint(drawContext: DrawContext, color: Color, x: Float, value: Float, divisor: Float) {
val height = drawContext.size.height
val ratio = value / divisor
val y = height - (ratio * height)
drawContext.canvas.drawCircle(
center = Offset(x, y),
radius = RADIUS,
paint = androidx.compose.ui.graphics.Paint().apply { this.color = color },
)
}
/**
* Creates a [Path] that could be used to draw a line from the `index` to the end of `telemetries` or the last point
* before a time separation between [Telemetry]s.
*
* @param telemetries data used to create the [Path]
* @param index current place in the [List]
* @param path [Path] that will be used to draw
* @param timeRange The time range for the data set
* @param width of the [DrawContext]
* @param timeThreshold to determine significant breaks in time between [Telemetry]s
* @param calculateY (`index`) -> `y` coordinate
* @return the current index after iterating
*/
fun createPath(
telemetries: List<Telemetry>,
index: Int,
path: Path,
oldestTime: Int,
timeRange: Int,
width: Float,
timeThreshold: Long,
calculateY: (Int) -> Float,
): Int {
var i = index
var isNewLine = true
with(path) {
while (i < telemetries.size) {
val telemetry = telemetries[i]
val nextTelemetry = telemetries.getOrNull(i + 1) ?: telemetries.last()
/* Check to see if we have a significant time break between telemetries. */
if (nextTelemetry.time - telemetry.time > timeThreshold) {
i++
break
}
val x1Ratio = (telemetry.time - oldestTime).toFloat() / timeRange
val x1 = x1Ratio * width
val y1 = calculateY(i)
val x2Ratio = (nextTelemetry.time - oldestTime).toFloat() / timeRange
val x2 = x2Ratio * width
val y2 = calculateY(i + 1)
if (isNewLine || i == 0) {
isNewLine = false
moveTo(x1, y1)
}
quadraticTo(x1, y1, (x1 + x2) / 2f, (y1 + y2) / 2f)
i++
}
}
return i
}
fun DrawScope.drawPathWithGradient(path: Path, color: Color, height: Float, x1: Float, x2: Float) {
drawPath(path = path, color = color, style = Stroke(width = 2.dp.toPx(), cap = StrokeCap.Round))
val fillPath =
android.graphics.Path(path.asAndroidPath()).asComposePath().apply {
lineTo(x1, height)
lineTo(x2, height)
close()
}
drawPath(
path = fillPath,
brush = Brush.verticalGradient(colors = listOf(color.copy(alpha = 0.5f), Color.Transparent), endY = height),
)
}
}