Colorize headwind forecast line graph and the area beneath it (#155)

app/src/main/kotlin/de/timklge/karooheadwind/datatypes/LineGraphForecastDataType.kt

@@ -1,8 +1,10 @@
 package de.timklge.karooheadwind.datatypes
 
 import android.content.Context
+import android.graphics.Canvas
 import android.util.Log
 import androidx.compose.ui.unit.DpSize
+import androidx.core.graphics.createBitmap
 import androidx.glance.GlanceModifier
 import androidx.glance.Image
 import androidx.glance.ImageProvider
@@ -71,7 +73,8 @@ abstract class LineGraphForecastDataType(private val karooSystem: KarooSystemSer
         lineData: List<LineData>,
         isImperial: Boolean,
         upcomingRoute: UpcomingRoute?,
-        isPreview: Boolean
+        isPreview: Boolean,
+        context: Context
     ): Set<LineGraphBuilder.Line>
 
     private fun previewFlow(settingsAndProfileStream: Flow<SettingsAndProfile>): Flow<StreamData> =
@@ -265,8 +268,10 @@ abstract class LineGraphForecastDataType(private val karooSystem: KarooSystemSer
                         data,
                         settingsAndProfile.isImperialTemperature,
                         upcomingRoute,
-                        config.preview
+                        config.preview,
+                        context
                     )
+
                     val bitmap = LineGraphBuilder(context).drawLineGraph(config.viewSize.first, config.viewSize.second, config.gridSize.first, config.gridSize.second, pointData) { x ->
                         val startTime = data.firstOrNull()?.time
                         val time = startTime?.plus(floor(x).toLong(), ChronoUnit.HOURS)

app/src/main/kotlin/de/timklge/karooheadwind/datatypes/PrecipitationForecastDataType.kt

@@ -1,5 +1,6 @@
 package de.timklge.karooheadwind.datatypes
 
+import android.content.Context
 import de.timklge.karooheadwind.UpcomingRoute
 import de.timklge.karooheadwind.screens.LineGraphBuilder
 import io.hammerhead.karooext.KarooSystemService
@@ -9,7 +10,8 @@ class PrecipitationForecastDataType(karooSystem: KarooSystemService) : LineGraph
         lineData: List<LineData>,
         isImperial: Boolean,
         upcomingRoute: UpcomingRoute?,
-        isPreview: Boolean
+        isPreview: Boolean,
+        context: Context
     ): Set<LineGraphBuilder.Line> {
         val precipitationPoints = lineData.map { data ->
             if (isImperial) { // Convert mm to inches

app/src/main/kotlin/de/timklge/karooheadwind/datatypes/TailwindAndRideSpeedDataType.kt

@@ -16,6 +16,7 @@ import de.timklge.karooheadwind.HeadwindSettings
 import de.timklge.karooheadwind.KarooHeadwindExtension
 import de.timklge.karooheadwind.R
 import de.timklge.karooheadwind.getRelativeHeadingFlow
+import de.timklge.karooheadwind.screens.isNightMode
 import de.timklge.karooheadwind.streamCurrentWeatherData
 import de.timklge.karooheadwind.streamDataFlow
 import de.timklge.karooheadwind.streamDatatypeIsVisible
@@ -199,14 +200,10 @@ class TailwindAndRideSpeedDataType(
                     "$sign${headwindSpeedUserUnit.roundToInt().absoluteValue} ${windSpeedUserUnit.roundToInt()}${gustSpeedAddon}"
                 }
 
-
-                var dayColor = Color(ContextCompat.getColor(context, R.color.black))
-                var nightColor = Color(ContextCompat.getColor(context, R.color.white))
-
                 val headwindSpeed = cos( (windDirection + 180) * Math.PI / 180.0) * windSpeed
                 val windSpeedInKmh = headwindSpeed * 3.6
-                dayColor = interpolateWindColor(windSpeedInKmh, false, context)
-                nightColor = interpolateWindColor(windSpeedInKmh, true, context)
+                val dayColor = interpolateWindColor(windSpeedInKmh, false, context)
+                val nightColor = interpolateWindColor(windSpeedInKmh, true, context)
 
                 val result = glance.compose(context, DpSize.Unspecified) {
                     HeadwindDirection(

app/src/main/kotlin/de/timklge/karooheadwind/datatypes/TemperatureForecastDataType.kt

@@ -1,5 +1,6 @@
 package de.timklge.karooheadwind.datatypes
 
+import android.content.Context
 import de.timklge.karooheadwind.UpcomingRoute
 import de.timklge.karooheadwind.screens.LineGraphBuilder
 import io.hammerhead.karooext.KarooSystemService
@@ -9,7 +10,8 @@ class TemperatureForecastDataType(karooSystem: KarooSystemService) : LineGraphFo
         lineData: List<LineData>,
         isImperial: Boolean,
         upcomingRoute: UpcomingRoute?,
-        isPreview: Boolean
+        isPreview: Boolean,
+        context: Context
     ): Set<LineGraphBuilder.Line> {
         val linePoints = lineData.map { data ->
             if (isImperial) {

app/src/main/kotlin/de/timklge/karooheadwind/datatypes/WindForecastDataType.kt

@@ -1,12 +1,16 @@
 package de.timklge.karooheadwind.datatypes
 
+import android.content.Context
+import android.graphics.Color
 import android.util.Log
+import androidx.compose.ui.graphics.toArgb
 import com.mapbox.turf.TurfConstants
 import com.mapbox.turf.TurfMeasurement
 import de.timklge.karooheadwind.KarooHeadwindExtension
 import de.timklge.karooheadwind.UpcomingRoute
 import de.timklge.karooheadwind.lerpWeather
 import de.timklge.karooheadwind.screens.LineGraphBuilder
+import de.timklge.karooheadwind.screens.isNightMode
 import de.timklge.karooheadwind.util.signedAngleDifference
 import io.hammerhead.karooext.KarooSystemService
 import kotlin.math.ceil
@@ -23,7 +27,8 @@ class WindForecastDataType(karooSystem: KarooSystemService) : LineGraphForecastD
         lineData: List<LineData>,
         isImperial: Boolean,
         upcomingRoute: UpcomingRoute?,
-        isPreview: Boolean
+        isPreview: Boolean,
+        context: Context
     ): Set<LineGraphBuilder.Line> {
         val windPoints = lineData.map { data ->
             if (isImperial) { // Convert m/s to mph
@@ -47,16 +52,21 @@ class WindForecastDataType(karooSystem: KarooSystemService) : LineGraphForecastD
                     val t = i / HEADWIND_SAMPLE_COUNT.toDouble()
 
                     if (isPreview) {
-                        return@mapNotNull LineGraphBuilder.DataPoint(i.toFloat() * (windPoints.size / HEADWIND_SAMPLE_COUNT.toFloat()), (-10f) + (20f * kotlin.random.Random.nextFloat()))
+                        // Use a sine wave for headwind preview speed
+                        val headwindSpeed = 10f * kotlin.math.sin(i * Math.PI * 2 / HEADWIND_SAMPLE_COUNT).toFloat()
+                        val headwindSpeedInKmh = headwindSpeed * 3.6 // Convert m/s to km/h
+
+                        return@mapNotNull LineGraphBuilder.DataPoint(x = i.toFloat() * (windPoints.size / HEADWIND_SAMPLE_COUNT.toFloat()),
+                            y = headwindSpeed)
                     }
 
                     if (upcomingRoute == null) return@mapNotNull null
 
-                    val beforeLineData = lineData.getOrNull(floor(lineData.size * t).toInt()) ?: lineData.firstOrNull()
-                    val afterLineData = lineData.getOrNull(ceil(lineData.size * t).toInt()) ?: lineData.lastOrNull()
+                    val beforeLineData = lineData.getOrNull(floor((lineData.size) * t).toInt().coerceAtLeast(0)) ?: lineData.firstOrNull()
+                    val afterLineData = lineData.getOrNull(ceil((lineData.size) * t).toInt().coerceAtLeast(0)) ?: lineData.lastOrNull()
 
                     if (beforeLineData?.weatherData == null || afterLineData?.weatherData == null || beforeLineData.distance == null
-                        || afterLineData.distance == null) return@mapNotNull null
+                        || afterLineData.distance == null || beforeLineData == afterLineData) return@mapNotNull null
 
                     val dt = remap(t.toFloat(),
                         floor(lineData.size * t).toFloat() / lineData.size,
@@ -95,7 +105,10 @@ class WindForecastDataType(karooSystem: KarooSystemService) : LineGraphForecastD
                         headwindSpeed * 3.6 // Convert m/s to km/h
                     }
 
-                    LineGraphBuilder.DataPoint(i.toFloat() * (windPoints.size / HEADWIND_SAMPLE_COUNT.toFloat()), headwindSpeedInUserUnit.toFloat())
+                    LineGraphBuilder.DataPoint(
+                        x = i.toFloat() * (windPoints.size / HEADWIND_SAMPLE_COUNT.toFloat()),
+                        y = headwindSpeedInUserUnit.toFloat()
+                    )
                 }
             } else {
                 emptyList()
@@ -106,34 +119,40 @@ class WindForecastDataType(karooSystem: KarooSystemService) : LineGraphForecastD
         }
 
         return buildSet {
-            add(LineGraphBuilder.Line(
-                dataPoints = windPoints.mapIndexed { index, value ->
-                    LineGraphBuilder.DataPoint(index.toFloat(), value.toFloat())
-                },
-                color = android.graphics.Color.GRAY,
-                label = "Wind" // if (!isImperial) "Wind km/h" else "Wind mph",
-            ))
             add(LineGraphBuilder.Line(
                 dataPoints = gustPoints.mapIndexed { index, value ->
                     LineGraphBuilder.DataPoint(index.toFloat(), value.toFloat())
                 },
-                color = android.graphics.Color.DKGRAY,
+                color = Color.DKGRAY,
                 label = "Gust" // if (!isImperial) "Gust km/h" else "Gust mph",
             ))
 
+            add(LineGraphBuilder.Line(
+                dataPoints = windPoints.mapIndexed { index, value ->
+                    LineGraphBuilder.DataPoint(index.toFloat(), value.toFloat())
+                },
+                color = Color.GRAY,
+                label = "Wind" // if (!isImperial) "Wind km/h" else "Wind mph",
+            ))
+
             if (headwindPoints.isNotEmpty()) {
                 add(LineGraphBuilder.Line(
                     dataPoints = headwindPoints,
-                    color = android.graphics.Color.MAGENTA,
-                    label = "Headwind", // if (!isImperial) "Headwind km/h" else "Headwind mph",
-                    drawCircles = false
+                    color = if (isNightMode(context)) Color.WHITE else Color.BLACK,
+                    label = "Head", // if (!isImperial) "Headwind km/h" else "Headwind mph",
+                    drawCircles = false,
+                    colorFunc = { headwindSpeed ->
+                        val headwindSpeedInKmh = headwindSpeed * 3.6 // Convert m/s to km/h
+                        interpolateWindColor(headwindSpeedInKmh, isNightMode(context), context).toArgb()
+                    },
+                    alpha = 255
                 ))
             }
         }
     }
 
     companion object {
-        const val HEADWIND_SAMPLE_COUNT = 30
+        const val HEADWIND_SAMPLE_COUNT = 50
     }
 
 }

app/src/main/kotlin/de/timklge/karooheadwind/screens/LineGraph.kt

@@ -9,30 +9,33 @@ import android.graphics.Paint
 import android.graphics.Paint.Align
 import android.graphics.Path
 import androidx.annotation.ColorInt
-import kotlin.math.abs
 import androidx.core.graphics.createBitmap
+import kotlin.math.abs
+import kotlin.math.floor
 import kotlin.math.roundToInt
 
+fun isNightMode(context: Context): Boolean {
+    val nightModeFlags = context.resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK
+    return nightModeFlags == Configuration.UI_MODE_NIGHT_YES
+}
+
 class LineGraphBuilder(val context: Context) {
     enum class YAxis {
         LEFT, RIGHT
     }
 
-    data class DataPoint(val x: Float, val y: Float)
+    data class DataPoint(val x: Float, val y: Float) // color field removed
 
     data class Line(
-        val dataPoints: List<DataPoint>,
+        val dataPoints: List<DataPoint>, // DataPoint type is now the new one
         @ColorInt val color: Int,
         val label: String? = null,
         val yAxis: YAxis = YAxis.LEFT, // Default to left Y-axis
-        val drawCircles: Boolean = true // Default to true
+        val drawCircles: Boolean = true, // Default to true
+        val colorFunc: ((Float) -> Int)? = null, // Optional color function for dynamic colors,
+        val alpha: Int = 80
     )
 
-    private fun isNightMode(): Boolean {
-        val nightModeFlags = context.resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK
-        return nightModeFlags == Configuration.UI_MODE_NIGHT_YES
-    }
-
     fun drawLineGraph(
         width: Int,
         height: Int,
@@ -41,10 +44,9 @@ class LineGraphBuilder(val context: Context) {
         lines: Set<Line>,
         labelProvider: ((Float) -> String)
     ): Bitmap {
-        val isNightMode = isNightMode()
-
         val bitmap = createBitmap(width, height)
         val canvas = Canvas(bitmap)
+        val isNightMode = isNightMode(context)
 
         val backgroundColor = if (isNightMode) Color.BLACK else Color.WHITE
         val primaryTextColor = if (isNightMode) Color.WHITE else Color.BLACK
@@ -287,7 +289,7 @@ class LineGraphBuilder(val context: Context) {
             if (!hasRightYAxisData || abs(effectiveMaxYRight - effectiveMinYRight) < 0.0001f) 1f else (effectiveMaxYRight - effectiveMinYRight)
 
         fun mapX(originalX: Float): Float {
-            return graphLeft + ((originalX - effectiveMinX) / rangeX) * graphWidth
+            return floor(graphLeft + ((originalX - effectiveMinX) / rangeX) * graphWidth)
         }
 
         fun mapYLeft(originalY: Float): Float {
@@ -347,35 +349,113 @@ class LineGraphBuilder(val context: Context) {
         for (line in lines) {
             if (line.dataPoints.isEmpty()) continue
 
-            linePaint.color = line.color
-            val path = Path()
-            val firstPoint = line.dataPoints.first()
             val mapY = if (line.yAxis == YAxis.LEFT) ::mapYLeft else ::mapYRight
 
-            path.moveTo(mapX(firstPoint.x), mapY(firstPoint.y))
-            if (line.drawCircles) {
-                canvas.drawCircle(
-                    mapX(firstPoint.x),
-                    mapY(firstPoint.y),
-                    8f,
-                    linePaint.apply { style = Paint.Style.FILL })
-            }
-            linePaint.style = Paint.Style.STROKE
-
+            // Draw area between line and X axis, colorized per segment (match line colorization)
+            val zeroY = mapY((if (line.yAxis == YAxis.LEFT) effectiveMinYLeft else effectiveMinYRight).coerceAtLeast(0f))
             for (i in 1 until line.dataPoints.size) {
-                val point = line.dataPoints[i]
-                path.lineTo(mapX(point.x), mapY(point.y))
-                if (line.drawCircles) {
-                    canvas.drawCircle(
-                        mapX(point.x),
-                        mapY(point.y),
-                        8f,
-                        linePaint.apply { style = Paint.Style.FILL })
+                val prev = line.dataPoints[i - 1]
+                val curr = line.dataPoints[i]
+                if (line.colorFunc != null) {
+                    val N = 4 // Number of sub-segments (tweak for smoothness/performance)
+                    val adjustment = 0.5f // Pixel adjustment to help close seams
+
+                    for (j in 0 until N) {
+                        val t0 = j / N.toFloat()
+                        val t1 = (j + 1) / N.toFloat()
+                        val x0 = prev.x + (curr.x - prev.x) * t0
+                        val y0 = prev.y + (curr.y - prev.y) * t0
+                        val x1 = prev.x + (curr.x - prev.x) * t1
+                        val y1 = prev.y + (curr.y - prev.y) * t1
+                        val color0 = line.colorFunc.invoke(y0)
+
+                        val mappedX0 = mapX(x0)
+                        val mappedY0 = mapY(y0)
+                        val mappedX1 = mapX(x1)
+                        val mappedY1 = mapY(y1)
+
+                        // Extend the right edge of internal sub-segments to create an overlap
+                        val rightEdgeX = if (j < N - 1) mappedX1 + adjustment else mappedX1
+
+                        val areaPath = Path().apply {
+                            moveTo(mappedX0, mappedY0)
+                            lineTo(rightEdgeX, mappedY1)
+                            lineTo(rightEdgeX, zeroY)
+                            lineTo(mappedX0, zeroY)
+                            close()
+                        }
+                        val areaPaint = Paint().apply {
+                            style = Paint.Style.FILL
+                            color = color0
+                            isAntiAlias = true
+                            alpha = line.alpha
+                        }
+                        canvas.drawPath(areaPath, areaPaint)
+                    }
+                } else {
+                    val areaPath = Path().apply {
+                        moveTo(mapX(prev.x), mapY(prev.y))
+                        lineTo(mapX(curr.x), mapY(curr.y))
+                        lineTo(mapX(curr.x), zeroY)
+                        lineTo(mapX(prev.x), zeroY)
+                        close()
+                    }
+                    val areaPaint = Paint().apply {
+                        style = Paint.Style.FILL
+                        color = line.color
+                        isAntiAlias = true
+                        alpha = line.alpha
+                    }
+                    canvas.drawPath(areaPath, areaPaint)
                 }
-                linePaint.style = Paint.Style.STROKE
             }
 
-            canvas.drawPath(path, linePaint)
+            // Draw the line, colorized per segment (improved: split for colorFunc)
+            for (i in 1 until line.dataPoints.size) {
+                val prev = line.dataPoints[i - 1]
+                val curr = line.dataPoints[i]
+                if (line.colorFunc != null) {
+                    val N = 4 // Number of sub-segments (tweak for smoothness/performance)
+                    for (j in 0 until N) {
+                        val t0 = j / N.toFloat()
+                        val t1 = (j + 1) / N.toFloat()
+                        val x0 = prev.x + (curr.x - prev.x) * t0
+                        val y0 = prev.y + (curr.y - prev.y) * t0
+                        val x1 = prev.x + (curr.x - prev.x) * t1
+                        val y1 = prev.y + (curr.y - prev.y) * t1
+                        val color0 = line.colorFunc.invoke(y0)
+                        // Optionally, blend color0 and color1 for the segment, or just use color0
+                        val segPaint = Paint(linePaint).apply {
+                            color = color0
+                        }
+                        canvas.drawLine(
+                            mapX(x0), mapY(y0),
+                            mapX(x1), mapY(y1),
+                            segPaint
+                        )
+                    }
+                } else {
+                    val segPaint = Paint(linePaint).apply {
+                        color = line.color
+                    }
+                    canvas.drawLine(
+                        mapX(prev.x), mapY(prev.y),
+                        mapX(curr.x), mapY(curr.y),
+                        segPaint
+                    )
+                }
+            }
+
+            // Draw circles if enabled
+            if (line.drawCircles) {
+                for (point in line.dataPoints) {
+                    val circlePaint = Paint(linePaint).apply {
+                        style = Paint.Style.FILL
+                        color = line.colorFunc?.invoke(point.y) ?: line.color
+                    }
+                    canvas.drawCircle(mapX(point.x), mapY(point.y), 8f, circlePaint)
+                }
+            }
         }
 
         // Draw Left Y-axis ticks and labels