update particle samples

Author: SmartToolFactory

Tutorial1-1Basics/src/main/java/com/smarttoolfactory/tutorial1_1basics/ParticleAnimations.kt

@@ -21,7 +21,6 @@ import androidx.compose.material.Button
 import androidx.compose.material.Slider
 import androidx.compose.material.Text
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.Stable
 import androidx.compose.runtime.getValue
@@ -46,7 +45,7 @@ import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
-import com.smarttoolfactory.tutorial1_1basics.chapter6_graphics.mapInRange
+import com.smarttoolfactory.tutorial1_1basics.chapter6_graphics.scale
 import com.smarttoolfactory.tutorial1_1basics.chapter6_graphics.toPx
 import com.smarttoolfactory.tutorial1_1basics.ui.Pink400
 import kotlinx.coroutines.CancellationException
@@ -58,11 +57,11 @@ fun SingleParticleTrajectorySample() {
 
  var progress by remember { mutableFloatStateOf(0f) }
 
- var visibilityThresholdLow by remember {
+ var trajectoryProgressStart by remember {
  mutableFloatStateOf(0f)
  }
 
- var visibilityThresholdHigh by remember {
+ var trajectoryProgressEnd by remember {
  mutableFloatStateOf(1f)
  }
 
@@ -80,7 +79,7 @@ fun SingleParticleTrajectorySample() {
 
  val particleState = rememberParticleState()
 
- LaunchedEffect(visibilityThresholdLow, visibilityThresholdHigh) {
+ LaunchedEffect(trajectoryProgressStart, trajectoryProgressEnd) {
  particleState.particleList.clear()
  particleState.addParticle(
  Particle(
@@ -91,18 +90,17 @@ fun SingleParticleTrajectorySample() {
  ),
  initialSize = Size(5.dp.toPx(), 5.dp.toPx()),
  endSize = Size(sizePx, sizePx),
- finalCenter = Offset(
+ displacement = Offset(
  sizePxHalf,
  sizePxHalf
  ),
- trajectoryProgressRange = visibilityThresholdLow..visibilityThresholdHigh,
+ trajectoryProgressRange = trajectoryProgressStart..trajectoryProgressEnd,
  row = 0,
  column = 0
  )
  )
  }
 
-
  Column(
  modifier = Modifier.fillMaxSize()
  .verticalScroll(rememberScrollState())
@@ -158,22 +156,22 @@ fun SingleParticleTrajectorySample() {
  }
  )
 
- Text("visibilityThresholdLow: $visibilityThresholdLow")
+ Text("trajectoryProgressStart: $trajectoryProgressStart")
  Slider(
  modifier = Modifier.fillMaxWidth(),
- value = visibilityThresholdLow,
+ value = trajectoryProgressStart,
  onValueChange = {
- visibilityThresholdLow = it.coerceAtMost(visibilityThresholdHigh)
+ trajectoryProgressStart = it.coerceAtMost(trajectoryProgressEnd)
  },
  valueRange = 0f..1f
  )
 
- Text("visibilityThresholdHigh: $visibilityThresholdHigh")
+ Text("trajectoryProgressEnd: $trajectoryProgressEnd")
  Slider(
  modifier = Modifier.fillMaxWidth(),
- value = visibilityThresholdHigh,
+ value = trajectoryProgressEnd,
  onValueChange = {
- visibilityThresholdHigh = it.coerceAtLeast(visibilityThresholdLow)
+ trajectoryProgressEnd = it.coerceAtLeast(trajectoryProgressStart)
  },
  valueRange = 0f..1f
  )
@@ -188,7 +186,7 @@ fun ParticleAnimationSample() {
  modifier = Modifier
  .fillMaxSize()
  .verticalScroll(rememberScrollState())
- .padding(16.dp),
+ .padding(horizontal = 16.dp, vertical = 32.dp),
  verticalArrangement = Arrangement.spacedBy(8.dp)
  ) {
 
@@ -201,11 +199,15 @@ fun ParticleAnimationSample() {
 
  val context = LocalContext.current
 
+ var progress by remember {
+ mutableFloatStateOf(0f)
+ }
  Image(
  painter = painterResource(R.drawable.avatar_2_raster),
  modifier = Modifier
  .border(2.dp, Color.Red)
  .explode(
+ progress = progress,
  particleState = particleState,
  onStart = {
  Toast.makeText(context, "Animation started...", Toast.LENGTH_SHORT).show()
@@ -218,6 +220,12 @@ fun ParticleAnimationSample() {
  contentDescription = null
  )
 
+ Slider(
+ value = progress,
+ onValueChange = {
+ progress = it
+ }
+ )
  Button(
  modifier = Modifier.fillMaxWidth(),
  onClick = {
@@ -231,12 +239,12 @@ fun ParticleAnimationSample() {
 
 data class Particle(
  val initialCenter: Offset,
- val finalCenter: Offset,
+ val displacement: Offset,
  val initialSize: Size,
  val endSize: Size,
  val color: Color,
  val trajectoryProgressRange: ClosedRange<Float> = 0f..1f,
- val velocity: Float = 4 * finalCenter.y,
+ val velocity: Float = 4 * displacement.y,
  val acceleration: Float = -2 * velocity,
  val column: Int,
  val row: Int
@@ -254,6 +262,7 @@ data class Particle(
 }
 
 fun Modifier.explode(
+ progress: Float,
  particleState: ParticleState,
  onStart: () -> Unit = {},
  onEnd: () -> Unit = {}
@@ -305,11 +314,13 @@ fun Modifier.explode(
 
  if (animationStatus != AnimationStatus.Idle) {
 
- val progress = particleState.progress
+// val progress = particleState.progress
 
  particleState.particleList.forEach { particle ->
 
-// particleState.updateParticle(progress, particle)
+ if (progress > 0 && progress <= 1f) {
+ particleState.updateParticle(progress, particle)
+ }
 
  val color = particle.color
  val radius = particle.currentSize.width / 2f
@@ -341,7 +352,7 @@ fun rememberParticleState(): ParticleState {
 @Stable
 class ParticleState internal constructor() {
 
- var particleSize by mutableStateOf(50.dp)
+ var particleSize by mutableStateOf(200.dp)
 
  val animatable = Animatable(0f)
  val particleList = mutableStateListOf<Particle>()
@@ -396,17 +407,23 @@ class ParticleState internal constructor() {
  if (color != Color.Unspecified) {
 
  val initialCenter = Offset(pixelCenterX.toFloat(), pixelCenterY.toFloat())
+ val horizontalDisplacement = width / 2f
+ val verticalDisplacement = height / 2f
+
+ val velocity = 4 * verticalDisplacement
+ val acceleration = -2 * velocity
+
  particleList.add(
  Particle(
  initialCenter = initialCenter,
- finalCenter = initialCenter.plus(Offset(width / 2f, -height / 2f)),
+ displacement = Offset(horizontalDisplacement, verticalDisplacement),
  initialSize = Size(particleSize.toFloat(), particleSize.toFloat()),
  endSize = Size.Zero,
  color = color,
  column = column,
  row = row,
- velocity = 0f,
- acceleration = 0f
+ velocity = velocity,
+ acceleration = acceleration
  )
  )
 
@@ -416,7 +433,7 @@ class ParticleState internal constructor() {
  }
  }
 
-// println("PARTICLE count: ${particleList.size}")
+ println("PARTICLE count: ${particleList.size}")
 
  }
 
@@ -432,22 +449,27 @@ class ParticleState internal constructor() {
  // Each 0.1f change in trajectoryProgress 0.5f total range
  // corresponds to 0.2f change of current time
 
- val visibilityThresholdLow = trajectoryProgressRange.start
- val visibilityThresholdHigh = trajectoryProgressRange.endInclusive
+ val trajectoryProgressStart = trajectoryProgressRange.start
+ val trajectoryProgressEnd = trajectoryProgressRange.endInclusive
 
  val startXPosition = initialCenter.x
  val startYPosition = initialCenter.x
 
- val maxHorizontalDisplacement = finalCenter.x
+ val maxHorizontalDisplacement = displacement.x
 
  trajectoryProgress =
- if (explosionProgress < visibilityThresholdLow) {
+ if (explosionProgress < trajectoryProgressStart) {
  0f
- } else if (explosionProgress > visibilityThresholdHigh) {
+ } else if (explosionProgress > trajectoryProgressEnd) {
  1f
  } else {
- explosionProgress
- .mapInRange(visibilityThresholdLow, visibilityThresholdHigh, 0f, 1f)
+ scale(
+ a1 = trajectoryProgressStart,
+ b1 = trajectoryProgressEnd,
+ x1 = explosionProgress,
+ a2 = 0f,
+ b2 = 1f
+ )
  }
 
  currentTime = trajectoryProgress
@@ -457,12 +479,16 @@ class ParticleState internal constructor() {
 // alpha = if (trajectoryProgress < .7f) 1f else
 // scale(.7f, 1f, trajectoryProgress, 1f, 0f)
 
+ val horizontalDisplacement = maxHorizontalDisplacement * trajectoryProgress
+
  val verticalDisplacement =
- currentTime * velocity + 0.5 * acceleration * currentTime * currentTime
+ velocity * currentTime + 0.5f * acceleration * currentTime * currentTime
+
+ println("horizontalDisplacement: $horizontalDisplacement, verticalDisplacement: $verticalDisplacement")
 
  currentPosition = Offset(
- x = startXPosition + maxHorizontalDisplacement * trajectoryProgress,
- y = (startYPosition - verticalDisplacement).toFloat()
+ x = startXPosition + horizontalDisplacement,
+ y = startYPosition - verticalDisplacement
  )
  }
  }
@@ -475,7 +501,7 @@ class ParticleState internal constructor() {
  try {
  animatable.snapTo(0f)
  animatable.animateTo(1f, tween(2000))
- animationStatus = AnimationStatus.Idle
+// animationStatus = AnimationStatus.Idle
  } catch (e: CancellationException) {
  println("FAILED: ${e.message}")
  }

Tutorial1-1Basics/src/main/java/com/smarttoolfactory/tutorial1_1basics/chapter6_graphics/ParticlePhysics.kt

@@ -43,7 +43,6 @@ fun ControlledExplosion() {
  mutableFloatStateOf(1f)
  }
 
-
  val particleCount = 1
 
  val density = LocalDensity.current
@@ -219,8 +218,13 @@ class ExplodingParticle(
  } else if (explosionProgress > visibilityThresholdHigh) {
  1f
  } else {
- explosionProgress
- .mapInRange(visibilityThresholdLow, visibilityThresholdHigh, 0f, 1f)
+ scale(
+ a1 = visibilityThresholdLow,
+ b1 = visibilityThresholdHigh,
+ x1 = explosionProgress,
+ a2 = 0f,
+ b2 = 1f
+ )
  }
 
  currentTime = trajectoryProgress
@@ -240,11 +244,6 @@ class ExplodingParticle(
  }
 }
 
-fun Float.mapInRange(inMin: Float, inMax: Float, outMin: Float, outMax: Float): Float {
- return outMin + (((this - inMin) / (inMax - inMin)) * (outMax - outMin))
-}
-
-fun Int.dpToPx() = toFloat().dpToPx()
 fun Dp.toPx() = value.dpToPx()
 
 fun Float.dpToPx() = this * Resources.getSystem().displayMetrics.density