update particle sample

Author: SmartToolFactory

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

@@ -3,6 +3,7 @@ package com.smarttoolfactory.tutorial1_1basics
 import android.graphics.Bitmap
 import android.widget.Toast
 import androidx.compose.animation.core.Animatable
+import androidx.compose.animation.core.LinearEasing
 import androidx.compose.animation.core.tween
 import androidx.compose.foundation.Canvas
 import androidx.compose.foundation.Image
@@ -29,6 +30,7 @@ import androidx.compose.runtime.mutableStateListOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.composed
 import androidx.compose.ui.draw.drawWithCache
@@ -38,13 +40,15 @@ import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.ImageBitmap
 import androidx.compose.ui.graphics.asAndroidBitmap
 import androidx.compose.ui.graphics.asImageBitmap
+import androidx.compose.ui.graphics.drawscope.clipRect
 import androidx.compose.ui.graphics.rememberGraphicsLayer
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalDensity
 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.randomInRange
 import com.smarttoolfactory.tutorial1_1basics.chapter6_graphics.scale
 import com.smarttoolfactory.tutorial1_1basics.chapter6_graphics.toPx
 import com.smarttoolfactory.tutorial1_1basics.ui.Pink400
@@ -186,8 +190,9 @@ fun ParticleAnimationSample() {
  modifier = Modifier
  .fillMaxSize()
  .verticalScroll(rememberScrollState())
- .padding(horizontal = 16.dp, vertical = 32.dp),
- verticalArrangement = Arrangement.spacedBy(8.dp)
+ .padding(horizontal = 16.dp, vertical = 100.dp),
+ verticalArrangement = Arrangement.spacedBy(8.dp),
+ horizontalAlignment = Alignment.CenterHorizontally
  ) {
 
  val density = LocalDensity.current
@@ -244,8 +249,8 @@ data class Particle(
  val endSize: Size,
  val color: Color,
  val trajectoryProgressRange: ClosedRange<Float> = 0f..1f,
- val velocity: Float = 4 * displacement.y,
- val acceleration: Float = -2 * velocity,
+ var velocity: Float = 4 * displacement.y,
+ var acceleration: Float = -2 * velocity,
  val column: Int,
  val row: Int
 ) {
@@ -314,16 +319,14 @@ fun Modifier.explode(
 
  if (animationStatus != AnimationStatus.Idle) {
 
-// val progress = particleState.progress
+ val animatedProgress = particleState.progress
 
  particleState.particleList.forEach { particle ->
 
- if (progress > 0 && progress <= 1f) {
- particleState.updateParticle(progress, particle)
- }
+ particleState.updateParticle(animatedProgress, particle)
 
  val color = particle.color
- val radius = particle.currentSize.width / 2f
+ val radius = particle.currentSize.width * .7f
  val position = particle.currentPosition
  val alpha = particle.alpha
 
@@ -336,6 +339,12 @@ fun Modifier.explode(
 // alpha = alpha
  )
  }
+
+// clipRect(
+// left = animatedProgress * size.width
+// ) {
+// this@onDrawWithContent.drawContent()
+// }
  }
  }
  }
@@ -352,7 +361,7 @@ fun rememberParticleState(): ParticleState {
 @Stable
 class ParticleState internal constructor() {
 
- var particleSize by mutableStateOf(200.dp)
+ var particleSize by mutableStateOf(2.dp)
 
  val animatable = Animatable(0f)
  val particleList = mutableStateListOf<Particle>()
@@ -397,31 +406,34 @@ class ParticleState internal constructor() {
  val pixel: Int = bitmap.getPixel(pixelCenterX, pixelCenterY)
  val color = Color(pixel)
 
- println(
- "Column: $column, " +
- "row: $row," +
- " pixelCenterX: $pixelCenterX, " +
- "pixelCenterY: $pixelCenterY, color: $color"
- )
+// println(
+// "Column: $column, " +
+// "row: $row," +
+// " pixelCenterX: $pixelCenterX, " +
+// "pixelCenterY: $pixelCenterY, color: $color"
+// )
 
  if (color != Color.Unspecified) {
 
  val initialCenter = Offset(pixelCenterX.toFloat(), pixelCenterY.toFloat())
- val horizontalDisplacement = width / 2f
- val verticalDisplacement = height / 2f
+ val horizontalDisplacement = randomInRange(-50f, 50f)
+ val verticalDisplacement = randomInRange(-height * .1f, height * .2f)
 
- val velocity = 4 * verticalDisplacement
- val acceleration = -2 * velocity
+ val velocity = verticalDisplacement
+ val acceleration = randomInRange(-2f, 2f)
+ val progressStart = (initialCenter.x / width).coerceAtMost(.7f)
+ val progressEnd = progressStart + 0.3f
 
  particleList.add(
  Particle(
  initialCenter = initialCenter,
  displacement = Offset(horizontalDisplacement, verticalDisplacement),
  initialSize = Size(particleSize.toFloat(), particleSize.toFloat()),
+// trajectoryProgressRange = progressStart..progressEnd,
  endSize = Size.Zero,
  color = color,
- column = column,
- row = row,
+ column = column / particleSize,
+ row = row / particleRadius,
  velocity = velocity,
  acceleration = acceleration
  )
@@ -432,12 +444,9 @@ class ParticleState internal constructor() {
  }
  }
  }
-
- println("PARTICLE count: ${particleList.size}")
-
  }
 
- fun updateParticle(explosionProgress: Float, particle: Particle) {
+ fun updateParticle(progress: Float, particle: Particle) {
 
  particle.run {
  // Trajectory progress translates progress from 0f-1f to
@@ -449,58 +458,65 @@ class ParticleState internal constructor() {
  // Each 0.1f change in trajectoryProgress 0.5f total range
  // corresponds to 0.2f change of current time
 
- val trajectoryProgressStart = trajectoryProgressRange.start
- val trajectoryProgressEnd = trajectoryProgressRange.endInclusive
-
- val startXPosition = initialCenter.x
- val startYPosition = initialCenter.x
-
- val maxHorizontalDisplacement = displacement.x
-
- trajectoryProgress =
- if (explosionProgress < trajectoryProgressStart) {
- 0f
- } else if (explosionProgress > trajectoryProgressEnd) {
- 1f
- } else {
- scale(
- a1 = trajectoryProgressStart,
- b1 = trajectoryProgressEnd,
- x1 = explosionProgress,
- a2 = 0f,
- b2 = 1f
- )
- }
+ setTrajectoryProgress(progress)
 
  currentTime = trajectoryProgress
-// .mapInRange(0f, 1f, 0f, 1.4f)
+ // .mapInRange(0f, 1f, 0f, 1.4f)
+
+ // Set size
+ val width = initialSize.width + (endSize.width - initialSize.width) * currentTime
+ val height = initialSize.height + (endSize.height - initialSize.height) * currentTime
+// currentSize = Size(width, height)
 
+ // Set alpha
  // While trajectory progress is less than 70% have full alpha then slowly cre
-// alpha = if (trajectoryProgress < .7f) 1f else
-// scale(.7f, 1f, trajectoryProgress, 1f, 0f)
+// alpha = if (trajectoryProgress == 0f) 0f
+// else if (trajectoryProgress < .7f) 1f
+// else scale(.7f, 1f, trajectoryProgress, 1f, 0f)
 
- val horizontalDisplacement = maxHorizontalDisplacement * trajectoryProgress
+ // Set position
+// acceleration = randomInRange(-5f, 5f)
+// velocity = 1f * Random.nextInt(10)
 
+ val maxHorizontalDisplacement = displacement.x
+ val horizontalDisplacement = maxHorizontalDisplacement * trajectoryProgress
  val verticalDisplacement =
  velocity * currentTime + 0.5f * acceleration * currentTime * currentTime
-
- println("horizontalDisplacement: $horizontalDisplacement, verticalDisplacement: $verticalDisplacement")
-
  currentPosition = Offset(
- x = startXPosition + horizontalDisplacement,
- y = startYPosition - verticalDisplacement
+ x = initialCenter.x + horizontalDisplacement,
+ y = initialCenter.y - verticalDisplacement
  )
  }
  }
 
+ private fun Particle.setTrajectoryProgress(progress: Float) {
+ val trajectoryProgressStart = trajectoryProgressRange.start
+ val trajectoryProgressEnd = trajectoryProgressRange.endInclusive
+
+ trajectoryProgress =
+ if (progress < trajectoryProgressStart) {
+ 0f
+ } else if (progress > trajectoryProgressEnd) {
+ 1f
+ } else {
+ scale(
+ a1 = trajectoryProgressStart,
+ b1 = trajectoryProgressEnd,
+ x1 = progress,
+ a2 = 0f,
+ b2 = 1f
+ )
+ }
+ }
+
  fun startAnimation() {
  animationStatus = AnimationStatus.Initializing
  }
 
  suspend fun animate() {
  try {
  animatable.snapTo(0f)
- animatable.animateTo(1f, tween(2000))
+ animatable.animateTo(1f, tween(durationMillis = 2000, easing = LinearEasing))
 // animationStatus = AnimationStatus.Idle
  } catch (e: CancellationException) {
  println("FAILED: ${e.message}")