vanishing particle test

src/net/torvald/terrarum/gameparticles/ParticleBase.kt

@@ -0,0 +1,90 @@
+package net.torvald.terrarum.gameparticles
+
+import com.badlogic.gdx.graphics.Color
+import com.badlogic.gdx.graphics.g2d.SpriteBatch
+import com.badlogic.gdx.graphics.g2d.TextureRegion
+import net.torvald.terrarum.*
+import net.torvald.terrarum.blockproperties.Block
+import net.torvald.terrarum.blockproperties.BlockCodex
+import net.torvald.terrarum.gameactors.Actor
+import net.torvald.terrarum.gameactors.Hitbox
+import org.dyn4j.geometry.Vector2
+
+/**
+ * Actors with static sprites and very simple physics
+ *
+ * Created by minjaesong on 2017-01-20.
+ */
+open class ParticleBase(renderOrder: Actor.RenderOrder, val despawnUponCollision: Boolean, maxLifeTime: Second? = null) : Runnable {
+
+    /** Will NOT actually delete from the CircularArray */
+    @Volatile var flagDespawn = false
+
+    override fun run() = update(AppLoader.UPDATE_RATE)
+
+    var isNoSubjectToGrav = false
+    var dragCoefficient = 3.0
+
+    val lifetimeMax = maxLifeTime ?: 5f
+    var lifetimeCounter = 0f
+        protected set
+
+    val velocity = Vector2(0.0, 0.0)
+    val hitbox = Hitbox(0.0, 0.0, 0.0, 0.0)
+
+    open lateinit var body: TextureRegion // you might want to use SpriteAnimation
+    open var glow: TextureRegion? = null
+
+    val drawColour = Color(1f, 1f, 1f, 1f)
+
+    init {
+
+    }
+
+    open fun update(delta: Float) {
+        if (!flagDespawn) {
+            lifetimeCounter += delta
+            if (despawnUponCollision) {
+                if (velocity.isZero ||
+                    // simple stuck check
+                    BlockCodex[(Terrarum.ingame!!.world).getTileFromTerrain(
+                            hitbox.canonicalX.div(TerrarumAppConfiguration.TILE_SIZE).floorInt(),
+                            hitbox.canonicalY.div(TerrarumAppConfiguration.TILE_SIZE).floorInt()
+                    ) ?: Block.STONE].isSolid) {
+                    flagDespawn = true
+                }
+            }
+
+            if (lifetimeCounter >= lifetimeMax) {
+                flagDespawn = true
+            }
+
+            // gravity, winds, etc. (external forces)
+            if (!isNoSubjectToGrav) {
+                velocity.plusAssign((Terrarum.ingame!!.world).gravitation / dragCoefficient)
+            }
+
+
+            // combine external forces
+            hitbox.translate(velocity)
+        }
+    }
+
+    open fun drawBody(batch: SpriteBatch) {
+        if (!flagDespawn) {
+            batch.color = drawColour
+            batch.draw(body, hitbox.startX.toFloat(), hitbox.startY.toFloat(), hitbox.width.toFloat(), hitbox.height.toFloat())
+        }
+    }
+
+    open fun drawGlow(batch: SpriteBatch) {
+        if (!flagDespawn && glow != null) {
+            batch.color = drawColour
+            batch.draw(glow, hitbox.startX.toFloat(), hitbox.startY.toFloat(), hitbox.width.toFloat(), hitbox.height.toFloat())
+        }
+    }
+
+    open fun dispose() {
+
+    }
+}

src/net/torvald/terrarum/gameparticles/ParticleVanishingTexture.kt

@@ -0,0 +1,58 @@
+package net.torvald.terrarum.gameparticles
+
+import com.badlogic.gdx.graphics.g2d.SpriteBatch
+import com.badlogic.gdx.graphics.g2d.TextureRegion
+import net.torvald.terrarum.gameactors.Actor
+import net.torvald.terrarum.imagefont.TinyAlphNum
+
+/**
+ * @param tex image
+ * @param x x-coord of the particle's initial spawn position, bottom-centre
+ * @param y y-coord of the particle's initial spawn position, bottom-centre
+ */
+open class ParticleVanishingTexture(val tex: TextureRegion, x: Double, y: Double) : ParticleBase(Actor.RenderOrder.OVERLAY, false, 2f) {
+
+    init {
+        velocity.set(0.0, -1.0)
+        hitbox.setDimension(2.0, 2.0)
+        hitbox.setPositionFromPointed(x, y)
+
+        body = tex
+
+        isNoSubjectToGrav = true
+    }
+
+    override fun update(delta: Float) {
+        super.update(delta)
+
+        drawColour.a = (lifetimeMax - lifetimeCounter) / lifetimeMax
+    }
+}
+
+class ParticleVanishingText(val text: String, x: Double, y: Double) : ParticleBase(Actor.RenderOrder.OVERLAY, false, 2f) {
+
+    private val lines = text.split('\n')
+
+    init {
+        velocity.set(0.0, -1.0)
+
+        hitbox.setDimension(lines.maxOf { TinyAlphNum.getWidth(it) }.toDouble(), lines.size * TinyAlphNum.H.toDouble())
+        hitbox.setPositionFromPointed(x, y)
+
+        isNoSubjectToGrav = true
+    }
+
+    override fun update(delta: Float) {
+        super.update(delta)
+        drawColour.a = (lifetimeMax - lifetimeCounter) / lifetimeMax
+    }
+
+    override fun drawBody(batch: SpriteBatch) {
+        if (!flagDespawn) {
+            batch.color = drawColour
+            lines.forEachIndexed { index, line ->
+                TinyAlphNum.draw(batch, line, hitbox.startX.toFloat(), hitbox.startY.toFloat() + TinyAlphNum.H * index)
+            }
+        }
+    }
+}