feat: draw matte sprite with PorterDuffXfermode(PorterDuff.Mode.DST_IN).

Author: errnull

app/src/main/assets/01_VectorColorArea_1.x.svga

@@ -14,15 +14,15 @@ open internal class SGVADrawer(val videoItem: SVGAVideoEntity) {
 
     val scaleInfo = SVGAScaleInfo()
 
-    inner class SVGADrawerSprite(val imageKey: String?, val frameEntity: SVGAVideoSpriteFrameEntity)
+    inner class SVGADrawerSprite(val matteKey: String?, val imageKey: String?, val frameEntity: SVGAVideoSpriteFrameEntity)
 
     internal fun requestFrameSprites(frameIndex: Int): List<SVGADrawerSprite> {
         return videoItem.sprites.mapNotNull {
             if (frameIndex >= 0 && frameIndex < it.frames.size) {
                 if (it.frames[frameIndex].alpha <= 0.0) {
                     return@mapNotNull null
                 }
-                return@mapNotNull SVGADrawerSprite(it.imageKey, it.frames[frameIndex])
+                return@mapNotNull SVGADrawerSprite(it.matteKey, it.imageKey, it.frames[frameIndex])
             }
             return@mapNotNull null
         }

app/src/main/assets/02_BitmapColorArea_1.x.svga

@@ -21,8 +21,58 @@ internal class SVGACanvasDrawer(videoItem: SVGAVideoEntity, val dynamicItem: SVG
         super.drawFrame(canvas,frameIndex, scaleType)
         this.pathCache.onSizeChanged(canvas)
         val sprites = requestFrameSprites(frameIndex)
-        sprites.forEach {
-            drawSprite(it, canvas, frameIndex)
+        val matteSprites = mutableMapOf<String, SVGADrawerSprite>()
+
+        var isMatteing = false
+
+        sprites.forEachIndexed { index, svgaDrawerSprite ->
+
+            // save matte sprite
+            svgaDrawerSprite.imageKey?.let {
+                if (it.endsWith(".matte")) {
+                    matteSprites.put(it, svgaDrawerSprite)
+                    // continue
+                    return@forEachIndexed
+                }
+            }
+
+            sprites.get(index - 1)?.let { lastSprite ->
+                if (isMatteing && (svgaDrawerSprite.matteKey == null || svgaDrawerSprite.matteKey != lastSprite.matteKey)) {
+                    isMatteing = false
+
+                    matteSprites.get(svgaDrawerSprite.matteKey)?.let {
+                        val matteBitmap = Bitmap.createBitmap(canvas.width, canvas.height, Bitmap.Config.ARGB_8888)
+                        val matteCanvas = Canvas(matteBitmap)
+                        val paint = Paint()
+                        paint.setXfermode(PorterDuffXfermode(PorterDuff.Mode.DST_IN))
+
+                        drawSprite(it, matteCanvas, frameIndex)
+                        canvas.drawBitmap(matteBitmap, 0f, 0f, paint)
+                        canvas.restore()
+                    }
+                }
+                if (svgaDrawerSprite.matteKey != null && (lastSprite.matteKey == null || lastSprite.matteKey != svgaDrawerSprite.matteKey)) {
+                    isMatteing = true
+                    canvas.save()
+                }
+            }
+
+            drawSprite(svgaDrawerSprite, canvas, frameIndex)
+
+            // if current sprite is the last one and isMatteing
+            if (isMatteing && index == sprites.count() - 1) {
+                matteSprites.get(svgaDrawerSprite.matteKey)?.let {
+                    val matteBitmap = Bitmap.createBitmap(canvas.width, canvas.height, Bitmap.Config.ARGB_8888)
+                    val matteCanvas = Canvas(matteBitmap)
+                    val paint = Paint()
+                    paint.setXfermode(PorterDuffXfermode(PorterDuff.Mode.DST_IN))
+
+                    drawSprite(it, matteCanvas, frameIndex)
+                    canvas.drawBitmap(matteBitmap, 0f, 0f, paint)
+                    canvas.restore()
+                }
+            }
+
         }
         playAudio(frameIndex)
     }

library/src/main/java/com/opensource/svgaplayer/drawer/SGVADrawer.kt

@@ -8,11 +8,14 @@ import org.json.JSONObject
  */
 internal class SVGAVideoSpriteEntity {
 
+    val matteKey: String?
+
     val imageKey: String?
 
     val frames: List<SVGAVideoSpriteFrameEntity>
 
     constructor(obj: JSONObject) {
+        this.matteKey = obj.optString("matteKey")
         this.imageKey = obj.optString("imageKey")
         val mutableFrames: MutableList<SVGAVideoSpriteFrameEntity> = mutableListOf()
         obj.optJSONArray("frames")?.let {
@@ -34,6 +37,7 @@ internal class SVGAVideoSpriteEntity {
     }
 
     constructor(obj: SpriteEntity) {
+        this.matteKey = obj.imageKey
         this.imageKey = obj.imageKey
         var lastFrame: SVGAVideoSpriteFrameEntity? = null
         frames = obj.frames?.map {