animated textures: fix mipmap generation

src/main/java/de/bixilon/minosoft/gui/rendering/system/base/texture/texture/MemoryTexture.kt

@@ -61,10 +61,10 @@ class MemoryTexture(
                     data.put(index++, pixel.alpha.toByte())
                 }
             }
+            this.mipmapData = generateMipMaps(data)
         }
 
         this.data = data
-        this.mipmapData = generateMipMaps(data)
     }
 
     override val state: TextureStates = TextureStates.LOADED

src/main/java/de/bixilon/minosoft/gui/rendering/system/base/texture/texture/SpriteTexture.kt

@@ -61,6 +61,7 @@ class SpriteTexture(private val original: AbstractTexture) : AbstractTexture {
             splitTexture.data!!.let {
                 it.copyFrom(original.data!!, bytesPerTexture * i, 0, bytesPerTexture)
                 it.flip()
+                splitTexture.mipmapData = splitTexture.generateMipMaps(it)
             }
             splitTextures += splitTexture
         }