A struct containing input data to pack sprites.
| colorData | A NativeArray containing texture data (pixels) of all the sprites. | 
| indexData | A NativeArray containing indices of all the sprites. | 
| spriteData | A NativeArray containing sprite data of all the sprites. | 
| textureData | A NativeArray containing texture data of all the sprites that includes width, height and offset to read from colorData array. | 
| vertexData | A NativeArray containing vertices of all the sprites. |