Revised Snippet

task BackGroundEffect06{
	let id			= [ObjPrim_Create(OBJ_SPRITE_2D),
						ObjPrim_Create(OBJ_SPRITE_2D),
						ObjPrim_Create(OBJ_SPRITE_2D),
						ObjPrim_Create(OBJ_SPRITE_2D)];
	let cc			= 0;
	let alpha1		= 0;
	let alphaA		= 0;
	let alpha2		= 0;
	let alphaB		= 0;
	let i			= 0;
	let flg			= GetAreaCommonData("anime","back",false);
	let sca1		= 0;
	let scaA		= 0;
	let sca			= 1;

		ObjPrim_SetTexture(id[0],csd~"./stg6img/enm6a.png");
		ObjPrim_SetTexture(id[1],csd~"./stg6img/enm6a.png");
		ObjPrim_SetTexture(id[2],csd~"./stg6img/enm6b.png");
		ObjPrim_SetTexture(id[3],csd~"./stg6img/enm6c.png");
		ascent(i in 0..4)
		{
            ObjRender_SetPosition(id[i],CenX,CenY,0);
            Obj_SetRenderPriorityI(id[i],22);
            ObjRender_SetBlendType(id[i],BLEND_ALPHA);
            ObjRender_SetScaleXYZ(id[i],1,1,0);
            ObjSprite2D_SetSourceRect(id[i],0,0,384,448);
            ObjSprite2D_SetDestCenter(id[i]);
		}
		ObjRender_SetScaleXYZ(id[3],1.1,1.1,0);

	ObjRender_SetAngleXYZ(id[1],0,180,0);
	ObjPrim_SetVertexPosition(id[2],0,1024/-2,1024/-2,0);
	ObjPrim_SetVertexPosition(id[2],1,1024/-2,1024/2,0);
	ObjPrim_SetVertexPosition(id[2],2,1024/2,1024/-2,0);
	ObjPrim_SetVertexPosition(id[2],3,1024/2,1024/2,0);
	ObjPrim_SetVertexUVT(id[2],0,0,0);
	ObjPrim_SetVertexUVT(id[2],1,0,1024);
	ObjPrim_SetVertexUVT(id[2],2,1024,0);
	ObjPrim_SetVertexUVT(id[2],3,1024,1024);

	while(!Obj_IsDeleted(enm) && !flg){
		flg = GetAreaCommonData("anime","back",false);
		cc++;

		if(alpha1<255){alphaA+=2;}
		alpha1=255*sin(alphaA);
		if(alpha2<255 && alpha1>=128){alphaB+=5;}
		alpha2=255*sin(alphaB);

		ObjPrim_SetVertexAlpha(id[2],0,alpha1);
		ObjPrim_SetVertexAlpha(id[2],1,alpha2);
		ObjPrim_SetVertexAlpha(id[2],2,alpha1);
		ObjPrim_SetVertexAlpha(id[2],3,alpha2);

		ObjPrim_SetVertexColor(id[2],0,alpha1/2,alpha1/8,alpha1/4);
		ObjPrim_SetVertexColor(id[2],1,alpha2/2,alpha2/8,alpha2/4);
		ObjPrim_SetVertexColor(id[2],2,alpha1/2,alpha1/8,alpha1/4);
		ObjPrim_SetVertexColor(id[2],3,alpha2/2,alpha2/8,alpha2/4);

		ObjPrim_SetVertexColor(id[3],0,128,128,64);
		ObjPrim_SetVertexColor(id[3],1,64,64,64);
		ObjPrim_SetVertexColor(id[3],2,128,128,64);
		ObjPrim_SetVertexColor(id[3],3,64,64,64);

		yield;
	}
	Obj_SetRenderPriorityI(id[0],22);
	Obj_SetRenderPriorityI(id[1],22);
	Obj_SetRenderPriorityI(id[3],22);
	Obj_SetRenderPriorityI(id[2],23);
	while(sca1<sca && flg){
		scaA+=2;
		sca1=sca*sin(scaA);
		ObjRender_SetScaleXYZ(id[0],1-sca1,1,0);
		ObjRender_SetScaleXYZ(id[1],1-sca1,1,0);
		ObjRender_SetScaleXYZ(id[2],1-sca1,1,0);
		ObjRender_SetScaleXYZ(id[3],1.1-sca1*1.1,1.1,0);
		yield;
	}
	Obj_Delete(id[0]);
	Obj_Delete(id[1]);
	Obj_Delete(id[2]);
	Obj_Delete(id[3]);
}