已知函数\(f(x)=\sin ωx\cos ωx+\sin ^{2} ωx- \dfrac {1}{2} (ω > 0)\)，若对满足\(f(x _{1} )= \dfrac { \sqrt {2}}{2},f(x_{2})=- \dfrac { \sqrt {2}}{2}\)的\(x _{1}\)，\(x _{2}\)，有\(|x _{1} -x _{2} |\)最小值为\( \dfrac {π}{2} .\)若将其图象沿\(x\)轴向右平移\( \dfrac {π}{4}\)个单位，再将得到的图象各点的横坐标伸长到原来的两倍\((\)纵坐标不变\()\)，得到函数\(y=g(x)\)的解析式为______．
