vec3 ddy, ivec3 offset);uvec4 texture2DRectGradOffset(usampler2DRect sampler, vec2 coord, vec2 ddx, vec2 ddy, ivec2 offset);uvec4 texture2DRectProjGradOffset(usampler2DRect sampler, vec3 coord, vec2 ddx, vec2 ddy, ivec2 offset);uvec4 texture2DRectProjGradOffset(usampler2DRect sampler, vec4 coord, vec2 ddx, vec2 ddy, ivec2 offset);