Push2dImage

How‘s “float z” and “stereoDepth” parameter used?

void CD3D9Renderer::Push2dImage(float xpos, float ypos, float w, float h, int textureid, float s0, float t0, float s1, float t1, float angle, float r, float g, float b, float a, float z, float stereoDepth)

When I execute the code below, the image shows

gEnv->pRenderer->Push2dImage( 0, 0, 600, 400, texx->GetTextureID(), 0.0f, 1.0f,1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,0);

When I execute the following code, the image cannot be displayed

gEnv->pRenderer->Push2dImage( 0, 0, 600, 400, texx->GetTextureID(), 0.0f, 1.0f,1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 4.0f,0);

Thank you very much