Integrated direct-photon yield in the \pt range $1 \pt 5$~\GeVc (or $1 \pt 3$~\GeVc) in Pb--Pb collisions at \fivenn and \twosevensixnn~, in \AuAu collisions at \twoHnn as measured by the PHENIX~ and STAR~ collaborations, and in \pp collisions at \twoH~. The data are compared to predictions from a state-of-the-art model~. The error bars and boxes represent the statistical and systematicuncertainties of the data along the y-axis, respectively. The horizontal width of the boxes shows the total uncertainty of the measured $\frac{{\rm d}N_{\rm ch}}{{\rm d}\eta}|_{\eta = 0}$~.