+ if(drawscreenstart)
+ {
+ drawscreendelta = Sys_DirtyTime() - drawscreenstart;
+ if (cl_minfps.value > 0 && (cl_minfps_force.integer || !(cls.timedemo || (cls.capturevideo.active && !cls.capturevideo.realtime))) && drawscreendelta >= 0 && drawscreendelta < 60)
+ {
+ // quality adjustment according to render time
+ double actualframetime;
+ double targetframetime;
+ double adjust;
+ double f;
+ double h;
+
+ // fade lastdrawscreentime
+ r_refdef.lastdrawscreentime += (drawscreendelta - r_refdef.lastdrawscreentime) * cl_minfps_fade.value;
+
+ // find actual and target frame times
+ actualframetime = r_refdef.lastdrawscreentime;
+ targetframetime = (1.0 / cl_minfps.value);
+
+ // we scale hysteresis by quality
+ h = cl_updatescreen_quality * cl_minfps_qualityhysteresis.value;
+
+ // calculate adjustment assuming linearity
+ f = cl_updatescreen_quality / actualframetime * cl_minfps_qualitymultiply.value;
+ adjust = (targetframetime - actualframetime) * f;
+
+ // one sided hysteresis
+ if(adjust > 0)
+ adjust = max(0, adjust - h);
+
+ // adjust > 0 if:
+ // (targetframetime - actualframetime) * f > h
+ // ((1.0 / cl_minfps.value) - actualframetime) * (cl_updatescreen_quality / actualframetime * cl_minfps_qualitymultiply.value) > (cl_updatescreen_quality * cl_minfps_qualityhysteresis.value)
+ // ((1.0 / cl_minfps.value) - actualframetime) * (cl_minfps_qualitymultiply.value / actualframetime) > cl_minfps_qualityhysteresis.value
+ // (1.0 / cl_minfps.value) * (cl_minfps_qualitymultiply.value / actualframetime) - cl_minfps_qualitymultiply.value > cl_minfps_qualityhysteresis.value
+ // (1.0 / cl_minfps.value) * (cl_minfps_qualitymultiply.value / actualframetime) > cl_minfps_qualityhysteresis.value + cl_minfps_qualitymultiply.value
+ // (1.0 / cl_minfps.value) / actualframetime > (cl_minfps_qualityhysteresis.value + cl_minfps_qualitymultiply.value) / cl_minfps_qualitymultiply.value
+ // (1.0 / cl_minfps.value) / actualframetime > 1.0 + cl_minfps_qualityhysteresis.value / cl_minfps_qualitymultiply.value
+ // cl_minfps.value * actualframetime < 1.0 / (1.0 + cl_minfps_qualityhysteresis.value / cl_minfps_qualitymultiply.value)
+ // actualframetime < 1.0 / cl_minfps.value / (1.0 + cl_minfps_qualityhysteresis.value / cl_minfps_qualitymultiply.value)
+ // actualfps > cl_minfps.value * (1.0 + cl_minfps_qualityhysteresis.value / cl_minfps_qualitymultiply.value)
+
+ // adjust < 0 if:
+ // (targetframetime - actualframetime) * f < 0
+ // ((1.0 / cl_minfps.value) - actualframetime) * (cl_updatescreen_quality / actualframetime * cl_minfps_qualitymultiply.value) < 0
+ // ((1.0 / cl_minfps.value) - actualframetime) < 0
+ // -actualframetime) < -(1.0 / cl_minfps.value)
+ // actualfps < cl_minfps.value
+
+ /*
+ Con_Printf("adjust UP if fps > %f, adjust DOWN if fps < %f\n",
+ cl_minfps.value * (1.0 + cl_minfps_qualityhysteresis.value / cl_minfps_qualitymultiply.value),
+ cl_minfps.value);
+ */
+
+ // don't adjust too much at once
+ adjust = bound(-cl_minfps_qualitystepmax.value, adjust, cl_minfps_qualitystepmax.value);
+
+ // adjust!
+ cl_updatescreen_quality += adjust;
+ cl_updatescreen_quality = bound(max(0.01, cl_minfps_qualitymin.value), cl_updatescreen_quality, cl_minfps_qualitymax.value);
+ }
+ else
+ {
+ cl_updatescreen_quality = 1;
+ r_refdef.lastdrawscreentime = 0;
+ }
+ }
+
+ drawscreenstart = Sys_DirtyTime();
+