X-Git-Url: https://git.xonotic.org/?p=xonotic%2Fxonotic-data.pk3dir.git;a=blobdiff_plain;f=physicsCPMA.cfg;h=7653219633599d30c41a59530ddcf616bbbc89d9;hp=3c1614dcd3b1943061a3c35ca3489127fdb7f2e1;hb=HEAD;hpb=ac7aeb0215b2f4efd7564de1ff9298dd2cf02125

diff --git a/physicsCPMA.cfg b/physicsCPMA.cfg
index 3c1614dcd..b6317debd 100644
--- a/physicsCPMA.cfg
+++ b/physicsCPMA.cfg
@@ -1,13 +1,37 @@
 g_mod_physics CPMA
 // these values match CPMA
 
-sv_gravity 800
+// CPMA uses gravity 800 but the strength of Q3 gravity is frametime-dependent.
+// It also differs slightly between ascending and descending, which we don't attempt to replicate.
+// Modern CPMA has frametime-independent physics that ~match 125fps frametime-dependent.
+// DeFRaG still has frametime-dependent physics and DFWC rules mandate 125fps.
+// 125 * round(800/125) = 750 simulates 125fps Q3 gravity in Xonotic,
+// tested mathematically by k9 and ingame with printf by bones_was_here.
+
+// Jump height:
+// Taking into account the effect of velocity snapping, a general formula for origin.z k frames after jumping can be derived:
+// kT(270 + (round(gT) - GT)/2) - 1/2 k^2 T round(gT)
+// Inputting g=750, T=1/125 and solving on the 45th frame, we find that the jump height in Quake 3 is 48.528 units.
+// Q3 test results: 48.527999872 in every test (at end of frame).
+// Xonotic test results: 48.6 as expected by (270^2)/(2*750) (see: physicsX.cfg)
+
+// Jump distance/duration:
+// The above formula can also be used to calculate that landing in Q3 occurs after 89.93333... 8ms frames,
+// for a duration of 720ms at end of frame, as predicted by (2*270)/750 (see: physicsX.cfg),
+// so the expected distance is 230.4 units at 320ups.
+// Q3 test results: 230.405274 230.405274 230.404723 230.404969 (at end of frame when ONGROUND is set).
+// Xonotic test results: 230.39637 in every test (Xonotic can set ONGROUND earlier in the frame, when the collision occurs).
+
+sv_gravity 750
+
 sv_maxspeed 320
 sv_maxairspeed 320
 sv_stopspeed 100
-sv_accelerate 15
+sv_accelerate 15 // from cpm1_dev_docs
 sv_airaccelerate 1
-sv_friction 8
+// The cpm1_dev_docs.zip (only CPMA source code release) used friction 8,
+// but friction is 6 in all ~modern CPMA releases, and in DeFRaG CPM.
+sv_friction 6
 edgefriction 1
 sv_stepheight 18
 sv_jumpvelocity 270
@@ -17,11 +41,11 @@ sv_waterfriction 1
 sv_airaccel_sideways_friction 0
 sv_airaccel_qw 1
 sv_airaccel_qw_stretchfactor 0
-sv_airstopaccelerate 2.5
-sv_airstrafeaccelerate 70
-sv_maxairstrafespeed 30
+sv_airstopaccelerate 2.5   // from cpm1_dev_docs
+sv_airstrafeaccelerate 70  // from cpm1_dev_docs strafeaccelerate
+sv_maxairstrafespeed 30    // from cpm1_dev_docs wishspeed
 sv_airstrafeaccel_qw 0
-sv_aircontrol 150
+sv_aircontrol 150          // from cpm1_dev_docs
 sv_aircontrol_penalty 0
 sv_aircontrol_power 2
 sv_aircontrol_backwards 0
@@ -32,9 +56,15 @@ sv_warsowbunny_accel 0.1593
 sv_warsowbunny_topspeed 925
 sv_warsowbunny_backtosideratio 0.8
 sv_friction_on_land 0
+sv_friction_slick 0
 sv_doublejump 0
-sv_jumpspeedcap_min ""
+// match the downhill ramp jumping behaviour of CPMA
+sv_jumpspeedcap_min 0
 sv_jumpspeedcap_max ""
-sv_jumpspeedcap_max_disable_on_ramps 0
+// CPMA has ramp jumping
+sv_jumpspeedcap_max_disable_on_ramps 1
 g_teleport_maxspeed 400
-sv_track_canjump 0
+g_teleport_minspeed 400
+sv_track_canjump 1
+sv_gameplayfix_stepdown_maxspeed 0
+g_movement_highspeed_q3_compat 1