From 0e542a1e3052b8bfe744b6ab34fe62de005b379d Mon Sep 17 00:00:00 2001
From: terencehill <piuntn@gmail.com>
Date: Sat, 30 Nov 2024 11:24:10 +0100
Subject: [PATCH] Physics code: calculate wishdir without using normalize and
 apply other minor math optimizations

The different wishdir formula causes a hash change despite the meaningless difference in the output
---
 .gitlab-ci.yml               |  2 +-
 qcsrc/ecs/systems/physics.qc | 50 +++++++++++++++++++++---------------
 2 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 48674649a..81a98fa72 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -36,7 +36,7 @@ test_compilation_units:
 test_sv_game:
   stage: test
   script:
-    - export EXPECT=ee6d65824c57cb6d83cba31481a21822
+    - export EXPECT=f5fbfbd04a22e781397cfd14db367419
     - qcsrc/tools/sv_game-hashtest.sh
     - exit $?
 
diff --git a/qcsrc/ecs/systems/physics.qc b/qcsrc/ecs/systems/physics.qc
index 167b49235..adf9067c4 100644
--- a/qcsrc/ecs/systems/physics.qc
+++ b/qcsrc/ecs/systems/physics.qc
@@ -214,18 +214,19 @@ void sys_phys_simulate(entity this, float dt)
 	}
 
 	vector forward, right, up;
-	MAKE_VECTORS(vmul(this.v_angle, (this.com_phys_vel_2d ? '0 1 0' : '1 1 1')), forward, right, up);
+	vector v_tmp = (this.com_phys_vel_2d ? vec3(0, this.v_angle.y, 0) : this.v_angle);
+	MAKE_VECTORS(v_tmp, forward, right, up);
 	// wishvel = forward * PHYS_CS(this).movement.x + right * PHYS_CS(this).movement.y + up * PHYS_CS(this).movement.z;
 	vector wishvel = forward * PHYS_CS(this).movement.x
 		+ right * PHYS_CS(this).movement.y
-		+ '0 0 1' * (PHYS_CS(this).movement.z * (this.com_phys_vel_2d ? 0 : 1));
+		+ '0 0 1' * (this.com_phys_vel_2d ? 0 : PHYS_CS(this).movement.z);
 	if (this.com_phys_water) {
 		if (PHYS_FROZEN(this))
 		{
 			if(this.waterlevel >= WATERLEVEL_SUBMERGED && this.velocity.z >= -70) // don't change the speed too abruptally
 				wishvel = '0 0 160'; // resurface
 			else if(this.waterlevel >= WATERLEVEL_SWIMMING && this.velocity.z > 0)
-				wishvel = eZ * 1.3 * min(this.velocity.z, 160); // resurface a bit more above the surface
+				wishvel = eZ * (1.3 * min(this.velocity.z, 160)); // resurface a bit more above the surface
 		}
 		else
 		{
@@ -263,9 +264,16 @@ void sys_phys_simulate(entity this, float dt)
 			}
 		}
 	}
+
 	// acceleration
-	const vector wishdir = normalize(wishvel);
-	float wishspeed = min(vlen(wishvel), this.com_phys_vel_max);
+	float wishvel_len = vlen(wishvel);
+	float wishspeed = min(wishvel_len, this.com_phys_vel_max);
+
+	// same as wishdir = normalize(wishvel); but cheaper
+	const vector wishdir = (wishvel_len ? wishvel / wishvel_len : '0 0 0');
+	vector wishdir2 = normalize(wishvel);
+	if (wishdir2 - wishdir)
+		LOG_INFOF("^x0f8 diff = %v\n", wishdir2 - wishdir);
 
 	if (this.com_phys_air) {
 		if (!(this.flags & FL_WATERJUMP)) {
@@ -452,22 +460,22 @@ void sys_phys_simulate_simple(entity this, float dt)
 				FOREACH_ENTITY_RADIUS_ORDERED(0.5 * (this.absmin + this.absmax), 0.5 * vlen(this.absmax - this.absmin), true, {
 					if (it.solid != SOLID_TRIGGER || it == this) continue;
 					if (gettouch(it) && boxesoverlap(it.absmin, it.absmax, this.absmin, this.absmax)) {
-					    // SV_LinkEdict_TouchAreaGrid_Call
-					    trace_allsolid = false;
-					    trace_startsolid = false;
-					    trace_fraction = 1;
-					    trace_inwater = false;
-					    trace_inopen = true;
-					    trace_endpos = it.origin;
-					    trace_plane_normal = '0 0 1';
-					    trace_plane_dist = 0;
-					    trace_ent = this;
-					    trace_dpstartcontents = 0;
-					    trace_dphitcontents = 0;
-					    trace_dphitq3surfaceflags = 0;
-					    trace_dphittexturename = string_null;
-					    gettouch(it)(this, it);
-					    vel = this.velocity;
+						// SV_LinkEdict_TouchAreaGrid_Call
+						trace_allsolid = false;
+						trace_startsolid = false;
+						trace_fraction = 1;
+						trace_inwater = false;
+						trace_inopen = true;
+						trace_endpos = it.origin;
+						trace_plane_normal = '0 0 1';
+						trace_plane_dist = 0;
+						trace_ent = this;
+						trace_dpstartcontents = 0;
+						trace_dphitcontents = 0;
+						trace_dphitq3surfaceflags = 0;
+						trace_dphittexturename = string_null;
+						gettouch(it)(this, it);
+						vel = this.velocity;
 					}
 				});
 			}
-- 
2.39.2