From 59b5a3ceceacafffb83832dd2e80753b6dca4c8e Mon Sep 17 00:00:00 2001
From: Rudolf Polzer <divverent@xonotic.org>
Date: Wed, 23 Jan 2013 13:06:59 +0100
Subject: [PATCH] _animblend_fixbone: try fixing the animations when blending
 animations

This will ensure the aiming direction is always forward, at the cost of
possibly screwing up the anims.
---
 qcsrc/client/autocvars.qh       |  1 +
 qcsrc/client/player_skeleton.qc | 80 ++++++++++++++++++++++++++++++++-
 qcsrc/common/animdecide.qc      |  1 +
 3 files changed, 80 insertions(+), 2 deletions(-)

diff --git a/qcsrc/client/autocvars.qh b/qcsrc/client/autocvars.qh
index 0c926d43c..01f392519 100644
--- a/qcsrc/client/autocvars.qh
+++ b/qcsrc/client/autocvars.qh
@@ -408,4 +408,5 @@ float autocvar_cl_precacheplayermodels;
 float autocvar_cl_deathglow;
 float autocvar_developer_csqcentities;
 float autocvar__animblend;
+float autocvar__animblend_fixbone;
 float autocvar_g_jetpack_attenuation;
diff --git a/qcsrc/client/player_skeleton.qc b/qcsrc/client/player_skeleton.qc
index 48fb8a34b..dd4d0a696 100644
--- a/qcsrc/client/player_skeleton.qc
+++ b/qcsrc/client/player_skeleton.qc
@@ -3,6 +3,9 @@
 #define BONETYPE_UPPER 1
 #define MAX_BONES 128
 .float skeleton_bonetype[MAX_BONES];
+.float skeleton_fixrotatebone;
+.float skeleton_fixtargetbone;
+.float skeleton_bone;
 .float skeleton_aimbone;
 .float skeleton_numbones;
 
@@ -11,6 +14,8 @@ void skeleton_identifybones(entity e)
 	float s = e.skeletonindex;
 	float n = (e.skeleton_numbones = skel_get_numbones(s));
 	e.skeleton_aimbone = 0;
+	e.skeleton_fixrotatebone = 0;
+	e.skeleton_fixtargetbone = 0;
 	float i;
 	for(i = 1; i <= n; ++i)
 	{
@@ -20,13 +25,62 @@ void skeleton_identifybones(entity e)
 			t = e.(skeleton_bonetype[p-1]);
 		string nm = skel_get_bonename(s, i);
 		if(nm == "spine2")
+		{
+			e.skeleton_fixrotatebone = i;
 			t = BONETYPE_UPPER;
+		}
+		if(nm == "weapon" || nm == "tag_weapon" || nm == "bip01 r hand")
+			if(t == BONETYPE_UPPER)
+				e.skeleton_fixtargetbone = i;
 		if(nm == "upperarm_R")
 			e.skeleton_aimbone = i;
 		e.(skeleton_bonetype[i-1]) = t;
 	}
 }
 
+void skel_set_bone_lerp(float skel, float bone, vector org, float strength)
+{
+	if(strength >= 1)
+		return skel_set_bone(skel, bone, org);
+
+	vector fo = v_forward;
+	vector ri = v_right;
+	vector up = v_up;
+	vector oldorg = skel_get_bonerel(skel, bone);
+
+	org = org * strength + oldorg * (1 - strength);
+	v_forward = fo * strength + v_forward * (1 - strength);
+	v_right = ri * strength + v_right * (1 - strength);
+	v_up = up * strength + v_up * (1 - strength);
+	return skel_set_bone(skel, bone, org);
+}
+
+void skeleton_fixbone(entity e, float strength)
+{
+	if(!e.skeleton_fixrotatebone)
+		return;
+	if(strength <= 0)
+		return;
+	// model:
+	// T  = M_before_fixrotate * M_fixrotate  * M_after_fixrotate
+	// T' = M_before_fixrotate^-1 * M_fixrotate' * M_after_fixrotate
+	// M_fixrotate' = M_before_fixrotate^-1 * T' * M_after_fixrotate^-1
+	float s = e.skeletonindex;
+
+	skel_get_boneabs(s, skel_get_boneparent(s, e.skeleton_fixrotatebone));
+	vector M_before_fixrotate = fixedvectoangles2(v_forward, v_up);
+	skel_get_boneabs(s, e.skeleton_fixrotatebone);
+	vector M_including_fixrotate = fixedvectoangles2(v_forward, v_up);
+	skel_get_boneabs(s, e.skeleton_fixtargetbone);
+	vector T = fixedvectoangles2(v_forward, v_up);
+	vector M_after_fixrotate = AnglesTransform_LeftDivide(M_including_fixrotate, T);
+	vector T_ = '0 0 0';
+	vector M_fixrotate_ = AnglesTransform_LeftDivide(M_before_fixrotate, AnglesTransform_RightDivide(T_, M_after_fixrotate));
+	vector org = skel_get_bonerel(s, e.skeleton_fixrotatebone);
+	fixedmakevectors(M_fixrotate_);
+	skel_set_bone_lerp(s, e.skeleton_fixrotatebone, org, strength);
+}
+
 void free_skeleton_from_frames(entity e)
 {
 	if(e.skeletonindex)
@@ -86,6 +140,28 @@ void skeleton_from_frames(entity e)
 		skel_build(s, e, m, 0, firstbone + 1, bone);
 	}
 	e.lerpfrac = savelerpfrac;
-	e.lerpfrac3 = savelerpfrac;
-	e.lerpfrac4 = savelerpfrac;
+	e.lerpfrac3 = savelerpfrac3;
+	e.lerpfrac4 = savelerpfrac4;
+
+	if(autocvar__animblend_fixbone)
+	{
+		float l4 = e.lerpfrac4;
+		float l3 = e.lerpfrac3;
+		float l2 = e.lerpfrac;
+		float l1 = 1 - l2 - l3 - l4;
+
+		// how much of upper body animates same way as lower body?
+		float equalamount =
+			(e.frame == e.frame2) * (l1 * l2) +
+			(e.frame == e.frame4) * (l1 * l4) +
+			(e.frame3 == e.frame2) * (l3 * l2) +
+			(e.frame3 == e.frame4) * (l3 * l4);
+		float maxequalamount = (l1 + l3) * (l2 + l4);
+
+		// now how strong is the lerp?
+		float lerpstrength = 1 - equalamount / maxequalamount;
+
+		// FIX IT
+		skeleton_fixbone(e, lerpstrength);
+	}
 }
diff --git a/qcsrc/common/animdecide.qc b/qcsrc/common/animdecide.qc
index f10c466be..3efdab4a3 100644
--- a/qcsrc/common/animdecide.qc
+++ b/qcsrc/common/animdecide.qc
@@ -225,6 +225,7 @@ void animdecide_setimplicitstate(entity e, float onground)
 	vector v;
 	v_x = e.velocity * v_forward;
 	v_y = e.velocity * v_right;
+	v_z = 0;
 
 	// we want to match like this:
 	// the 8 directions shall be "evenly spaced"
-- 
2.39.2