From bf38e6073e0262ea4cf113a6fc22a8c811494f13 Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Thu, 10 May 2012 14:47:46 +0900
Subject: [PATCH] Implement iqm joint loading.

---
 include/QF/iqm.h            | 13 ++++++++++++-
 libs/models/iqm/model_iqm.c | 21 +++++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/include/QF/iqm.h b/include/QF/iqm.h
index cca4cee0c..974741d2e 100644
--- a/include/QF/iqm.h
+++ b/include/QF/iqm.h
@@ -114,14 +114,25 @@ typedef struct iqmextension_s {
     uint32_t    ofs_extensions; // pointer to next extension
 } iqmextension;
 
+// QF stuff
+
+typedef struct {
+	DualQuat_t  rt;
+	quat_t      shear;
+	quat_t      scale;
+} iqmframe_t;
+
 typedef struct {
 	byte       *vertices;
 	uint16_t   *elements;
 	int         num_arrays;
 	iqmvertexarray *vertexarrays;
 	int         num_joints;
+	iqmjoint   *joints;
+	mat4_t     *baseframe;
+	mat4_t     *inverse_baseframe;
 	int         num_frames;
-	DualQuat_t **frames;
+	iqmframe_t **frames;
 } iqm_t;
 
 #endif//__QF_iqm_h__
diff --git a/libs/models/iqm/model_iqm.c b/libs/models/iqm/model_iqm.c
index e4f8fcbe0..33dca1d8e 100644
--- a/libs/models/iqm/model_iqm.c
+++ b/libs/models/iqm/model_iqm.c
@@ -118,6 +118,7 @@ get_joints (const iqmheader *hdr, byte *buffer)
 {
 	iqmjoint   *joint;
 	uint32_t    i, j;
+	float       t;
 
 	if (hdr->ofs_joints + hdr->num_joints * sizeof (iqmjoint) > hdr->filesize)
 		return 0;
@@ -134,6 +135,10 @@ get_joints (const iqmheader *hdr, byte *buffer)
 			joint[i].translate[j] = LittleFloat (joint[i].translate[j]);
 		for (j = 0; j < 4; j++)
 			joint[i].rotate[j] = LittleFloat (joint[i].rotate[j]);
+		// iqm quaternions use xyzw but QF quaternions use wxyz
+		t = joint[i].rotate[3];
+		memmove (&joint[i].rotate[1], &joint[i].rotate[0], 3 * sizeof (float));
+		joint[i].rotate[0] = t;
 		for (j = 0; j < 3; j++)
 			joint[i].scale[j] = LittleFloat (joint[i].scale[j]);
 	}
@@ -345,6 +350,22 @@ load_iqm_meshes (model_t *mod, const iqmheader *hdr, byte *buffer)
 		return false;
 	if (!(joints = get_joints (hdr, buffer)))
 		return false;
+	iqm->num_joints = hdr->num_joints;
+	iqm->joints = malloc (iqm->num_joints * sizeof (iqmjoint));
+	iqm->baseframe = malloc (iqm->num_joints * sizeof (mat4_t));
+	iqm->inverse_baseframe = malloc (iqm->num_joints * sizeof (mat4_t));
+	memcpy (iqm->joints, joints, iqm->num_joints * sizeof (iqmjoint));
+	for (i = 0; i < hdr->num_joints; i++) {
+		iqmjoint   *j = &iqm->joints[i];
+		mat4_t     *bf = &iqm->baseframe[i];
+		mat4_t     *ibf = &iqm->inverse_baseframe[i];
+		Mat4Init (j->rotate, j->scale, j->translate, *bf);
+		Mat4Inverse (*bf, *ibf);
+		if (j->parent >= 0) {
+			Mat4Mult (iqm->baseframe[j->parent], *bf, *bf);
+			Mat4Mult (*ibf, iqm->inverse_baseframe[j->parent], *ibf);
+		}
+	}
 	return true;
 }