small quadric library ported from Laurence Bourn's LOD_decimator LOD_Quadric class. not used just yet.

1 files changed, 131 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/quadric.c b/source/blender/blenlib/intern/quadric.c
new file mode 100644
index 00000000000..1c04beacbfb
--- /dev/null
+++ b/source/blender/blenlib/intern/quadric.c
@@ -0,0 +1,131 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
+ * All rights reserved.
+ *
+ * Contributor(s): Laurence Bourn, Campbell Barton
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/blenlib/intern/quadric.c
+ *  \ingroup bli
+ *
+ * \note This isn't fully complete,
+ * possible there are other useful functions to add here.
+ *
+ * \note try to follow BLI_math naming convention here.
+ */
+
+//#include <string.h>
+
+#include "BLI_math.h"
+#include "BLI_quadric.h"  /* own include */
+
+
+#define QUADRIC_FLT_TOT (sizeof(Quadric) / sizeof(float))
+
+void BLI_quadric_from_v3_dist(Quadric *q, const float v[3], const float offset)
+{
+	q->a2 = v[0] * v[0];
+	q->b2 = v[1] * v[1];
+	q->c2 = v[2] * v[2];
+
+	q->ab = v[0] * v[1];
+	q->ac = v[0] * v[2];
+	q->bc = v[1] * v[2];
+
+	q->ad = v[0] * offset;
+	q->bd = v[1] * offset;
+	q->cd = v[2] * offset;
+
+	q->d2 = offset * offset;
+}
+
+void BLI_quadric_to_tensor_m3(const Quadric *q, float m[3][3])
+{
+	m[0][0] = q->a2;
+	m[0][1] = q->ab;
+	m[0][2] = q->ac;
+
+	m[1][0] = q->ab;
+	m[1][1] = q->b2;
+	m[1][2] = q->bc;
+
+	m[2][0] = q->ac;
+	m[2][1] = q->bc;
+	m[2][2] = q->c2;
+}
+
+void BLI_quadric_to_vector_v3(const Quadric *q, float v[3])
+{
+	v[0] = q->ad;
+	v[1] = q->bd;
+	v[2] = q->cd;
+}
+
+void BLI_quadric_clear(Quadric *q)
+{
+	memset(q, 0, sizeof(*q));
+}
+
+void BLI_quadric_add_qu_qu(Quadric *a, const Quadric *b)
+{
+	add_vn_vn((float *)a, (float *)b, QUADRIC_FLT_TOT);
+}
+
+void BLI_quadric_add_qu_ququ(Quadric *r, const Quadric *a, const Quadric *b)
+{
+	add_vn_vnvn((float *)r, (const float *)a, (const float *)b, QUADRIC_FLT_TOT);
+}
+
+void BLI_quadric_mul(Quadric *a, const float scalar)
+{
+	mul_vn_fl((float *)a, QUADRIC_FLT_TOT, scalar);
+}
+
+float BLI_quadric_evaluate(const Quadric *q, const float v[3])
+{
+	return  (v[0] * v[0] * q->a2 + 2.0f * v[0] * v[1] * q->ab + 2.0f * v[0] * v[2] * q->ac + 2.0f * v[0] * q->ad +
+	         v[1] * v[1] * q->b2 + 2.0f * v[1] * v[2] * q->bc + 2.0f * v[1] * q->bd +
+	         v[2] * v[2] * q->c2 + 2.0f * v[2] * q->cd +
+	         q->d2);
+}
+
+int BLI_quadric_optimize(const Quadric *q, float v[3])
+{
+	float m[3][3];
+	float det;
+
+	BLI_quadric_to_tensor_m3(q, m);
+	det = determinant_m3(m[0][0], m[0][1], m[0][2],
+	                     m[1][0], m[1][1], m[1][2],
+	                     m[2][0], m[2][1], m[2][2]);
+
+	if (det != 0.0f) {
+		invert_m3(m);
+		BLI_quadric_to_vector_v3(q, v);
+		mul_m3_v3(m, v);
+		negate_v3(v);
+
+		return TRUE;
+	}
+	else {
+		return FALSE;
+	}
+}