1 files changed, 142 insertions, 0 deletions
diff --git a/intern/cycles/util/util_transform.cpp b/intern/cycles/util/util_transform.cpp
new file mode 100644
index 00000000000..5c2f28af318
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+++ b/intern/cycles/util/util_transform.cpp
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+/*
+ * Copyright 2011, Blender Foundation.
+ *
+ * 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.
+ */
+
+/*
+ * Adapted from code with license:
+ * 
+ * Copyright (c) 2002, Industrial Light & Magic, a division of Lucas
+ * Digital Ltd. LLC. All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in
+ *   the documentation and/or other materials provided with the
+ *   distribution.
+ * * Neither the name of Industrial Light & Magic nor the names of its
+ *   contributors may be used to endorse or promote products derived
+ *   from this software without specific prior written permission. 
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "util_math.h"
+#include "util_transform.h"
+
+CCL_NAMESPACE_BEGIN
+
+static bool transform_matrix4_gj_inverse(float R[][4], float M[][4])
+{
+	/* forward elimination */
+	for(int i = 0; i < 4; i++) {
+		int pivot = i;
+		float pivotsize = M[i][i];
+
+		if(pivotsize < 0)
+			pivotsize = -pivotsize;
+
+		for(int j = i + 1; j < 4; j++) {
+			float tmp = M[j][i];
+
+			if(tmp < 0)
+				tmp = -tmp;
+
+			if(tmp > pivotsize) {
+				pivot = j;
+				pivotsize = tmp;
+			}
+		}
+
+		if(pivotsize == 0)
+			return false;
+
+		if(pivot != i) {
+			for(int j = 0; j < 4; j++) {
+				float tmp;
+
+				tmp = M[i][j];
+				M[i][j] = M[pivot][j];
+				M[pivot][j] = tmp;
+
+				tmp = R[i][j];
+				R[i][j] = R[pivot][j];
+				R[pivot][j] = tmp;
+			}
+		}
+
+		for(int j = i + 1; j < 4; j++) {
+			float f = M[j][i] / M[i][i];
+
+			for(int k = 0; k < 4; k++) {
+				M[j][k] -= f*M[i][k];
+				R[j][k] -= f*R[i][k];
+			}
+		}
+	}
+
+	/* backward substitution */
+	for(int i = 3; i >= 0; --i) {
+		float f;
+
+		if((f = M[i][i]) == 0)
+			return false;
+
+		for(int j = 0; j < 4; j++) {
+			M[i][j] /= f;
+			R[i][j] /= f;
+		}
+
+		for(int j = 0; j < i; j++) {
+			f = M[j][i];
+
+			for(int k = 0; k < 4; k++) {
+				M[j][k] -= f*M[i][k];
+				R[j][k] -= f*R[i][k];
+			}
+		}
+	}
+
+	return true;
+}
+
+Transform transform_inverse(const Transform& tfm)
+{
+	Transform R = transform_identity();
+	Transform M = tfm;
+
+	if(!transform_matrix4_gj_inverse((float(*)[4])&R, (float(*)[4])&M))
+		return transform_identity();
+
+	return R;
+}
+
+CCL_NAMESPACE_END
+