Initial open sourcing of MuJoCo.

PiperOrigin-RevId: 450374687
Change-Id: Ie3225a46ce095fc28ae8e63c326a640261f562bb

src/render/render_util.h

@@ -0,0 +1,73 @@
+// Copyright 2021 DeepMind Technologies Limited
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef THIRD_PARTY_MUJOCO_SRC_RENDER_RENDER_UTIL_
+#define THIRD_PARTY_MUJOCO_SRC_RENDER_RENDER_UTIL_
+
+#include <mujoco/mjexport.h>
+#include <mujoco/mjrender.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+// compute normal vector to given triangle, return length
+void mjr_makeNormal(float* normal, const float* p1, const float* p2, const float* p3);
+
+// set 4 floats
+void mjr_setf4(float* vec, float f0, float f1, float f2, float f3);
+
+// set 3 floats
+void mjr_setf3(float* vec, float f0, float f1, float f2);
+
+// multiply 4-by-4 matrices, column-major
+void mjr_mulMat44(float* res, const float* A, const float* B);
+
+// get row from 4-by-4 matrix, column-major
+void mjr_getrow4(float* res, const float* A, int r);
+
+// compute 3D vector cross-product a = b x c
+void mjr_crossVec(float* a, const float* b, const float* c);
+
+// normalize 3D vector
+void mjr_normalizeVec(float* v);
+
+// construct orthogonal vector (for up-direction)
+void mjr_orthoVec(float* res, const float* v);
+
+// compute dot-product
+float mjr_dotVec(const float* a, const float* b);
+
+// multiply 4x4 matrix by vector; column-major (OpenGL format)
+void mjr_multiply4(float* res, const float* mat, const float* vec);
+
+// gluLookAt replacement, with forward instead of center
+void mjr_lookAt(const float* eye, const float* forward, const float* up);
+
+// gluPerspective replacement
+void mjr_perspective(float fovy, float aspect, float znear, float zfar);
+
+// set reflection matrix
+void mjr_reflect(const float* pos, const float* mat);
+
+// set transformation matrix
+void mjr_transform(const float* translate, const float* rotate, float scale);
+
+// Find first rectangle containing mouse, -1: not found.
+MJAPI int mjr_findRect(int x, int y, int nrect, const mjrRect* rect);
+
+#if defined(__cplusplus)
+}
+#endif
+#endif  // THIRD_PARTY_MUJOCO_SRC_RENDER_RENDER_UTIL_