MATH: added few GLU helpers

2026-05-21 05:40:43 +00:00 · 2014-07-10 07:27:18 +02:00
parent 6625530d88
commit 46a91377d8
4 changed files with 338 additions and 6 deletions
@@ -0,0 +1,74 @@
+/* ResidualVM - A 3D game interpreter
+ *
+ * ResidualVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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.
+ *
+ */
+
+#include "math/glmath.h"
+
+namespace Math {
+
+// function based on gluPerspective from Mesa 5.0 glu GPLv2+ licensed sources
+Matrix4 makePerspectiveMatrix(double fovy, double aspect, double zNear, double zFar) {
+	double xmin, xmax, ymin, ymax;
+
+	ymax = zNear * tan(fovy * M_PI / 360.0);
+	ymin = -ymax;
+	xmin = ymin * aspect;
+	xmax = ymax * aspect;
+
+	return makeFrustumMatrix(xmin, xmax, ymin, ymax, zNear, zFar);
+}
+
+Matrix4 makeFrustumMatrix(double left, double right, double bottom, double top, double zNear, double zFar) {
+	Matrix4 proj;
+	proj(0, 0) = (2.0f * zNear) / (right - left);
+	proj(1, 1) = (2.0f * zNear) / (top - bottom);
+	proj(2, 0) = (right + left) / (right - left);
+	proj(2, 1) = (top + bottom) / (top - bottom);
+	proj(2, 2) = -(zFar + zNear) / (zFar - zNear);
+	proj(2, 3) = -1.0f;
+	proj(3, 2) = -(2.0f * zFar * zNear) / (zFar - zNear);
+	proj(3, 3) = 0.0f;
+
+	return proj;
+}
+
+Matrix4 makeLookAtMatrix(const Vector3d &eye, const Vector3d &center, const Vector3d &up) {
+	Vector3d f = (center - eye).getNormalized();
+	Vector3d u = up.getNormalized();
+	Vector3d s = Vector3d::crossProduct(f, u).getNormalized();
+	u = Vector3d::crossProduct(s, f);
+
+	Math::Matrix4 look;
+	look(0, 0) = s.x();
+	look(1, 0) = s.y();
+	look(2, 0) = s.z();
+	look(0, 1) = u.x();
+	look(1, 1) = u.y();
+	look(2, 1) = u.z();
+	look(0, 2) = -f.x();
+	look(1, 2) = -f.y();
+	look(2, 2) = -f.z();
+	look(3, 3) = 1.0;
+
+	return look;
+}
+
+}