From d624e3dc123c3730a438b7468c7ce5d49dbeb62f Mon Sep 17 00:00:00 2001
From: Marko Luukkainen <marko.luukkainen@semantum.fi>
Date: Mon, 27 May 2019 19:23:51 +0300
Subject: [PATCH] Projection matrices following OpenGL spec

gitlab #6

Change-Id: Ia2fe79cb6beaeba65e51de1c5830427533441aed
---
 .../src/org/simantics/g3d/math/MathTools.java | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/org.simantics.g3d/src/org/simantics/g3d/math/MathTools.java b/org.simantics.g3d/src/org/simantics/g3d/math/MathTools.java
index 73d5e606..63ac1ccc 100644
--- a/org.simantics.g3d/src/org/simantics/g3d/math/MathTools.java
+++ b/org.simantics.g3d/src/org/simantics/g3d/math/MathTools.java
@@ -328,6 +328,19 @@ public class MathTools {
 
    }
    
+   public static void getMatrix(Quat4d quat, Matrix4d m) {
+	   m.setZero();
+	   m.m00 = 1.0f - 2.0 * (quat.y * quat.y + quat.z * quat.z);
+	   m.m01 = 2.0 * (quat.x * quat.y + quat.w * quat.z);
+	   m.m02 = 2.0 * (quat.x * quat.z - quat.w * quat.y);
+	   m.m10 = 2.0 * (quat.x * quat.y - quat.w * quat.z);
+	   m.m11 = 1.0 - 2.0f * (quat.x * quat.x + quat.z * quat.z);
+	   m.m12 = 2.0 * (quat.y * quat.z + quat.w * quat.x);
+	   m.m20 = 2.0 * (quat.x * quat.z + quat.w * quat.y);
+	   m.m21 = 2.0 * (quat.y * quat.z - quat.w * quat.x);
+	   m.m22 = 1.0 - 2.0f * (quat.x * quat.x + quat.y * quat.y);
+	   m.m33 = 1.0;
+   }
    
    private static double q[] = new double[3];
    private static int nxt[] = { 1, 2, 0 };
@@ -917,4 +930,28 @@ public class MathTools {
          }
          return t;
 	 }
+	 
+	 public static Matrix4d glFrustum(double l, double r, double b, double t, double n, double f) {
+		 Matrix4d mat = new Matrix4d();
+		 mat.m00 = 2.0 * n / (r - l);
+		 mat.m11 = 2.0 * n / (t - b);
+		 mat.m02 = (r+l) / (r-l);
+		 mat.m12 = (t+b) / (t-b);
+		 mat.m22 = -(f+n) / (f-n);
+		 mat.m23 = -(2.0 *f * n) / (f-n);
+		 mat.m32 = -1.0;
+		 return mat;
+	 }
+	 
+	 public static Matrix4d glOrtho(double l, double r, double b, double t, double n, double f) {
+		 Matrix4d mat = new Matrix4d();
+		 mat.m00 = 2.0 / (r - l);
+		 mat.m11 = 2.0 / (t - b);
+		 mat.m22 = -2.0 / (f-n);
+		 mat.m33 =  1.0;
+		 mat.m03 = -(r+l)/(r-l);
+		 mat.m13 = -(t+b)/(t-b);
+		 mat.m23 = -(f+n)/(f-n);
+		 return mat;
+	 }
 }
-- 
2.47.1