From d78d3024cc0b6e92b31d9f60c46f5cbcf44c8898 Mon Sep 17 00:00:00 2001
From: Michael Fabian 'Xaymar' Dirks <info@xaymar.com>
Date: Thu, 14 Dec 2017 00:28:35 +0100
Subject: [PATCH] util-math: Add commonly used mathematical functions

---
 CMakeLists.txt       |  2 ++
 source/util-math.cpp | 21 +++++++++++++++++++++
 source/util-math.h   | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 56 insertions(+)
 create mode 100644 source/util-math.cpp
 create mode 100644 source/util-math.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5b8f14e7..ac44b589 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -47,6 +47,7 @@ SET(obs-stream-effects_HEADERS
 	"${PROJECT_SOURCE_DIR}/source/gs-mipmapper.h"
 	"${PROJECT_BINARY_DIR}/source/version.h"
 	"${PROJECT_SOURCE_DIR}/source/strings.h"
+	"${PROJECT_SOURCE_DIR}/source/util-math.h"
 )
 SET(obs-stream-effects_SOURCES
 	"${PROJECT_SOURCE_DIR}/source/plugin.cpp"
@@ -63,6 +64,7 @@ SET(obs-stream-effects_SOURCES
 	"${PROJECT_SOURCE_DIR}/source/gs-vertex.cpp"
 	"${PROJECT_SOURCE_DIR}/source/gs-vertexbuffer.cpp"
 	"${PROJECT_SOURCE_DIR}/source/gs-mipmapper.cpp"
+	"${PROJECT_SOURCE_DIR}/source/util-math.cpp"
 )
 SET(obs-stream-effects_LOCALE
 	"${PROJECT_SOURCE_DIR}/data/locale/en-US.ini"
diff --git a/source/util-math.cpp b/source/util-math.cpp
new file mode 100644
index 00000000..4e5d3c92
--- /dev/null
+++ b/source/util-math.cpp
@@ -0,0 +1,21 @@
+/*
+* Modern effects for a modern Streamer
+* Copyright (C) 2017 Michael Fabian Dirks
+*
+* 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 "util-math.h"
+
diff --git a/source/util-math.h b/source/util-math.h
new file mode 100644
index 00000000..c48d98dc
--- /dev/null
+++ b/source/util-math.h
@@ -0,0 +1,33 @@
+/*
+* Modern effects for a modern Streamer
+* Copyright (C) 2017 Michael Fabian Dirks
+*
+* 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
+*/
+
+#pragma once
+#include <math.h>
+#include <inttypes.h>
+
+#define PI		3.1415926535897932384626433832795
+#define PI2		6.283185307179586476925286766559
+#define PI2_SQROOT	2.506628274631000502415765284811		
+
+inline double_t Gaussian1D(double_t x, double_t o) {
+	double_t c = (x / o);
+	double_t b = exp(-0.5 * c * c);
+	double_t a = (1.0 / (o * PI2_SQROOT));
+	return a * b;
+}