From 79406b0b08795107e84c0f7c33652a01e8e640b3 Mon Sep 17 00:00:00 2001
From: Michael Fabian 'Xaymar' Dirks <info@xaymar.com>
Date: Sat, 28 Mar 2020 22:17:33 +0100
Subject: [PATCH] gfx-shader: Additional stable time values

'Time.x' gets inaccurate if OBS Studio is running for more than two hours, therefore we have to do something to fix it. By allowing the shader code to control when things loop using 'Time.y' (0..1) and 'Time.z' (the number of times 'Time.y' wrapped back to 0), a much more stable animation can be achieved.
---
 source/gfx/shader/gfx-shader.cpp | 13 +++++++++++--
 source/gfx/shader/gfx-shader.hpp |  8 +++++---
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/source/gfx/shader/gfx-shader.cpp b/source/gfx/shader/gfx-shader.cpp
index dc8506b7..08716e2c 100644
--- a/source/gfx/shader/gfx-shader.cpp
+++ b/source/gfx/shader/gfx-shader.cpp
@@ -38,7 +38,7 @@ gfx::shader::shader::shader(obs_source_t* self, shader_mode mode)
 
 	  _width_type(size_type::Percent), _width_value(1.0), _height_type(size_type::Percent), _height_value(1.0),
 
-	  _time(0), _random(), _have_current_params(false)
+	  _time(0), _time_loop(0), _loops(0), _random(), _have_current_params(false)
 {
 	_random.seed(static_cast<unsigned long long>(time(NULL)));
 }
@@ -362,6 +362,15 @@ bool gfx::shader::shader::tick(float_t time)
 
 	// Update State
 	_time += time;
+	_time_loop += time;
+	if (_time_loop > 1.) {
+		_time_loop -= 1.;
+
+		// Loops
+		_loops += 1;
+		if (_loops >= 4194304)
+			_loops = -_loops;
+	}
 
 	return false;
 }
@@ -379,7 +388,7 @@ void gfx::shader::shader::prepare_render()
 	if (gs::effect_parameter el = _shader.get_parameter("Time"); el != nullptr) {
 		if (el.get_type() == gs::effect_parameter::type::Float4) {
 			el.set_float4(
-				_time, 0, 0,
+				_time, _time_loop, static_cast<float_t>(_loops),
 				static_cast<float_t>(static_cast<double_t>(_random())
 									 / static_cast<double_t>(std::numeric_limits<unsigned long long>::max())));
 		}
diff --git a/source/gfx/shader/gfx-shader.hpp b/source/gfx/shader/gfx-shader.hpp
index 2ba28133..7b714a40 100644
--- a/source/gfx/shader/gfx-shader.hpp
+++ b/source/gfx/shader/gfx-shader.hpp
@@ -56,9 +56,9 @@ namespace gfx {
 			obs_source_t* _self;
 
 			// Inputs
-			shader_mode                  _mode;
-			uint32_t                     _base_width;
-			uint32_t                     _base_height;
+			shader_mode _mode;
+			uint32_t    _base_width;
+			uint32_t    _base_height;
 
 			// Shader
 			gs::effect                      _shader;
@@ -77,6 +77,8 @@ namespace gfx {
 
 			// Cache
 			float_t         _time;
+			float_t         _time_loop;
+			int32_t			_loops;
 			std::mt19937_64 _random;
 			bool            _have_current_params;