From b346a4a8582dbaafa8c91cca5af0036f51a16869 Mon Sep 17 00:00:00 2001
From: Cody Glassman <glassmancody.info@gmail.com>
Date: Tue, 10 Sep 2024 16:58:27 +0000
Subject: [PATCH] Add frame number to available postprocess uniforms

---
 CMakeLists.txt                                 | 2 +-
 apps/openmw/mwrender/postprocessor.cpp         | 2 ++
 components/fx/stateupdater.hpp                 | 9 ++++++++-
 docs/source/reference/postprocessing/omwfx.rst | 2 ++
 4 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 411f3e4681..759ada4f6d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -83,7 +83,7 @@ set(OPENMW_VERSION_MAJOR 0)
 set(OPENMW_VERSION_MINOR 49)
 set(OPENMW_VERSION_RELEASE 0)
 set(OPENMW_LUA_API_REVISION 68)
-set(OPENMW_POSTPROCESSING_API_REVISION 1)
+set(OPENMW_POSTPROCESSING_API_REVISION 2)
 
 set(OPENMW_VERSION_COMMITHASH "")
 set(OPENMW_VERSION_TAGHASH "")
diff --git a/apps/openmw/mwrender/postprocessor.cpp b/apps/openmw/mwrender/postprocessor.cpp
index 59559d70e7..623edcb82c 100644
--- a/apps/openmw/mwrender/postprocessor.cpp
+++ b/apps/openmw/mwrender/postprocessor.cpp
@@ -323,6 +323,8 @@ namespace MWRender
 
             mStateUpdater->setSimulationTime(static_cast<float>(stamp->getSimulationTime()));
             mStateUpdater->setDeltaSimulationTime(static_cast<float>(stamp->getSimulationTime() - mLastSimulationTime));
+            // Use a signed int because 'uint' type is not supported in GLSL 120 without extensions
+            mStateUpdater->setFrameNumber(static_cast<int>(stamp->getFrameNumber()));
             mLastSimulationTime = stamp->getSimulationTime();
 
             for (const auto& dispatchNode : mCanvases[frameId]->getPasses())
diff --git a/components/fx/stateupdater.hpp b/components/fx/stateupdater.hpp
index 9b7a25286a..33a7a09fe6 100644
--- a/components/fx/stateupdater.hpp
+++ b/components/fx/stateupdater.hpp
@@ -89,6 +89,8 @@ namespace fx
 
         void setDeltaSimulationTime(float time) { mData.get<DeltaSimulationTime>() = time; }
 
+        void setFrameNumber(int frame) { mData.get<FrameNumber>() = frame; }
+
         void setWindSpeed(float speed) { mData.get<WindSpeed>() = speed; }
 
         void setWeatherTransition(float transition)
@@ -233,6 +235,11 @@ namespace fx
             static constexpr std::string_view sName = "deltaSimulationTime";
         };
 
+        struct FrameNumber : std140::Int
+        {
+            static constexpr std::string_view sName = "frameNumber";
+        };
+
         struct WindSpeed : std140::Float
         {
             static constexpr std::string_view sName = "windSpeed";
@@ -267,7 +274,7 @@ namespace fx
             = std140::UBO<ProjectionMatrix, InvProjectionMatrix, ViewMatrix, PrevViewMatrix, InvViewMatrix, EyePos,
                 EyeVec, FogColor, AmbientColor, SkyColor, SunColor, SunPos, Resolution, RcpResolution, FogNear, FogFar,
                 Near, Far, Fov, GameHour, SunVis, WaterHeight, IsWaterEnabled, SimulationTime, DeltaSimulationTime,
-                WindSpeed, WeatherTransition, WeatherID, NextWeatherID, IsUnderwater, IsInterior>;
+                FrameNumber, WindSpeed, WeatherTransition, WeatherID, NextWeatherID, IsUnderwater, IsInterior>;
 
         UniformData mData;
         bool mUseUBO;
diff --git a/docs/source/reference/postprocessing/omwfx.rst b/docs/source/reference/postprocessing/omwfx.rst
index e5246bec8e..60fd2663c4 100644
--- a/docs/source/reference/postprocessing/omwfx.rst
+++ b/docs/source/reference/postprocessing/omwfx.rst
@@ -107,6 +107,8 @@ Builtin Uniforms
 +-------------+------------------------------+--------------------------------------------------+
 | float       | ``omw.deltaSimulationTime``  | The change in `omw.simulationTime`               |
 +-------------+------------------------------+--------------------------------------------------+
+| int         | ``omw.frameNumber``          | The current frame number                         |
++-------------+------------------------------+--------------------------------------------------+
 | float       | ``omw.windSpeed``            | The current wind speed                           |
 +-------------+------------------------------+--------------------------------------------------+
 | float       | ``omw.weatherTransition``    | The transition factor between weathers [0, 1]    |