link rain water ripple effect to actual rain

apps/openmw/mwrender/renderingmanager.cpp

@@ -251,6 +251,10 @@ namespace MWRender
         sceneRoot->setNodeMask(Mask_Scene);
         sceneRoot->setName("Scene Root");
 
+        mUniformRainIntensity = new osg::Uniform("rainIntensity",(float) 0.0);
+        
+        mRootNode->getOrCreateStateSet()->addUniform(mUniformRainIntensity);
+
         mSky.reset(new SkyManager(sceneRoot, resourceSystem->getSceneManager()));
 
         source->setStateSetModes(*mRootNode->getOrCreateStateSet(), osg::StateAttribute::ON);
@@ -799,6 +803,7 @@ namespace MWRender
     {
         mEffectManager->clear();
         mWater->clearRipples();
+        mUniformRainIntensity->set((float) 0.0);  // for interiors
     }
 
     void RenderingManager::clear()

apps/openmw/mwrender/renderingmanager.hpp

@@ -85,6 +85,7 @@ namespace MWRender
 
         osg::Uniform* mUniformNear;
         osg::Uniform* mUniformFar;
+        osg::Uniform* mUniformRainIntensity;
 
         void preloadCommonAssets();
 

apps/openmw/mwrender/sky.cpp

@@ -1305,13 +1305,19 @@ public:
         std::vector<osg::ref_ptr<AlphaFader> > mAlphaFaders;
     };
 
-private:
+protected:
     float mAlpha;
 };
 
 class RainFader : public AlphaFader
 {
 public:
+
+    RainFader(osg::Uniform *rainIntensityUniform): AlphaFader()
+    {
+        mRainIntensityUniform = rainIntensityUniform;
+    }
+
     virtual void setDefaults(osg::StateSet* stateset)
     {
         osg::ref_ptr<osg::Material> mat (new osg::Material);
@@ -1320,6 +1326,15 @@ public:
         mat->setColorMode(osg::Material::OFF);
         stateset->setAttributeAndModes(mat, osg::StateAttribute::ON);
     }
+
+    virtual void apply(osg::StateSet *stateset, osg::NodeVisitor *nv)
+    {
+        AlphaFader::apply(stateset,nv);
+        mRainIntensityUniform->set((float) (mAlpha * 2.0));  // mAlpha is limited to 0.6 so multiply by 2 to reach full intensity
+    }
+
+protected:
+    osg::Uniform* mRainIntensityUniform;
 };
 
 void SkyManager::createRain()
@@ -1375,7 +1390,7 @@ void SkyManager::createRain()
     mRainNode->addChild(mRainParticleSystem);
     mRainNode->addChild(updater);
 
-    mRainFader = new RainFader;
+    mRainFader = new RainFader(mRootNode->getParent(0)->getParent(0)->getStateSet()->getUniform("rainIntensity"));
     mRainNode->addUpdateCallback(mRainFader);
     mRainNode->addCullCallback(mUnderwaterSwitch);
     mRainNode->setNodeMask(Mask_WeatherParticles);

apps/openmw/mwrender/sky.hpp

@@ -4,6 +4,7 @@
 #include <string>
 #include <memory>
 #include <vector>
+#include <iostream>
 
 #include <osg/ref_ptr>
 #include <osg/Vec4f>

files/shaders/water_fragment.glsl

@@ -65,12 +65,14 @@ vec4 circle(vec2 coords, vec2 i_part, float phase)
   vec2 center = vec2(0.5,0.5) + (0.5 - RAIN_RIPPLE_RADIUS) * (2.0 * randOffset(i_part) - 1.0);
   vec2 toCenter = coords - center;
   float d = length(toCenter);
+
   float r = RAIN_RIPPLE_RADIUS * phase;
         
   if (d > r)
     return vec4(0.0,0.0,1.0,0.0);
         
   float sinValue = (sin(d / r * 1.2) + 0.7) / 2.0;
+
   float height = (1.0 - abs(phase)) * pow(sinValue,3.0);
 
   vec3 normal = normalize(mix(vec3(0.0,0.0,1.0),vec3(normalize(toCenter),0.0),height));
@@ -138,6 +140,8 @@ uniform float near;
 uniform float far;
 uniform vec3 nodePosition;
 
+uniform float rainIntensity;
+
 float frustumDepth;
 
 float linearizeDepth(float depth)  // takes <0,1> non-linear depth value and returns <0,1> linearized value
@@ -170,7 +174,13 @@ void main(void)
     vec3 normal4 = 2.0 * texture2D(normalMap,normalCoords(UV, 1.0,  0.4,  waterTimer, -0.02,   0.1,   normal3)).rgb - 1.0;
     vec3 normal5 = 2.0 * texture2D(normalMap,normalCoords(UV, 2.0,  0.7,  waterTimer,  0.1,   -0.06,  normal4)).rgb - 1.0;
 
-    vec4 rainRipple = rainCombined(position.xy / 1000.0,waterTimer); 
+    vec4 rainRipple;
+
+    if (rainIntensity > 0.01)
+      rainRipple = rainCombined(position.xy / 1000.0,waterTimer) * clamp(rainIntensity,0.0,1.0);
+    else
+      rainRipple = vec4(0.0,0.0,0.0,0.0);
+ 
     vec3 rippleAdd = rainRipple.xyz * rainRipple.w * 10.0;
 
     vec3 normal = (normal0 * BIG_WAVES_X + normal1 * BIG_WAVES_Y +