From 5e12a1b4ef904c35c976526542ee306c0dc5787e Mon Sep 17 00:00:00 2001
From: scrawl <scrawl@baseoftrash.de>
Date: Thu, 18 Feb 2016 23:05:44 +0100
Subject: [PATCH] Add enchanted item glow to the shader

---
 apps/openmw/mwrender/animation.cpp  | 20 +++++++++++++++-----
 components/shader/shadervisitor.cpp |  2 +-
 files/shaders/objects_fragment.glsl | 14 ++++++++++++--
 files/shaders/objects_vertex.glsl   | 15 +++++++++++++--
 4 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/apps/openmw/mwrender/animation.cpp b/apps/openmw/mwrender/animation.cpp
index 3d030febf..ec0dab082 100644
--- a/apps/openmw/mwrender/animation.cpp
+++ b/apps/openmw/mwrender/animation.cpp
@@ -52,8 +52,8 @@ namespace
     class GlowUpdater : public SceneUtil::StateSetUpdater
     {
     public:
-        GlowUpdater(osg::Vec4f color, const std::vector<osg::ref_ptr<osg::Texture2D> >& textures)
-            : mTexUnit(1) // FIXME: might not always be 1
+        GlowUpdater(int texUnit, osg::Vec4f color, const std::vector<osg::ref_ptr<osg::Texture2D> >& textures)
+            : mTexUnit(texUnit)
             , mColor(color)
             , mTextures(textures)
         {
@@ -1055,17 +1055,27 @@ namespace MWRender
 
             osg::ref_ptr<osg::Image> image = mResourceSystem->getImageManager()->getImage(stream.str());
             osg::ref_ptr<osg::Texture2D> tex (new osg::Texture2D(image));
+            tex->setName("envMap");
             tex->setWrap(osg::Texture::WRAP_S, osg::Texture2D::REPEAT);
             tex->setWrap(osg::Texture::WRAP_T, osg::Texture2D::REPEAT);
             mResourceSystem->getSceneManager()->applyFilterSettings(tex);
             textures.push_back(tex);
         }
 
-        osg::ref_ptr<GlowUpdater> glowupdater (new GlowUpdater(glowColor, textures));
+        int texUnit = 1; // FIXME: might not always be 1
+        osg::ref_ptr<GlowUpdater> glowupdater (new GlowUpdater(texUnit, glowColor, textures));
         node->addUpdateCallback(glowupdater);
 
-        // TODO: regenerate shader
-        // allowedToModifyStatesets = false
+        // set a texture now so that the ShaderVisitor can find it
+        osg::ref_ptr<osg::StateSet> writableStateSet = NULL;
+        if (!node->getStateSet())
+            writableStateSet = node->getOrCreateStateSet();
+        else
+            writableStateSet = osg::clone(node->getStateSet(), osg::CopyOp::SHALLOW_COPY);
+        writableStateSet->setTextureAttributeAndModes(texUnit, textures.front(), osg::StateAttribute::ON);
+        writableStateSet->addUniform(new osg::Uniform("envMapColor", glowColor));
+
+        mResourceSystem->getSceneManager()->recreateShaders(node);
     }
 
     // TODO: Should not be here
diff --git a/components/shader/shadervisitor.cpp b/components/shader/shadervisitor.cpp
index fcb9b8057..331beab34 100644
--- a/components/shader/shadervisitor.cpp
+++ b/components/shader/shadervisitor.cpp
@@ -152,7 +152,7 @@ namespace Shader
             writableStateSet = getWritableStateSet(node);
 
         ShaderManager::DefineMap defineMap;
-        const char* defaultTextures[] = { "diffuseMap", "normalMap", "emissiveMap", "darkMap", "detailMap" };
+        const char* defaultTextures[] = { "diffuseMap", "normalMap", "emissiveMap", "darkMap", "detailMap", "envMap" };
         for (unsigned int i=0; i<sizeof(defaultTextures)/sizeof(defaultTextures[0]); ++i)
         {
             defineMap[defaultTextures[i]] = "0";
diff --git a/files/shaders/objects_fragment.glsl b/files/shaders/objects_fragment.glsl
index 37c715e1a..6366da82b 100644
--- a/files/shaders/objects_fragment.glsl
+++ b/files/shaders/objects_fragment.glsl
@@ -26,6 +26,12 @@ varying vec2 normalMapUV;
 varying vec3 viewTangent;
 #endif
 
+#if @envMap
+uniform sampler2D envMap;
+varying vec2 envMapUV;
+uniform vec4 envMapColor;
+#endif
+
 varying float depth;
 
 #define PER_PIXEL_LIGHTING (@normalMap || @forcePPL)
@@ -35,7 +41,7 @@ varying vec4 lighting;
 #else
 varying vec3 passViewPos;
 varying vec3 passViewNormal;
-varying vec4 passColour;
+varying vec4 passColor;
 #endif
 
 #include "lighting.glsl"
@@ -73,13 +79,17 @@ void main()
 #if !PER_PIXEL_LIGHTING
     gl_FragData[0] *= lighting;
 #else
-    gl_FragData[0] *= doLighting(passViewPos, normalize(viewNormal), passColour);
+    gl_FragData[0] *= doLighting(passViewPos, normalize(viewNormal), passColor);
 #endif
 
 #if @emissiveMap
     gl_FragData[0].xyz += texture2D(emissiveMap, emissiveMapUV).xyz;
 #endif
 
+#if @envMap
+    gl_FragData[0].xyz += texture2D(envMap, envMapUV).xyz * envMapColor.xyz;
+#endif
+
     float fogValue = clamp((depth - gl_Fog.start) * gl_Fog.scale, 0.0, 1.0);
     gl_FragData[0].xyz = mix(gl_FragData[0].xyz, gl_Fog.color.xyz, fogValue);
 }
diff --git a/files/shaders/objects_vertex.glsl b/files/shaders/objects_vertex.glsl
index 940a2306e..a2c0e7d21 100644
--- a/files/shaders/objects_vertex.glsl
+++ b/files/shaders/objects_vertex.glsl
@@ -21,6 +21,10 @@ varying vec2 normalMapUV;
 varying vec3 viewTangent;
 #endif
 
+#if @envMap
+varying vec2 envMapUV;
+#endif
+
 varying float depth;
 
 #define PER_PIXEL_LIGHTING (@normalMap || @forcePPL)
@@ -30,7 +34,7 @@ varying vec4 lighting;
 #else
 varying vec3 passViewPos;
 varying vec3 passViewNormal;
-varying vec4 passColour;
+varying vec4 passColor;
 #endif
 
 #include "lighting.glsl"
@@ -44,6 +48,13 @@ void main(void)
     gl_ClipVertex = viewPos;
     vec3 viewNormal = normalize((gl_NormalMatrix * gl_Normal).xyz);
 
+#if @envMap
+    vec3 viewVec = normalize(viewPos.xyz);
+    vec3 r = reflect( viewVec, viewNormal );
+    float m = 2.0 * sqrt( r.x*r.x + r.y*r.y + (r.z+1.0)*(r.z+1.0) );
+    envMapUV = vec2(r.x/m + 0.5, r.y/m + 0.5);
+#endif
+
 #if @diffuseMap
     diffuseMapUV = (gl_TextureMatrix[@diffuseMapUV] * gl_MultiTexCoord@diffuseMapUV).xy;
 #endif
@@ -70,6 +81,6 @@ void main(void)
 #else
     passViewPos = viewPos.xyz;
     passViewNormal = viewNormal;
-    passColour = gl_Color;
+    passColor = gl_Color;
 #endif
 }