From 937681121348b8ed38b20225f62951fd7d568b0c Mon Sep 17 00:00:00 2001
From: scrawl <scrawl@baseoftrash.de>
Date: Tue, 16 Feb 2016 23:30:23 +0100
Subject: [PATCH] Vertex lighting shader

---
 apps/openmw/mwrender/animation.cpp    |  5 ++++
 components/sceneutil/lightmanager.cpp | 12 ++++++++
 components/shader/shadervisitor.cpp   |  1 +
 files/shaders/objects_fragment.glsl   |  4 +++
 files/shaders/objects_vertex.glsl     | 42 ++++++++++++++++++++++++++-
 5 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/apps/openmw/mwrender/animation.cpp b/apps/openmw/mwrender/animation.cpp
index abca3b266..65ac7d877 100644
--- a/apps/openmw/mwrender/animation.cpp
+++ b/apps/openmw/mwrender/animation.cpp
@@ -1063,6 +1063,9 @@ namespace MWRender
 
         osg::ref_ptr<GlowUpdater> glowupdater (new GlowUpdater(glowColor, textures));
         node->addUpdateCallback(glowupdater);
+
+        // TODO: regenerate shader
+        // allowedToModifyStatesets = false
     }
 
     // TODO: Should not be here
@@ -1243,6 +1246,8 @@ namespace MWRender
             material->setAmbient(osg::Material::FRONT_AND_BACK, osg::Vec4f(1,1,1,1));
             stateset->setAttributeAndModes(material, osg::StateAttribute::ON|osg::StateAttribute::OVERRIDE);
 
+            // FIXME: regenerate shader (mVertexColorMode)
+
             mObjectRoot->setStateSet(stateset);
         }
         else
diff --git a/components/sceneutil/lightmanager.cpp b/components/sceneutil/lightmanager.cpp
index 64448e73e..ca1fc7eb8 100644
--- a/components/sceneutil/lightmanager.cpp
+++ b/components/sceneutil/lightmanager.cpp
@@ -56,6 +56,18 @@ namespace SceneUtil
             }
 
             state.applyModelViewMatrix(modelViewMatrix);
+
+            /*
+            for (int i=0; i<8; ++i)
+            {
+                osg::ref_ptr<osg::Light> defaultLight (new osg::Light(i));
+                defaultLight->setAmbient(osg::Vec4());
+                defaultLight->setDiffuse(osg::Vec4());
+                defaultLight->setSpecular(osg::Vec4());
+                defaultLight->setConstantAttenuation(0.f);
+                state.setGlobalDefaultAttribute(defaultLight);
+            }
+            */
         }
 
     private:
diff --git a/components/shader/shadervisitor.cpp b/components/shader/shadervisitor.cpp
index 235e63d95..02ece3296 100644
--- a/components/shader/shadervisitor.cpp
+++ b/components/shader/shadervisitor.cpp
@@ -79,6 +79,7 @@ namespace Shader
             if (it->first.first == osg::StateAttribute::MATERIAL)
             {
                 const osg::Material* mat = static_cast<const osg::Material*>(it->second.first.get());
+                mRequirements.back().mColorMaterial = (mat->getColorMode() != osg::Material::OFF);
                 mRequirements.back().mVertexColorMode = mat->getColorMode();
             }
         }
diff --git a/files/shaders/objects_fragment.glsl b/files/shaders/objects_fragment.glsl
index 288760229..07a524ba1 100644
--- a/files/shaders/objects_fragment.glsl
+++ b/files/shaders/objects_fragment.glsl
@@ -7,6 +7,8 @@ varying vec2 diffuseMapUV;
 
 varying float depth;
 
+varying vec3 lighting;
+
 void main()
 {
 #if @diffuseMap
@@ -15,6 +17,8 @@ void main()
     gl_FragData[0] = vec4(1.0, 1.0, 1.0, 1.0);
 #endif
 
+    gl_FragData[0].xyz *= lighting;
+
     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 47ae20572..679abda1d 100644
--- a/files/shaders/objects_vertex.glsl
+++ b/files/shaders/objects_vertex.glsl
@@ -5,7 +5,44 @@ varying vec2 diffuseMapUV;
 #endif
 
 varying float depth;
-    
+
+varying vec3 lighting;
+
+#define MAX_LIGHTS 8
+
+vec3 doLighting(vec4 vertex, vec3 normal, vec3 vertexColor)
+{
+    vec3 viewPos = (gl_ModelViewMatrix * vertex).xyz;
+    vec3 viewNormal = normalize((gl_NormalMatrix * normal).xyz);
+    vec3 lightDir;
+    float d;
+
+#if @colorMode == 2
+    vec3 diffuse = vertexColor;
+    vec3 ambient = vertexColor;
+#else
+    vec3 diffuse = gl_FrontMaterial.diffuse.xyz;
+    vec3 ambient = gl_FrontMaterial.ambient.xyz;
+#endif
+
+    vec3 lightResult = vec3(0.0, 0.0, 0.0);
+    for (int i=0; i<MAX_LIGHTS; ++i)
+    {
+        lightDir = gl_LightSource[i].position.xyz - (viewPos * gl_LightSource[i].position.w);
+        d = length(lightDir);
+        lightDir = normalize(lightDir);
+
+        lightResult.xyz += ambient * gl_LightSource[i].ambient.xyz;
+        lightResult.xyz += diffuse * gl_LightSource[i].diffuse.xyz * clamp(1.0 / (gl_LightSource[i].constantAttenuation + gl_LightSource[i].linearAttenuation * d + gl_LightSource[i].quadraticAttenuation * d * d), 0.0, 1.0)
+                * max(dot(viewNormal.xyz, lightDir), 0.0);
+    }
+
+    lightResult += gl_LightModel.ambient.xyz * ambient;
+
+    return lightResult;
+}
+
+
 void main(void)
 {
     gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
@@ -14,4 +51,7 @@ void main(void)
 #if @diffuseMap
     diffuseMapUV = gl_MultiTexCoord@diffuseMapUV.xy;
 #endif
+
+    lighting = doLighting(gl_Vertex, gl_Normal.xyz, gl_Color.xyz);
+    lighting = clamp(lighting, vec3(0.0, 0.0, 0.0), vec3(1.0, 1.0, 1.0));
 }