From b7147ff5327104adba17494c0d68678c1855c50b Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Fri, 16 Mar 2018 11:33:03 +0000
Subject: [PATCH] Updated ShaderGen shaders

---
 src/osgUtil/shaders/shadergen_frag.cpp | 12 +-------
 src/osgUtil/shaders/shadergen_vert.cpp | 40 ++++++++++++++------------
 2 files changed, 22 insertions(+), 30 deletions(-)

diff --git a/src/osgUtil/shaders/shadergen_frag.cpp b/src/osgUtil/shaders/shadergen_frag.cpp
index 5018219f3..c28e9e3c8 100644
--- a/src/osgUtil/shaders/shadergen_frag.cpp
+++ b/src/osgUtil/shaders/shadergen_frag.cpp
@@ -4,16 +4,7 @@ char shadergen_frag[] = "// ShaderGen shader\n"
                         "    precision highp float;\n"
                         "#endif\n"
                         "\n"
-                        "#pragma import_defines(GL_LIGHTING, GL_TEXTURE_2D, GL_FOG)\n"
-                        "\n"
-                        "#if defined(GL_LIGHTING)\n"
-                        "varying vec3 normalDir;\n"
-                        "varying vec3 lightDir;\n"
-                        "#endif\n"
-                        "\n"
-                        "#if defined(GL_LIGHTING) || defined(GL_FOG)\n"
-                        "varying vec3 viewDir;\n"
-                        "#endif\n"
+                        "#pragma import_defines(GL_TEXTURE_2D)\n"
                         "\n"
                         "varying vec4 vertexColor;\n"
                         "\n"
@@ -29,7 +20,6 @@ char shadergen_frag[] = "// ShaderGen shader\n"
                         "  color = color * texture2D(diffuseMap, gl_TexCoord[0].st);\n"
                         "#endif\n"
                         "\n"
-                        "\n"
                         "  gl_FragColor = color;\n"
                         "}\n"
                         "\n";
diff --git a/src/osgUtil/shaders/shadergen_vert.cpp b/src/osgUtil/shaders/shadergen_vert.cpp
index 08e8dfc8b..ede1afd0f 100644
--- a/src/osgUtil/shaders/shadergen_vert.cpp
+++ b/src/osgUtil/shaders/shadergen_vert.cpp
@@ -4,20 +4,31 @@ char shadergen_vert[] = "// ShaderGen shader\n"
                         "    precision highp float;\n"
                         "#endif\n"
                         "\n"
-                        "#pragma import_defines(GL_LIGHTING, GL_TEXTURE_2D, GL_FOG)\n"
+                        "#pragma import_defines(GL_LIGHTING, GL_TEXTURE_2D)\n"
                         "\n"
-                        "#if defined(GL_LIGHTING)\n"
-                        "varying vec3 normalDir;\n"
-                        "varying vec3 lightDir;\n"
-                        "#endif\n"
                         "\n"
-                        "#if defined(GL_LIGHTING) || defined(GL_FOG)\n"
-                        "varying vec3 viewDir;\n"
+                        "#ifdef GL_LIGHTING\n"
+                        "void directionalLight( int lightNum, vec3 normal, inout vec4 color )\n"
+                        "{\n"
+                        "    vec3 n = normalize(gl_NormalMatrix * normal);\n"
+                        "\n"
+                        "    float NdotL = dot( n, normalize(gl_LightSource[lightNum].position.xyz) );\n"
+                        "    NdotL = max( 0.0, NdotL );\n"
+                        "\n"
+                        "    float NdotHV = dot( n, gl_LightSource[lightNum].halfVector.xyz );\n"
+                        "    NdotHV = max( 0.0, NdotHV );\n"
+                        "\n"
+                        "    color *= gl_FrontLightModelProduct.sceneColor +\n"
+                        "             gl_FrontLightProduct[lightNum].ambient +\n"
+                        "             gl_FrontLightProduct[lightNum].diffuse * NdotL;\n"
+                        "\n"
+                        "    if ( NdotL * NdotHV > 0.0 )\n"
+                        "        color += gl_FrontLightProduct[lightNum].specular * pow( NdotHV, gl_FrontMaterial.shininess );\n"
+                        "}\n"
                         "#endif\n"
                         "\n"
                         "varying vec4 vertexColor;\n"
                         "\n"
-                        "\n"
                         "void main()\n"
                         "{\n"
                         "  gl_Position = ftransform();\n"
@@ -26,19 +37,10 @@ char shadergen_vert[] = "// ShaderGen shader\n"
                         "  gl_TexCoord[0] = gl_MultiTexCoord0;\n"
                         "#endif\n"
                         "\n"
-                        "#if defined(GL_LIGHTING) || defined(GL_FOG)\n"
-                        "  viewDir = -vec3(gl_ModelViewMatrix * gl_Vertex);\n"
-                        "#endif\n"
+                        "  vertexColor = gl_Color;\n"
                         "\n"
                         "#if defined(GL_LIGHTING)\n"
-                        "  normalDir = gl_NormalMatrix * gl_Normal;\n"
-                        "  vec4 lpos = gl_LightSource[0].position;\n"
-                        "  if (lpos.w == 0.0)\n"
-                        "    lightDir = lpos.xyz;\n"
-                        "  else\n"
-                        "    lightDir = lpos.xyz + viewDir;\n"
+                        "    directionalLight(0, gl_Normal, vertexColor);\n"
                         "#endif\n"
-                        "\n"
-                        "  vertexColor = gl_Color;\n"
                         "}\n"
                         "\n";