From b0829cc3521cc85f49d3d3bc0ce9316e44025989 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Wed, 20 Sep 2017 11:02:06 +0100
Subject: [PATCH] Updated text_sdf.frag shader to handle GLES2+ versions

---
 src/osgText/shaders/text_sdf_frag.cpp | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/osgText/shaders/text_sdf_frag.cpp b/src/osgText/shaders/text_sdf_frag.cpp
index d04362a0f..38f508f09 100644
--- a/src/osgText/shaders/text_sdf_frag.cpp
+++ b/src/osgText/shaders/text_sdf_frag.cpp
@@ -1,19 +1,23 @@
 char text_sdf_frag[] = "$OSG_GLSL_VERSION\n"
-                       "$OSG_PRECISION_FLOAT\n"
                        "\n"
                        "#pragma import_defines( BACKDROP_COLOR, OUTLINE )\n"
                        "\n"
-                       "#if __VERSION__>=400\n"
-                       "    #define osg_TextureQueryLOD textureQueryLod\n"
-                       "    #define USE_SIGNED_DISTNACE_FIELD\n"
-                       "#else\n"
-                       "    #extension GL_ARB_texture_query_lod : enable\n"
-                       "    #ifdef GL_ARB_texture_query_lod\n"
-                       "        #define osg_TextureQueryLOD textureQueryLOD\n"
+                       "#if !defined(GL_ES)\n"
+                       "    #if __VERSION__>=400\n"
+                       "        #define osg_TextureQueryLOD textureQueryLod\n"
                        "        #define USE_SIGNED_DISTNACE_FIELD\n"
+                       "    #else\n"
+                       "        #extension GL_ARB_texture_query_lod : enable\n"
+                       "        #ifdef GL_ARB_texture_query_lod\n"
+                       "            #define osg_TextureQueryLOD textureQueryLOD\n"
+                       "            #define USE_SIGNED_DISTNACE_FIELD\n"
+                       "        #endif\n"
                        "    #endif\n"
                        "#endif\n"
                        "\n"
+                       "\n"
+                       "$OSG_PRECISION_FLOAT\n"
+                       "\n"
                        "//#undef USE_SIGNED_DISTNACE_FIELD\n"
                        "\n"
                        "#if __VERSION__>=130\n"
@@ -35,7 +39,7 @@ char text_sdf_frag[] = "$OSG_GLSL_VERSION\n"
                        "        // glyph.rgba = (signed_distance, thin_outline, thick_outline, glyph_alpha)\n"
                        "        vec4 glyph = TEXTURE(glyphTexture, texCoord);\n"
                        "\n"
-                       "    #if 0\n"
+                       "    #if 1\n"
                        "        float blend_ratio = OUTLINE*17.0;\n"
                        "\n"
                        "        float outline_alpha = 0.0;\n"