Make the shaders work on NVidia

diff --git a/glutil_gl2.cpp b/glutil_gl2.cpp
index 8e55b9311d0fd64e74fc14bd4f46c6c8ed5114ba..87d8e0cb33c2ec7f8153985e3bc08bf4cc5f3284 100644 (file)
--- a/glutil_gl2.cpp
+++ b/glutil_gl2.cpp
@@ -128,6 +128,8 @@ void resolveFunctionPointers(T_glGetProcAddress p_glGetProcAddress)
 // shaders
 static const char *vertex_shader_source =
 "#version 100 \n\
+precision mediump float;\n\
+precision mediump int;\n\
 attribute vec2 position; \n\
 attribute vec3 color; \n\
 varying vec3 frag_color; \n\
@@ -138,6 +140,8 @@ void main() \n\
 }";
 static const char *fragment_shader_source =
 "#version 100 \n\
+precision mediump float;\n\
+precision mediump int;\n\
 varying vec3 frag_color; \n\
 void main(void) \n\
 { \n\