Shaders: `const` for readonly variables is since GLSL 4.20.

src/Shaders/MeshVisualizer.frag

@@ -25,6 +25,9 @@
 #ifndef NEW_GLSL
 #define in varying
 #define fragmentColor gl_FragColor
+#endif
+
+#ifndef RUNTIME_CONST
 #define const
 #endif
 

src/Shaders/MeshVisualizer.geom

@@ -22,6 +22,10 @@
     DEALINGS IN THE SOFTWARE.
 */
 
+#ifndef RUNTIME_CONST
+#define const
+#endif
+
 layout(location = 1) uniform vec2 viewportSize;
 
 layout(triangles) in;

src/Shaders/Phong.frag

@@ -27,6 +27,10 @@
 #define color gl_FragColor
 #endif
 
+#ifndef RUNTIME_CONST
+#define const
+#endif
+
 #ifndef GL_ES
 #ifdef EXPLICIT_UNIFORM_LOCATION
 layout(location = 7) uniform vec3 lightColor = vec3(1.0, 1.0, 1.0);

src/Shaders/compatibility.glsl

@@ -56,3 +56,9 @@
 #define mediump
 #define lowp
 #endif
+
+/* const qualifier can be used for readonly variables since GLSL 4.20, however
+   it's not supported even in ES 3.0 */
+#if !defined(GL_ES) && __VERSION__ >= 420
+#define RUNTIME_CONST
+#endif