Shaders: really ported MeshVisualizer to ES.

src/Shaders/MeshVisualizer.cpp

@@ -36,6 +36,9 @@ MeshVisualizer::MeshVisualizer(const Flags flags): flags(flags), transformationP
     #ifndef MAGNUM_TARGET_GLES
     if(flags & Flag::Wireframe && !(flags & Flag::NoGeometryShader))
         MAGNUM_ASSERT_EXTENSION_SUPPORTED(Extensions::GL::ARB::geometry_shader4);
+    #elif defined(MAGNUM_TARGET_GLES2)
+    if(flags & Flag::Wireframe)
+        MAGNUM_ASSERT_EXTENSION_SUPPORTED(Extensions::GL::OES::standard_derivatives);
     #endif
 
     Utility::Resource rs("MagnumShaders");
@@ -109,6 +112,16 @@ MeshVisualizer::MeshVisualizer(const Flags flags): flags(flags), transformationP
                 viewportSizeUniform = uniformLocation("viewportSize");
         }
     }
+
+    /* Set defaults in OpenGL ES (for desktop they are set in shader code itself) */
+    #ifdef MAGNUM_TARGET_GLES
+    setColor(Color3<>(1.0f));
+    if(flags & Flag::Wireframe) {
+        setWireframeColor(Color3<>(0.0f));
+        setWireframeWidth(1.0f);
+        setSmoothness(2.0f);
+    }
+    #endif
 }
 
 }}

src/Shaders/MeshVisualizer.frag

@@ -25,6 +25,7 @@
 #ifndef NEW_GLSL
 #define in varying
 #define fragmentColor gl_FragColor
+#define const
 #endif
 
 #ifndef EXPLICIT_UNIFORM_LOCATION
@@ -49,15 +50,17 @@ uniform lowp float smoothness;
 #endif
 
 #ifndef NO_GEOMETRY_SHADER
-noperspective in vec3 dist;
+noperspective in lowp vec3 dist;
 #else
-in vec3 barycentric;
+in lowp vec3 barycentric;
 #endif
 #endif
 
+#ifdef NEW_GLSL
 out vec4 fragmentColor;
+#endif
 
-#if defined(WIREFRAME_RENDERING) && defined(NO_GEOMETRY_SHADER) && defined(GL_ES)
+#if defined(WIREFRAME_RENDERING) && defined(GL_ES) && __VERSION__ < 300
 #extension GL_OES_standard_derivatives : enable
 #endif
 
@@ -70,9 +73,9 @@ void main() {
     /* Smooth step between face color and wireframe color based on distance */
     fragmentColor = mix(wireframeColor, color, smoothstep(wireframeWidth-smoothness, wireframeWidth+smoothness, nearest));
     #else
-    const vec3 d = fwidth(barycentric);
-    const vec3 factor = smoothstep(vec3(0.0), d*1.5, barycentric);
-    const float nearest = min(min(factor.x, factor.y), factor.z);
+    const lowp vec3 d = fwidth(barycentric);
+    const lowp vec3 factor = smoothstep(vec3(0.0), d*1.5, barycentric);
+    const lowp float nearest = min(min(factor.x, factor.y), factor.z);
     fragmentColor = mix(wireframeColor, color, nearest);
     #endif
 

src/Shaders/MeshVisualizer.vert

@@ -42,7 +42,7 @@ in highp vec4 position;
 #if defined(WIREFRAME_RENDERING) && defined(NO_GEOMETRY_SHADER)
 #if (!defined(GL_ES) && __VERSION__ < 140) || (defined(GL_ES) && __VERSION__ < 300)
 #ifdef EXPLICIT_ATTRIB_LOCATION
-layout(location = 1) highp in float vertexIndex;
+layout(location = 1) in lowp float vertexIndex;
 #else
 in lowp float vertexIndex;
 #endif
@@ -57,6 +57,10 @@ void main() {
 
     #if defined(WIREFRAME_RENDERING) && defined(NO_GEOMETRY_SHADER)
     barycentric = vec3(0.0);
+    #ifndef NEW_GLSL
+    barycentric[int(mod(vertexIndex, 3.0))] = 1.0;
+    #else
     barycentric[gl_VertexID % 3] = 1.0;
     #endif
+    #endif
 }