Shaders: don't define & format irrelevant skinning values for UBOs.

The UBO use case doesn't need any initializers or uniform locations for
these, it's just wasted allocations.

src/Magnum/Shaders/FlatGL.cpp

@@ -179,6 +179,7 @@ template<UnsignedInt dimensions> typename FlatGL<dimensions>::CompileState FlatG
         .addSource(configuration.flags() >= Flag::InstancedTextureOffset ? "#define INSTANCED_TEXTURE_OFFSET\n"_s : ""_s);
     #ifndef MAGNUM_TARGET_GLES2
     if(configuration.perVertexJointCount() || configuration.secondaryPerVertexJointCount()) {
+        if(!(configuration.flags() >= Flag::UniformBuffers)) {
             vert.addSource(Utility::format(
                 "#define JOINT_COUNT {}\n"
                 "#define PER_VERTEX_JOINT_COUNT {}u\n"
@@ -194,12 +195,25 @@ template<UnsignedInt dimensions> typename FlatGL<dimensions>::CompileState FlatG
                 ((dimensions == 2 ? "mat3(1.0), "_s : "mat4(1.0), "_s)*configuration.jointCount()).exceptSuffix(2),
                 #endif
                 out._perInstanceJointCountUniform));
+        } else {
+            vert.addSource(Utility::format(
+                "#define JOINT_COUNT {}\n"
+                "#define PER_VERTEX_JOINT_COUNT {}u\n"
+                "#define SECONDARY_PER_VERTEX_JOINT_COUNT {}u\n",
+                configuration.jointCount(),
+                configuration.perVertexJointCount(),
+                configuration.secondaryPerVertexJointCount()));
+        }
     }
     if(configuration.flags() >= Flag::DynamicPerVertexJointCount) {
+        if(!(configuration.flags() >= Flag::UniformBuffers)) {
             vert.addSource(Utility::format(
                 "#define DYNAMIC_PER_VERTEX_JOINT_COUNT\n"
                 "#define PER_VERTEX_JOINT_COUNT_LOCATION {}\n",
                 out._perVertexJointCountUniform));
+        } else {
+            vert.addSource("#define DYNAMIC_PER_VERTEX_JOINT_COUNT\n"_s);
+        }
     }
     #endif
     #ifndef MAGNUM_TARGET_GLES2

src/Magnum/Shaders/MeshVisualizerGL.cpp

@@ -198,6 +198,7 @@ GL::Version MeshVisualizerGLBase::setupShaders(GL::Shader& vert, GL::Shader& fra
         ;
     #ifndef MAGNUM_TARGET_GLES2
     if(perVertexJointCount || secondaryPerVertexJointCount) {
+        if(!(flags >= FlagBase::UniformBuffers)) {
             vert.addSource(Utility::format(
                 "#define JOINT_COUNT {}\n"
                 "#define PER_VERTEX_JOINT_COUNT {}u\n"
@@ -213,12 +214,25 @@ GL::Version MeshVisualizerGLBase::setupShaders(GL::Shader& vert, GL::Shader& fra
                 ((dimensions == 2 ? "mat3(1.0), "_s : "mat4(1.0), "_s)*jointCount).exceptSuffix(2),
                 #endif
                 perInstanceJointCountUniform));
+        } else {
+            vert.addSource(Utility::format(
+                "#define JOINT_COUNT {}\n"
+                "#define PER_VERTEX_JOINT_COUNT {}u\n"
+                "#define SECONDARY_PER_VERTEX_JOINT_COUNT {}u\n",
+                jointCount,
+                perVertexJointCount,
+                secondaryPerVertexJointCount));
+        }
     }
     if(flags >= FlagBase::DynamicPerVertexJointCount) {
+        if(!(flags >= FlagBase::UniformBuffers)) {
             vert.addSource(Utility::format(
                 "#define DYNAMIC_PER_VERTEX_JOINT_COUNT\n"
                 "#define PER_VERTEX_JOINT_COUNT_LOCATION {}\n",
                 perVertexJointCountUniform));
+        } else {
+            vert.addSource("#define DYNAMIC_PER_VERTEX_JOINT_COUNT\n"_s);
+        }
     }
     #endif
     #ifndef MAGNUM_TARGET_GLES2

src/Magnum/Shaders/PhongGL.cpp

@@ -224,6 +224,7 @@ PhongGL::CompileState PhongGL::compile(const Configuration& configuration) {
         .addSource(configuration.flags() >= Flag::InstancedTextureOffset ? "#define INSTANCED_TEXTURE_OFFSET\n"_s : ""_s);
     #ifndef MAGNUM_TARGET_GLES2
     if(configuration.perVertexJointCount() || configuration.secondaryPerVertexJointCount()) {
+        if(!(configuration.flags() >= Flag::UniformBuffers)) {
             vert.addSource(Utility::format(
                 "#define JOINT_COUNT {}\n"
                 "#define PER_VERTEX_JOINT_COUNT {}u\n"
@@ -241,12 +242,25 @@ PhongGL::CompileState PhongGL::compile(const Configuration& configuration) {
                 ("mat4(1.0), "_s*configuration.jointCount()).exceptSuffix(2),
                 #endif
                 out._perInstanceJointCountUniform));
+        } else {
+            vert.addSource(Utility::format(
+                "#define JOINT_COUNT {}\n"
+                "#define PER_VERTEX_JOINT_COUNT {}u\n"
+                "#define SECONDARY_PER_VERTEX_JOINT_COUNT {}u\n",
+                configuration.jointCount(),
+                configuration.perVertexJointCount(),
+                configuration.secondaryPerVertexJointCount()));
+        }
     }
     if(configuration.flags() >= Flag::DynamicPerVertexJointCount) {
+        if(!(configuration.flags() >= Flag::UniformBuffers)) {
             vert.addSource(Utility::format(
                 "#define DYNAMIC_PER_VERTEX_JOINT_COUNT\n"
                 "#define PER_VERTEX_JOINT_COUNT_LOCATION {}\n",
                 out._perVertexJointCountUniform));
+        } else {
+            vert.addSource("#define DYNAMIC_PER_VERTEX_JOINT_COUNT\n"_s);
+        }
     }
     #endif
     #ifndef MAGNUM_TARGET_GLES2