Shaders: add ColorOutput constant to all shaders for consistency.

src/Magnum/Shaders/AbstractVector.h

@@ -59,6 +59,15 @@ template<UnsignedInt dimensions> class AbstractVector: public GL::AbstractShader
          */
         typedef typename Generic<dimensions>::TextureCoordinates TextureCoordinates;
 
+        enum: UnsignedInt {
+            /**
+             * Color shader output. @ref shaders-generic "Generic output",
+             * present always. Expects three- or four-component floating-point
+             * or normalized buffer attachment.
+             */
+            ColorOutput = Generic<dimensions>::ColorOutput
+        };
+
         /** @brief Copying is not allowed */
         AbstractVector(const AbstractVector<dimensions>&) = delete;
 

src/Magnum/Shaders/DistanceFieldVector.cpp

@@ -61,7 +61,8 @@ template<UnsignedInt dimensions> DistanceFieldVector<dimensions>::DistanceFieldV
 
     vert.addSource(rs.get("generic.glsl"))
         .addSource(rs.get(vertexShaderName<dimensions>()));
-    frag.addSource(rs.get("DistanceFieldVector.frag"));
+    frag.addSource(rs.get("generic.glsl"))
+        .addSource(rs.get("DistanceFieldVector.frag"));
 
     CORRADE_INTERNAL_ASSERT_OUTPUT(GL::Shader::compile({vert, frag}));
 

src/Magnum/Shaders/DistanceFieldVector.frag

@@ -69,6 +69,9 @@ uniform lowp sampler2D vectorTexture;
 in mediump vec2 fragmentTextureCoordinates;
 
 #ifdef NEW_GLSL
+#ifdef EXPLICIT_ATTRIB_LOCATION
+layout(location = COLOR_OUTPUT_ATTRIBUTE_LOCATION)
+#endif
 out lowp vec4 fragmentColor;
 #endif
 

src/Magnum/Shaders/MeshVisualizer.cpp

@@ -85,6 +85,7 @@ MeshVisualizer::MeshVisualizer(const Flags flags): _flags{flags} {
         .addSource(rs.get("MeshVisualizer.vert"));
     frag.addSource(flags & Flag::Wireframe ? "#define WIREFRAME_RENDERING\n" : "")
         .addSource(flags & Flag::NoGeometryShader ? "#define NO_GEOMETRY_SHADER\n" : "")
+        .addSource(rs.get("generic.glsl"))
         .addSource(rs.get("MeshVisualizer.frag"));
 
     #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)

src/Magnum/Shaders/MeshVisualizer.frag

@@ -92,6 +92,9 @@ in lowp vec3 barycentric;
 #endif
 
 #ifdef NEW_GLSL
+#ifdef EXPLICIT_ATTRIB_LOCATION
+layout(location = COLOR_OUTPUT_ATTRIBUTE_LOCATION)
+#endif
 out lowp vec4 fragmentColor;
 #endif
 

src/Magnum/Shaders/MeshVisualizer.h

@@ -128,6 +128,15 @@ class MAGNUM_SHADERS_EXPORT MeshVisualizer: public GL::AbstractShaderProgram {
          */
         typedef GL::Attribute<3, Float> VertexIndex;
 
+        enum: UnsignedInt {
+            /**
+             * Color shader output. @ref shaders-generic "Generic output",
+             * present always. Expects three- or four-component floating-point
+             * or normalized buffer attachment.
+             */
+            ColorOutput = Generic3D::ColorOutput
+        };
+
         /**
          * @brief Flag
          *

src/Magnum/Shaders/Vector.cpp

@@ -61,7 +61,8 @@ template<UnsignedInt dimensions> Vector<dimensions>::Vector() {
 
     vert.addSource(rs.get("generic.glsl"))
         .addSource(rs.get(vertexShaderName<dimensions>()));
-    frag.addSource(rs.get("Vector.frag"));
+    frag.addSource(rs.get("generic.glsl"))
+        .addSource(rs.get("Vector.frag"));
 
     CORRADE_INTERNAL_ASSERT_OUTPUT(GL::Shader::compile({vert, frag}));
 

src/Magnum/Shaders/Vector.frag

@@ -51,6 +51,9 @@ uniform lowp sampler2D vectorTexture;
 in mediump vec2 fragmentTextureCoordinates;
 
 #ifdef NEW_GLSL
+#ifdef EXPLICIT_ATTRIB_LOCATION
+layout(location = COLOR_OUTPUT_ATTRIBUTE_LOCATION)
+#endif
 out lowp vec4 fragmentColor;
 #endif
 

src/Magnum/Shaders/VertexColor.cpp

@@ -61,7 +61,8 @@ template<UnsignedInt dimensions> VertexColor<dimensions>::VertexColor() {
 
     vert.addSource(rs.get("generic.glsl"))
         .addSource(rs.get(vertexShaderName<dimensions>()));
-    frag.addSource(rs.get("VertexColor.frag"));
+    frag.addSource(rs.get("generic.glsl"))
+        .addSource(rs.get("VertexColor.frag"));
 
     CORRADE_INTERNAL_ASSERT_OUTPUT(GL::Shader::compile({vert, frag}));
 

src/Magnum/Shaders/VertexColor.frag

@@ -31,6 +31,9 @@
 in lowp vec4 interpolatedColor;
 
 #ifdef NEW_GLSL
+#ifdef EXPLICIT_ATTRIB_LOCATION
+layout(location = COLOR_OUTPUT_ATTRIBUTE_LOCATION)
+#endif
 out lowp vec4 fragmentColor;
 #endif
 

src/Magnum/Shaders/VertexColor.h

@@ -89,6 +89,15 @@ template<UnsignedInt dimensions> class MAGNUM_SHADERS_EXPORT VertexColor: public
          */
         typedef typename Generic<dimensions>::Color4 Color4;
 
+        enum: UnsignedInt {
+            /**
+             * Color shader output. @ref shaders-generic "Generic output",
+             * present always. Expects three- or four-component floating-point
+             * or normalized buffer attachment.
+             */
+            ColorOutput = Generic<dimensions>::ColorOutput
+        };
+
         #ifdef MAGNUM_BUILD_DEPRECATED
         /**
          * @brief Vertex color