Shaders: add a 2D variant of MeshVisualizer.

doc/changelog.dox

@@ -204,6 +204,7 @@ See also:
 
 @subsubsection changelog-latest-new-shaders Shaders library
 
+-   New @ref Shaders::MeshVisualizer2D for 2D mesh visualization
 -   Texture coordinate transformation in @ref Shaders::DistanceFieldVector,
     @ref Shaders::Flat, @ref Shaders::Phong and @ref Shaders::Vector
 -   New attribute definitions and an location allocation scheme in
@@ -495,6 +496,8 @@ See also:
     @ref MeshTools::compressIndices(), @ref MeshTools::duplicate(),
     @ref MeshTools::removeDuplicatesInPlace() and @ref MeshTools::subdivide() /
     @ref MeshTools::subdivideInPlace() overloads instead
+-   @cpp Shaders::MeshVisualizer @ce is deprecated as the shader can now handle
+    both 2D and 3D, use @ref Shaders::MeshVisualizer3D instead
 
 @subsection changelog-latest-compatibility Potential compatibility breakages, removed APIs
 

doc/generated/primitives.cpp

@@ -275,17 +275,12 @@ int PrimitiveVisualizer::exec() {
         }
     }
 
-    Shaders::MeshVisualizer wireframe2D{Shaders::MeshVisualizer::Flag::Wireframe};
+    Shaders::MeshVisualizer2D wireframe2D{Shaders::MeshVisualizer2D::Flag::Wireframe};
     wireframe2D.setColor(0x00000000_srgbaf)
         .setWireframeColor(OutlineColor)
         .setWireframeWidth(2.0f)
         .setViewportSize(Vector2{ImageSize})
-        .setTransformationProjectionMatrix(Matrix4{
-            /** @todo clean up once Matrix4 from Matrix3 constructor exists */
-            {(Projection2D*Transformation2D)[0], 0.0f},
-            {(Projection2D*Transformation2D)[1], 0.0f},
-            {0.0f, 0.0f, 1.0f, 0.0f},
-            {{(Projection2D*Transformation2D)[2].xy(), 0.0f}, 1.0f}});
+        .setTransformationProjectionMatrix(Projection2D*Transformation2D);
 
     {
         Shaders::Flat2D flat;
@@ -312,7 +307,7 @@ int PrimitiveVisualizer::exec() {
         }
     }
 
-    Shaders::MeshVisualizer wireframe3D{Shaders::MeshVisualizer::Flag::Wireframe};
+    Shaders::MeshVisualizer3D wireframe3D{Shaders::MeshVisualizer3D::Flag::Wireframe};
     wireframe3D.setColor(0x00000000_srgbaf)
         .setWireframeColor(OutlineColor)
         .setWireframeWidth(2.0f)

doc/generated/shaders.cpp

@@ -78,7 +78,8 @@ struct ShaderVisualizer: Platform::WindowlessApplication {
     int exec() override;
 
     std::string phong();
-    std::string meshVisualizer();
+    std::string meshVisualizer2D();
+    std::string meshVisualizer3D();
     std::string flat();
     std::string vertexColor();
 
@@ -127,7 +128,8 @@ int ShaderVisualizer::exec() {
     GL::Renderer::setClearColor(0x000000_srgbaf);
 
     for(auto fun: {&ShaderVisualizer::phong,
-                   &ShaderVisualizer::meshVisualizer,
+                   &ShaderVisualizer::meshVisualizer2D,
+                   &ShaderVisualizer::meshVisualizer3D,
                    &ShaderVisualizer::flat,
                    &ShaderVisualizer::vertexColor,
                    &ShaderVisualizer::vector,
@@ -167,12 +169,28 @@ std::string ShaderVisualizer::phong() {
     return "phong.png";
 }
 
-std::string ShaderVisualizer::meshVisualizer() {
+std::string ShaderVisualizer::meshVisualizer2D() {
+    const Matrix3 projection =
+        Matrix3::projection(Vector2{3.0f})*
+        Matrix3::rotation(13.7_degf);
+
+    Shaders::MeshVisualizer2D{Shaders::MeshVisualizer2D::Flag::Wireframe}
+        .setColor(BaseColor)
+        .setWireframeColor(OutlineColor)
+        .setWireframeWidth(2.0f)
+        .setViewportSize(Vector2{ImageSize})
+        .setTransformationProjectionMatrix(projection)
+        .draw(MeshTools::compile(Primitives::circle2DSolid(8)));
+
+    return "meshvisualizer2d.png";
+}
+
+std::string ShaderVisualizer::meshVisualizer3D() {
     const Matrix4 projection = Projection*Transformation*
         Matrix4::rotationZ(13.7_degf)*
         Matrix4::rotationX(-12.6_degf);
 
-    Shaders::MeshVisualizer{Shaders::MeshVisualizer::Flag::Wireframe}
+    Shaders::MeshVisualizer3D{Shaders::MeshVisualizer3D::Flag::Wireframe}
         .setColor(BaseColor)
         .setWireframeColor(OutlineColor)
         .setWireframeWidth(2.0f)
@@ -180,7 +198,7 @@ std::string ShaderVisualizer::meshVisualizer() {
         .setTransformationProjectionMatrix(projection)
         .draw(MeshTools::compile(Primitives::icosphereSolid(1)));
 
-    return "meshvisualizer.png";
+    return "meshvisualizer3d.png";
 }
 
 std::string ShaderVisualizer::flat() {

doc/namespaces.dox

@@ -449,24 +449,21 @@ See @ref building, @ref cmake and @ref shaders for more information.
 
 @parblock
 
-@m_div{m-col-m-3 m-col-t-6 m-text-center m-nopadt m-nopadx}
-@image html shaders-flat.png
+@m_div{m-col-m-4 m-col-t-6 m-text-center m-nopadt m-nopadx}
+@image html shaders-flat.png width=256px
 @ref Flat @m_class{m-label m-success} **2D** @m_class{m-label m-primary} **3D**
 @m_enddiv
 
-@m_div{m-col-m-3 m-col-t-6 m-text-center m-nopadt m-nopadx}
-@image html shaders-phong.png
+@m_div{m-col-m-4 m-col-t-6 m-text-center m-nopadt m-nopadx}
+@image html shaders-phong.png width=256px
 @ref Phong @m_class{m-label m-primary} **3D**
 @m_enddiv
 
-@m_div{m-col-m-3 m-col-t-6 m-text-center m-nopadt m-nopadx}
-@image html shaders-vertexcolor.png
-@ref VertexColor @m_class{m-label m-success} **2D** @m_class{m-label m-primary} **3D**
-@m_enddiv
+@m_div{m-clearfix-t} @m_enddiv
 
-@m_div{m-col-m-3 m-col-t-6 m-text-center m-nopadt m-nopadx}
-@image html shaders-meshvisualizer.png
-@ref MeshVisualizer @m_class{m-label m-primary} **3D**
+@m_div{m-col-m-4 m-push-t-3 m-push-m-0 m-col-t-6 m-text-center m-nopadt m-nopadx}
+@image html shaders-vertexcolor.png width=256px
+@ref VertexColor @m_class{m-label m-success} **2D** @m_class{m-label m-primary} **3D**
 @m_enddiv
 
 @endparblock
@@ -475,13 +472,25 @@ See @ref building, @ref cmake and @ref shaders for more information.
 
 @parblock
 
-@m_div{m-col-m-3 m-push-m-3 m-col-t-6 m-text-center m-nopadt m-nopadx}
-@image html shaders-vector.png
+@m_div{m-clearfix-m} @m_enddiv
+
+@m_div{m-col-m-3 m-col-t-6 m-text-center m-nopadt m-nopadx}
+@image html shaders-meshvisualizer2d.png width=256px
+@ref MeshVisualizer2D "MeshVisualizer2D" @m_class{m-label m-success} **2D**
+@m_enddiv
+
+@m_div{m-col-m-3 m-col-t-6 m-text-center m-nopadt m-nopadx}
+@image html shaders-meshvisualizer3d.png width=256px
+@ref MeshVisualizer3D "MeshVisualizer3D" @m_class{m-label m-primary} **3D**
+@m_enddiv
+
+@m_div{m-col-m-3 m-col-t-6 m-text-center m-nopadt m-nopadx}
+@image html shaders-vector.png width=256px
 @ref Vector @m_class{m-label m-success} **2D** @m_class{m-label m-primary} **3D**
 @m_enddiv
 
-@m_div{m-col-m-3 m-push-m-3 m-col-t-6 m-text-center m-nopadt m-nopadx}
-@image html shaders-distancefieldvector.png
+@m_div{m-col-m-3 m-col-t-6 m-text-center m-nopadt m-nopadx}
+@image html shaders-distancefieldvector.png width=256px
 @ref DistanceFieldVector @m_class{m-label m-success} **2D** @m_class{m-label m-primary} **3D**
 @m_enddiv
 

doc/snippets/MagnumShaders.cpp

@@ -95,7 +95,7 @@ mesh.addVertexBuffer(vertices, 0,
 /* [shaders-generic] */
 
 /* [shaders-meshvisualizer] */
-Shaders::MeshVisualizer visualizerShader{Shaders::MeshVisualizer::Flag::Wireframe};
+Shaders::MeshVisualizer3D visualizerShader{Shaders::MeshVisualizer3D::Flag::Wireframe};
 visualizerShader
     .setColor(0x2f83cc_rgbf)
     .setWireframeColor(0xdcdcdc_rgbf)
@@ -254,7 +254,7 @@ GL::Buffer vertices;
 vertices.setData(data, GL::BufferUsage::StaticDraw);
 
 GL::Mesh mesh;
-mesh.addVertexBuffer(vertices, 0, Shaders::MeshVisualizer::Position{});
+mesh.addVertexBuffer(vertices, 0, Shaders::MeshVisualizer3D::Position{});
 /* [MeshVisualizer-usage-geom1] */
 
 /* [MeshVisualizer-usage-geom2] */
@@ -262,7 +262,7 @@ Matrix4 transformationMatrix = Matrix4::translation(Vector3::zAxis(-5.0f));
 Matrix4 projectionMatrix =
     Matrix4::perspectiveProjection(35.0_degf, 1.0f, 0.001f, 100.0f);
 
-Shaders::MeshVisualizer shader{Shaders::MeshVisualizer::Flag::Wireframe};
+Shaders::MeshVisualizer3D shader{Shaders::MeshVisualizer3D::Flag::Wireframe};
 shader.setColor(0x2f83cc_rgbf)
     .setWireframeColor(0xdcdcdc_rgbf)
     .setViewportSize(Vector2{GL::defaultFramebuffer.viewport().size()})
@@ -277,7 +277,7 @@ std::iota(vertexIndex.begin(), vertexIndex.end(), 0.0f);
 GL::Buffer vertexIndices;
 vertexIndices.setData(vertexIndex, GL::BufferUsage::StaticDraw);
 
-mesh.addVertexBuffer(vertexIndices, 0, Shaders::MeshVisualizer::VertexIndex{});
+mesh.addVertexBuffer(vertexIndices, 0, Shaders::MeshVisualizer3D::VertexIndex{});
 /* [MeshVisualizer-usage-no-geom-old] */
 }
 #endif
@@ -291,7 +291,7 @@ Containers::StridedArrayView1D<const Vector3> indexedPositions;
 GL::Buffer vertices{MeshTools::duplicate(indices, indexedPositions)};
 
 GL::Mesh mesh;
-mesh.addVertexBuffer(vertices, 0, Shaders::MeshVisualizer::Position{});
+mesh.addVertexBuffer(vertices, 0, Shaders::MeshVisualizer3D::Position{});
 /* [MeshVisualizer-usage-no-geom1] */
 }
 
@@ -300,8 +300,9 @@ GL::Mesh mesh;
 /* [MeshVisualizer-usage-no-geom2] */
 Matrix4 transformationMatrix, projectionMatrix;
 
-Shaders::MeshVisualizer shader{Shaders::MeshVisualizer::Flag::Wireframe|
-                               Shaders::MeshVisualizer::Flag::NoGeometryShader};
+Shaders::MeshVisualizer3D shader{
+    Shaders::MeshVisualizer3D::Flag::Wireframe|
+    Shaders::MeshVisualizer3D::Flag::NoGeometryShader};
 shader.setColor(0x2f83cc_rgbf)
     .setWireframeColor(0xdcdcdc_rgbf)
     .setTransformationProjectionMatrix(projectionMatrix*transformationMatrix)

src/Magnum/Shaders/MeshVisualizer.cpp

@@ -31,6 +31,7 @@
 #include <Corrade/Utility/Resource.h>
 
 #include "Magnum/Math/Color.h"
+#include "Magnum/Math/Matrix3.h"
 #include "Magnum/Math/Matrix4.h"
 #include "Magnum/GL/Context.h"
 #include "Magnum/GL/Extensions.h"
@@ -40,9 +41,11 @@
 
 namespace Magnum { namespace Shaders {
 
-MeshVisualizer::MeshVisualizer(const Flags flags): _flags{flags} {
+namespace Implementation {
+
+MeshVisualizerBase::MeshVisualizerBase(FlagsBase flags): _flags{flags} {
     #ifndef MAGNUM_TARGET_GLES2
-    if(flags & Flag::Wireframe && !(flags & Flag::NoGeometryShader)) {
+    if(_flags & FlagBase::Wireframe && !(_flags & FlagBase::NoGeometryShader)) {
         #ifndef MAGNUM_TARGET_GLES
         MAGNUM_ASSERT_GL_VERSION_SUPPORTED(GL::Version::GL320);
         MAGNUM_ASSERT_GL_EXTENSION_SUPPORTED(GL::Extensions::ARB::geometry_shader4);
@@ -51,7 +54,7 @@ MeshVisualizer::MeshVisualizer(const Flags flags): _flags{flags} {
         #endif
     }
     #else
-    if(_flags & Flag::Wireframe)
+    if(_flags & FlagBase::Wireframe)
         MAGNUM_ASSERT_GL_EXTENSION_SUPPORTED(GL::Extensions::OES::standard_derivatives);
     #endif
 
@@ -60,34 +63,85 @@ MeshVisualizer::MeshVisualizer(const Flags flags): _flags{flags} {
     if(!Utility::Resource::hasGroup("MagnumShaders"))
         importShaderResources();
     #endif
-    Utility::Resource rs("MagnumShaders");
+}
 
+GL::Version MeshVisualizerBase::setupShaders(GL::Shader& vert, GL::Shader& frag, const Utility::Resource& rs) const {
     #ifndef MAGNUM_TARGET_GLES
     const GL::Version version = GL::Context::current().supportedVersion({GL::Version::GL320, GL::Version::GL310, GL::Version::GL300, GL::Version::GL210});
-    CORRADE_INTERNAL_ASSERT(!flags || flags & Flag::NoGeometryShader || version >= GL::Version::GL320);
+    CORRADE_INTERNAL_ASSERT(!_flags || _flags & FlagBase::NoGeometryShader || version >= GL::Version::GL320);
     #elif !defined(MAGNUM_TARGET_WEBGL)
     const GL::Version version = GL::Context::current().supportedVersion({GL::Version::GLES310, GL::Version::GLES300, GL::Version::GLES200});
-    CORRADE_INTERNAL_ASSERT(!flags || flags & Flag::NoGeometryShader || version >= GL::Version::GLES310);
+    CORRADE_INTERNAL_ASSERT(!_flags || _flags & FlagBase::NoGeometryShader || version >= GL::Version::GLES310);
     #else
     const GL::Version version = GL::Context::current().supportedVersion({GL::Version::GLES300, GL::Version::GLES200});
     #endif
 
-    GL::Shader vert = Implementation::createCompatibilityShader(rs, version, GL::Shader::Type::Vertex);
-    GL::Shader frag = Implementation::createCompatibilityShader(rs, version, GL::Shader::Type::Fragment);
+    vert = Implementation::createCompatibilityShader(rs, version, GL::Shader::Type::Vertex);
+    frag = Implementation::createCompatibilityShader(rs, version, GL::Shader::Type::Fragment);
 
-    vert.addSource(flags & Flag::Wireframe ? "#define WIREFRAME_RENDERING\n" : "")
-        .addSource(flags & Flag::NoGeometryShader ? "#define NO_GEOMETRY_SHADER\n" : "")
+    vert.addSource(_flags & FlagBase::Wireframe ? "#define WIREFRAME_RENDERING\n" : "")
+        .addSource(_flags & FlagBase::NoGeometryShader ? "#define NO_GEOMETRY_SHADER\n" : "")
         #ifdef MAGNUM_TARGET_WEBGL
         .addSource("#define SUBSCRIPTING_WORKAROUND\n")
         #elif defined(MAGNUM_TARGET_GLES2)
         .addSource(GL::Context::current().detectedDriver() & GL::Context::DetectedDriver::Angle ?
             "#define SUBSCRIPTING_WORKAROUND\n" : "")
         #endif
+        ;
+    frag.addSource(_flags & FlagBase::Wireframe ? "#define WIREFRAME_RENDERING\n" : "")
+        .addSource(_flags & FlagBase::NoGeometryShader ? "#define NO_GEOMETRY_SHADER\n" : "");
+
+    return version;
+}
+
+MeshVisualizerBase& MeshVisualizerBase::setViewportSize(const Vector2& size) {
+    /* Not asserting here, since the relation to wireframe is a bit vague.
+       Also it's an ugly hack that should be removed, ideally. */
+    if(_flags & FlagBase::Wireframe && !(_flags & FlagBase::NoGeometryShader))
+        setUniform(_viewportSizeUniform, size);
+    return *this;
+}
+
+MeshVisualizerBase& MeshVisualizerBase::setColor(const Color4& color) {
+    setUniform(_colorUniform, color);
+    return *this;
+}
+
+MeshVisualizerBase& MeshVisualizerBase::setWireframeColor(const Color4& color) {
+    CORRADE_ASSERT(_flags & FlagBase::Wireframe,
+        "Shaders::MeshVisualizer::setWireframeColor(): the shader was not created with wireframe enabled", *this);
+    setUniform(_wireframeColorUniform, color);
+    return *this;
+}
+
+MeshVisualizerBase& MeshVisualizerBase::setWireframeWidth(const Float width) {
+    CORRADE_ASSERT(_flags & FlagBase::Wireframe,
+        "Shaders::MeshVisualizer::setWireframeWidth(): the shader was not created with wireframe enabled", *this);
+    setUniform(_wireframeWidthUniform, width);
+    return *this;
+}
+
+MeshVisualizerBase& MeshVisualizerBase::setSmoothness(const Float smoothness) {
+    /* This is a bit vaguely related too, but less vague than setViewportSize()
+       so asserting. */
+    CORRADE_ASSERT(_flags & FlagBase::Wireframe,
+        "Shaders::MeshVisualizer::setSmoothness(): the shader was not created with wireframe enabled", *this);
+    setUniform(_smoothnessUniform, smoothness);
+    return *this;
+}
+
+}
+
+MeshVisualizer2D::MeshVisualizer2D(const Flags flags): Implementation::MeshVisualizerBase{Implementation::MeshVisualizerBase::FlagBase(UnsignedByte(flags))} {
+    Utility::Resource rs{"MagnumShaders"};
+    GL::Shader vert{NoCreate};
+    GL::Shader frag{NoCreate};
+    const GL::Version version = setupShaders(vert, frag, rs);
+
+    vert.addSource("#define TWO_DIMENSIONS\n")
         .addSource(rs.get("generic.glsl"))
         .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"))
+    frag.addSource(rs.get("generic.glsl"))
         .addSource(rs.get("MeshVisualizer.frag"));
 
     #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
@@ -96,6 +150,8 @@ MeshVisualizer::MeshVisualizer(const Flags flags): _flags{flags} {
         geom = Implementation::createCompatibilityShader(rs, version, GL::Shader::Type::Geometry);
         geom->addSource(rs.get("MeshVisualizer.geom"));
     }
+    #else
+    static_cast<void>(version);
     #endif
 
     #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
@@ -149,7 +205,7 @@ MeshVisualizer::MeshVisualizer(const Flags flags): _flags{flags} {
     #ifdef MAGNUM_TARGET_GLES
     setTransformationProjectionMatrix({});
     setColor(Color3(1.0f));
-    if(_flags & Flag::Wireframe) {
+    if(flags & Flag::Wireframe) {
         /* Viewport size is zero by default */
         setWireframeColor(Color3{0.0f});
         setWireframeWidth(1.0f);
@@ -158,53 +214,119 @@ MeshVisualizer::MeshVisualizer(const Flags flags): _flags{flags} {
     #endif
 }
 
-MeshVisualizer& MeshVisualizer::setTransformationProjectionMatrix(const Matrix4& matrix) {
+MeshVisualizer2D& MeshVisualizer2D::setTransformationProjectionMatrix(const Matrix3& matrix) {
     setUniform(_transformationProjectionMatrixUniform, matrix);
     return *this;
 }
 
-MeshVisualizer& MeshVisualizer::setViewportSize(const Vector2& size) {
-    /* Not asserting here, since the relation to wireframe is a bit vague.
-       Also it's an ugly hack that should be removed, ideally. */
-    if(_flags & Flag::Wireframe && !(_flags & Flag::NoGeometryShader))
-        setUniform(_viewportSizeUniform, size);
-    return *this;
-}
+MeshVisualizer3D::MeshVisualizer3D(const Flags flags): Implementation::MeshVisualizerBase{Implementation::MeshVisualizerBase::FlagBase(UnsignedByte(flags))} {
+    Utility::Resource rs{"MagnumShaders"};
+    GL::Shader vert{NoCreate};
+    GL::Shader frag{NoCreate};
+    const GL::Version version = setupShaders(vert, frag, rs);
 
-MeshVisualizer& MeshVisualizer::setColor(const Color4& color) {
-    setUniform(_colorUniform, color);
-    return *this;
-}
+    vert.addSource("#define THREE_DIMENSIONS\n")
+        .addSource(rs.get("generic.glsl"))
+        .addSource(rs.get("MeshVisualizer.vert"));
+    frag.addSource(rs.get("generic.glsl"))
+        .addSource(rs.get("MeshVisualizer.frag"));
 
-MeshVisualizer& MeshVisualizer::setWireframeColor(const Color4& color) {
-    CORRADE_ASSERT(_flags & Flag::Wireframe,
-        "Shaders::MeshVisualizer::setWireframeColor(): the shader was not created with wireframe enabled", *this);
-    setUniform(_wireframeColorUniform, color);
-    return *this;
+    #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+    Containers::Optional<GL::Shader> geom;
+    if(flags & Flag::Wireframe && !(flags & Flag::NoGeometryShader)) {
+        geom = Implementation::createCompatibilityShader(rs, version, GL::Shader::Type::Geometry);
+        geom->addSource(rs.get("MeshVisualizer.geom"));
+    }
+    #else
+    static_cast<void>(version);
+    #endif
+
+    #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+    if(geom) CORRADE_INTERNAL_ASSERT_OUTPUT(GL::Shader::compile({vert, *geom, frag}));
+    else
+    #endif
+        CORRADE_INTERNAL_ASSERT_OUTPUT(GL::Shader::compile({vert, frag}));
+
+    attachShaders({vert, frag});
+    #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+    if(geom) attachShader(*geom);
+    #endif
+
+    /* ES3 has this done in the shader directly */
+    #if !defined(MAGNUM_TARGET_GLES) || defined(MAGNUM_TARGET_GLES2)
+    #ifndef MAGNUM_TARGET_GLES
+    if(!GL::Context::current().isExtensionSupported<GL::Extensions::ARB::explicit_attrib_location>(version))
+    #endif
+    {
+        bindAttributeLocation(Position::Location, "position");
+
+        #if !defined(MAGNUM_TARGET_GLES) || defined(MAGNUM_TARGET_GLES2)
+        #ifndef MAGNUM_TARGET_GLES
+        if(!GL::Context::current().isVersionSupported(GL::Version::GL310))
+        #endif
+        {
+            bindAttributeLocation(VertexIndex::Location, "vertexIndex");
+        }
+        #endif
+    }
+    #endif
+
+    CORRADE_INTERNAL_ASSERT_OUTPUT(link());
+
+    #ifndef MAGNUM_TARGET_GLES
+    if(!GL::Context::current().isExtensionSupported<GL::Extensions::ARB::explicit_uniform_location>(version))
+    #endif
+    {
+        _transformationProjectionMatrixUniform = uniformLocation("transformationProjectionMatrix");
+        _colorUniform = uniformLocation("color");
+        if(flags & Flag::Wireframe) {
+            _wireframeColorUniform = uniformLocation("wireframeColor");
+            _wireframeWidthUniform = uniformLocation("wireframeWidth");
+            _smoothnessUniform = uniformLocation("smoothness");
+            if(!(flags & Flag::NoGeometryShader))
+                _viewportSizeUniform = uniformLocation("viewportSize");
+        }
+    }
+
+    /* Set defaults in OpenGL ES (for desktop they are set in shader code itself) */
+    #ifdef MAGNUM_TARGET_GLES
+    setTransformationProjectionMatrix({});
+    setColor(Color3(1.0f));
+    if(flags & Flag::Wireframe) {
+        /* Viewport size is zero by default */
+        setWireframeColor(Color3{0.0f});
+        setWireframeWidth(1.0f);
+        setSmoothness(2.0f);
+    }
+    #endif
 }
 
-MeshVisualizer& MeshVisualizer::setWireframeWidth(const Float width) {
-    CORRADE_ASSERT(_flags & Flag::Wireframe,
-        "Shaders::MeshVisualizer::setWireframeWidth(): the shader was not created with wireframe enabled", *this);
-    setUniform(_wireframeWidthUniform, width);
+MeshVisualizer3D& MeshVisualizer3D::setTransformationProjectionMatrix(const Matrix4& matrix) {
+    setUniform(_transformationProjectionMatrixUniform, matrix);
     return *this;
 }
 
-MeshVisualizer& MeshVisualizer::setSmoothness(const Float smoothness) {
-    /* This is a bit vaguely related too, but less vague than setViewportSize()
-       so asserting. */
-    CORRADE_ASSERT(_flags & Flag::Wireframe,
-        "Shaders::MeshVisualizer::setSmoothness(): the shader was not created with wireframe enabled", *this);
-    setUniform(_smoothnessUniform, smoothness);
-    return *this;
+Debug& operator<<(Debug& debug, const MeshVisualizer2D::Flag value) {
+    debug << "Shaders::MeshVisualizer2D::Flag" << Debug::nospace;
+
+    switch(value) {
+        /* LCOV_EXCL_START */
+        #define _c(v) case MeshVisualizer2D::Flag::v: return debug << "::" #v;
+        _c(NoGeometryShader)
+        _c(Wireframe)
+        #undef _c
+        /* LCOV_EXCL_STOP */
+    }
+
+    return debug << "(" << Debug::nospace << reinterpret_cast<void*>(UnsignedByte(value)) << Debug::nospace << ")";
 }
 
-Debug& operator<<(Debug& debug, const MeshVisualizer::Flag value) {
-    debug << "Shaders::MeshVisualizer::Flag" << Debug::nospace;
+Debug& operator<<(Debug& debug, const MeshVisualizer3D::Flag value) {
+    debug << "Shaders::MeshVisualizer3D::Flag" << Debug::nospace;
 
     switch(value) {
         /* LCOV_EXCL_START */
-        #define _c(v) case MeshVisualizer::Flag::v: return debug << "::" #v;
+        #define _c(v) case MeshVisualizer3D::Flag::v: return debug << "::" #v;
         _c(NoGeometryShader)
         _c(Wireframe)
         #undef _c
@@ -214,11 +336,19 @@ Debug& operator<<(Debug& debug, const MeshVisualizer::Flag value) {
     return debug << "(" << Debug::nospace << reinterpret_cast<void*>(UnsignedByte(value)) << Debug::nospace << ")";
 }
 
-Debug& operator<<(Debug& debug, const MeshVisualizer::Flags value) {
-    return Containers::enumSetDebugOutput(debug, value, "Shaders::MeshVisualizer::Flags{}", {
-        MeshVisualizer::Flag::Wireframe,
+Debug& operator<<(Debug& debug, const MeshVisualizer2D::Flags value) {
+    return Containers::enumSetDebugOutput(debug, value, "Shaders::MeshVisualizer2D::Flags{}", {
+        MeshVisualizer2D::Flag::Wireframe,
+        /* Wireframe contains this on ES2 so it's not reported there */
+        MeshVisualizer2D::Flag::NoGeometryShader
+    });
+}
+
+Debug& operator<<(Debug& debug, const MeshVisualizer3D::Flags value) {
+    return Containers::enumSetDebugOutput(debug, value, "Shaders::MeshVisualizer3D::Flags{}", {
+        MeshVisualizer3D::Flag::Wireframe,
         /* Wireframe contains this on ES2 so it's not reported there */
-        MeshVisualizer::Flag::NoGeometryShader
+        MeshVisualizer3D::Flag::NoGeometryShader
     });
 }
 

src/Magnum/Shaders/MeshVisualizer.h

@@ -26,25 +26,248 @@
 */
 
 /** @file
- * @brief Class @ref Magnum::Shaders::MeshVisualizer
+ * @brief Class @ref Magnum::Shaders::MeshVisualizer2D, @ref Magnum::Shaders::MeshVisualizer3D
  */
 
+#include <Corrade/Utility/Utility.h>
+
+#include "Magnum/DimensionTraits.h"
 #include "Magnum/GL/AbstractShaderProgram.h"
 #include "Magnum/Shaders/Generic.h"
 #include "Magnum/Shaders/visibility.h"
 
 namespace Magnum { namespace Shaders {
 
+namespace Implementation {
+
+class MAGNUM_SHADERS_EXPORT MeshVisualizerBase: public GL::AbstractShaderProgram {
+    protected:
+        enum class FlagBase: UnsignedByte {
+            #ifndef MAGNUM_TARGET_GLES2
+            Wireframe = 1 << 0,
+            #else
+            Wireframe = (1 << 0) | (1 << 1),
+            #endif
+            NoGeometryShader = 1 << 1
+        };
+        typedef Containers::EnumSet<FlagBase> FlagsBase;
+
+        CORRADE_ENUMSET_FRIEND_OPERATORS(FlagsBase)
+
+        explicit MeshVisualizerBase(FlagsBase flags);
+        explicit MeshVisualizerBase(NoCreateT) noexcept: GL::AbstractShaderProgram{NoCreate} {}
+
+        MAGNUM_SHADERS_LOCAL GL::Version setupShaders(GL::Shader& vert, GL::Shader& frag, const Utility::Resource& rs) const;
+
+        MeshVisualizerBase& setViewportSize(const Vector2& size);
+        MeshVisualizerBase& setColor(const Color4& color);
+        MeshVisualizerBase& setWireframeColor(const Color4& color);
+        MeshVisualizerBase& setWireframeWidth(Float width);
+        MeshVisualizerBase& setSmoothness(Float smoothness);
+
+        /* Prevent accidentally calling irrelevant functions */
+        #ifndef MAGNUM_TARGET_GLES
+        using GL::AbstractShaderProgram::drawTransformFeedback;
+        #endif
+        #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+        using GL::AbstractShaderProgram::dispatchCompute;
+        #endif
+
+        FlagsBase _flags;
+        Int _colorUniform{1},
+            _wireframeColorUniform{2},
+            _wireframeWidthUniform{3},
+            _smoothnessUniform{4},
+            _viewportSizeUniform{5};
+};
+
+}
+
 /**
-@brief Mesh visualization shader
+@brief 2D mesh visualization shader
+@m_since_latest
 
-Uses geometry shader to visualize wireframe of 3D meshes. You need to provide
-the @ref Position attribute in your triangle mesh. By default, the shader
-renders the mesh with a white color in an identity transformation. Use
+Uses the geometry shader to visualize wireframe of 3D meshes. You need to
+provide the @ref Position attribute in your triangle mesh. By default, the
+shader renders the mesh with a white color in an identity transformation. Use
 @ref setTransformationProjectionMatrix(), @ref setColor() and others to
 configure the shader.
 
-@image html shaders-meshvisualizer.png width=256px
+@image html shaders-meshvisualizer2d.png width=256px
+
+This shader is a 2D variant of @ref MeshVisualizer3D with mostly identical
+workflow. See its documentation for more information.
+*/
+class MAGNUM_SHADERS_EXPORT MeshVisualizer2D: public Implementation::MeshVisualizerBase {
+    public:
+        /**
+         * @brief Vertex position
+         *
+         * @ref shaders-generic "Generic attribute",
+         * @ref Magnum::Vector2 "Vector2".
+         */
+        typedef typename Generic2D::Position Position;
+
+        /**
+         * @brief Vertex index
+         *
+         * See @ref MeshVisualizer3D::VertexIndex for more information.
+         */
+        typedef GL::Attribute<4, 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 = Generic2D::ColorOutput
+        };
+
+        /**
+         * @brief Flag
+         *
+         * @see @ref Flags, @ref MeshVisualizer2D()
+         */
+        enum class Flag: UnsignedByte {
+            /**
+             * Visualize wireframe. On OpenGL ES 2.0 this also enables
+             * @ref Flag::NoGeometryShader.
+             */
+            #ifndef MAGNUM_TARGET_GLES2
+            Wireframe = 1 << 0,
+            #else
+            Wireframe = (1 << 0) | (1 << 1),
+            #endif
+
+            /**
+             * Don't use a geometry shader for wireframe visualization. If
+             * enabled, you might need to provide also the @ref VertexIndex
+             * attribute in the mesh. In OpenGL ES 2.0 enabled alongside
+             * @ref Flag::Wireframe.
+             */
+            NoGeometryShader = 1 << 1
+        };
+
+        /** @brief Flags */
+        typedef Containers::EnumSet<Flag> Flags;
+
+        /**
+         * @brief Constructor
+         * @param flags     Flags
+         */
+        explicit MeshVisualizer2D(Flags flags = {});
+
+        /**
+         * @brief Construct without creating the underlying OpenGL object
+         *
+         * The constructed instance is equivalent to a moved-from state. Useful
+         * in cases where you will overwrite the instance later anyway. Move
+         * another object over it to make it useful.
+         *
+         * This function can be safely used for constructing (and later
+         * destructing) objects even without any OpenGL context being active.
+         * However note that this is a low-level and a potentially dangerous
+         * API, see the documentation of @ref NoCreate for alternatives.
+         */
+        explicit MeshVisualizer2D(NoCreateT) noexcept: Implementation::MeshVisualizerBase{NoCreate} {}
+
+        /** @brief Copying is not allowed */
+        MeshVisualizer2D(const MeshVisualizer2D&) = delete;
+
+        /** @brief Move constructor */
+        MeshVisualizer2D(MeshVisualizer2D&&) noexcept = default;
+
+        /** @brief Copying is not allowed */
+        MeshVisualizer2D& operator=(const MeshVisualizer2D&) = delete;
+
+        /** @brief Move assignment */
+        MeshVisualizer2D& operator=(MeshVisualizer2D&&) noexcept = default;
+
+        /** @brief Flags */
+        Flags flags() const {
+            return reinterpret_cast<const Flags&>(Implementation::MeshVisualizerBase::_flags);
+        }
+
+        /**
+         * @brief Set transformation and projection matrix
+         * @return Reference to self (for method chaining)
+         *
+         * Initial value is an identity matrix.
+         */
+        MeshVisualizer2D& setTransformationProjectionMatrix(const Matrix3& matrix);
+
+        /**
+         * @brief Set viewport size
+         * @return Reference to self (for method chaining)
+         *
+         * Has effect only if @ref Flag::Wireframe is enabled and geometry
+         * shaders are used, otherwise it does nothing. Initial value is a zero
+         * vector.
+         */
+        MeshVisualizer2D& setViewportSize(const Vector2& size) {
+            return static_cast<MeshVisualizer2D&>(Implementation::MeshVisualizerBase::setViewportSize(size));
+        }
+
+        /**
+         * @brief Set base object color
+         * @return Reference to self (for method chaining)
+         *
+         * Initial value is @cpp 0xffffffff_rgbaf @ce.
+         */
+        MeshVisualizer2D& setColor(const Color4& color) {
+            return static_cast<MeshVisualizer2D&>(Implementation::MeshVisualizerBase::setColor(color));
+        }
+
+        /**
+         * @brief Set wireframe color
+         * @return Reference to self (for method chaining)
+         *
+         * Initial value is @cpp 0x000000ff_rgbaf @ce. Expects that
+         * @ref Flag::Wireframe is enabled.
+         */
+        MeshVisualizer2D& setWireframeColor(const Color4& color) {
+            return static_cast<MeshVisualizer2D&>(Implementation::MeshVisualizerBase::setWireframeColor(color));
+        }
+
+        /**
+         * @brief Set wireframe width
+         * @return Reference to self (for method chaining)
+         *
+         * Value is in screen space (depending on @ref setViewportSize()),
+         * initial value is @cpp 1.0f @ce. Expects that @ref Flag::Wireframe is
+         * enabled.
+         */
+        MeshVisualizer2D& setWireframeWidth(Float width) {
+            return static_cast<MeshVisualizer2D&>(Implementation::MeshVisualizerBase::setWireframeWidth(width));
+        }
+
+        /**
+         * @brief Set line smoothness
+         * @return Reference to self (for method chaining)
+         *
+         * Value is in screen space (depending on @ref setViewportSize()),
+         * initial value is @cpp 2.0f @ce. Expects that @ref Flag::Wireframe is
+         * enabled.
+         */
+        MeshVisualizer2D& setSmoothness(Float smoothness) {
+            return static_cast<MeshVisualizer2D&>(Implementation::MeshVisualizerBase::setSmoothness(smoothness));
+        }
+
+    private:
+        Int _transformationProjectionMatrixUniform{0};
+};
+
+/**
+@brief 3D mesh visualization shader
+
+Uses the geometry shader to visualize wireframe of 3D meshes. You need to
+provide the @ref Position attribute in your triangle mesh. By default, the
+shader renders the mesh with a white color in an identity transformation. Use
+@ref setTransformationProjectionMatrix(), @ref setColor() and others to
+configure the shader.
+
+@image html shaders-meshvisualizer3d.png width=256px
 
 @section Shaders-MeshVisualizer-wireframe Wireframe visualization
 
@@ -100,10 +323,10 @@ addition to the above*:
 
 Rendering setup the same as above.
 
-@see @ref shaders
+@see @ref shaders, @ref MeshVisualizer2D
 @todo Understand and add support wireframe width/smoothness without GS
 */
-class MAGNUM_SHADERS_EXPORT MeshVisualizer: public GL::AbstractShaderProgram {
+class MAGNUM_SHADERS_EXPORT MeshVisualizer3D: public Implementation::MeshVisualizerBase {
     public:
         /**
          * @brief Vertex position
@@ -111,7 +334,7 @@ class MAGNUM_SHADERS_EXPORT MeshVisualizer: public GL::AbstractShaderProgram {
          * @ref shaders-generic "Generic attribute",
          * @ref Magnum::Vector3 "Vector3".
          */
-        typedef Generic3D::Position Position;
+        typedef typename Generic3D::Position Position;
 
         /**
          * @brief Vertex index
@@ -157,8 +380,8 @@ class MAGNUM_SHADERS_EXPORT MeshVisualizer: public GL::AbstractShaderProgram {
             #endif
 
             /**
-             * Don't use geometry shader for wireframe visualization. If
-             * enabled, you might need to provide also @ref VertexIndex
+             * Don't use a geometry shader for wireframe visualization. If
+             * enabled, you might need to provide also the @ref VertexIndex
              * attribute in the mesh. In OpenGL ES 2.0 enabled alongside
              * @ref Flag::Wireframe.
              */
@@ -172,7 +395,7 @@ class MAGNUM_SHADERS_EXPORT MeshVisualizer: public GL::AbstractShaderProgram {
          * @brief Constructor
          * @param flags     Flags
          */
-        explicit MeshVisualizer(Flags flags = {});
+        explicit MeshVisualizer3D(Flags flags = {});
 
         /**
          * @brief Construct without creating the underlying OpenGL object
@@ -186,22 +409,24 @@ class MAGNUM_SHADERS_EXPORT MeshVisualizer: public GL::AbstractShaderProgram {
          * However note that this is a low-level and a potentially dangerous
          * API, see the documentation of @ref NoCreate for alternatives.
          */
-        explicit MeshVisualizer(NoCreateT) noexcept: GL::AbstractShaderProgram{NoCreate} {}
+        explicit MeshVisualizer3D(NoCreateT) noexcept: Implementation::MeshVisualizerBase{NoCreate} {}
 
         /** @brief Copying is not allowed */
-        MeshVisualizer(const MeshVisualizer&) = delete;
+        MeshVisualizer3D(const MeshVisualizer3D&) = delete;
 
         /** @brief Move constructor */
-        MeshVisualizer(MeshVisualizer&&) noexcept = default;
+        MeshVisualizer3D(MeshVisualizer3D&&) noexcept = default;
 
         /** @brief Copying is not allowed */
-        MeshVisualizer& operator=(const MeshVisualizer&) = delete;
+        MeshVisualizer3D& operator=(const MeshVisualizer3D&) = delete;
 
         /** @brief Move assignment */
-        MeshVisualizer& operator=(MeshVisualizer&&) noexcept = default;
+        MeshVisualizer3D& operator=(MeshVisualizer3D&&) noexcept = default;
 
         /** @brief Flags */
-        Flags flags() const { return _flags; }
+        Flags flags() const {
+            return reinterpret_cast<const Flags&>(Implementation::MeshVisualizerBase::_flags);
+        }
 
         /**
          * @brief Set transformation and projection matrix
@@ -209,7 +434,7 @@ class MAGNUM_SHADERS_EXPORT MeshVisualizer: public GL::AbstractShaderProgram {
          *
          * Initial value is an identity matrix.
          */
-        MeshVisualizer& setTransformationProjectionMatrix(const Matrix4& matrix);
+        MeshVisualizer3D& setTransformationProjectionMatrix(const Matrix4& matrix);
 
         /**
          * @brief Set viewport size
@@ -218,7 +443,9 @@ class MAGNUM_SHADERS_EXPORT MeshVisualizer: public GL::AbstractShaderProgram {
          * Has effect only if @ref Flag::Wireframe is enabled and geometry
          * shaders are used. Initial value is a zero vector.
          */
-        MeshVisualizer& setViewportSize(const Vector2& size);
+        MeshVisualizer3D& setViewportSize(const Vector2& size) {
+            return static_cast<MeshVisualizer3D&>(Implementation::MeshVisualizerBase::setViewportSize(size));
+        }
 
         /**
          * @brief Set base object color
@@ -226,60 +453,70 @@ class MAGNUM_SHADERS_EXPORT MeshVisualizer: public GL::AbstractShaderProgram {
          *
          * Initial value is @cpp 0xffffffff_rgbaf @ce.
          */
-        MeshVisualizer& setColor(const Color4& color);
+        MeshVisualizer3D& setColor(const Color4& color) {
+            return static_cast<MeshVisualizer3D&>(Implementation::MeshVisualizerBase::setColor(color));
+        }
 
         /**
          * @brief Set wireframe color
          * @return Reference to self (for method chaining)
          *
-         * Initial value is @cpp 0x000000ff_rgbaf @ce. Has effect only if
+         * Initial value is @cpp 0x000000ff_rgbaf @ce. Expects that
          * @ref Flag::Wireframe is enabled.
          */
-        MeshVisualizer& setWireframeColor(const Color4& color);
+        MeshVisualizer3D& setWireframeColor(const Color4& color) {
+            return static_cast<MeshVisualizer3D&>(Implementation::MeshVisualizerBase::setWireframeColor(color));
+        }
 
         /**
          * @brief Set wireframe width
          * @return Reference to self (for method chaining)
          *
-         * Initial value is @cpp 1.0f @ce. Has effect only if @ref Flag::Wireframe
-         * is enabled.
+         * Initial value is @cpp 1.0f @ce. Has effect only if
+         * @ref Flag::Wireframe is enabled.
          */
-        MeshVisualizer& setWireframeWidth(Float width);
+        MeshVisualizer3D& setWireframeWidth(Float width) {
+            return static_cast<MeshVisualizer3D&>(Implementation::MeshVisualizerBase::setWireframeWidth(width));
+        }
 
         /**
          * @brief Set line smoothness
          * @return Reference to self (for method chaining)
          *
-         * Initial value is @cpp 2.0f @ce. Has effect only if @ref Flag::Wireframe
+         * Value is in screen space (depending on @ref setViewportSize()),
+         * initial value is @cpp 2.0f @ce. Expects that @ref Flag::Wireframe
          * is enabled.
          */
-        MeshVisualizer& setSmoothness(Float smoothness);
+        MeshVisualizer3D& setSmoothness(Float smoothness) {
+            return static_cast<MeshVisualizer3D&>(Implementation::MeshVisualizerBase::setSmoothness(smoothness));
+        }
 
     private:
-        /* Prevent accidentally calling irrelevant functions */
-        #ifndef MAGNUM_TARGET_GLES
-        using GL::AbstractShaderProgram::drawTransformFeedback;
-        #endif
-        #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
-        using GL::AbstractShaderProgram::dispatchCompute;
-        #endif
-
-        Flags _flags;
-        Int _transformationProjectionMatrixUniform{0},
-            _colorUniform{1},
-            _wireframeColorUniform{2},
-            _wireframeWidthUniform{3},
-            _smoothnessUniform{4},
-            _viewportSizeUniform{5};
+        Int _transformationProjectionMatrixUniform{0};
 };
 
-/** @debugoperatorclassenum{MeshVisualizer,MeshVisualizer::Flag} */
-MAGNUM_SHADERS_EXPORT Debug& operator<<(Debug& debug, MeshVisualizer::Flag value);
+#ifdef MAGNUM_BUILD_DEPRECATED
+/**
+@brief 3D mesh visualizer shader
+@m_deprecated_since_latest Use @ref MeshVisualizer3D instead.
+*/
+typedef CORRADE_DEPRECATED("use MeshVisualizer3D instead") MeshVisualizer3D MeshVisualizer;
+#endif
+
+/** @debugoperatorclassenum{MeshVisualizer2D,MeshVisualizer2D::Flag} */
+MAGNUM_SHADERS_EXPORT Debug& operator<<(Debug& debug, MeshVisualizer2D::Flag value);
+
+/** @debugoperatorclassenum{MeshVisualizer3D,MeshVisualizer3D::Flag} */
+MAGNUM_SHADERS_EXPORT Debug& operator<<(Debug& debug, MeshVisualizer3D::Flag value);
+
+/** @debugoperatorclassenum{MeshVisualizer2D,MeshVisualizer2D::Flags} */
+MAGNUM_SHADERS_EXPORT Debug& operator<<(Debug& debug, MeshVisualizer2D::Flags value);
 
-/** @debugoperatorclassenum{MeshVisualizer,MeshVisualizer::Flags} */
-MAGNUM_SHADERS_EXPORT Debug& operator<<(Debug& debug, MeshVisualizer::Flags value);
+/** @debugoperatorclassenum{MeshVisualizer3D,MeshVisualizer3D::Flags} */
+MAGNUM_SHADERS_EXPORT Debug& operator<<(Debug& debug, MeshVisualizer3D::Flags value);
 
-CORRADE_ENUMSET_OPERATORS(MeshVisualizer::Flags)
+CORRADE_ENUMSET_OPERATORS(MeshVisualizer2D::Flags)
+CORRADE_ENUMSET_OPERATORS(MeshVisualizer3D::Flags)
 
 }}
 

src/Magnum/Shaders/MeshVisualizer.vert

@@ -31,16 +31,32 @@
 #ifdef EXPLICIT_UNIFORM_LOCATION
 layout(location = 0)
 #endif
+#ifdef TWO_DIMENSIONS
+uniform highp mat3 transformationProjectionMatrix
+    #ifndef GL_ES
+    = mat3(1.0)
+    #endif
+    ;
+#elif defined(THREE_DIMENSIONS)
 uniform highp mat4 transformationProjectionMatrix
     #ifndef GL_ES
     = mat4(1.0)
     #endif
     ;
+#else
+#error
+#endif
 
 #ifdef EXPLICIT_ATTRIB_LOCATION
 layout(location = POSITION_ATTRIBUTE_LOCATION)
 #endif
+#ifdef TWO_DIMENSIONS
+in highp vec2 position;
+#elif defined(THREE_DIMENSIONS)
 in highp vec4 position;
+#else
+#error
+#endif
 
 #if defined(WIREFRAME_RENDERING) && defined(NO_GEOMETRY_SHADER)
 #if (!defined(GL_ES) && __VERSION__ < 140) || (defined(GL_ES) && __VERSION__ < 300)
@@ -55,7 +71,13 @@ out vec3 barycentric;
 #endif
 
 void main() {
+    #ifdef TWO_DIMENSIONS
+    gl_Position.xywz = vec4(transformationProjectionMatrix*vec3(position, 1.0), 0.0);
+    #elif defined(THREE_DIMENSIONS)
     gl_Position = transformationProjectionMatrix*position;
+    #else
+    #error
+    #endif
 
     #if defined(WIREFRAME_RENDERING) && defined(NO_GEOMETRY_SHADER)
     barycentric = vec3(0.0);

src/Magnum/Shaders/Shaders.h

@@ -31,6 +31,10 @@
 
 #include "Magnum/Types.h"
 
+#ifdef MAGNUM_BUILD_DEPRECATED
+#include <Corrade/Utility/Macros.h>
+#endif
+
 namespace Magnum { namespace Shaders {
 
 #ifndef DOXYGEN_GENERATING_OUTPUT
@@ -48,7 +52,12 @@ typedef Flat<3> Flat3D;
 
 /* Generic is used only statically */
 
-class MeshVisualizer;
+class MeshVisualizer2D;
+class MeshVisualizer3D;
+#ifdef MAGNUM_BUILD_DEPRECATED
+typedef CORRADE_DEPRECATED("use MeshVisualizer3D instead") MeshVisualizer3D MeshVisualizer;
+#endif
+
 class Phong;
 
 template<UnsignedInt> class Vector;

src/Magnum/Shaders/Test/CMakeLists.txt

@@ -153,10 +153,14 @@ if(BUILD_GL_TESTS)
         FILES
             FlatTestFiles/defaults.tga
             FlatTestFiles/colored3D.tga
-            MeshVisualizerTestFiles/defaults-wireframe.tga
-            MeshVisualizerTestFiles/wireframe.tga
-            MeshVisualizerTestFiles/wireframe-nogeo.tga
-            MeshVisualizerTestFiles/wireframe-wide.tga)
+            MeshVisualizerTestFiles/defaults-wireframe2D.tga
+            MeshVisualizerTestFiles/defaults-wireframe3D.tga
+            MeshVisualizerTestFiles/wireframe2D.tga
+            MeshVisualizerTestFiles/wireframe3D.tga
+            MeshVisualizerTestFiles/wireframe-nogeo2D.tga
+            MeshVisualizerTestFiles/wireframe-nogeo3D.tga
+            MeshVisualizerTestFiles/wireframe-wide2D.tga
+            MeshVisualizerTestFiles/wireframe-wide3D.tga)
     target_include_directories(ShadersMeshVisualizerGLTest PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>)
     if(BUILD_PLUGINS_STATIC)
         if(WITH_ANYIMAGEIMPORTER)

src/Magnum/Shaders/Test/MeshVisualizerGLTest.cpp

@@ -43,9 +43,11 @@
 #include "Magnum/ImageView.h"
 #include "Magnum/PixelFormat.h"
 #include "Magnum/Math/Color.h"
+#include "Magnum/Math/Matrix3.h"
 #include "Magnum/Math/Matrix4.h"
 #include "Magnum/MeshTools/Compile.h"
 #include "Magnum/MeshTools/Duplicate.h"
+#include "Magnum/MeshTools/GenerateIndices.h"
 #include "Magnum/Primitives/Circle.h"
 #include "Magnum/Primitives/Icosphere.h"
 #include "Magnum/Primitives/UVSphere.h"
@@ -60,25 +62,33 @@ namespace Magnum { namespace Shaders { namespace Test { namespace {
 struct MeshVisualizerGLTest: GL::OpenGLTester {
     explicit MeshVisualizerGLTest();
 
-    void construct();
+    void construct2D();
+    void construct3D();
+
     #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
-    void constructWireframeGeometryShader();
+    void constructWireframeGeometryShader2D();
+    void constructWireframeGeometryShader3D();
     #endif
-    void constructWireframeNoGeometryShader();
 
-    void constructMove();
+    void constructMove2D();
+    void constructMove3D();
 
-    void setWireframeNotEnabled();
+    void setWireframeNotEnabled2D();
+    void setWireframeNotEnabled3D();
 
     void renderSetup();
     void renderTeardown();
 
-    void renderDefaults();
+    void renderDefaults2D();
+    void renderDefaults3D();
     #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
-    void renderDefaultsWireframe();
+    void renderDefaultsWireframe2D();
+    void renderDefaultsWireframe3D();
     #endif
-    void render();
-    void renderWireframe();
+    void render2D();
+    void render3D();
+    void renderWireframe2D();
+    void renderWireframe3D();
 
     private:
         PluginManager::Manager<Trade::AbstractImporter> _manager{"nonexistent"};
@@ -106,40 +116,97 @@ using namespace Math::Literals;
 
 constexpr struct {
     const char* name;
-    MeshVisualizer::Flags flags;
+    MeshVisualizer2D::Flags flags;
+} ConstructData2D[] {
+    {"", {}},
+    {"wireframe w/o GS", MeshVisualizer2D::Flag::Wireframe|MeshVisualizer2D::Flag::NoGeometryShader},
+};
+
+constexpr struct {
+    const char* name;
+    MeshVisualizer3D::Flags flags;
+} ConstructData3D[] {
+    {"", {}},
+    {"wireframe w/o GS", MeshVisualizer3D::Flag::Wireframe|MeshVisualizer3D::Flag::NoGeometryShader}
+};
+
+constexpr struct {
+    const char* name;
+    MeshVisualizer2D::Flags flags;
+    Float width, smoothness;
+    const char* file;
+    const char* fileXfail;
+} WireframeData2D[] {
+    #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+    {"", MeshVisualizer2D::Flags{},
+        1.0f, 2.0f, "wireframe2D.tga", nullptr},
+    {"wide/sharp", MeshVisualizer2D::Flags{},
+        3.0f, 1.0f, "wireframe-wide2D.tga", nullptr},
+    #endif
+    {"no geometry shader", MeshVisualizer2D::Flag::NoGeometryShader,
+        1.0f, 2.0f, "wireframe2D.tga", "wireframe-nogeo2D.tga"},
+    {"no geometry shader, wide/sharp", MeshVisualizer2D::Flag::NoGeometryShader,
+        3.0f, 1.0f, "wireframe-wide2D.tga", "wireframe-nogeo2D.tga"}
+};
+
+constexpr struct {
+    const char* name;
+    MeshVisualizer3D::Flags flags;
     Float width, smoothness;
     const char* file;
     const char* fileXfail;
-} WireframeData[] {
+} WireframeData3D[] {
     #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
-    {"", MeshVisualizer::Flags{}, 1.0f, 2.0f, "wireframe.tga", nullptr},
-    {"wide/sharp", MeshVisualizer::Flags{}, 3.0f, 1.0f, "wireframe-wide.tga", nullptr},
+    {"", MeshVisualizer3D::Flags{},
+        1.0f, 2.0f, "wireframe3D.tga", nullptr},
+    {"wide/sharp", MeshVisualizer3D::Flags{},
+        3.0f, 1.0f, "wireframe-wide3D.tga", nullptr},
     #endif
-    {"no geometry shader", MeshVisualizer::Flag::NoGeometryShader, 1.0f, 2.0f, "wireframe.tga", "wireframe-nogeo.tga"},
-    {"no geometry shader, wide/sharp", MeshVisualizer::Flag::NoGeometryShader, 3.0f, 1.0f, "wireframe-wide.tga", "wireframe-nogeo.tga"}
+    {"no geometry shader",
+        MeshVisualizer3D::Flag::NoGeometryShader,
+        1.0f, 2.0f, "wireframe3D.tga", "wireframe-nogeo3D.tga"},
+    {"no geometry shader, wide/sharp",
+        MeshVisualizer3D::Flag::NoGeometryShader,
+        3.0f, 1.0f, "wireframe-wide3D.tga", "wireframe-nogeo3D.tga"}
 };
 
 MeshVisualizerGLTest::MeshVisualizerGLTest() {
-    addTests({&MeshVisualizerGLTest::construct,
+    addInstancedTests({&MeshVisualizerGLTest::construct2D},
+        Containers::arraySize(ConstructData2D));
+
+    addInstancedTests({&MeshVisualizerGLTest::construct3D},
+        Containers::arraySize(ConstructData3D));
+
+    addTests({
               #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
-              &MeshVisualizerGLTest::constructWireframeGeometryShader,
+              &MeshVisualizerGLTest::constructWireframeGeometryShader2D,
+              &MeshVisualizerGLTest::constructWireframeGeometryShader3D,
               #endif
-              &MeshVisualizerGLTest::constructWireframeNoGeometryShader,
 
-              &MeshVisualizerGLTest::constructMove,
+              &MeshVisualizerGLTest::constructMove2D,
+              &MeshVisualizerGLTest::constructMove3D,
 
-              &MeshVisualizerGLTest::setWireframeNotEnabled});
+              &MeshVisualizerGLTest::setWireframeNotEnabled2D,
+              &MeshVisualizerGLTest::setWireframeNotEnabled3D});
 
-    addTests({&MeshVisualizerGLTest::renderDefaults,
+    addTests({&MeshVisualizerGLTest::renderDefaults2D,
+              &MeshVisualizerGLTest::renderDefaults3D,
               #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
-              &MeshVisualizerGLTest::renderDefaultsWireframe,
+              &MeshVisualizerGLTest::renderDefaultsWireframe2D,
+              &MeshVisualizerGLTest::renderDefaultsWireframe3D,
               #endif
-              &MeshVisualizerGLTest::render},
+              &MeshVisualizerGLTest::render2D,
+              &MeshVisualizerGLTest::render3D},
+        &MeshVisualizerGLTest::renderSetup,
+        &MeshVisualizerGLTest::renderTeardown);
+
+    addInstancedTests({&MeshVisualizerGLTest::renderWireframe2D},
+        Containers::arraySize(WireframeData2D),
         &MeshVisualizerGLTest::renderSetup,
         &MeshVisualizerGLTest::renderTeardown);
 
-    addInstancedTests({&MeshVisualizerGLTest::renderWireframe},
-        Containers::arraySize(WireframeData),
+    addInstancedTests({&MeshVisualizerGLTest::renderWireframe3D},
+        Containers::arraySize(WireframeData3D),
         &MeshVisualizerGLTest::renderSetup,
         &MeshVisualizerGLTest::renderTeardown);
 
@@ -167,9 +234,29 @@ MeshVisualizerGLTest::MeshVisualizerGLTest() {
     }
 }
 
-void MeshVisualizerGLTest::construct() {
-    MeshVisualizer shader;
-    CORRADE_COMPARE(shader.flags(), MeshVisualizer::Flags{});
+void MeshVisualizerGLTest::construct2D() {
+    auto&& data = ConstructData2D[testCaseInstanceId()];
+    setTestCaseDescription(data.name);
+
+    MeshVisualizer2D shader{data.flags};
+    CORRADE_COMPARE(shader.flags(), data.flags);
+    CORRADE_VERIFY(shader.id());
+    {
+        #ifdef CORRADE_TARGET_APPLE
+        CORRADE_EXPECT_FAIL("macOS drivers need insane amount of state to validate properly.");
+        #endif
+        CORRADE_VERIFY(shader.validate().first);
+    }
+
+    MAGNUM_VERIFY_NO_GL_ERROR();
+}
+
+void MeshVisualizerGLTest::construct3D() {
+    auto&& data = ConstructData3D[testCaseInstanceId()];
+    setTestCaseDescription(data.name);
+
+    MeshVisualizer3D shader{data.flags};
+    CORRADE_COMPARE(shader.flags(), data.flags);
     CORRADE_VERIFY(shader.id());
     {
         #ifdef CORRADE_TARGET_APPLE
@@ -182,7 +269,7 @@ void MeshVisualizerGLTest::construct() {
 }
 
 #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
-void MeshVisualizerGLTest::constructWireframeGeometryShader() {
+void MeshVisualizerGLTest::constructWireframeGeometryShader2D() {
     #ifndef MAGNUM_TARGET_GLES
     if(!GL::Context::current().isExtensionSupported<GL::Extensions::ARB::geometry_shader4>())
         CORRADE_SKIP(GL::Extensions::ARB::geometry_shader4::string() + std::string(" is not supported"));
@@ -196,8 +283,8 @@ void MeshVisualizerGLTest::constructWireframeGeometryShader() {
         Debug() << "Using" << GL::Extensions::NV::shader_noperspective_interpolation::string();
     #endif
 
-    MeshVisualizer shader{MeshVisualizer::Flag::Wireframe};
-    CORRADE_COMPARE(shader.flags(), MeshVisualizer::Flag::Wireframe);
+    MeshVisualizer2D shader{MeshVisualizer2D::Flag::Wireframe};
+    CORRADE_COMPARE(shader.flags(), MeshVisualizer2D::Flag::Wireframe);
     {
         #ifdef CORRADE_TARGET_APPLE
         CORRADE_EXPECT_FAIL("macOS drivers need insane amount of state to validate properly.");
@@ -206,11 +293,23 @@ void MeshVisualizerGLTest::constructWireframeGeometryShader() {
         CORRADE_VERIFY(shader.validate().first);
     }
 }
-#endif
 
-void MeshVisualizerGLTest::constructWireframeNoGeometryShader() {
-    MeshVisualizer shader{MeshVisualizer::Flag::Wireframe|MeshVisualizer::Flag::NoGeometryShader};
-    CORRADE_COMPARE(shader.flags(), MeshVisualizer::Flag::Wireframe|MeshVisualizer::Flag::NoGeometryShader);
+void MeshVisualizerGLTest::constructWireframeGeometryShader3D() {
+    #ifndef MAGNUM_TARGET_GLES
+    if(!GL::Context::current().isExtensionSupported<GL::Extensions::ARB::geometry_shader4>())
+        CORRADE_SKIP(GL::Extensions::ARB::geometry_shader4::string() + std::string(" is not supported"));
+    #else
+    if(!GL::Context::current().isExtensionSupported<GL::Extensions::EXT::geometry_shader>())
+        CORRADE_SKIP(GL::Extensions::EXT::geometry_shader::string() + std::string(" is not supported"));
+    #endif
+
+    #ifdef MAGNUM_TARGET_GLES
+    if(GL::Context::current().isExtensionSupported<GL::Extensions::NV::shader_noperspective_interpolation>())
+        Debug() << "Using" << GL::Extensions::NV::shader_noperspective_interpolation::string();
+    #endif
+
+    MeshVisualizer3D shader{MeshVisualizer3D::Flag::Wireframe};
+    CORRADE_COMPARE(shader.flags(), MeshVisualizer3D::Flag::Wireframe);
     {
         #ifdef CORRADE_TARGET_APPLE
         CORRADE_EXPECT_FAIL("macOS drivers need insane amount of state to validate properly.");
@@ -219,31 +318,66 @@ void MeshVisualizerGLTest::constructWireframeNoGeometryShader() {
         CORRADE_VERIFY(shader.validate().first);
     }
 }
+#endif
+
+void MeshVisualizerGLTest::constructMove2D() {
+    MeshVisualizer2D a{MeshVisualizer2D::Flag::Wireframe|MeshVisualizer2D::Flag::NoGeometryShader};
+    const GLuint id = a.id();
+    CORRADE_VERIFY(id);
+
+    MAGNUM_VERIFY_NO_GL_ERROR();
+
+    MeshVisualizer2D b{std::move(a)};
+    CORRADE_COMPARE(b.id(), id);
+    CORRADE_COMPARE(b.flags(), MeshVisualizer2D::Flag::Wireframe|MeshVisualizer2D::Flag::NoGeometryShader);
+    CORRADE_VERIFY(!a.id());
+
+    MeshVisualizer2D c{NoCreate};
+    c = std::move(b);
+    CORRADE_COMPARE(c.id(), id);
+    CORRADE_COMPARE(c.flags(), MeshVisualizer2D::Flag::Wireframe|MeshVisualizer2D::Flag::NoGeometryShader);
+    CORRADE_VERIFY(!b.id());
+}
 
-void MeshVisualizerGLTest::constructMove() {
-    MeshVisualizer a{MeshVisualizer::Flag::Wireframe|MeshVisualizer::Flag::NoGeometryShader};
+void MeshVisualizerGLTest::constructMove3D() {
+    MeshVisualizer3D a{MeshVisualizer3D::Flag::Wireframe|MeshVisualizer3D::Flag::NoGeometryShader};
     const GLuint id = a.id();
     CORRADE_VERIFY(id);
 
     MAGNUM_VERIFY_NO_GL_ERROR();
 
-    MeshVisualizer b{std::move(a)};
+    MeshVisualizer3D b{std::move(a)};
     CORRADE_COMPARE(b.id(), id);
-    CORRADE_COMPARE(b.flags(), MeshVisualizer::Flag::Wireframe|MeshVisualizer::Flag::NoGeometryShader);
+    CORRADE_COMPARE(b.flags(), MeshVisualizer3D::Flag::Wireframe|MeshVisualizer3D::Flag::NoGeometryShader);
     CORRADE_VERIFY(!a.id());
 
-    MeshVisualizer c{NoCreate};
+    MeshVisualizer3D c{NoCreate};
     c = std::move(b);
     CORRADE_COMPARE(c.id(), id);
-    CORRADE_COMPARE(c.flags(), MeshVisualizer::Flag::Wireframe|MeshVisualizer::Flag::NoGeometryShader);
+    CORRADE_COMPARE(c.flags(), MeshVisualizer3D::Flag::Wireframe|MeshVisualizer3D::Flag::NoGeometryShader);
     CORRADE_VERIFY(!b.id());
 }
 
-void MeshVisualizerGLTest::setWireframeNotEnabled() {
+void MeshVisualizerGLTest::setWireframeNotEnabled2D() {
+    std::ostringstream out;
+    Error redirectError{&out};
+
+    MeshVisualizer2D shader;
+    shader.setWireframeColor({})
+        .setWireframeWidth({})
+        .setSmoothness({});
+
+    CORRADE_COMPARE(out.str(),
+        "Shaders::MeshVisualizer::setWireframeColor(): the shader was not created with wireframe enabled\n"
+        "Shaders::MeshVisualizer::setWireframeWidth(): the shader was not created with wireframe enabled\n"
+        "Shaders::MeshVisualizer::setSmoothness(): the shader was not created with wireframe enabled\n");
+}
+
+void MeshVisualizerGLTest::setWireframeNotEnabled3D() {
     std::ostringstream out;
     Error redirectError{&out};
 
-    MeshVisualizer shader;
+    MeshVisualizer3D shader;
     shader.setWireframeColor({})
         .setWireframeWidth({})
         .setSmoothness({});
@@ -281,10 +415,36 @@ void MeshVisualizerGLTest::renderTeardown() {
     _color = GL::Renderbuffer{NoCreate};
 }
 
-void MeshVisualizerGLTest::renderDefaults() {
+void MeshVisualizerGLTest::renderDefaults2D() {
+    GL::Mesh circle = MeshTools::compile(Primitives::circle2DSolid(32));
+
+    MeshVisualizer2D{}
+        .draw(circle);
+
+    MAGNUM_VERIFY_NO_GL_ERROR();
+
+    if(!(_manager.loadState("AnyImageImporter") & PluginManager::LoadState::Loaded) ||
+       !(_manager.loadState("TgaImporter") & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP("AnyImageImporter / TgaImageImporter plugins not found.");
+
+    #if !(defined(MAGNUM_TARGET_GLES2) && defined(MAGNUM_TARGET_WEBGL))
+    /* SwiftShader has differently rasterized edges on four pixels */
+    const Float maxThreshold = 238.0f, meanThreshold = 0.298f;
+    #else
+    /* WebGL 1 doesn't have 8bit renderbuffer storage, so it's way worse */
+    const Float maxThreshold = 238.0f, meanThreshold = 0.298f;
+    #endif
+    CORRADE_COMPARE_WITH(
+        /* Dropping the alpha channel, as it's always 1.0 */
+        Containers::arrayCast<Color3ub>(_framebuffer.read(_framebuffer.viewport(), {PixelFormat::RGBA8Unorm}).pixels<Color4ub>()),
+        Utility::Directory::join(_testDir, "FlatTestFiles/defaults.tga"),
+        (DebugTools::CompareImageToFile{_manager, maxThreshold, meanThreshold}));
+}
+
+void MeshVisualizerGLTest::renderDefaults3D() {
     GL::Mesh sphere = MeshTools::compile(Primitives::uvSphereSolid(16, 32));
 
-    MeshVisualizer{}
+    MeshVisualizer3D{}
         .draw(sphere);
 
     MAGNUM_VERIFY_NO_GL_ERROR();
@@ -308,7 +468,56 @@ void MeshVisualizerGLTest::renderDefaults() {
 }
 
 #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
-void MeshVisualizerGLTest::renderDefaultsWireframe() {
+void MeshVisualizerGLTest::renderDefaultsWireframe2D() {
+    #ifndef MAGNUM_TARGET_GLES
+    if(!GL::Context::current().isExtensionSupported<GL::Extensions::ARB::geometry_shader4>())
+        CORRADE_SKIP(GL::Extensions::ARB::geometry_shader4::string() + std::string(" is not supported"));
+    #else
+    if(!GL::Context::current().isExtensionSupported<GL::Extensions::EXT::geometry_shader>())
+        CORRADE_SKIP(GL::Extensions::EXT::geometry_shader::string() + std::string(" is not supported"));
+    #endif
+
+    #ifdef MAGNUM_TARGET_GLES
+    if(GL::Context::current().isExtensionSupported<GL::Extensions::NV::shader_noperspective_interpolation>())
+        Debug() << "Using" << GL::Extensions::NV::shader_noperspective_interpolation::string();
+    #endif
+
+    GL::Mesh circle = MeshTools::compile(Primitives::circle2DSolid(16));
+
+    MeshVisualizer2D shader{MeshVisualizer2D::Flag::Wireframe};
+    shader.draw(circle);
+
+    MAGNUM_VERIFY_NO_GL_ERROR();
+
+    if(!(_manager.loadState("AnyImageImporter") & PluginManager::LoadState::Loaded) ||
+       !(_manager.loadState("TgaImporter") & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP("AnyImageImporter / TgaImageImporter plugins not found.");
+
+    {
+        CORRADE_EXPECT_FAIL("Defaults don't work for wireframe as line width is derived from viewport size.");
+        CORRADE_COMPARE_WITH(
+            /* Dropping the alpha channel, as it's always 1.0 */
+            Containers::arrayCast<Color3ub>(_framebuffer.read(_framebuffer.viewport(), {PixelFormat::RGBA8Unorm}).pixels<Color4ub>()),
+            Utility::Directory::join(_testDir, "MeshVisualizerTestFiles/defaults-wireframe2D.tga"),
+            (DebugTools::CompareImageToFile{_manager}));
+    }
+
+    /** @todo make this unnecessary */
+    shader
+        .setViewportSize({80, 80})
+        .draw(circle);
+
+    MAGNUM_VERIFY_NO_GL_ERROR();
+
+    CORRADE_COMPARE_WITH(
+        /* Dropping the alpha channel, as it's always 1.0 */
+        Containers::arrayCast<Color3ub>(_framebuffer.read(_framebuffer.viewport(), {PixelFormat::RGBA8Unorm}).pixels<Color4ub>()),
+        Utility::Directory::join(_testDir, "MeshVisualizerTestFiles/defaults-wireframe2D.tga"),
+        /* AMD has off-by-one errors on edges compared to Intel */
+        (DebugTools::CompareImageToFile{_manager, 1.0f, 0.082f}));
+}
+
+void MeshVisualizerGLTest::renderDefaultsWireframe3D() {
     #ifndef MAGNUM_TARGET_GLES
     if(!GL::Context::current().isExtensionSupported<GL::Extensions::ARB::geometry_shader4>())
         CORRADE_SKIP(GL::Extensions::ARB::geometry_shader4::string() + std::string(" is not supported"));
@@ -324,7 +533,7 @@ void MeshVisualizerGLTest::renderDefaultsWireframe() {
 
     GL::Mesh sphere = MeshTools::compile(Primitives::icosphereSolid(1));
 
-    MeshVisualizer shader{MeshVisualizer::Flag::Wireframe};
+    MeshVisualizer3D shader{MeshVisualizer3D::Flag::Wireframe};
     shader.draw(sphere);
 
     MAGNUM_VERIFY_NO_GL_ERROR();
@@ -338,7 +547,7 @@ void MeshVisualizerGLTest::renderDefaultsWireframe() {
         CORRADE_COMPARE_WITH(
             /* Dropping the alpha channel, as it's always 1.0 */
             Containers::arrayCast<Color3ub>(_framebuffer.read(_framebuffer.viewport(), {PixelFormat::RGBA8Unorm}).pixels<Color4ub>()),
-            Utility::Directory::join(_testDir, "MeshVisualizerTestFiles/defaults-wireframe.tga"),
+            Utility::Directory::join(_testDir, "MeshVisualizerTestFiles/defaults-wireframe3D.tga"),
             (DebugTools::CompareImageToFile{_manager}));
     }
 
@@ -352,16 +561,44 @@ void MeshVisualizerGLTest::renderDefaultsWireframe() {
     CORRADE_COMPARE_WITH(
         /* Dropping the alpha channel, as it's always 1.0 */
         Containers::arrayCast<Color3ub>(_framebuffer.read(_framebuffer.viewport(), {PixelFormat::RGBA8Unorm}).pixels<Color4ub>()),
-        Utility::Directory::join(_testDir, "MeshVisualizerTestFiles/defaults-wireframe.tga"),
+        Utility::Directory::join(_testDir, "MeshVisualizerTestFiles/defaults-wireframe3D.tga"),
         /* AMD has off-by-one errors on edges compared to Intel */
         (DebugTools::CompareImageToFile{_manager, 1.0f, 0.06f}));
 }
 #endif
 
-void MeshVisualizerGLTest::render() {
+void MeshVisualizerGLTest::render2D() {
+    GL::Mesh circle = MeshTools::compile(Primitives::circle2DSolid(32));
+
+    MeshVisualizer2D{}
+        .setColor(0x9999ff_rgbf)
+        .setTransformationProjectionMatrix(Matrix3::projection({2.1f, 2.1f}))
+        .draw(circle);
+
+    MAGNUM_VERIFY_NO_GL_ERROR();
+
+    if(!(_manager.loadState("AnyImageImporter") & PluginManager::LoadState::Loaded) ||
+       !(_manager.loadState("TgaImporter") & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP("AnyImageImporter / TgaImageImporter plugins not found.");
+
+    #if !(defined(MAGNUM_TARGET_GLES2) && defined(MAGNUM_TARGET_WEBGL))
+    /* SwiftShader has differently rasterized edges on four pixels */
+    const Float maxThreshold = 170.0f, meanThreshold = 0.133f;
+    #else
+    /* WebGL 1 doesn't have 8bit renderbuffer storage, so it's way worse */
+    const Float maxThreshold = 170.0f, meanThreshold = 0.456f;
+    #endif
+    CORRADE_COMPARE_WITH(
+        /* Dropping the alpha channel, as it's always 1.0 */
+        Containers::arrayCast<Color3ub>(_framebuffer.read(_framebuffer.viewport(), {PixelFormat::RGBA8Unorm}).pixels<Color4ub>()),
+        Utility::Directory::join(_testDir, "FlatTestFiles/colored2D.tga"),
+        (DebugTools::CompareImageToFile{_manager, maxThreshold, meanThreshold}));
+}
+
+void MeshVisualizerGLTest::render3D() {
     GL::Mesh sphere = MeshTools::compile(Primitives::uvSphereSolid(16, 32));
 
-    MeshVisualizer{}
+    MeshVisualizer3D{}
         .setColor(0x9999ff_rgbf)
         .setTransformationProjectionMatrix(
             Matrix4::perspectiveProjection(60.0_degf, 1.0f, 0.1f, 10.0f)*
@@ -390,13 +627,105 @@ void MeshVisualizerGLTest::render() {
         (DebugTools::CompareImageToFile{_manager, maxThreshold, meanThreshold}));
 }
 
-void MeshVisualizerGLTest::renderWireframe() {
-    auto&& data = WireframeData[testCaseInstanceId()];
+void MeshVisualizerGLTest::renderWireframe2D() {
+    auto&& data = WireframeData2D[testCaseInstanceId()];
+    setTestCaseDescription(data.name);
+
+    #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+    #ifndef MAGNUM_TARGET_GLES
+    if(!(data.flags & MeshVisualizer2D::Flag::NoGeometryShader) && !GL::Context::current().isExtensionSupported<GL::Extensions::ARB::geometry_shader4>())
+        CORRADE_SKIP(GL::Extensions::ARB::geometry_shader4::string() + std::string(" is not supported"));
+    #else
+    if(!(data.flags & MeshVisualizer2D::Flag::NoGeometryShader) && !GL::Context::current().isExtensionSupported<GL::Extensions::EXT::geometry_shader>())
+        CORRADE_SKIP(GL::Extensions::EXT::geometry_shader::string() + std::string(" is not supported"));
+    #endif
+
+    #ifdef MAGNUM_TARGET_GLES
+    if(GL::Context::current().isExtensionSupported<GL::Extensions::NV::shader_noperspective_interpolation>())
+        Debug() << "Using" << GL::Extensions::NV::shader_noperspective_interpolation::string();
+    #endif
+    #endif
+
+    const Trade::MeshData circleData = Primitives::circle2DSolid(16);
+
+    GL::Mesh circle{NoCreate};
+    if(data.flags & MeshVisualizer2D::Flag::NoGeometryShader) {
+        /* Duplicate the vertices. The circle primitive is  */
+        const Trade::MeshData circleDataIndexed =
+            MeshTools::generateIndices(circleData);
+        circle = MeshTools::compile(MeshTools::duplicate(circleDataIndexed));
+
+        /* Supply also the vertex ID, if needed */
+        #ifndef MAGNUM_TARGET_GLES2
+        if(!GL::Context::current().isExtensionSupported<GL::Extensions::MAGNUM::shader_vertex_id>())
+        #endif
+        {
+            Containers::Array<Float> vertexIndex{circleDataIndexed.indexCount()};
+            std::iota(vertexIndex.begin(), vertexIndex.end(), 0.0f);
+
+            GL::Buffer vertexId;
+            vertexId.setData(vertexIndex);
+            circle.addVertexBuffer(std::move(vertexId), 0, MeshVisualizer2D::VertexIndex{});
+        }
+    } else circle = MeshTools::compile(circleData);
+
+    MeshVisualizer2D{data.flags|MeshVisualizer2D::Flag::Wireframe}
+        .setColor(0xffff99_rgbf)
+        .setWireframeColor(0x9999ff_rgbf)
+        .setWireframeWidth(data.width)
+        .setSmoothness(data.smoothness)
+        .setViewportSize({80, 80})
+        .setTransformationProjectionMatrix(Matrix3::projection({2.1f, 2.1f}))
+        .draw(circle);
+
+    MAGNUM_VERIFY_NO_GL_ERROR();
+
+    if(!(_manager.loadState("AnyImageImporter") & PluginManager::LoadState::Loaded) ||
+       !(_manager.loadState("TgaImporter") & PluginManager::LoadState::Loaded))
+        CORRADE_SKIP("AnyImageImporter / TgaImageImporter plugins not found.");
+
+    {
+        CORRADE_EXPECT_FAIL_IF(data.flags & MeshVisualizer2D::Flag::NoGeometryShader,
+            "Line width is currently not configurable w/o geometry shader.");
+        #if !(defined(MAGNUM_TARGET_GLES2) && defined(MAGNUM_TARGET_WEBGL))
+        /* SwiftShader has differently rasterized edges on four pixels */
+        const Float maxThreshold = 170.0f, meanThreshold = 0.327f;
+        #else
+        /* WebGL 1 doesn't have 8bit renderbuffer storage, so it's way worse */
+        const Float maxThreshold = 170.0f, meanThreshold = 1.699f;
+        #endif
+        CORRADE_COMPARE_WITH(
+            /* Dropping the alpha channel, as it's always 1.0 */
+            Containers::arrayCast<Color3ub>(_framebuffer.read(_framebuffer.viewport(), {PixelFormat::RGBA8Unorm}).pixels<Color4ub>()),
+            Utility::Directory::join({_testDir, "MeshVisualizerTestFiles", data.file}),
+            (DebugTools::CompareImageToFile{_manager, maxThreshold, meanThreshold}));
+    }
+
+    /* Test it's not *too* off, at least */
+    if(data.flags & MeshVisualizer2D::Flag::NoGeometryShader) {
+        #if !(defined(MAGNUM_TARGET_GLES2) && defined(MAGNUM_TARGET_WEBGL))
+        /* SwiftShader has differently rasterized edges on four pixels. Apple
+           A8 on more. */
+        const Float maxThreshold = 170.0f, meanThreshold = 0.330f;
+        #else
+        /* WebGL 1 doesn't have 8bit renderbuffer storage, so it's way worse */
+        const Float maxThreshold = 170.0f, meanThreshold = 2.077f;
+        #endif
+        CORRADE_COMPARE_WITH(
+            /* Dropping the alpha channel, as it's always 1.0 */
+            Containers::arrayCast<Color3ub>(_framebuffer.read(_framebuffer.viewport(), {PixelFormat::RGBA8Unorm}).pixels<Color4ub>()),
+            Utility::Directory::join({_testDir, "MeshVisualizerTestFiles", data.fileXfail}),
+            (DebugTools::CompareImageToFile{_manager, maxThreshold, meanThreshold}));
+    }
+}
+
+void MeshVisualizerGLTest::renderWireframe3D() {
+    auto&& data = WireframeData3D[testCaseInstanceId()];
     setTestCaseDescription(data.name);
 
     #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
     #ifndef MAGNUM_TARGET_GLES
-    if(!(data.flags & MeshVisualizer::Flag::NoGeometryShader) && !GL::Context::current().isExtensionSupported<GL::Extensions::ARB::geometry_shader4>())
+    if(!(data.flags & MeshVisualizer3D::Flag::NoGeometryShader) && !GL::Context::current().isExtensionSupported<GL::Extensions::ARB::geometry_shader4>())
         CORRADE_SKIP(GL::Extensions::ARB::geometry_shader4::string() + std::string(" is not supported"));
     #else
     if(!(data.flags & MeshVisualizer::Flag::NoGeometryShader) && !GL::Context::current().isExtensionSupported<GL::Extensions::EXT::geometry_shader>())
@@ -412,7 +741,7 @@ void MeshVisualizerGLTest::renderWireframe() {
     const Trade::MeshData sphereData = Primitives::icosphereSolid(1);
 
     GL::Mesh sphere{NoCreate};
-    if(data.flags & MeshVisualizer::Flag::NoGeometryShader) {
+    if(data.flags & MeshVisualizer3D::Flag::NoGeometryShader) {
         /* Duplicate the vertices */
         sphere = MeshTools::compile(MeshTools::duplicate(sphereData));
 
@@ -426,11 +755,11 @@ void MeshVisualizerGLTest::renderWireframe() {
 
             GL::Buffer vertexId;
             vertexId.setData(vertexIndex);
-            sphere.addVertexBuffer(std::move(vertexId), 0, MeshVisualizer::VertexIndex{});
+            sphere.addVertexBuffer(std::move(vertexId), 0, MeshVisualizer3D::VertexIndex{});
         }
     } else sphere = MeshTools::compile(sphereData);
 
-    MeshVisualizer{data.flags|MeshVisualizer::Flag::Wireframe}
+    MeshVisualizer3D{data.flags|MeshVisualizer3D::Flag::Wireframe}
         .setColor(0xffff99_rgbf)
         .setWireframeColor(0x9999ff_rgbf)
         .setWireframeWidth(data.width)
@@ -450,7 +779,7 @@ void MeshVisualizerGLTest::renderWireframe() {
         CORRADE_SKIP("AnyImageImporter / TgaImageImporter plugins not found.");
 
     {
-        CORRADE_EXPECT_FAIL_IF(data.flags & MeshVisualizer::Flag::NoGeometryShader,
+        CORRADE_EXPECT_FAIL_IF(data.flags & MeshVisualizer3D::Flag::NoGeometryShader,
             "Line width is currently not configurable w/o geometry shader.");
         #if !(defined(MAGNUM_TARGET_GLES2) && defined(MAGNUM_TARGET_WEBGL))
         /* SwiftShader has differently rasterized edges on four pixels */
@@ -467,7 +796,7 @@ void MeshVisualizerGLTest::renderWireframe() {
     }
 
     /* Test it's not *too* off, at least */
-    if(data.flags & MeshVisualizer::Flag::NoGeometryShader) {
+    if(data.flags & MeshVisualizer3D::Flag::NoGeometryShader) {
         #if !(defined(MAGNUM_TARGET_GLES2) && defined(MAGNUM_TARGET_WEBGL))
         /* SwiftShader has differently rasterized edges on four pixels. Apple
            A8 on more. */

src/Magnum/Shaders/Test/MeshVisualizerTest.cpp

@@ -34,62 +34,111 @@ namespace Magnum { namespace Shaders { namespace Test { namespace {
 struct MeshVisualizerTest: TestSuite::Tester {
     explicit MeshVisualizerTest();
 
-    void constructNoCreate();
-    void constructCopy();
+    void constructNoCreate2D();
+    void constructNoCreate3D();
+
+    void constructCopy2D();
+    void constructCopy3D();
 
     void vertexIndexSameAsObjectId();
 
-    void debugFlag();
-    void debugFlags();
+    void debugFlag2D();
+    void debugFlag3D();
+    void debugFlags2D();
+    void debugFlags3D();
 };
 
 MeshVisualizerTest::MeshVisualizerTest() {
-    addTests({&MeshVisualizerTest::constructNoCreate,
-              &MeshVisualizerTest::constructCopy,
+    addTests({&MeshVisualizerTest::constructNoCreate2D,
+              &MeshVisualizerTest::constructNoCreate3D,
+
+              &MeshVisualizerTest::constructCopy2D,
+              &MeshVisualizerTest::constructCopy3D,
 
               &MeshVisualizerTest::vertexIndexSameAsObjectId,
 
-              &MeshVisualizerTest::debugFlag,
-              &MeshVisualizerTest::debugFlags});
+              &MeshVisualizerTest::debugFlag2D,
+              &MeshVisualizerTest::debugFlag3D,
+              &MeshVisualizerTest::debugFlags2D,
+              &MeshVisualizerTest::debugFlags3D});
+}
+
+void MeshVisualizerTest::constructNoCreate2D() {
+    {
+        MeshVisualizer2D shader{NoCreate};
+        CORRADE_COMPARE(shader.id(), 0);
+    }
+
+    CORRADE_VERIFY(true);
 }
 
-void MeshVisualizerTest::constructNoCreate() {
+void MeshVisualizerTest::constructNoCreate3D() {
     {
-        MeshVisualizer shader{NoCreate};
+        MeshVisualizer3D shader{NoCreate};
         CORRADE_COMPARE(shader.id(), 0);
     }
 
     CORRADE_VERIFY(true);
 }
 
-void MeshVisualizerTest::constructCopy() {
-    CORRADE_VERIFY(!(std::is_constructible<MeshVisualizer, const MeshVisualizer&>{}));
-    CORRADE_VERIFY(!(std::is_assignable<MeshVisualizer, const MeshVisualizer&>{}));
+void MeshVisualizerTest::constructCopy2D() {
+    CORRADE_VERIFY((std::is_constructible<MeshVisualizer2D, MeshVisualizer2D&&>{}));
+    CORRADE_VERIFY(!(std::is_constructible<MeshVisualizer2D, const MeshVisualizer2D&>{}));
+
+    CORRADE_VERIFY((std::is_assignable<MeshVisualizer2D, MeshVisualizer2D&&>{}));
+    CORRADE_VERIFY(!(std::is_assignable<MeshVisualizer2D, const MeshVisualizer2D&>{}));
+}
+
+void MeshVisualizerTest::constructCopy3D() {
+    CORRADE_VERIFY((std::is_constructible<MeshVisualizer3D, MeshVisualizer3D&&>{}));
+    CORRADE_VERIFY(!(std::is_constructible<MeshVisualizer3D, const MeshVisualizer3D&>{}));
+
+    CORRADE_VERIFY((std::is_assignable<MeshVisualizer3D, MeshVisualizer3D&&>{}));
+    CORRADE_VERIFY(!(std::is_assignable<MeshVisualizer3D, const MeshVisualizer3D&>{}));
 }
 
 void MeshVisualizerTest::vertexIndexSameAsObjectId() {
     #ifdef MAGNUM_TARGET_GLES2
     CORRADE_SKIP("Object ID is not available on ES2.");
     #else
-    CORRADE_COMPARE(MeshVisualizer::VertexIndex::Location, Generic3D::ObjectId::Location);
+    CORRADE_COMPARE(MeshVisualizer2D::VertexIndex::Location, Generic2D::ObjectId::Location);
+    CORRADE_COMPARE(MeshVisualizer3D::VertexIndex::Location, Generic3D::ObjectId::Location);
     #endif
 }
 
-void MeshVisualizerTest::debugFlag() {
+void MeshVisualizerTest::debugFlag2D() {
+    std::ostringstream out;
+
+    Debug{&out} << MeshVisualizer2D::Flag::Wireframe << MeshVisualizer2D::Flag(0xf0);
+    CORRADE_COMPARE(out.str(), "Shaders::MeshVisualizer2D::Flag::Wireframe Shaders::MeshVisualizer2D::Flag(0xf0)\n");
+}
+
+void MeshVisualizerTest::debugFlag3D() {
+    std::ostringstream out;
+
+    Debug{&out} << MeshVisualizer3D::Flag::Wireframe << MeshVisualizer3D::Flag(0xf0);
+    CORRADE_COMPARE(out.str(), "Shaders::MeshVisualizer3D::Flag::Wireframe Shaders::MeshVisualizer3D::Flag(0xf0)\n");
+}
+
+void MeshVisualizerTest::debugFlags2D() {
     std::ostringstream out;
 
-    Debug{&out} << MeshVisualizer::Flag::Wireframe << MeshVisualizer::Flag(0xf0);
-    CORRADE_COMPARE(out.str(), "Shaders::MeshVisualizer::Flag::Wireframe Shaders::MeshVisualizer::Flag(0xf0)\n");
+    Debug{&out} << (MeshVisualizer2D::Flag::Wireframe|MeshVisualizer2D::Flag::NoGeometryShader) << MeshVisualizer2D::Flags{};
+    #ifndef MAGNUM_TARGET_GLES2
+    CORRADE_COMPARE(out.str(), "Shaders::MeshVisualizer2D::Flag::Wireframe|Shaders::MeshVisualizer2D::Flag::NoGeometryShader Shaders::MeshVisualizer2D::Flags{}\n");
+    #else
+    CORRADE_COMPARE(out.str(), "Shaders::MeshVisualizer2D::Flag::Wireframe Shaders::MeshVisualizer2D::Flags{}\n");
+    #endif
 }
 
-void MeshVisualizerTest::debugFlags() {
+void MeshVisualizerTest::debugFlags3D() {
     std::ostringstream out;
 
-    Debug{&out} << (MeshVisualizer::Flag::Wireframe|MeshVisualizer::Flag::NoGeometryShader) << MeshVisualizer::Flags{};
+    Debug{&out} << (MeshVisualizer3D::Flag::Wireframe|MeshVisualizer3D::Flag::NoGeometryShader) << MeshVisualizer3D::Flags{};
     #ifndef MAGNUM_TARGET_GLES2
-    CORRADE_COMPARE(out.str(), "Shaders::MeshVisualizer::Flag::Wireframe|Shaders::MeshVisualizer::Flag::NoGeometryShader Shaders::MeshVisualizer::Flags{}\n");
+    CORRADE_COMPARE(out.str(), "Shaders::MeshVisualizer3D::Flag::Wireframe|Shaders::MeshVisualizer3D::Flag::NoGeometryShader Shaders::MeshVisualizer3D::Flags{}\n");
     #else
-    CORRADE_COMPARE(out.str(), "Shaders::MeshVisualizer::Flag::Wireframe Shaders::MeshVisualizer::Flags{}\n");
+    CORRADE_COMPARE(out.str(), "Shaders::MeshVisualizer3D::Flag::Wireframe Shaders::MeshVisualizer3D::Flags{}\n");
     #endif
 }
 

src/Magnum/Shaders/visibility.h

@@ -39,8 +39,10 @@
 #else
     #define MAGNUM_SHADERS_EXPORT CORRADE_VISIBILITY_STATIC
 #endif
+#define MAGNUM_SHADERS_LOCAL CORRADE_VISIBILITY_LOCAL
 #else
 #define MAGNUM_SHADERS_EXPORT
+#define MAGNUM_SHADERS_LOCAL
 #endif
 
 #endif