/*
    This file is part of Magnum.

    Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019
              Vladimír Vondruš <mosra@centrum.cz>

    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included
    in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
*/

#include <sstream>
#include <Corrade/Utility/Resource.h>
#include <Corrade/TestSuite/Compare/Container.h>

#include "Magnum/Image.h"
#include "Magnum/GL/AbstractShaderProgram.h"
#include "Magnum/GL/Context.h"
#include "Magnum/GL/Extensions.h"
#if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
#include "Magnum/GL/ImageFormat.h"
#endif
#include "Magnum/GL/PixelFormat.h"
#include "Magnum/GL/Shader.h"
#include "Magnum/GL/Texture.h"
#include "Magnum/GL/TextureFormat.h"
#include "Magnum/GL/OpenGLTester.h"
#include "Magnum/Math/Matrix.h"
#include "Magnum/Math/Vector4.h"
#include "Magnum/Math/Color.h"

namespace Magnum { namespace GL { namespace Test { namespace {

struct AbstractShaderProgramGLTest: OpenGLTester {
    explicit AbstractShaderProgramGLTest();

    void construct();
    void constructMove();

    #ifndef MAGNUM_TARGET_WEBGL
    void label();
    #endif

    void create();
    void createMultipleOutputs();
    #ifndef MAGNUM_TARGET_GLES
    void createMultipleOutputsIndexed();
    #endif

    void linkFailure();
    void uniformNotFound();

    void uniform();
    void uniformVector();
    void uniformMatrix();
    void uniformArray();
    #ifndef MAGNUM_TARGET_GLES
    void uniformDouble();
    void uniformDoubleVector();
    void uniformDoubleMatrix();
    void uniformDoubleArray();
    #endif

    #ifndef MAGNUM_TARGET_GLES2
    void createUniformBlocks();
    void uniformBlockIndexNotFound();
    void uniformBlock();

    #ifndef MAGNUM_TARGET_WEBGL
    void compute();
    #endif
    #endif
};

AbstractShaderProgramGLTest::AbstractShaderProgramGLTest() {
    addTests({&AbstractShaderProgramGLTest::construct,
              &AbstractShaderProgramGLTest::constructMove,

              #ifndef MAGNUM_TARGET_WEBGL
              &AbstractShaderProgramGLTest::label,
              #endif

              &AbstractShaderProgramGLTest::create,
              &AbstractShaderProgramGLTest::createMultipleOutputs,
              #ifndef MAGNUM_TARGET_GLES
              &AbstractShaderProgramGLTest::createMultipleOutputsIndexed,
              #endif

              &AbstractShaderProgramGLTest::linkFailure,
              &AbstractShaderProgramGLTest::uniformNotFound,

              &AbstractShaderProgramGLTest::uniform,
              &AbstractShaderProgramGLTest::uniformVector,
              &AbstractShaderProgramGLTest::uniformMatrix,
              &AbstractShaderProgramGLTest::uniformArray,
              #ifndef MAGNUM_TARGET_GLES
              &AbstractShaderProgramGLTest::uniformDouble,
              &AbstractShaderProgramGLTest::uniformDoubleVector,
              &AbstractShaderProgramGLTest::uniformDoubleMatrix,
              &AbstractShaderProgramGLTest::uniformDoubleArray,
              #endif

              #ifndef MAGNUM_TARGET_GLES2
              &AbstractShaderProgramGLTest::createUniformBlocks,
              &AbstractShaderProgramGLTest::uniformBlockIndexNotFound,
              &AbstractShaderProgramGLTest::uniformBlock,

              #ifndef MAGNUM_TARGET_WEBGL
              &AbstractShaderProgramGLTest::compute
              #endif
              #endif
              });
}

class DummyShader: public AbstractShaderProgram {
    public:
        explicit DummyShader() {}
};

void AbstractShaderProgramGLTest::construct() {
    {
        const DummyShader shader;

        MAGNUM_VERIFY_NO_GL_ERROR();
        CORRADE_VERIFY(shader.id() > 0);
    }

    MAGNUM_VERIFY_NO_GL_ERROR();
}

void AbstractShaderProgramGLTest::constructMove() {
    DummyShader a;
    const Int id = a.id();

    MAGNUM_VERIFY_NO_GL_ERROR();
    CORRADE_VERIFY(id > 0);

    DummyShader b(std::move(a));

    CORRADE_COMPARE(a.id(), 0);
    CORRADE_COMPARE(b.id(), id);

    DummyShader c;
    const Int cId = c.id();
    c = std::move(b);

    MAGNUM_VERIFY_NO_GL_ERROR();
    CORRADE_VERIFY(cId > 0);
    CORRADE_COMPARE(b.id(), cId);
    CORRADE_COMPARE(c.id(), id);
}

#ifndef MAGNUM_TARGET_WEBGL
void AbstractShaderProgramGLTest::label() {
    /* No-Op version is tested in AbstractObjectGLTest */
    if(!Context::current().isExtensionSupported<Extensions::KHR::debug>() &&
       !Context::current().isExtensionSupported<Extensions::EXT::debug_label>())
        CORRADE_SKIP("Required extension is not available");

    DummyShader shader;
    CORRADE_COMPARE(shader.label(), "");

    shader.setLabel("DummyShader");
    CORRADE_COMPARE(shader.label(), "DummyShader");

    MAGNUM_VERIFY_NO_GL_ERROR();
}
#endif

struct MyPublicShader: AbstractShaderProgram {
    using AbstractShaderProgram::attachShaders;
    using AbstractShaderProgram::bindAttributeLocation;
    #ifndef MAGNUM_TARGET_GLES
    using AbstractShaderProgram::bindFragmentDataLocationIndexed;
    using AbstractShaderProgram::bindFragmentDataLocation;
    #endif
    using AbstractShaderProgram::link;
    using AbstractShaderProgram::uniformLocation;
    #ifndef MAGNUM_TARGET_GLES2
    using AbstractShaderProgram::uniformBlockIndex;
    #endif
};

void AbstractShaderProgramGLTest::create() {
    Utility::Resource rs("AbstractShaderProgramGLTest");

    Shader vert(
        #ifndef MAGNUM_TARGET_GLES
        #ifndef CORRADE_TARGET_APPLE
        Version::GL210
        #else
        Version::GL310
        #endif
        #else
        Version::GLES200
        #endif
        , Shader::Type::Vertex);
    vert.addSource(rs.get("MyShader.vert"));
    const bool vertCompiled = vert.compile();

    Shader frag(
        #ifndef MAGNUM_TARGET_GLES
        #ifndef CORRADE_TARGET_APPLE
        Version::GL210
        #else
        Version::GL310
        #endif
        #else
        Version::GLES200
        #endif
        , Shader::Type::Fragment);
    frag.addSource(rs.get("MyShader.frag"));
    const bool fragCompiled = frag.compile();

    MAGNUM_VERIFY_NO_GL_ERROR();
    CORRADE_VERIFY(vertCompiled);
    CORRADE_VERIFY(fragCompiled);

    MyPublicShader program;
    program.attachShaders({vert, frag});

    MAGNUM_VERIFY_NO_GL_ERROR();

    program.bindAttributeLocation(0, "position");
    const bool linked = program.link();
    const bool valid = program.validate().first;

    MAGNUM_VERIFY_NO_GL_ERROR();
    CORRADE_VERIFY(linked);
    {
        #ifdef CORRADE_TARGET_APPLE
        CORRADE_EXPECT_FAIL("macOS drivers need insane amount of state to validate properly.");
        #endif
        CORRADE_VERIFY(valid);
    }

    const Int matrixUniform = program.uniformLocation("matrix");
    const Int multiplierUniform = program.uniformLocation("multiplier");
    const Int colorUniform = program.uniformLocation("color");
    const Int additionsUniform = program.uniformLocation("additions");

    MAGNUM_VERIFY_NO_GL_ERROR();
    CORRADE_VERIFY(matrixUniform >= 0);
    CORRADE_VERIFY(multiplierUniform >= 0);
    CORRADE_VERIFY(colorUniform >= 0);
    CORRADE_VERIFY(additionsUniform >= 0);
}

void AbstractShaderProgramGLTest::createMultipleOutputs() {
    #ifndef MAGNUM_TARGET_GLES
    Utility::Resource rs("AbstractShaderProgramGLTest");

    Shader vert(
        #ifndef CORRADE_TARGET_APPLE
        Version::GL210
        #else
        Version::GL310
        #endif
        , Shader::Type::Vertex);
    vert.addSource(rs.get("MyShader.vert"));
    const bool vertCompiled = vert.compile();

    Shader frag(
        #ifndef CORRADE_TARGET_APPLE
        Version::GL300
        #else
        Version::GL310
        #endif
        , Shader::Type::Fragment);
    frag.addSource(rs.get("MyShaderFragmentOutputs.frag"));
    const bool fragCompiled = frag.compile();

    MAGNUM_VERIFY_NO_GL_ERROR();
    CORRADE_VERIFY(vertCompiled);
    CORRADE_VERIFY(fragCompiled);

    MyPublicShader program;
    program.attachShaders({vert, frag});

    MAGNUM_VERIFY_NO_GL_ERROR();

    program.bindAttributeLocation(0, "position");
    program.bindFragmentDataLocation(0, "first");
    program.bindFragmentDataLocation(1, "second");
    const bool linked = program.link();
    const bool valid = program.validate().first;

    MAGNUM_VERIFY_NO_GL_ERROR();
    CORRADE_VERIFY(linked);
    {
        #ifdef CORRADE_TARGET_APPLE
        CORRADE_EXPECT_FAIL("macOS drivers need insane amount of state to validate properly.");
        #endif
        CORRADE_VERIFY(valid);
    }
    #elif !defined(MAGNUM_TARGET_GLES2)
    CORRADE_SKIP("Only explicit location specification supported in ES 3.0.");
    #else
    CORRADE_SKIP("Only gl_FragData[n] supported in ES 2.0.");
    #endif
}

#ifndef MAGNUM_TARGET_GLES
void AbstractShaderProgramGLTest::createMultipleOutputsIndexed() {
    Utility::Resource rs("AbstractShaderProgramGLTest");

    Shader vert(
        #ifndef CORRADE_TARGET_APPLE
        Version::GL210
        #else
        Version::GL310
        #endif
        , Shader::Type::Vertex);
    vert.addSource(rs.get("MyShader.vert"));
    const bool vertCompiled = vert.compile();

    Shader frag(
        #ifndef CORRADE_TARGET_APPLE
        Version::GL300
        #else
        Version::GL310
        #endif
        , Shader::Type::Fragment);
    frag.addSource(rs.get("MyShaderFragmentOutputs.frag"));
    const bool fragCompiled = frag.compile();

    MAGNUM_VERIFY_NO_GL_ERROR();
    CORRADE_VERIFY(vertCompiled);
    CORRADE_VERIFY(fragCompiled);

    MyPublicShader program;
    program.attachShaders({vert, frag});

    MAGNUM_VERIFY_NO_GL_ERROR();

    program.bindAttributeLocation(0, "position");
    program.bindFragmentDataLocationIndexed(0, 0, "first");
    program.bindFragmentDataLocationIndexed(0, 1, "second");
    const bool linked = program.link();
    const bool valid = program.validate().first;

    MAGNUM_VERIFY_NO_GL_ERROR();
    CORRADE_VERIFY(linked);
    {
        #ifdef CORRADE_TARGET_APPLE
        CORRADE_EXPECT_FAIL("macOS drivers need insane amount of state to validate properly.");
        #endif
        CORRADE_VERIFY(valid);
    }
}
#endif

void AbstractShaderProgramGLTest::linkFailure() {
    Shader shader(
        #ifndef MAGNUM_TARGET_GLES
        #ifndef CORRADE_TARGET_APPLE
        Version::GL210
        #else
        Version::GL310
        #endif
        #else
        Version::GLES200
        #endif
        , Shader::Type::Fragment);
    shader.addSource("[fu] bleh error #:! stuff\n");

    {
        Error redirectError{nullptr};
        CORRADE_VERIFY(!shader.compile());
    }

    MyPublicShader program;
    program.attachShaders({shader});
    CORRADE_VERIFY(!program.link());
}

void AbstractShaderProgramGLTest::uniformNotFound() {
    MyPublicShader program;

    Shader vert(
        #ifndef MAGNUM_TARGET_GLES
        #ifndef CORRADE_TARGET_APPLE
        Version::GL210
        #else
        Version::GL310
        #endif
        #else
        Version::GLES200
        #endif
        , Shader::Type::Vertex);
    Shader frag(
        #ifndef MAGNUM_TARGET_GLES
        #ifndef CORRADE_TARGET_APPLE
        Version::GL210
        #else
        Version::GL310
        #endif
        #else
        Version::GLES200
        #endif
        , Shader::Type::Fragment);
    vert.addSource("void main() { gl_Position = vec4(0.0); }");
    frag.addSource(
        #ifndef CORRADE_TARGET_APPLE
        "void main() { gl_FragColor = vec4(1.0); }"
        #else
        "out vec4 color;\n"
        "void main() { color = vec4(1.0); }"
        #endif
        );

    CORRADE_VERIFY(Shader::compile({vert, frag}));
    program.attachShaders({vert, frag});
    CORRADE_VERIFY(program.link());

    std::ostringstream out;
    Warning redirectWarning{&out};
    program.uniformLocation("nonexistent");
    program.uniformLocation(std::string{"another"});
    CORRADE_COMPARE(out.str(),
        "GL::AbstractShaderProgram: location of uniform 'nonexistent' cannot be retrieved\n"
        "GL::AbstractShaderProgram: location of uniform 'another' cannot be retrieved\n");
}

struct MyShader: AbstractShaderProgram {
    explicit MyShader();

    using AbstractShaderProgram::setUniform;

    Int matrixUniform,
        multiplierUniform,
        colorUniform,
        additionsUniform;
};

#ifndef DOXYGEN_GENERATING_OUTPUT
MyShader::MyShader() {
    Utility::Resource rs("AbstractShaderProgramGLTest");

    Shader vert(
        #ifndef MAGNUM_TARGET_GLES
        #ifndef CORRADE_TARGET_APPLE
        Version::GL210
        #else
        Version::GL310
        #endif
        #else
        Version::GLES200
        #endif
        , Shader::Type::Vertex);
    Shader frag(
        #ifndef MAGNUM_TARGET_GLES
        #ifndef CORRADE_TARGET_APPLE
        Version::GL210
        #else
        Version::GL310
        #endif
        #else
        Version::GLES200
        #endif
        , Shader::Type::Fragment);
    vert.addSource(rs.get("MyShader.vert"));
    frag.addSource(rs.get("MyShader.frag"));

    Shader::compile({vert, frag});

    attachShaders({vert, frag});

    bindAttributeLocation(0, "position");
    link();

    matrixUniform = uniformLocation("matrix");
    multiplierUniform = uniformLocation("multiplier");
    colorUniform = uniformLocation("color");
    additionsUniform = uniformLocation("additions");
}
#endif

void AbstractShaderProgramGLTest::uniform() {
    MyShader shader;

    MAGNUM_VERIFY_NO_GL_ERROR();

    shader.setUniform(shader.multiplierUniform, 0.35f);

    MAGNUM_VERIFY_NO_GL_ERROR();
}

void AbstractShaderProgramGLTest::uniformVector() {
    MyShader shader;

    MAGNUM_VERIFY_NO_GL_ERROR();

    shader.setUniform(shader.colorUniform, Vector4(0.3f, 0.7f, 1.0f, 0.25f));

    MAGNUM_VERIFY_NO_GL_ERROR();
}

void AbstractShaderProgramGLTest::uniformMatrix() {
    MyShader shader;

    MAGNUM_VERIFY_NO_GL_ERROR();

    shader.setUniform(shader.matrixUniform, Matrix4x4::fromDiagonal({0.3f, 0.7f, 1.0f, 0.25f}));

    MAGNUM_VERIFY_NO_GL_ERROR();
}

void AbstractShaderProgramGLTest::uniformArray() {
    MyShader shader;

    MAGNUM_VERIFY_NO_GL_ERROR();

    /* Testing also implicit conversion to base type (Vector4[] -> Math::Vector<4, Float>[]) */
    #ifndef CORRADE_MSVC2015_COMPATIBILITY /* Causes ICE */
    constexpr
    #endif
    const Vector4 values[] = {
        {0.5f, 1.0f, 0.4f, 0.0f},
        {0.0f, 0.1f, 0.7f, 0.3f},
        {0.9f, 0.8f, 0.3f, 0.1f}
    };
    shader.setUniform(shader.additionsUniform, values);

    MAGNUM_VERIFY_NO_GL_ERROR();
}

#ifndef MAGNUM_TARGET_GLES
struct MyDoubleShader: AbstractShaderProgram {
    explicit MyDoubleShader();

    using AbstractShaderProgram::setUniform;

    Int matrixUniform,
        multiplierUniform,
        colorUniform,
        additionsUniform;
};

#ifndef DOXYGEN_GENERATING_OUTPUT
MyDoubleShader::MyDoubleShader() {
    Utility::Resource rs("AbstractShaderProgramGLTest");

    Shader vert(Version::GL400, Shader::Type::Vertex);
    Shader frag(Version::GL400, Shader::Type::Fragment);
    vert.addSource(rs.get("MyDoubleShader.vert"));
    frag.addSource(rs.get("MyDoubleShader.frag"));

    Shader::compile({vert, frag});

    attachShaders({vert, frag});

    bindAttributeLocation(0, "position");
    link();

    matrixUniform = uniformLocation("matrix");
    multiplierUniform = uniformLocation("multiplier");
    colorUniform = uniformLocation("color");
    additionsUniform = uniformLocation("additions");
}
#endif

void AbstractShaderProgramGLTest::uniformDouble() {
    MyDoubleShader shader;

    MAGNUM_VERIFY_NO_GL_ERROR();

    shader.setUniform(shader.multiplierUniform, 0.35);

    MAGNUM_VERIFY_NO_GL_ERROR();
}

void AbstractShaderProgramGLTest::uniformDoubleVector() {
    MyDoubleShader shader;

    MAGNUM_VERIFY_NO_GL_ERROR();

    shader.setUniform(shader.colorUniform, Vector4d{0.3, 0.7, 1.0, 0.25});

    MAGNUM_VERIFY_NO_GL_ERROR();
}

void AbstractShaderProgramGLTest::uniformDoubleMatrix() {
    MyDoubleShader shader;

    MAGNUM_VERIFY_NO_GL_ERROR();

    shader.setUniform(shader.matrixUniform, Matrix4x4d::fromDiagonal({0.3, 0.7, 1.0f, 0.25}));

    MAGNUM_VERIFY_NO_GL_ERROR();
}

void AbstractShaderProgramGLTest::uniformDoubleArray() {
    MyDoubleShader shader;

    MAGNUM_VERIFY_NO_GL_ERROR();

    /* Testing also implicit conversion to base type (Vector4d[] -> Math::Vector<4, Double>[]) */
    #ifndef CORRADE_MSVC2015_COMPATIBILITY /* Causes ICE */
    constexpr
    #endif
    const Vector4d values[] = {
        {0.5, 1.0, 0.4, 0.0},
        {0.0, 0.1, 0.7, 0.3},
        {0.9, 0.8, 0.3, 0.1}
    };
    shader.setUniform(shader.additionsUniform, values);

    MAGNUM_VERIFY_NO_GL_ERROR();
}
#endif

#ifndef MAGNUM_TARGET_GLES2
void AbstractShaderProgramGLTest::createUniformBlocks() {
    Utility::Resource rs("AbstractShaderProgramGLTest");

    Shader vert(
        #ifndef MAGNUM_TARGET_GLES
        Version::GL310
        #else
        Version::GLES300
        #endif
        , Shader::Type::Vertex);
    vert.addSource(rs.get("UniformBlockShader.vert"));
    const bool vertCompiled = vert.compile();

    Shader frag(
        #ifndef MAGNUM_TARGET_GLES
        Version::GL310
        #else
        Version::GLES300
        #endif
        , Shader::Type::Fragment);
    frag.addSource(rs.get("UniformBlockShader.frag"));
    const bool fragCompiled = frag.compile();

    MAGNUM_VERIFY_NO_GL_ERROR();
    CORRADE_VERIFY(vertCompiled);
    CORRADE_VERIFY(fragCompiled);

    MyPublicShader program;
    program.attachShaders({vert, frag});

    MAGNUM_VERIFY_NO_GL_ERROR();

    const bool linked = program.link();
    const bool valid = program.validate().first;

    MAGNUM_VERIFY_NO_GL_ERROR();
    CORRADE_VERIFY(linked);
    {
        #ifdef CORRADE_TARGET_APPLE
        CORRADE_EXPECT_FAIL("macOS drivers need insane amount of state to validate properly.");
        #endif
        CORRADE_VERIFY(valid);
    }

    const Int matricesUniformBlock = program.uniformBlockIndex("matrices");
    const Int materialUniformBlock = program.uniformBlockIndex("material");

    MAGNUM_VERIFY_NO_GL_ERROR();
    CORRADE_VERIFY(matricesUniformBlock >= 0);
    CORRADE_VERIFY(materialUniformBlock >= 0);
}

void AbstractShaderProgramGLTest::uniformBlockIndexNotFound() {
    MyPublicShader program;

    Shader vert(
        #ifndef MAGNUM_TARGET_GLES
        Version::GL310
        #else
        Version::GLES300
        #endif
        , Shader::Type::Vertex);
    Shader frag(
        #ifndef MAGNUM_TARGET_GLES
        Version::GL310
        #else
        Version::GLES300
        #endif
        , Shader::Type::Fragment);
    vert.addSource("void main() { gl_Position = vec4(0.0); }");
    frag.addSource("out lowp vec4 color;\n"
                   "void main() { color = vec4(1.0); }");

    CORRADE_VERIFY(Shader::compile({vert, frag}));
    program.attachShaders({vert, frag});
    CORRADE_VERIFY(program.link());

    std::ostringstream out;
    Warning redirectWarning{&out};
    program.uniformBlockIndex("nonexistent");
    program.uniformBlockIndex(std::string{"another"});
    CORRADE_COMPARE(out.str(),
        "GL::AbstractShaderProgram: index of uniform block 'nonexistent' cannot be retrieved\n"
        "GL::AbstractShaderProgram: index of uniform block 'another' cannot be retrieved\n");
}

struct UniformBlockShader: AbstractShaderProgram {
    explicit UniformBlockShader();

    using AbstractShaderProgram::setUniformBlockBinding;

    Int matricesUniformBlock,
        materialUniformBlock;
};

#ifndef DOXYGEN_GENERATING_OUTPUT
UniformBlockShader::UniformBlockShader() {
    Utility::Resource rs("AbstractShaderProgramGLTest");

    Shader vert(
        #ifndef MAGNUM_TARGET_GLES
        Version::GL310
        #else
        Version::GLES300
        #endif
        , Shader::Type::Vertex);
    Shader frag(
        #ifndef MAGNUM_TARGET_GLES
        Version::GL310
        #else
        Version::GLES300
        #endif
        , Shader::Type::Fragment);
    vert.addSource(rs.get("UniformBlockShader.vert"));
    frag.addSource(rs.get("UniformBlockShader.frag"));

    Shader::compile({vert, frag});
    attachShaders({vert, frag});

    link();

    matricesUniformBlock = uniformBlockIndex("matrices");
    materialUniformBlock = uniformBlockIndex("material");
}
#endif

void AbstractShaderProgramGLTest::uniformBlock() {
    UniformBlockShader shader;

    MAGNUM_VERIFY_NO_GL_ERROR();

    shader.setUniformBlockBinding(shader.matricesUniformBlock, 0);
    shader.setUniformBlockBinding(shader.materialUniformBlock, 1);

    MAGNUM_VERIFY_NO_GL_ERROR();
}

#ifndef MAGNUM_TARGET_WEBGL
void AbstractShaderProgramGLTest::compute() {
    #ifndef MAGNUM_TARGET_GLES
    if(!Context::current().isExtensionSupported<Extensions::ARB::compute_shader>())
        CORRADE_SKIP(Extensions::ARB::compute_shader::string() + std::string(" is not supported."));
    #else
    if(!Context::current().isVersionSupported(Version::GLES310))
        CORRADE_SKIP("OpenGL ES 3.1 is not supported.");
    #endif

    struct ComputeShader: AbstractShaderProgram {
        explicit ComputeShader() {
            Utility::Resource rs("AbstractShaderProgramGLTest");

            Shader compute(
                #ifndef MAGNUM_TARGET_GLES
                Version::GL430,
                #else
                Version::GLES310,
                #endif
                Shader::Type::Compute);
            compute.addSource(rs.get("ComputeShader.comp"));
            CORRADE_INTERNAL_ASSERT(compute.compile());

            attachShader(compute);
            link();
        }

        ComputeShader& setImages(Texture2D& input, Texture2D& output) {
            input.bindImage(0, 0, ImageAccess::ReadOnly, ImageFormat::RGBA8UI);
            output.bindImage(1, 0, ImageAccess::WriteOnly, ImageFormat::RGBA8UI);
            return *this;
        }
    } shader;

    MAGNUM_VERIFY_NO_GL_ERROR();

    const Color4ub inData[] = {
        { 10,  20,  30,  40},
        { 50,  60,  70,  80},
        { 90, 100, 110, 120},
        {130, 140, 150, 160}
    };

    #ifndef MAGNUM_TARGET_GLES
    const Color4ub outData[] = {
        { 15,  30,  45,  60},
        { 75,  90, 105, 120},
        {135, 150, 165, 180},
        {195, 210, 225, 240}
    };
    #endif

    Texture2D in;
    in.setStorage(1, TextureFormat::RGBA8UI, {2, 2})
        .setSubImage(0, {}, ImageView2D{PixelFormat::RGBAInteger, PixelType::UnsignedByte, {2, 2}, inData});

    Texture2D out;
    out.setStorage(1, TextureFormat::RGBA8UI, {2, 2});

    MAGNUM_VERIFY_NO_GL_ERROR();

    shader.setImages(in, out)
        .dispatchCompute({1, 1, 1});

    MAGNUM_VERIFY_NO_GL_ERROR();

    /** @todo Test on ES */
    #ifndef MAGNUM_TARGET_GLES
    const auto data = out.image(0, {PixelFormat::RGBAInteger, PixelType::UnsignedByte}).release();

    MAGNUM_VERIFY_NO_GL_ERROR();

    CORRADE_COMPARE_AS(Containers::arrayCast<const Color4ub>(data),
        Containers::arrayView(outData),
        TestSuite::Compare::Container);
    #endif
}
#endif
#endif

}}}}

CORRADE_TEST_MAIN(Magnum::GL::Test::AbstractShaderProgramGLTest)