ladybird/Meta/Lagom/Tools/CodeGenerators/LibWeb/GenerateWebGLRenderingContext.cpp

/*
 * Copyright (c) 2024, Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
 * Copyright (c) 2024, Luke Wilde <luke@ladybird.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include "BindingsGenerator/IDLGenerators.h"

#include <AK/LexicalPath.h>
#include <AK/SourceGenerator.h>
#include <AK/StringBuilder.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/File.h>
#include <LibIDL/IDLParser.h>
#include <LibMain/Main.h>

static bool is_webgl_object_type(StringView type_name)
{
    return type_name == "WebGLBuffer"sv
        || type_name == "WebGLFramebuffer"sv
        || type_name == "WebGLProgram"sv
        || type_name == "WebGLRenderbuffer"sv
        || type_name == "WebGLSampler"sv
        || type_name == "WebGLShader"sv
        || type_name == "WebGLTexture"sv
        || type_name == "WebGLVertexArrayObject"sv;
}

static bool gl_function_modifies_framebuffer(StringView function_name)
{
    return function_name == "clear"sv
        || function_name == "clearBufferfv"sv
        || function_name == "clearBufferiv"sv
        || function_name == "clearBufferuiv"sv
        || function_name == "clearBufferfi"sv
        || function_name == "drawArrays"sv
        || function_name == "drawElements"sv
        || function_name == "drawElementsInstanced"sv
        || function_name == "blitFramebuffer"sv
        || function_name == "invalidateFramebuffer"sv;
}

static ByteString to_cpp_type(const IDL::Type& type, const IDL::Interface& interface)
{
    if (type.name() == "undefined"sv)
        return "void"sv;
    if (type.name() == "object"sv) {
        if (type.is_nullable())
            return "JS::Object*"sv;
        return "JS::Object&"sv;
    }
    if (type.name() == "DOMString"sv) {
        if (type.is_nullable())
            return "Optional<String>"sv;
        return "String"sv;
    }
    auto cpp_type = idl_type_name_to_cpp_type(type, interface);
    return cpp_type.name;
}

static ByteString idl_to_gl_function_name(StringView function_name)
{
    StringBuilder gl_function_name_builder;
    gl_function_name_builder.append("gl"sv);
    for (size_t i = 0; i < function_name.length(); ++i) {
        if (i == 0) {
            gl_function_name_builder.append(to_ascii_uppercase(function_name[i]));
        } else {
            gl_function_name_builder.append(function_name[i]);
        }
    }
    if (function_name == "clearDepth"sv || function_name == "depthRange"sv) {
        gl_function_name_builder.append("f"sv);
    }
    return gl_function_name_builder.to_byte_string();
}

struct NameAndType {
    StringView name;
    struct {
        StringView type;
        int element_count { 0 };
    } return_type;
    Optional<int> webgl_version { OptionalNone {} };
};

static void generate_get_parameter(SourceGenerator& generator, int webgl_version)
{
    Vector<NameAndType> const name_to_type = {
        { "ACTIVE_TEXTURE"sv, { "GLenum"sv } },
        { "ALIASED_LINE_WIDTH_RANGE"sv, { "Float32Array"sv, 2 } },
        { "ALIASED_POINT_SIZE_RANGE"sv, { "Float32Array"sv, 2 } },
        { "ALPHA_BITS"sv, { "GLint"sv } },
        { "ARRAY_BUFFER_BINDING"sv, { "WebGLBuffer"sv } },
        { "BLEND"sv, { "GLboolean"sv } },
        { "BLEND_COLOR"sv, { "Float32Array"sv, 4 } },
        { "BLEND_DST_ALPHA"sv, { "GLenum"sv } },
        { "BLEND_DST_RGB"sv, { "GLenum"sv } },
        { "BLEND_EQUATION_ALPHA"sv, { "GLenum"sv } },
        { "BLEND_EQUATION_RGB"sv, { "GLenum"sv } },
        { "BLEND_SRC_ALPHA"sv, { "GLenum"sv } },
        { "BLEND_SRC_RGB"sv, { "GLenum"sv } },
        { "BLUE_BITS"sv, { "GLint"sv } },
        { "COLOR_CLEAR_VALUE"sv, { "Float32Array"sv, 4 } },
        // FIXME: { "COLOR_WRITEMASK"sv, { "sequence<GLboolean>"sv, 4 } },
        // FIXME: { "COMPRESSED_TEXTURE_FORMATS"sv, { "Uint32Array"sv } },
        { "CULL_FACE"sv, { "GLboolean"sv } },
        { "CULL_FACE_MODE"sv, { "GLenum"sv } },
        { "CURRENT_PROGRAM"sv, { "WebGLProgram"sv } },
        { "DEPTH_BITS"sv, { "GLint"sv } },
        { "DEPTH_CLEAR_VALUE"sv, { "GLfloat"sv } },
        { "DEPTH_FUNC"sv, { "GLenum"sv } },
        { "DEPTH_RANGE"sv, { "Float32Array"sv, 2 } },
        { "DEPTH_TEST"sv, { "GLboolean"sv } },
        { "DEPTH_WRITEMASK"sv, { "GLboolean"sv } },
        { "DITHER"sv, { "GLboolean"sv } },
        { "ELEMENT_ARRAY_BUFFER_BINDING"sv, { "WebGLBuffer"sv } },
        { "FRAMEBUFFER_BINDING"sv, { "WebGLFramebuffer"sv } },
        { "FRONT_FACE"sv, { "GLenum"sv } },
        { "GENERATE_MIPMAP_HINT"sv, { "GLenum"sv } },
        { "GREEN_BITS"sv, { "GLint"sv } },
        { "IMPLEMENTATION_COLOR_READ_FORMAT"sv, { "GLenum"sv } },
        { "IMPLEMENTATION_COLOR_READ_TYPE"sv, { "GLenum"sv } },
        { "LINE_WIDTH"sv, { "GLfloat"sv } },
        { "MAX_COMBINED_TEXTURE_IMAGE_UNITS"sv, { "GLint"sv } },
        { "MAX_CUBE_MAP_TEXTURE_SIZE"sv, { "GLint"sv } },
        { "MAX_FRAGMENT_UNIFORM_VECTORS"sv, { "GLint"sv } },
        { "MAX_RENDERBUFFER_SIZE"sv, { "GLint"sv } },
        { "MAX_TEXTURE_IMAGE_UNITS"sv, { "GLint"sv } },
        { "MAX_TEXTURE_SIZE"sv, { "GLint"sv } },
        { "MAX_VARYING_VECTORS"sv, { "GLint"sv } },
        { "MAX_VERTEX_ATTRIBS"sv, { "GLint"sv } },
        { "MAX_VERTEX_TEXTURE_IMAGE_UNITS"sv, { "GLint"sv } },
        { "MAX_VERTEX_UNIFORM_VECTORS"sv, { "GLint"sv } },
        { "MAX_VIEWPORT_DIMS"sv, { "Int32Array"sv, 2 } },
        { "PACK_ALIGNMENT"sv, { "GLint"sv } },
        { "POLYGON_OFFSET_FACTOR"sv, { "GLfloat"sv } },
        { "POLYGON_OFFSET_FILL"sv, { "GLboolean"sv } },
        { "POLYGON_OFFSET_UNITS"sv, { "GLfloat"sv } },
        { "RED_BITS"sv, { "GLint"sv } },
        { "RENDERBUFFER_BINDING"sv, { "WebGLRenderbuffer"sv } },
        { "RENDERER"sv, { "DOMString"sv } },
        { "SAMPLE_ALPHA_TO_COVERAGE"sv, { "GLboolean"sv } },
        { "SAMPLE_BUFFERS"sv, { "GLint"sv } },
        { "SAMPLE_COVERAGE"sv, { "GLboolean"sv } },
        { "SAMPLE_COVERAGE_INVERT"sv, { "GLboolean"sv } },
        { "SAMPLE_COVERAGE_VALUE"sv, { "GLfloat"sv } },
        { "SAMPLES"sv, { "GLint"sv } },
        { "SCISSOR_BOX"sv, { "Int32Array"sv, 4 } },
        { "SCISSOR_TEST"sv, { "GLboolean"sv } },
        { "SHADING_LANGUAGE_VERSION"sv, { "DOMString"sv } },
        { "STENCIL_BACK_FAIL"sv, { "GLenum"sv } },
        { "STENCIL_BACK_FUNC"sv, { "GLenum"sv } },
        { "STENCIL_BACK_PASS_DEPTH_FAIL"sv, { "GLenum"sv } },
        { "STENCIL_BACK_PASS_DEPTH_PASS"sv, { "GLenum"sv } },
        { "STENCIL_BACK_REF"sv, { "GLint"sv } },
        { "STENCIL_BACK_VALUE_MASK"sv, { "GLuint"sv } },
        { "STENCIL_BACK_WRITEMASK"sv, { "GLuint"sv } },
        { "STENCIL_BITS"sv, { "GLint"sv } },
        { "STENCIL_CLEAR_VALUE"sv, { "GLint"sv } },
        { "STENCIL_FAIL"sv, { "GLenum"sv } },
        { "STENCIL_FUNC"sv, { "GLenum"sv } },
        { "STENCIL_PASS_DEPTH_FAIL"sv, { "GLenum"sv } },
        { "STENCIL_PASS_DEPTH_PASS"sv, { "GLenum"sv } },
        { "STENCIL_REF"sv, { "GLint"sv } },
        { "STENCIL_TEST"sv, { "GLboolean"sv } },
        { "STENCIL_VALUE_MASK"sv, { "GLuint"sv } },
        { "STENCIL_WRITEMASK"sv, { "GLuint"sv } },
        { "SUBPIXEL_BITS"sv, { "GLint"sv } },
        { "TEXTURE_BINDING_2D"sv, { "WebGLTexture"sv } },
        { "TEXTURE_BINDING_CUBE_MAP"sv, { "WebGLTexture"sv } },
        { "UNPACK_ALIGNMENT"sv, { "GLint"sv } },
        // FIXME: { "UNPACK_COLORSPACE_CONVERSION_WEBGL"sv, { "GLenum"sv } },
        // FIXME: { "UNPACK_FLIP_Y_WEBGL"sv, { "GLboolean"sv } },
        // FIXME: { "UNPACK_PREMULTIPLY_ALPHA_WEBGL"sv, { "GLboolean"sv } },
        { "VENDOR"sv, { "DOMString"sv } },
        { "VERSION"sv, { "DOMString"sv } },
        { "VIEWPORT"sv, { "Int32Array"sv, 4 } },
        { "MAX_SAMPLES"sv, { "GLint"sv }, 2 },
        { "MAX_3D_TEXTURE_SIZE"sv, { "GLint"sv }, 2 },
        { "MAX_ARRAY_TEXTURE_LAYERS"sv, { "GLint"sv }, 2 },
        { "MAX_COLOR_ATTACHMENTS"sv, { "GLint"sv }, 2 },
        { "MAX_VERTEX_UNIFORM_COMPONENTS"sv, { "GLint"sv }, 2 },
        { "MAX_UNIFORM_BLOCK_SIZE"sv, { "GLint64"sv }, 2 },
        { "MAX_UNIFORM_BUFFER_BINDINGS"sv, { "GLint"sv }, 2 },
        { "UNIFORM_BUFFER_OFFSET_ALIGNMENT"sv, { "GLint"sv }, 2 },
        { "MAX_DRAW_BUFFERS"sv, { "GLint"sv }, 2 },
        { "MAX_VERTEX_UNIFORM_BLOCKS"sv, { "GLint"sv }, 2 },
        { "MAX_FRAGMENT_INPUT_COMPONENTS"sv, { "GLint"sv }, 2 },
        { "MAX_COMBINED_UNIFORM_BLOCKS"sv, { "GLint"sv }, 2 },
        { "UNIFORM_BUFFER_BINDING"sv, { "WebGLBuffer"sv }, 2 },
        { "TEXTURE_BINDING_2D_ARRAY"sv, { "WebGLTexture"sv }, 2 },
        { "COPY_READ_BUFFER_BINDING"sv, { "WebGLBuffer"sv }, 2 },
        { "COPY_WRITE_BUFFER_BINDING"sv, { "WebGLBuffer"sv }, 2 },
        { "MAX_ELEMENT_INDEX"sv, { "GLint64"sv }, 2 },
        { "MAX_FRAGMENT_UNIFORM_BLOCKS"sv, { "GLint"sv }, 2 },
        { "MAX_VARYING_COMPONENTS"sv, { "GLint"sv }, 2 },
    };

    auto is_primitive_type = [](StringView type) {
        return type == "GLboolean"sv || type == "GLint"sv || type == "GLfloat"sv || type == "GLenum"sv || type == "GLuint"sv;
    };

    generator.append("    switch (pname) {");
    for (auto const& name_and_type : name_to_type) {
        if (name_and_type.webgl_version.has_value() && name_and_type.webgl_version.value() != webgl_version)
            continue;

        auto const& parameter_name = name_and_type.name;
        auto const& type_name = name_and_type.return_type.type;

        StringBuilder string_builder;
        SourceGenerator impl_generator { string_builder };
        impl_generator.set("parameter_name", parameter_name);
        impl_generator.set("type_name", type_name);
        impl_generator.append(R"~~~(
    case GL_@parameter_name@: {)~~~");
        if (is_primitive_type(type_name)) {
            impl_generator.append(R"~~~(
        GLint result;
        glGetIntegerv(GL_@parameter_name@, &result);
        return JS::Value(result);
)~~~");
        } else if (type_name == "GLint64"sv) {
            impl_generator.append(R"~~~(
        GLint64 result;
        glGetInteger64v(GL_@parameter_name@, &result);
        return JS::Value(static_cast<double>(result));
)~~~");
        } else if (type_name == "DOMString"sv) {
            impl_generator.append(R"~~~(
        auto result = reinterpret_cast<const char*>(glGetString(GL_@parameter_name@));
        return JS::PrimitiveString::create(m_realm->vm(), ByteString { result });)~~~");
        } else if (type_name == "Float32Array"sv || type_name == "Int32Array"sv) {
            auto element_count = name_and_type.return_type.element_count;
            impl_generator.set("element_count", MUST(String::formatted("{}", element_count)));
            if (type_name == "Int32Array"sv) {
                impl_generator.set("gl_function_name", "glGetIntegerv"sv);
                impl_generator.set("element_type", "GLint"sv);
            } else if (type_name == "Float32Array"sv) {
                impl_generator.set("gl_function_name", "glGetFloatv"sv);
                impl_generator.set("element_type", "GLfloat"sv);
            } else {
                VERIFY_NOT_REACHED();
            }
            impl_generator.append(R"~~~(
        Array<@element_type@, @element_count@> result;
        @gl_function_name@(GL_@parameter_name@, result.data());
        auto byte_buffer = MUST(ByteBuffer::copy(result.data(), @element_count@ * sizeof(@element_type@)));
        auto array_buffer = JS::ArrayBuffer::create(m_realm, move(byte_buffer));
        return JS::@type_name@::create(m_realm, @element_count@, array_buffer);
)~~~");
        } else if (type_name == "WebGLProgram"sv || type_name == "WebGLBuffer"sv || type_name == "WebGLTexture"sv || type_name == "WebGLFramebuffer"sv || type_name == "WebGLRenderbuffer"sv) {
            impl_generator.set("stored_name", name_and_type.name.to_lowercase_string());
            impl_generator.append(R"~~~(
        if (!m_@stored_name@)
            return JS::js_null();
        return JS::Value(m_@stored_name@);
)~~~");
        } else {
            VERIFY_NOT_REACHED();
        }

        impl_generator.append("    }");

        generator.append(string_builder.string_view());
    }

    generator.appendln(R"~~~(
    default:
        dbgln("Unknown WebGL parameter name: {:x}", pname);
        set_error(GL_INVALID_ENUM);
        return JS::js_null();
    })~~~");
}

static void generate_get_buffer_parameter(SourceGenerator& generator)
{
    Vector<NameAndType> const name_to_type = {
        { "BUFFER_SIZE"sv, { "GLint"sv } },
        { "BUFFER_USAGE"sv, { "GLenum"sv } },
    };

    generator.append("    switch (pname) {");

    for (auto const& name_and_type : name_to_type) {
        auto const& parameter_name = name_and_type.name;
        auto const& type_name = name_and_type.return_type.type;

        StringBuilder string_builder;
        SourceGenerator impl_generator { string_builder };
        impl_generator.set("parameter_name", parameter_name);
        impl_generator.set("type_name", type_name);
        impl_generator.append(R"~~~(
    case GL_@parameter_name@: {
        GLint result;
        glGetBufferParameteriv(target, GL_@parameter_name@, &result);
        return JS::Value(result);
    }
)~~~");

        generator.append(string_builder.string_view());
    }

    generator.appendln(R"~~~(
    default:
        dbgln("Unknown WebGL buffer parameter name: {:x}", pname);
        set_error(GL_INVALID_ENUM);
        return JS::js_null();
    })~~~");
}

static void generate_get_internal_format_parameter(SourceGenerator& generator)
{
    generator.append(R"~~~(
    switch (pname) {
    case GL_SAMPLES: {
        GLint num_sample_counts { 0 };
        glGetInternalformativ(target, internalformat, GL_NUM_SAMPLE_COUNTS, 1, &num_sample_counts);
        auto samples_buffer = MUST(ByteBuffer::create_zeroed(num_sample_counts * sizeof(GLint)));
        glGetInternalformativ(target, internalformat, GL_SAMPLES, num_sample_counts, reinterpret_cast<GLint*>(samples_buffer.data()));
        auto array_buffer = JS::ArrayBuffer::create(m_realm, move(samples_buffer));
        return JS::Int32Array::create(m_realm, num_sample_counts, array_buffer);
    }
    default:
        dbgln("Unknown WebGL internal format parameter name: {:x}", pname);
        set_error(GL_INVALID_ENUM);
        return JS::js_null();
    }
)~~~");
}

static void generate_webgl_object_handle_unwrap(SourceGenerator& generator, StringView object_name, StringView early_return_value)
{
    StringBuilder string_builder;
    SourceGenerator unwrap_generator { string_builder };
    unwrap_generator.set("object_name", object_name);
    unwrap_generator.set("early_return_value", early_return_value);
    unwrap_generator.append(R"~~~(
    GLuint @object_name@_handle = 0;
    if (@object_name@) {
        auto handle_or_error = @object_name@->handle(this);
        if (handle_or_error.is_error()) {
            set_error(GL_INVALID_OPERATION);
            return @early_return_value@;
        }
        @object_name@_handle = handle_or_error.release_value();
    }
)~~~");

    generator.append(unwrap_generator.as_string_view());
}

static void generate_get_active_uniform_block_parameter(SourceGenerator& generator)
{
    generate_webgl_object_handle_unwrap(generator, "program"sv, "JS::js_null()"sv);
    generator.append(R"~~~(
    switch (pname) {
    case GL_UNIFORM_BLOCK_BINDING:
    case GL_UNIFORM_BLOCK_DATA_SIZE:
    case GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS: {
        GLint result = 0;
        glGetActiveUniformBlockiv(program_handle, uniform_block_index, pname, &result);
        return JS::Value(result);
    }
    case GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES: {
        GLint num_active_uniforms = 0;
        glGetActiveUniformBlockiv(program_handle, uniform_block_index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS, &num_active_uniforms);
        auto active_uniform_indices_buffer = MUST(ByteBuffer::create_zeroed(num_active_uniforms * sizeof(GLint)));
        glGetActiveUniformBlockiv(program_handle, uniform_block_index, GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES, reinterpret_cast<GLint*>(active_uniform_indices_buffer.data()));
        auto array_buffer = JS::ArrayBuffer::create(m_realm, move(active_uniform_indices_buffer));
        return JS::Uint32Array::create(m_realm, num_active_uniforms, array_buffer);
    }
    case GL_UNIFORM_BLOCK_REFERENCED_BY_VERTEX_SHADER:
    case GL_UNIFORM_BLOCK_REFERENCED_BY_FRAGMENT_SHADER: {
        GLint result = 0;
        glGetActiveUniformBlockiv(program_handle, uniform_block_index, pname, &result);
        return JS::Value(result == GL_TRUE);
    }
    default:
        dbgln("Unknown WebGL active uniform block parameter name: {:x}", pname);
        set_error(GL_INVALID_ENUM);
        return JS::js_null();
    }
)~~~");
}

ErrorOr<int> serenity_main(Main::Arguments arguments)
{
    StringView generated_header_path;
    StringView generated_implementation_path;
    Vector<ByteString> base_paths;
    StringView webgl_context_idl_path;

    Core::ArgsParser args_parser;
    args_parser.add_option(webgl_context_idl_path, "Path to the WebGLRenderingContext idl file", "webgl-idl-path", 'i', "webgl-idl-path");
    args_parser.add_option(Core::ArgsParser::Option {
        .argument_mode = Core::ArgsParser::OptionArgumentMode::Required,
        .help_string = "Path to root of IDL file tree(s)",
        .long_name = "base-path",
        .short_name = 'b',
        .value_name = "base-path",
        .accept_value = [&](StringView s) {
            base_paths.append(s);
            return true;
        },
    });
    args_parser.add_option(generated_header_path, "Path to the header file to generate", "generated-header-path", 'h', "generated-header-path");
    args_parser.add_option(generated_implementation_path, "Path to the implementation file to generate", "generated-implementation-path", 'c', "generated-implementation-path");
    args_parser.parse(arguments);

    auto generated_header_file = TRY(Core::File::open(generated_header_path, Core::File::OpenMode::Write));
    auto generated_implementation_file = TRY(Core::File::open(generated_implementation_path, Core::File::OpenMode::Write));

    auto idl_file = MUST(Core::File::open(webgl_context_idl_path, Core::File::OpenMode::Read));
    auto webgl_context_idl_file_content = MUST(idl_file->read_until_eof());

    Vector<ByteString> import_base_paths;
    for (auto const& base_path : base_paths) {
        VERIFY(!base_path.is_empty());
        import_base_paths.append(base_path);
    }

    IDL::Parser parser(webgl_context_idl_path, StringView(webgl_context_idl_file_content), import_base_paths);
    auto const& interface = parser.parse();

    auto path = LexicalPath(generated_header_path);
    auto title = path.title();
    auto first_dot = title.find('.');
    ByteString class_name = title;
    if (first_dot.has_value())
        class_name = title.substring_view(0, *first_dot);

    StringBuilder header_file_string_builder;
    SourceGenerator header_file_generator { header_file_string_builder };
    header_file_generator.set("class_name", class_name);

    StringBuilder implementation_file_string_builder;
    SourceGenerator implementation_file_generator { implementation_file_string_builder };
    implementation_file_generator.set("class_name", class_name);

    auto webgl_version = class_name == "WebGLRenderingContextImpl" ? 1 : 2;
    if (webgl_version == 1) {
        implementation_file_generator.append(R"~~~(
#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>
)~~~");
    } else {
        implementation_file_generator.append(R"~~~(
#include <GLES3/gl3.h>
)~~~");
    }

    implementation_file_generator.append(R"~~~(
#include <LibJS/Runtime/ArrayBuffer.h>
#include <LibJS/Runtime/DataView.h>
#include <LibJS/Runtime/TypedArray.h>
#include <LibWeb/HTML/HTMLCanvasElement.h>
#include <LibWeb/HTML/HTMLImageElement.h>
#include <LibWeb/HTML/HTMLVideoElement.h>
#include <LibWeb/HTML/ImageBitmap.h>
#include <LibWeb/HTML/ImageData.h>
#include <LibWeb/WebGL/OpenGLContext.h>
#include <LibWeb/WebGL/WebGLActiveInfo.h>
#include <LibWeb/WebGL/WebGLBuffer.h>
#include <LibWeb/WebGL/WebGLFramebuffer.h>
#include <LibWeb/WebGL/WebGLProgram.h>
#include <LibWeb/WebGL/WebGLRenderbuffer.h>
#include <LibWeb/WebGL/@class_name@.h>
#include <LibWeb/WebGL/WebGLSampler.h>
#include <LibWeb/WebGL/WebGLShader.h>
#include <LibWeb/WebGL/WebGLSync.h>
#include <LibWeb/WebGL/WebGLShaderPrecisionFormat.h>
#include <LibWeb/WebGL/WebGLTexture.h>
#include <LibWeb/WebGL/WebGLUniformLocation.h>
#include <LibWeb/WebGL/WebGLVertexArrayObject.h>
#include <LibWeb/WebIDL/Buffers.h>

namespace Web::WebGL {

static Vector<GLchar> null_terminated_string(StringView string)
{
    Vector<GLchar> result;
    for (auto c : string.bytes())
        result.append(c);
    result.append('\\0');
    return result;
}

@class_name@::@class_name@(JS::Realm& realm, NonnullOwnPtr<OpenGLContext> context)
    : m_realm(realm)
    , m_context(move(context))
{
}

)~~~");

    header_file_generator.append(R"~~~(
#pragma once

#include <AK/NonnullOwnPtr.h>
#include <LibGC/Ptr.h>
#include <LibGfx/Bitmap.h>
#include <LibWeb/Bindings/PlatformObject.h>
#include <LibWeb/Forward.h>
#include <LibWeb/WebGL/WebGLRenderingContextBase.h>
#include <LibWeb/WebIDL/Types.h>

namespace Web::WebGL {

using namespace Web::HTML;

class @class_name@ : public WebGLRenderingContextBase {
public:
    @class_name@(JS::Realm&, NonnullOwnPtr<OpenGLContext>);

    OpenGLContext& context() { return *m_context; }

    virtual void present() = 0;
    virtual void needs_to_present() = 0;
    virtual void set_error(GLenum) = 0;
)~~~");

    for (auto const& function : interface.functions) {
        if (function.extended_attributes.contains("FIXME")) {
            continue;
        }

        if (function.name == "getSupportedExtensions"sv || function.name == "getExtension"sv || function.name == "getContextAttributes"sv || function.name == "isContextLost"sv) {
            // Implemented in WebGLRenderingContext
            continue;
        }

        StringBuilder function_declaration;

        StringBuilder function_parameters;
        for (size_t i = 0; i < function.parameters.size(); ++i) {
            auto const& parameter = function.parameters[i];
            function_parameters.append(to_cpp_type(*parameter.type, interface));
            function_parameters.append(" "sv);
            function_parameters.append(parameter.name.to_snakecase());
            if (i != function.parameters.size() - 1) {
                function_parameters.append(", "sv);
            }
        }

        auto function_name = function.name.to_snakecase();
        function_declaration.append(to_cpp_type(*function.return_type, interface));
        function_declaration.append(" "sv);
        function_declaration.append(function_name);
        function_declaration.append("("sv);

        function_declaration.append(function_parameters.string_view());
        function_declaration.append(");"sv);

        header_file_generator.append("    "sv);
        header_file_generator.append(function_declaration.string_view());
        header_file_generator.append("\n"sv);

        StringBuilder function_impl;
        SourceGenerator function_impl_generator { function_impl };
        function_impl_generator.set("class_name", class_name);

        ScopeGuard function_guard { [&] {
            function_impl_generator.append("}\n"sv);
            implementation_file_generator.append(function_impl_generator.as_string_view().bytes());
        } };

        function_impl_generator.set("function_name", function_name);
        function_impl_generator.set("function_parameters", function_parameters.string_view());
        function_impl_generator.set("function_return_type", to_cpp_type(*function.return_type, interface));
        function_impl_generator.append(R"~~~(
@function_return_type@ @class_name@::@function_name@(@function_parameters@)
{
    m_context->make_current();
)~~~");

        if (gl_function_modifies_framebuffer(function.name)) {
            function_impl_generator.append("    m_context->notify_content_will_change();\n"sv);
        }

        if (function.name == "getUniformLocation"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "program"sv, "{}"sv);
            function_impl_generator.append(R"~~~(
    auto name_null_terminated = null_terminated_string(name);
    return WebGLUniformLocation::create(m_realm, glGetUniformLocation(program_handle, name_null_terminated.data()));
)~~~");
            continue;
        }

        if (function.name == "createBuffer"sv) {
            function_impl_generator.append(R"~~~(
    GLuint handle = 0;
    glGenBuffers(1, &handle);
    return WebGLBuffer::create(m_realm, *this, handle);
)~~~");
            continue;
        }

        if (function.name == "createTexture"sv) {
            function_impl_generator.append(R"~~~(
    GLuint handle = 0;
    glGenTextures(1, &handle);
    return WebGLTexture::create(m_realm, *this, handle);
)~~~");
            continue;
        }

        if (function.name == "createFramebuffer"sv) {
            function_impl_generator.append(R"~~~(
    GLuint handle = 0;
    glGenFramebuffers(1, &handle);
    return WebGLFramebuffer::create(m_realm, *this, handle);
)~~~");
            continue;
        }

        if (function.name == "createRenderbuffer"sv) {
            function_impl_generator.append(R"~~~(
    GLuint handle = 0;
    glGenRenderbuffers(1, &handle);
    return WebGLRenderbuffer::create(m_realm, *this, handle);
)~~~");
            continue;
        }

        if (function.name == "invalidateFramebuffer"sv) {
            function_impl_generator.append(R"~~~(
    glInvalidateFramebuffer(target, attachments.size(), attachments.data());
    needs_to_present();
)~~~");
            continue;
        }

        if (function.name == "createVertexArray"sv) {
            function_impl_generator.append(R"~~~(
    GLuint handle = 0;
    glGenVertexArrays(1, &handle);
    return WebGLVertexArrayObject::create(m_realm, *this, handle);
)~~~");
            continue;
        }

        if (function.name == "createSampler"sv) {
            function_impl_generator.append(R"~~~(
    GLuint handle = 0;
    glGenSamplers(1, &handle);
    return WebGLSampler::create(m_realm, *this, handle);
)~~~");
            continue;
        }

        if (function.name == "fenceSync"sv) {
            function_impl_generator.append(R"~~~(
    GLsync handle = glFenceSync(condition, flags);
    return WebGLSync::create(m_realm, *this, handle);
)~~~");
            continue;
        }

        if (function.name == "shaderSource"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "shader"sv, ""sv);
            function_impl_generator.append(R"~~~(
    Vector<GLchar*> strings;
    auto string = null_terminated_string(source);
    strings.append(string.data());
    Vector<GLint> length;
    length.append(source.bytes().size());
    glShaderSource(shader_handle, 1, strings.data(), length.data());
)~~~");
            continue;
        }

        if (function.name == "vertexAttribPointer"sv) {
            function_impl_generator.append(R"~~~(
    glVertexAttribPointer(index, size, type, normalized, stride, reinterpret_cast<void*>(offset));
)~~~");
            continue;
        }

        if (function.name == "texStorage2D") {
            function_impl_generator.append(R"~~~(
    glTexStorage2D(target, levels, internalformat, width, height);
)~~~");
            continue;
        }

        if (function.name == "texImage2D"sv && function.overload_index == 0) {
            function_impl_generator.append(R"~~~(
    void const* pixels_ptr = nullptr;
    if (pixels) {
        auto const& viewed_array_buffer = pixels->viewed_array_buffer();
        auto const& byte_buffer = viewed_array_buffer->buffer();
        pixels_ptr = byte_buffer.data();
    }
    glTexImage2D(target, level, internalformat, width, height, border, format, type, pixels_ptr);
)~~~");
            continue;
        }

        if (function.name == "texImage3D"sv && function.overload_index == 0) {
            // FIXME: If a WebGLBuffer is bound to the PIXEL_UNPACK_BUFFER target, generates an INVALID_OPERATION error.
            // FIXME: If srcData is null, a buffer of sufficient size initialized to 0 is passed.
            // FIXME: If type is specified as FLOAT_32_UNSIGNED_INT_24_8_REV, srcData must be null; otherwise, generates an INVALID_OPERATION error.
            // FIXME: If srcData is non-null, the type of srcData must match the type according to the above table; otherwise, generate an INVALID_OPERATION error.
            // FIXME: If an attempt is made to call this function with no WebGLTexture bound (see above), generates an INVALID_OPERATION error.
            // FIXME: If there's not enough data in srcData starting at srcOffset, generate INVALID_OPERATION.
            function_impl_generator.append(R"~~~(
    void const* src_data_ptr = nullptr;
    if (src_data) {
        auto const& viewed_array_buffer = src_data->viewed_array_buffer();
        auto const& byte_buffer = viewed_array_buffer->buffer();
        src_data_ptr = byte_buffer.data();
    }
    glTexImage3D(target, level, internalformat, width, height, depth, border, format, type, src_data_ptr);
)~~~");
            continue;
        }

        if (function.name == "texImage3D"sv && function.overload_index == 1) {
            // FIXME: If a WebGLBuffer is bound to the PIXEL_UNPACK_BUFFER target, generates an INVALID_OPERATION error.
            // FIXME: If srcData is null, a buffer of sufficient size initialized to 0 is passed.
            // FIXME: If type is specified as FLOAT_32_UNSIGNED_INT_24_8_REV, srcData must be null; otherwise, generates an INVALID_OPERATION error.
            // FIXME: If srcData is non-null, the type of srcData must match the type according to the above table; otherwise, generate an INVALID_OPERATION error.
            // FIXME: If an attempt is made to call this function with no WebGLTexture bound (see above), generates an INVALID_OPERATION error.
            // FIXME: If there's not enough data in srcData starting at srcOffset, generate INVALID_OPERATION.
            function_impl_generator.append(R"~~~(
    void const* src_data_ptr = nullptr;
    if (src_data) {
        auto const& viewed_array_buffer = src_data->viewed_array_buffer();
        auto const& byte_buffer = viewed_array_buffer->buffer();
        src_data_ptr = byte_buffer.data() + src_offset;
    }
    glTexImage3D(target, level, internalformat, width, height, depth, border, format, type, src_data_ptr);
)~~~");
            continue;
        }

        if (function.name == "texImage2D"sv && (function.overload_index == 1 || (webgl_version == 2 && function.overload_index == 2))) {
            // FIXME: If this function is called with an ImageData whose data attribute has been neutered,
            //        an INVALID_VALUE error is generated.
            // FIXME: If this function is called with an ImageBitmap that has been neutered, an INVALID_VALUE
            //        error is generated.
            // FIXME: If this function is called with an HTMLImageElement or HTMLVideoElement whose origin
            //        differs from the origin of the containing Document, or with an HTMLCanvasElement,
            //        ImageBitmap or OffscreenCanvas whose bitmap's origin-clean flag is set to false,
            //        a SECURITY_ERR exception must be thrown. See Origin Restrictions.
            // FIXME: If source is null then an INVALID_VALUE error is generated.
            function_impl_generator.append(R"~~~(
    auto bitmap = source.visit(
        [](GC::Root<HTMLImageElement> const& source) -> RefPtr<Gfx::ImmutableBitmap> {
            return source->immutable_bitmap();
        },
        [](GC::Root<HTMLCanvasElement> const& source) -> RefPtr<Gfx::ImmutableBitmap> {
            auto surface = source->surface();
            if (!surface)
                return {};
            auto bitmap = MUST(Gfx::Bitmap::create(Gfx::BitmapFormat::RGBA8888, Gfx::AlphaType::Premultiplied, surface->size()));
            surface->read_into_bitmap(*bitmap);
            return Gfx::ImmutableBitmap::create(*bitmap);
        },
        [](GC::Root<HTMLVideoElement> const& source) -> RefPtr<Gfx::ImmutableBitmap> {
            return Gfx::ImmutableBitmap::create(*source->bitmap());
        },
        [](GC::Root<ImageBitmap> const& source) -> RefPtr<Gfx::ImmutableBitmap> {
            return Gfx::ImmutableBitmap::create(*source->bitmap());
        },
        [](GC::Root<ImageData> const& source) -> RefPtr<Gfx::ImmutableBitmap> {
            return Gfx::ImmutableBitmap::create(source->bitmap());
        });
    if (!bitmap)
        return;

    void const* pixels_ptr = bitmap->bitmap()->begin();
)~~~");

            if (webgl_version == 2 && function.overload_index == 2) {
                function_impl_generator.append(R"~~~(
    glTexImage2D(target, level, internalformat, width, height, border, format, type, pixels_ptr);
)~~~");
            } else {
                function_impl_generator.append(R"~~~(
    int width = bitmap->width();
    int height = bitmap->height();
    glTexImage2D(target, level, internalformat, width, height, 0, format, type, pixels_ptr);
)~~~");
            }
            continue;
        }

        if (webgl_version == 2 && function.name == "texImage2D"sv && function.overload_index == 3) {
            function_impl_generator.append(R"~~~(
    void const* pixels_ptr = nullptr;
    if (src_data) {
        auto const& viewed_array_buffer = src_data->viewed_array_buffer();
        auto const& byte_buffer = viewed_array_buffer->buffer();
        pixels_ptr = byte_buffer.data() + src_offset;
    }
    glTexImage2D(target, level, internalformat, width, height, border, format, type, pixels_ptr);
)~~~");
            continue;
        }

        if (function.name == "texSubImage2D"sv && function.overload_index == 0) {
            function_impl_generator.append(R"~~~(
    void const* pixels_ptr = nullptr;
    if (pixels) {
        auto const& viewed_array_buffer = pixels->viewed_array_buffer();
        auto const& byte_buffer = viewed_array_buffer->buffer();
        pixels_ptr = byte_buffer.data();
    }
    glTexSubImage2D(target, level, xoffset, yoffset, width, height, format, type, pixels_ptr);
)~~~");
            continue;
        }

        if (function.name == "texSubImage2D" && (function.overload_index == 1 || (webgl_version == 2 && function.overload_index == 2))) {
            // FIXME: If this function is called with an ImageData whose data attribute has been neutered,
            //        an INVALID_VALUE error is generated.
            // FIXME: If this function is called with an ImageBitmap that has been neutered, an INVALID_VALUE
            //        error is generated.
            // FIXME: If this function is called with an HTMLImageElement or HTMLVideoElement whose origin
            //        differs from the origin of the containing Document, or with an HTMLCanvasElement,
            //        ImageBitmap or OffscreenCanvas whose bitmap's origin-clean flag is set to false,
            //        a SECURITY_ERR exception must be thrown. See Origin Restrictions.
            // FIXME: If source is null then an INVALID_VALUE error is generated.
            function_impl_generator.append(R"~~~(
    auto bitmap = source.visit(
        [](GC::Root<HTMLImageElement> const& source) -> RefPtr<Gfx::ImmutableBitmap> {
            return source->immutable_bitmap();
        },
        [](GC::Root<HTMLCanvasElement> const& source) -> RefPtr<Gfx::ImmutableBitmap> {
            auto surface = source->surface();
            if (!surface)
                return {};
            auto bitmap = MUST(Gfx::Bitmap::create(Gfx::BitmapFormat::RGBA8888, Gfx::AlphaType::Premultiplied, surface->size()));
            surface->read_into_bitmap(*bitmap);
            return Gfx::ImmutableBitmap::create(*bitmap);
        },
        [](GC::Root<HTMLVideoElement> const& source) -> RefPtr<Gfx::ImmutableBitmap> {
            return Gfx::ImmutableBitmap::create(*source->bitmap());
        },
        [](GC::Root<ImageBitmap> const& source) -> RefPtr<Gfx::ImmutableBitmap> {
            return Gfx::ImmutableBitmap::create(*source->bitmap());
        },
        [](GC::Root<ImageData> const& source) -> RefPtr<Gfx::ImmutableBitmap> {
            return Gfx::ImmutableBitmap::create(source->bitmap());
        });
    if (!bitmap)
        return;

    void const* pixels_ptr = bitmap->bitmap()->begin();
)~~~");
            if (webgl_version == 2 && function.overload_index == 2) {
                function_impl_generator.append(R"~~~(
    glTexSubImage2D(target, level, xoffset, yoffset, width, height, format, type, pixels_ptr);
)~~~");
            } else {
                function_impl_generator.append(R"~~~(
    int width = bitmap->width();
    int height = bitmap->height();
    glTexSubImage2D(target, level, xoffset, yoffset, width, height, format, type, pixels_ptr);
)~~~");
            }
            continue;
        }

        if (webgl_version == 2 && function.name == "texSubImage2D"sv && function.overload_index == 3) {
            function_impl_generator.append(R"~~~(
    void const* pixels_ptr = nullptr;
    if (src_data) {
        auto const& viewed_array_buffer = src_data->viewed_array_buffer();
        auto const& byte_buffer = viewed_array_buffer->buffer();
        pixels_ptr = byte_buffer.data() + src_offset;
    }
    glTexSubImage2D(target, level, xoffset, yoffset, width, height, format, type, pixels_ptr);
)~~~");
            continue;
        }

        if (function.name == "texSubImage3D"sv && function.overload_index == 0) {
            function_impl_generator.append(R"~~~(
    void const* pixels_ptr = nullptr;
    if (src_data) {
        auto const& viewed_array_buffer = src_data->viewed_array_buffer();
        auto const& byte_buffer = viewed_array_buffer->buffer();
        pixels_ptr = byte_buffer.data() + src_offset;
    }
    glTexSubImage3D(target, level, xoffset, yoffset, zoffset, width, height, depth, format, type, pixels_ptr);
)~~~");
            continue;
        }

        if (function.name == "getShaderParameter"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "shader"sv, "JS::js_null()"sv);
            function_impl_generator.append(R"~~~(
    GLint result = 0;
    glGetShaderiv(shader_handle, pname, &result);
    return JS::Value(result);
)~~~");
            continue;
        }

        if (function.name == "getProgramParameter"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "program"sv, "JS::js_null()"sv);
            function_impl_generator.append(R"~~~(
    GLint result = 0;
    glGetProgramiv(program_handle, pname, &result);
    return JS::Value(result);
)~~~");
            continue;
        }

        if (function.name == "getActiveUniformBlockParameter"sv) {
            generate_get_active_uniform_block_parameter(function_impl_generator);
            continue;
        }

        if (function.name == "bufferData"sv && function.overload_index == 0) {
            function_impl_generator.append(R"~~~(
    glBufferData(target, size, 0, usage);
)~~~");
            continue;
        }

        if (webgl_version == 2 && function.name == "bufferData"sv && function.overload_index == 2) {
            function_impl_generator.append(R"~~~(
    VERIFY(src_data);
    auto const& viewed_array_buffer = src_data->viewed_array_buffer();
    auto const& byte_buffer = viewed_array_buffer->buffer();
    auto src_data_length = src_data->byte_length();
    auto src_data_element_size = src_data->element_size();
    u8 const* buffer_ptr = byte_buffer.data();

    u64 copy_length = length == 0 ? src_data_length - src_offset : length;
    copy_length *= src_data_element_size;

    if (src_offset > src_data_length) {
        set_error(GL_INVALID_VALUE);
        return;
    }

    if (src_offset + copy_length > src_data_length) {
        set_error(GL_INVALID_VALUE);
        return;
    }

    buffer_ptr += src_offset * src_data_element_size;
    glBufferData(target, copy_length, buffer_ptr, usage);
)~~~");
            continue;
        }

        if (webgl_version == 2 && function.name == "bufferSubData"sv && function.overload_index == 1) {
            function_impl_generator.append(R"~~~(
    VERIFY(src_data);
    auto const& viewed_array_buffer = src_data->viewed_array_buffer();
    auto const& byte_buffer = viewed_array_buffer->buffer();
    auto src_data_length = src_data->byte_length();
    auto src_data_element_size = src_data->element_size();
    u8 const* buffer_ptr = byte_buffer.data();

    u64 copy_length = length == 0 ? src_data_length - src_offset : length;
    copy_length *= src_data_element_size;

    if (src_offset > src_data_length) {
        set_error(GL_INVALID_VALUE);
        return;
    }

    if (src_offset + copy_length > src_data_length) {
        set_error(GL_INVALID_VALUE);
        return;
    }

    buffer_ptr += src_offset * src_data_element_size;
    glBufferSubData(target, dst_byte_offset, copy_length, buffer_ptr);
)~~~");
            continue;
        }

        if (function.name == "readPixels"sv) {
            function_impl_generator.append(R"~~~(
    if (!pixels) {
        return;
    }

    void *ptr = nullptr;
    if (pixels->is_data_view()) {
        auto& data_view = static_cast<JS::DataView&>(*pixels->raw_object());
        ptr = data_view.viewed_array_buffer()->buffer().data();
    } else if (pixels->is_typed_array_base()) {
        auto& typed_array_base = static_cast<JS::TypedArrayBase&>(*pixels->raw_object());
        ptr = typed_array_base.viewed_array_buffer()->buffer().data();
    } else {
        VERIFY_NOT_REACHED();
    }

    glReadPixels(x, y, width, height, format, type, ptr);
)~~~");
            continue;
        }

        if (function.name == "drawElements"sv) {
            function_impl_generator.append(R"~~~(
    glDrawElements(mode, count, type, reinterpret_cast<void*>(offset));
    needs_to_present();
)~~~");
            continue;
        }

        if (function.name == "drawElementsInstanced"sv) {
            function_impl_generator.append(R"~~~(
    glDrawElementsInstanced(mode, count, type, reinterpret_cast<void*>(offset), instance_count);
    needs_to_present();
)~~~");
            continue;
        }

        if (function.name == "drawBuffers"sv) {
            function_impl_generator.append(R"~~~(
    glDrawBuffers(buffers.size(), buffers.data());
)~~~");
            continue;
        }

        if (function.name.starts_with("uniformMatrix"sv)) {
            auto number_of_matrix_elements = function.name.substring_view(13, 1);
            function_impl_generator.set("number_of_matrix_elements", number_of_matrix_elements);

            if (webgl_version == 1) {
                function_impl_generator.set("array_argument_name", "value");
            } else {
                function_impl_generator.set("array_argument_name", "data");
            }

            function_impl_generator.append(R"~~~(
    auto matrix_size = @number_of_matrix_elements@ * @number_of_matrix_elements@;
    float const* raw_data = nullptr;
    u64 count = 0;
    if (@array_argument_name@.has<Vector<float>>()) {
        auto& vector_data = @array_argument_name@.get<Vector<float>>();
        raw_data = vector_data.data();
        count = vector_data.size() / matrix_size;
    } else {
        auto& typed_array_base = static_cast<JS::TypedArrayBase&>(*@array_argument_name@.get<GC::Root<WebIDL::BufferSource>>()->raw_object());
        auto& float32_array = verify_cast<JS::Float32Array>(typed_array_base);
        raw_data = float32_array.data().data();
        count = float32_array.array_length().length() / matrix_size;
    }
)~~~");

            if (webgl_version == 2) {
                function_impl_generator.append(R"~~~(
    if (src_offset + src_length > (count * matrix_size)) {
        set_error(GL_INVALID_VALUE);
        return;
    }

    raw_data += src_offset;
    if (src_length == 0) {
        count -= src_offset;
    } else {
        count = src_length;
    }
)~~~");
            }

            function_impl_generator.append(R"~~~(
    glUniformMatrix@number_of_matrix_elements@fv(location->handle(), count, transpose, raw_data);
)~~~");
            continue;
        }

        if (function.name == "uniform1fv"sv || function.name == "uniform2fv"sv || function.name == "uniform3fv"sv || function.name == "uniform4fv"sv || function.name == "uniform1iv"sv || function.name == "uniform2iv"sv || function.name == "uniform3iv"sv || function.name == "uniform4iv"sv) {
            auto number_of_vector_elements = function.name.substring_view(7, 1);
            auto element_type = function.name.substring_view(8, 1);
            if (element_type == "f"sv) {
                function_impl_generator.set("cpp_element_type", "float"sv);
                function_impl_generator.set("typed_array_type", "Float32Array"sv);
                function_impl_generator.set("gl_postfix", "f"sv);
            } else if (element_type == "i"sv) {
                function_impl_generator.set("cpp_element_type", "int"sv);
                function_impl_generator.set("typed_array_type", "Int32Array"sv);
                function_impl_generator.set("gl_postfix", "i"sv);
            } else {
                VERIFY_NOT_REACHED();
            }
            function_impl_generator.set("number_of_vector_elements", number_of_vector_elements);
            function_impl_generator.append(R"~~~(
    @cpp_element_type@ const* data = nullptr;
    size_t count = 0;
    if (v.has<Vector<@cpp_element_type@>>()) {
        auto& vector = v.get<Vector<@cpp_element_type@>>();
        data = vector.data();
        count = vector.size();
    } else if (v.has<GC::Root<WebIDL::BufferSource>>()) {
        auto& typed_array_base = static_cast<JS::TypedArrayBase&>(*v.get<GC::Root<WebIDL::BufferSource>>()->raw_object());
        auto& typed_array = verify_cast<JS::@typed_array_type@>(typed_array_base);
        data = typed_array.data().data();
        count = typed_array.array_length().length();
    } else {
        VERIFY_NOT_REACHED();
    }
)~~~");

            if (webgl_version == 2) {
                function_impl_generator.append(R"~~~(
    if (src_offset + src_length > count) {
        set_error(GL_INVALID_VALUE);
        return;
    }

    data += src_offset;
    if (src_length == 0) {
        count -= src_offset;
    } else {
        count = src_length;
    }
)~~~");
            }

            function_impl_generator.append(R"~~~(
    glUniform@number_of_vector_elements@@gl_postfix@v(location->handle(), count / @number_of_vector_elements@, data);
)~~~");
            continue;
        }

        if (function.name == "vertexAttrib1fv"sv || function.name == "vertexAttrib2fv"sv || function.name == "vertexAttrib3fv"sv || function.name == "vertexAttrib4fv"sv) {
            auto number_of_vector_elements = function.name.substring_view(12, 1);
            function_impl_generator.set("number_of_vector_elements", number_of_vector_elements);
            function_impl_generator.append(R"~~~(
    if (values.has<Vector<float>>()) {
        auto& data = values.get<Vector<float>>();
        glVertexAttrib@number_of_vector_elements@fv(index, data.data());
        return;
    }

    auto& typed_array_base = static_cast<JS::TypedArrayBase&>(*values.get<GC::Root<WebIDL::BufferSource>>()->raw_object());
    auto& float32_array = verify_cast<JS::Float32Array>(typed_array_base);
    float const* data = float32_array.data().data();
    glVertexAttrib@number_of_vector_elements@fv(index, data);
)~~~");
            continue;
        }

        if (function.name == "vertexAttribIPointer"sv) {
            function_impl_generator.append(R"~~~(
    glVertexAttribIPointer(index, size, type, stride, reinterpret_cast<void*>(offset));
)~~~");
            continue;
        }

        if (function.name == "getParameter"sv) {
            generate_get_parameter(function_impl_generator, webgl_version);
            continue;
        }

        if (function.name == "getBufferParameter"sv) {
            generate_get_buffer_parameter(function_impl_generator);
            continue;
        }

        if (function.name == "getInternalformatParameter") {
            generate_get_internal_format_parameter(function_impl_generator);
            continue;
        }

        if (function.name == "getActiveUniform"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "program"sv, "{}"sv);
            function_impl_generator.append(R"~~~(
    GLint size = 0;
    GLenum type = 0;
    GLsizei buf_size = 256;
    GLsizei length = 0;
    GLchar name[256];
    glGetActiveUniform(program_handle, index, buf_size, &length, &size, &type, name);
    auto readonly_bytes = ReadonlyBytes { name, static_cast<size_t>(length) };
    return WebGLActiveInfo::create(m_realm, String::from_utf8_without_validation(readonly_bytes), type, size);
)~~~");
            continue;
        }

        if (function.name == "getActiveAttrib"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "program"sv, "{}"sv);
            function_impl_generator.append(R"~~~(
    GLint size = 0;
    GLenum type = 0;
    GLsizei buf_size = 256;
    GLsizei length = 0;
    GLchar name[256];
    glGetActiveAttrib(program_handle, index, buf_size, &length, &size, &type, name);
    auto readonly_bytes = ReadonlyBytes { name, static_cast<size_t>(length) };
    return WebGLActiveInfo::create(m_realm, String::from_utf8_without_validation(readonly_bytes), type, size);
)~~~");
            continue;
        }

        if (function.name == "getShaderInfoLog"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "shader"sv, "{}"sv);
            function_impl_generator.append(R"~~~(
    GLint info_log_length = 0;
    glGetShaderiv(shader_handle, GL_INFO_LOG_LENGTH, &info_log_length);
    Vector<GLchar> info_log;
    info_log.resize(info_log_length);
    if (!info_log_length)
        return String {};
    glGetShaderInfoLog(shader_handle, info_log_length, nullptr, info_log.data());
    return String::from_utf8_without_validation(ReadonlyBytes { info_log.data(), static_cast<size_t>(info_log_length - 1) });
)~~~");
            continue;
        }

        if (function.name == "getProgramInfoLog"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "program"sv, "{}"sv);
            function_impl_generator.append(R"~~~(
    GLint info_log_length = 0;
    glGetProgramiv(program_handle, GL_INFO_LOG_LENGTH, &info_log_length);
    Vector<GLchar> info_log;
    info_log.resize(info_log_length);
    if (!info_log_length)
        return String {};
    glGetProgramInfoLog(program_handle, info_log_length, nullptr, info_log.data());
    return String::from_utf8_without_validation(ReadonlyBytes { info_log.data(), static_cast<size_t>(info_log_length - 1) });
)~~~");
            continue;
        }

        if (function.name == "getShaderPrecisionFormat"sv) {
            function_impl_generator.append(R"~~~(
    GLint range[2];
    GLint precision;
    glGetShaderPrecisionFormat(shadertype, precisiontype, range, &precision);
    return WebGLShaderPrecisionFormat::create(m_realm, range[0], range[1], precision);
)~~~");
            continue;
        }

        if (function.name == "getActiveUniformBlockName"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "program"sv, "OptionalNone {}"sv);
            function_impl_generator.append(R"~~~(
    GLint uniform_block_name_length = 0;
    glGetActiveUniformBlockiv(program_handle, uniform_block_index, GL_UNIFORM_BLOCK_NAME_LENGTH, &uniform_block_name_length);
    Vector<GLchar> uniform_block_name;
    uniform_block_name.resize(uniform_block_name_length);
    if (!uniform_block_name_length)
        return String {};
    glGetActiveUniformBlockName(program_handle, uniform_block_index, uniform_block_name_length, nullptr, uniform_block_name.data());
    return String::from_utf8_without_validation(ReadonlyBytes { uniform_block_name.data(), static_cast<size_t>(uniform_block_name_length - 1) });
)~~~");
            continue;
        }

        if (function.name == "deleteBuffer"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "buffer"sv, ""sv);
            function_impl_generator.append(R"~~~(
    glDeleteBuffers(1, &buffer_handle);
)~~~");
            continue;
        }

        if (function.name == "deleteFramebuffer"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "framebuffer"sv, ""sv);
            function_impl_generator.append(R"~~~(
    glDeleteFramebuffers(1, &framebuffer_handle);
)~~~");
            continue;
        }

        if (function.name == "deleteRenderbuffer"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "renderbuffer"sv, ""sv);
            function_impl_generator.append(R"~~~(
    glDeleteRenderbuffers(1, &renderbuffer_handle);
)~~~");
            continue;
        }

        if (function.name == "deleteTexture"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "texture"sv, ""sv);
            function_impl_generator.append(R"~~~(
    glDeleteTextures(1, &texture_handle);
)~~~");
            continue;
        }

        if (function.name == "deleteVertexArray"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "vertex_array"sv, ""sv);
            function_impl_generator.append(R"~~~(
    glDeleteVertexArrays(1, &vertex_array_handle);
)~~~");
            continue;
        }

        if (function.name == "deleteSampler"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "sampler"sv, ""sv);
            function_impl_generator.append(R"~~~(
    glDeleteSamplers(1, &sampler_handle);
)~~~");
            continue;
        }

        if (function.name == "bindBuffer"sv) {
            // FIXME: Implement Buffer Object Binding restrictions.
            generate_webgl_object_handle_unwrap(function_impl_generator, "buffer"sv, ""sv);
            function_impl_generator.append(R"~~~(
    switch (target) {
    case GL_ELEMENT_ARRAY_BUFFER:
        m_element_array_buffer_binding = buffer;
        break;
    case GL_ARRAY_BUFFER:
        m_array_buffer_binding = buffer;
        break;
)~~~");

            if (webgl_version == 2) {
                function_impl_generator.append(R"~~~(
    case GL_UNIFORM_BUFFER:
        m_uniform_buffer_binding = buffer;
        break;
    case GL_COPY_READ_BUFFER:
        m_copy_read_buffer_binding = buffer;
        break;
    case GL_COPY_WRITE_BUFFER:
        m_copy_write_buffer_binding = buffer;
        break;
)~~~");
            }

            function_impl_generator.append(R"~~~(
    default:
        dbgln("Unknown WebGL buffer object binding target for storing current binding: 0x{:04x}", target);
        break;
    }

    glBindBuffer(target, buffer_handle);
)~~~");
            continue;
        }

        if (function.name == "useProgram"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "program"sv, ""sv);
            function_impl_generator.append(R"~~~(
    glUseProgram(program_handle);
    m_current_program = program;
)~~~");
            continue;
        }

        if (function.name == "bindFramebuffer"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "framebuffer"sv, ""sv);
            function_impl_generator.append(R"~~~(
    glBindFramebuffer(target, framebuffer_handle);
    m_framebuffer_binding = framebuffer;
)~~~");
            continue;
        }

        if (function.name == "bindRenderbuffer"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "renderbuffer"sv, ""sv);
            function_impl_generator.append(R"~~~(
    glBindRenderbuffer(target, renderbuffer_handle);
    m_renderbuffer_binding = renderbuffer;
)~~~");
            continue;
        }

        if (function.name == "bindTexture"sv) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "texture"sv, ""sv);
            function_impl_generator.append(R"~~~(
    switch (target) {
    case GL_TEXTURE_2D:
        m_texture_binding_2d = texture;
        break;
    case GL_TEXTURE_CUBE_MAP:
        m_texture_binding_cube_map = texture;
        break;
)~~~");

            if (webgl_version == 2) {
                function_impl_generator.append(R"~~~(
    case GL_TEXTURE_2D_ARRAY:
        m_texture_binding_2d_array = texture;
        break;
    case GL_TEXTURE_3D:
        m_texture_binding_3d = texture;
        break;
)~~~");
            }

            function_impl_generator.append(R"~~~(
    default:
        dbgln("Unknown WebGL texture target for storing current binding: 0x{:04x}", target);
        break;
    }
    glBindTexture(target, texture_handle);
)~~~");
            continue;
        }

        if (function.name == "renderbufferStorage"sv) {
            // To be backward compatible with WebGL 1, also accepts internal format DEPTH_STENCIL, which should be
            // mapped to DEPTH24_STENCIL8 by implementations.
            if (webgl_version == 2) {
                function_impl_generator.append(R"~~~(
    if (internalformat == GL_DEPTH_STENCIL)
        internalformat = GL_DEPTH24_STENCIL8;
)~~~");
            }

            function_impl_generator.append(R"~~~(
    glRenderbufferStorage(target, internalformat, width, height);
)~~~");
            continue;
        }

        if (function.name.starts_with("samplerParameter"sv)) {
            generate_webgl_object_handle_unwrap(function_impl_generator, "sampler"sv, ""sv);
            function_impl_generator.set("param_type", function.name.substring_view(16, 1));
            // pname is given in the following table:
            // - TEXTURE_COMPARE_FUNC
            // - TEXTURE_COMPARE_MODE
            // - TEXTURE_MAG_FILTER
            // - TEXTURE_MAX_LOD
            // - TEXTURE_MIN_FILTER
            // - TEXTURE_MIN_LOD
            // - TEXTURE_WRAP_R
            // - TEXTURE_WRAP_S
            // - TEXTURE_WRAP_T
            // If pname is not in the table above, generates an INVALID_ENUM error.
            // NOTE: We have to do this ourselves, as OpenGL does not.
            function_impl_generator.append(R"~~~(
    switch (pname) {
    case GL_TEXTURE_COMPARE_FUNC:
    case GL_TEXTURE_COMPARE_MODE:
    case GL_TEXTURE_MAG_FILTER:
    case GL_TEXTURE_MAX_LOD:
    case GL_TEXTURE_MIN_FILTER:
    case GL_TEXTURE_MIN_LOD:
    case GL_TEXTURE_WRAP_R:
    case GL_TEXTURE_WRAP_S:
    case GL_TEXTURE_WRAP_T:
        break;
    default:
        dbgln("Unknown WebGL sampler parameter name: 0x{:04x}", pname);
        set_error(GL_INVALID_ENUM);
        return;
    }
    glSamplerParameter@param_type@(sampler_handle, pname, param);
)~~~");
            continue;
        }

        if (function.name.starts_with("clearBuffer"sv) && function.name.ends_with('v')) {
            auto element_type = function.name.substring_view(11, 2);
            if (element_type == "fv"sv) {
                function_impl_generator.set("cpp_element_type", "float"sv);
                function_impl_generator.set("typed_array_type", "Float32Array"sv);
                function_impl_generator.set("gl_postfix", "f"sv);
            } else if (element_type == "iv"sv) {
                function_impl_generator.set("cpp_element_type", "int"sv);
                function_impl_generator.set("typed_array_type", "Int32Array"sv);
                function_impl_generator.set("gl_postfix", "i"sv);
            } else if (element_type == "ui"sv) {
                function_impl_generator.set("cpp_element_type", "u32"sv);
                function_impl_generator.set("typed_array_type", "Uint32Array"sv);
                function_impl_generator.set("gl_postfix", "ui"sv);
            } else {
                VERIFY_NOT_REACHED();
            }
            function_impl_generator.append(R"~~~(
    @cpp_element_type@ const* data = nullptr;
    size_t count = 0;
    if (values.has<Vector<@cpp_element_type@>>()) {
        auto& vector = values.get<Vector<@cpp_element_type@>>();
        data = vector.data();
        count = vector.size();
    } else if (values.has<GC::Root<WebIDL::BufferSource>>()) {
        auto& typed_array_base = static_cast<JS::TypedArrayBase&>(*values.get<GC::Root<WebIDL::BufferSource>>()->raw_object());
        auto& typed_array = verify_cast<JS::@typed_array_type@>(typed_array_base);
        data = typed_array.data().data();
        count = typed_array.array_length().length();
    } else {
        VERIFY_NOT_REACHED();
    }

    switch (buffer) {
    case GL_COLOR:
        if (src_offset + 4 > count) {
            set_error(GL_INVALID_VALUE);
            return;
        }
        break;
    case GL_DEPTH:
    case GL_STENCIL:
        if (src_offset + 1 > count) {
            set_error(GL_INVALID_VALUE);
            return;
        }
        break;
    default:
        dbgln("Unknown WebGL buffer target for buffer clearing: 0x{:04x}", buffer);
        set_error(GL_INVALID_ENUM);
        return;
    }

    data += src_offset;
    glClearBuffer@gl_postfix@v(buffer, drawbuffer, data);
    needs_to_present();
)~~~");
            continue;
        }

        Vector<ByteString> gl_call_arguments;
        for (size_t i = 0; i < function.parameters.size(); ++i) {
            auto const& parameter = function.parameters[i];
            auto parameter_name = parameter.name.to_snakecase();
            if (parameter.type->is_numeric() || parameter.type->is_boolean()) {
                gl_call_arguments.append(parameter_name);
                continue;
            }
            if (parameter.type->is_string()) {
                function_impl_generator.set("parameter_name", parameter_name);
                function_impl_generator.append(R"~~~(
    auto @parameter_name@_null_terminated = null_terminated_string(@parameter_name@);
)~~~");
                gl_call_arguments.append(ByteString::formatted("{}_null_terminated.data()", parameter_name));
                continue;
            }
            if (is_webgl_object_type(parameter.type->name())) {
                if (function.return_type->name() == "undefined"sv) {
                    function_impl_generator.set("early_return_value", "");
                } else if (function.return_type->is_integer()) {
                    function_impl_generator.set("early_return_value", "-1");
                } else if (function.return_type->is_boolean()) {
                    function_impl_generator.set("early_return_value", "false");
                } else {
                    VERIFY_NOT_REACHED();
                }
                function_impl_generator.set("handle_parameter_name", parameter_name);
                function_impl_generator.append(R"~~~(
    auto @handle_parameter_name@_handle = 0;
    if (@handle_parameter_name@) {
        auto handle_or_error = @handle_parameter_name@->handle(this);
        if (handle_or_error.is_error()) {
            set_error(GL_INVALID_OPERATION);
            return @early_return_value@;
        }
        @handle_parameter_name@_handle = handle_or_error.release_value();
    }
)~~~");
                gl_call_arguments.append(ByteString::formatted("{}_handle", parameter_name));
                continue;
            }
            if (parameter.type->name() == "WebGLUniformLocation"sv) {
                gl_call_arguments.append(ByteString::formatted("{} ? {}->handle() : 0", parameter_name, parameter_name));
                continue;
            }
            if (parameter.type->name() == "WebGLSync"sv) {
                // FIXME: Remove the GLsync cast once sync_handle actually returns the proper GLsync type.
                gl_call_arguments.append(ByteString::formatted("(GLsync)({} ? {}->sync_handle() : nullptr)", parameter_name, parameter_name));
                continue;
            }
            if (parameter.type->name() == "BufferSource"sv) {
                function_impl_generator.set("buffer_source_name", parameter_name);
                function_impl_generator.append(R"~~~(
    void const* ptr = nullptr;
    size_t byte_size = 0;
    if (@buffer_source_name@->is_typed_array_base()) {
        auto& typed_array_base = static_cast<JS::TypedArrayBase&>(*@buffer_source_name@->raw_object());
        ptr = typed_array_base.viewed_array_buffer()->buffer().data() + typed_array_base.byte_offset();
        byte_size = @buffer_source_name@->byte_length();
    } else if (@buffer_source_name@->is_data_view()) {
        auto& data_view = static_cast<JS::DataView&>(*@buffer_source_name@->raw_object());
        ptr = data_view.viewed_array_buffer()->buffer().data();
        byte_size = data_view.viewed_array_buffer()->byte_length();
    } else if (@buffer_source_name@->is_array_buffer()) {
        auto& array_buffer = static_cast<JS::ArrayBuffer&>(*@buffer_source_name@->raw_object());
        ptr = array_buffer.buffer().data();
        byte_size = array_buffer.byte_length();
    } else {
        VERIFY_NOT_REACHED();
    }
)~~~");
                gl_call_arguments.append(ByteString::formatted("byte_size"));
                gl_call_arguments.append(ByteString::formatted("ptr"));
                continue;
            }
            VERIFY_NOT_REACHED();
        }

        StringBuilder gl_call_arguments_string_builder;
        gl_call_arguments_string_builder.join(", "sv, gl_call_arguments);

        auto gl_call_string = ByteString::formatted("{}({})", idl_to_gl_function_name(function.name), gl_call_arguments_string_builder.string_view());
        function_impl_generator.set("call_string", gl_call_string);

        if (gl_function_modifies_framebuffer(function.name)) {
            function_impl_generator.append("    needs_to_present();\n"sv);
        }

        if (function.return_type->name() == "undefined"sv) {
            function_impl_generator.append("    @call_string@;"sv);
        } else if (function.return_type->is_integer() || function.return_type->is_boolean()) {
            function_impl_generator.append("    return @call_string@;"sv);
        } else if (is_webgl_object_type(function.return_type->name())) {
            function_impl_generator.set("return_type_name", function.return_type->name());
            function_impl_generator.append("    return @return_type_name@::create(m_realm, *this, @call_string@);"sv);
        } else {
            VERIFY_NOT_REACHED();
        }

        function_impl_generator.append("\n"sv);
    }

    header_file_generator.append(R"~~~(
protected:
    virtual void visit_edges(JS::Cell::Visitor&) override;

private:
    GC::Ref<JS::Realm> m_realm;
    GC::Ptr<WebGLBuffer> m_array_buffer_binding;
    GC::Ptr<WebGLBuffer> m_element_array_buffer_binding;
    GC::Ptr<WebGLProgram> m_current_program;
    GC::Ptr<WebGLFramebuffer> m_framebuffer_binding;
    GC::Ptr<WebGLRenderbuffer> m_renderbuffer_binding;
    GC::Ptr<WebGLTexture> m_texture_binding_2d;
    GC::Ptr<WebGLTexture> m_texture_binding_cube_map;
)~~~");

    if (webgl_version == 2) {
        header_file_generator.append(R"~~~(
    GC::Ptr<WebGLBuffer> m_uniform_buffer_binding;
    GC::Ptr<WebGLBuffer> m_copy_read_buffer_binding;
    GC::Ptr<WebGLBuffer> m_copy_write_buffer_binding;
    GC::Ptr<WebGLTexture> m_texture_binding_2d_array;
    GC::Ptr<WebGLTexture> m_texture_binding_3d;
)~~~");
    }

    header_file_generator.append(R"~~~(
    NonnullOwnPtr<OpenGLContext> m_context;
};

}
)~~~");

    implementation_file_generator.append(R"~~~(
void @class_name@::visit_edges(JS::Cell::Visitor& visitor)
{
    visitor.visit(m_realm);
    visitor.visit(m_array_buffer_binding);
    visitor.visit(m_element_array_buffer_binding);
    visitor.visit(m_current_program);
    visitor.visit(m_framebuffer_binding);
    visitor.visit(m_renderbuffer_binding);
    visitor.visit(m_texture_binding_2d);
    visitor.visit(m_texture_binding_cube_map);
)~~~");

    if (webgl_version == 2) {
        implementation_file_generator.append(R"~~~(
    visitor.visit(m_uniform_buffer_binding);
    visitor.visit(m_copy_read_buffer_binding);
    visitor.visit(m_copy_write_buffer_binding);
    visitor.visit(m_texture_binding_2d_array);
    visitor.visit(m_texture_binding_3d);
)~~~");
    }

    implementation_file_generator.append(R"~~~(
}

}
)~~~");

    MUST(generated_header_file->write_until_depleted(header_file_generator.as_string_view().bytes()));
    MUST(generated_implementation_file->write_until_depleted(implementation_file_generator.as_string_view().bytes()));

    return 0;
}