Edit

kc3-lang/angle/include/platform/FeaturesGL.h

Branch :

  • Show log

    Commit

  • Author : Shahbaz Youssefi
    Date : 2021-08-03 01:31:03
    Hash : 09d5047b
    Message : GL: Remove the rewriteVectorScalarArithmetic workaround This workaround was implemented for a bug in Nvidia driver 387 which is end-of-life. More recent driver branches (390 and 4XX) are fixed, and so this workaround is no longer required. The implementation of the workaround itself could introduce bugs. Bug: chromium:772651 Bug: chromium:1201084 Change-Id: I3db179eb90d9124235bdad2daacc712302906d8e Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3067952 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Yuly Novikov <ynovikov@chromium.org> Reviewed-by: Kenneth Russell <kbr@chromium.org>

  • include/platform/FeaturesGL.h
  • //
    // Copyright 2015 The ANGLE Project Authors. All rights reserved.
    // Use of this source code is governed by a BSD-style license that can be
    // found in the LICENSE file.
    //
    
    // FeaturesGL.h: Features and workarounds for GL driver bugs and other issues.
    
    #ifndef ANGLE_PLATFORM_FEATURESGL_H_
    #define ANGLE_PLATFORM_FEATURESGL_H_
    
    #include "platform/Feature.h"
    
    namespace angle
    {
    
    struct FeaturesGL : FeatureSetBase
    {
        FeaturesGL();
        ~FeaturesGL();
    
        // When writing a float to a normalized integer framebuffer, desktop OpenGL is allowed to write
        // one of the two closest normalized integer representations (although round to nearest is
        // preferred) (see section 2.3.5.2 of the GL 4.5 core specification). OpenGL ES requires that
        // round-to-nearest is used (see "Conversion from Floating-Point to Framebuffer Fixed-Point" in
        // section 2.1.2 of the OpenGL ES 2.0.25 spec).  This issue only shows up on AMD drivers on
        // framebuffer formats that have 1-bit alpha, work around this by using higher precision formats
        // instead.
        Feature avoid1BitAlphaTextureFormats = {"avoid_1_bit_alpha_texture_formats",
                                                FeatureCategory::OpenGLWorkarounds,
                                                "Issue with 1-bit alpha framebuffer formats", &members};
    
        // On some older Intel drivers, GL_RGBA4 is not color renderable, glCheckFramebufferStatus
        // returns GL_FRAMEBUFFER_UNSUPPORTED. Work around this by using a known color-renderable
        // format.
        Feature rgba4IsNotSupportedForColorRendering = {"rgba4_is_not_supported_for_color_rendering",
                                                        FeatureCategory::OpenGLWorkarounds,
                                                        "GL_RGBA4 is not color renderable", &members};
    
        // Newer Intel GPUs natively support ETC2/EAC compressed texture formats.
        Feature allowEtcFormats = {"allow_etc_formats", FeatureCategory::OpenGLWorkarounds,
                                   "Enable ETC2/EAC on desktop OpenGL", &members};
    
        // When clearing a framebuffer on Intel or AMD drivers, when GL_FRAMEBUFFER_SRGB is enabled, the
        // driver clears to the linearized clear color despite the framebuffer not supporting SRGB
        // blending.  It only seems to do this when the framebuffer has only linear attachments, mixed
        // attachments appear to get the correct clear color.
        Feature doesSRGBClearsOnLinearFramebufferAttachments = {
            "does_srgb_clears_on_linear_framebuffer_attachments", FeatureCategory::OpenGLWorkarounds,
            "Issue clearing framebuffers with linear attachments when GL_FRAMEBUFFER_SRGB is enabled",
            &members};
    
        // On Mac some GLSL constructs involving do-while loops cause GPU hangs, such as the following:
        //  int i = 1;
        //  do {
        //      i --;
        //      continue;
        //  } while (i > 0)
        // Work around this by rewriting the do-while to use another GLSL construct (block + while)
        Feature doWhileGLSLCausesGPUHang = {
            "do_while_glsl_causes_gpu_hang", FeatureCategory::OpenGLWorkarounds,
            "Some GLSL constructs involving do-while loops cause GPU hangs", &members,
            "http://crbug.com/644669"};
    
        // On Mac AMD GPU gl_VertexID in GLSL vertex shader doesn't include base vertex value,
        // Work aronud this by replace gl_VertexID with (gl_VertexID - angle_BaseVertex) when
        // angle_BaseVertex is present.
        Feature addBaseVertexToVertexID = {
            "vertex_id_does_not_include_base_vertex", FeatureCategory::OpenGLWorkarounds,
            "gl_VertexID in GLSL vertex shader doesn't include base vertex value", &members};
    
        // Calling glFinish doesn't cause all queries to report that the result is available on some
        // (NVIDIA) drivers.  It was found that enabling GL_DEBUG_OUTPUT_SYNCHRONOUS before the finish
        // causes it to fully finish.
        Feature finishDoesNotCauseQueriesToBeAvailable = {
            "finish_does_not_cause_queries_to_be_available", FeatureCategory::OpenGLWorkarounds,
            "glFinish doesn't cause all queries to report available result", &members};
    
        // Always call useProgram after a successful link to avoid a driver bug.
        // This workaround is meant to reproduce the use_current_program_after_successful_link
        // workaround in Chromium (http://crbug.com/110263). It has been shown that this workaround is
        // not necessary for MacOSX 10.9 and higher (http://crrev.com/39eb535b).
        Feature alwaysCallUseProgramAfterLink = {
            "always_call_use_program_after_link", FeatureCategory::OpenGLWorkarounds,
            "Always call useProgram after a successful link to avoid a driver bug", &members,
            "http://crbug.com/110263"};
    
        // On NVIDIA, in the case of unpacking from a pixel unpack buffer, unpack overlapping rows row
        // by row.
        Feature unpackOverlappingRowsSeparatelyUnpackBuffer = {
            "unpack_overlapping_rows_separately_unpack_buffer", FeatureCategory::OpenGLWorkarounds,
            "In the case of unpacking from a pixel unpack buffer, unpack overlapping rows row by row",
            &members};
    
        // On NVIDIA, in the case of packing to a pixel pack buffer, pack overlapping rows row by row.
        Feature packOverlappingRowsSeparatelyPackBuffer = {
            "pack_overlapping_rows_separately_pack_buffer", FeatureCategory::OpenGLWorkarounds,
            "In the case of packing to a pixel pack buffer, pack overlapping rows row by row",
            &members};
    
        // On NVIDIA, during initialization, assign the current vertex attributes to the spec-mandated
        // defaults.
        Feature initializeCurrentVertexAttributes = {
            "initialize_current_vertex_attributes", FeatureCategory::OpenGLWorkarounds,
            "During initialization, assign the current vertex attributes to the spec-mandated defaults",
            &members};
    
        // abs(i) where i is an integer returns unexpected result on Intel Mac.
        // Emulate abs(i) with i * sign(i).
        Feature emulateAbsIntFunction = {"emulate_abs_int_function", FeatureCategory::OpenGLWorkarounds,
                                         "abs(i) where i is an integer returns unexpected result",
                                         &members, "http://crbug.com/642227"};
    
        // On Intel Mac, calculation of loop conditions in for and while loop has bug.
        // Add "&& true" to the end of the condition expression to work around the bug.
        Feature addAndTrueToLoopCondition = {
            "add_and_true_to_loop_condition", FeatureCategory::OpenGLWorkarounds,
            "Calculation of loop conditions in for and while loop has bug", &members};
    
        // When uploading textures from an unpack buffer, some drivers count an extra row padding when
        // checking if the pixel unpack buffer is big enough. Tracking bug: http://anglebug.com/1512
        // For example considering the pixel buffer below where in memory, each row data (D) of the
        // texture is followed by some unused data (the dots):
        //     +-------+--+
        //     |DDDDDDD|..|
        //     |DDDDDDD|..|
        //     |DDDDDDD|..|
        //     |DDDDDDD|..|
        //     +-------A--B
        // The last pixel read will be A, but the driver will think it is B, causing it to generate an
        // error when the pixel buffer is just big enough.
        Feature unpackLastRowSeparatelyForPaddingInclusion = {
            "unpack_last_row_separately_for_padding_inclusion", FeatureCategory::OpenGLWorkarounds,
            "When uploading textures from an unpack buffer, some drivers count an extra row padding",
            &members, "http://anglebug.com/1512"};
    
        // Equivalent workaround when uploading data from a pixel pack buffer.
        Feature packLastRowSeparatelyForPaddingInclusion = {
            "pack_last_row_separately_for_padding_inclusion", FeatureCategory::OpenGLWorkarounds,
            "When uploading textures from an pack buffer, some drivers count an extra row padding",
            &members, "http://anglebug.com/1512"};
    
        // On some Intel drivers, using isnan() on highp float will get wrong answer. To work around
        // this bug, we use an expression to emulate function isnan().
        // Tracking bug: http://crbug.com/650547
        Feature emulateIsnanFloat = {"emulate_isnan_float", FeatureCategory::OpenGLWorkarounds,
                                     "Using isnan() on highp float will get wrong answer", &members,
                                     "http://crbug.com/650547"};
    
        // On Mac with OpenGL version 4.1, unused std140 or shared uniform blocks will be
        // treated as inactive which is not consistent with WebGL2.0 spec. Reference all members in a
        // unused std140 or shared uniform block at the beginning of main to work around it.
        // Also used on Linux AMD.
        Feature useUnusedBlocksWithStandardOrSharedLayout = {
            "use_unused_blocks_with_standard_or_shared_layout", FeatureCategory::OpenGLWorkarounds,
            "Unused std140 or shared uniform blocks will be treated as inactive", &members};
    
        // This flag is used to fix spec difference between GLSL 4.1 or lower and ESSL3.
        Feature removeInvariantAndCentroidForESSL3 = {
            "remove_invarient_and_centroid_for_essl3", FeatureCategory::OpenGLWorkarounds,
            "Fix spec difference between GLSL 4.1 or lower and ESSL3", &members};
    
        // On Intel Mac OSX 10.11 driver, using "-float" will get wrong answer. Use "0.0 - float" to
        // replace "-float".
        // Tracking bug: http://crbug.com/308366
        Feature rewriteFloatUnaryMinusOperator = {
            "rewrite_float_unary_minus_operator", FeatureCategory::OpenGLWorkarounds,
            "Using '-<float>' will get wrong answer", &members, "http://crbug.com/308366"};
    
        // On NVIDIA drivers, atan(y, x) may return a wrong answer.
        // Tracking bug: http://crbug.com/672380
        Feature emulateAtan2Float = {"emulate_atan_2_float", FeatureCategory::OpenGLWorkarounds,
                                     "atan(y, x) may return a wrong answer", &members,
                                     "http://crbug.com/672380"};
    
        // Some drivers seem to forget about UBO bindings when using program binaries. Work around
        // this by re-applying the bindings after the program binary is loaded or saved.
        // This only seems to affect AMD OpenGL drivers, and some Android devices.
        // http://anglebug.com/1637
        Feature reapplyUBOBindingsAfterUsingBinaryProgram = {
            "reapply_ubo_bindings_after_using_binary_program", FeatureCategory::OpenGLWorkarounds,
            "Some drivers forget about UBO bindings when using program binaries", &members,
            "http://anglebug.com/1637"};
    
        // Some Linux OpenGL drivers return 0 when we query MAX_VERTEX_ATTRIB_STRIDE in an OpenGL 4.4 or
        // higher context.
        // This only seems to affect AMD OpenGL drivers.
        // Tracking bug: http://anglebug.com/1936
        Feature emulateMaxVertexAttribStride = {
            "emulate_max_vertex_attrib_stride", FeatureCategory::OpenGLWorkarounds,
            "Some drivers return 0 when MAX_VERTEX_ATTRIB_STRIED queried", &members,
            "http://anglebug.com/1936"};
    
        // Initializing uninitialized locals caused odd behavior on Android Qualcomm in a few WebGL 2
        // tests. Tracking bug: http://anglebug.com/2046
        Feature dontInitializeUninitializedLocals = {
            "dont_initialize_uninitialized_locals", FeatureCategory::OpenGLWorkarounds,
            "Initializing uninitialized locals caused odd behavior in a few WebGL 2 tests", &members,
            "http://anglebug.com/2046"};
    
        // On some NVIDIA drivers the point size range reported from the API is inconsistent with the
        // actual behavior. Clamp the point size to the value from the API to fix this.
        Feature clampPointSize = {
            "clamp_point_size", FeatureCategory::OpenGLWorkarounds,
            "The point size range reported from the API is inconsistent with the actual behavior",
            &members};
    
        // On some Android devices for loops used to initialize variables hit native GLSL compiler bugs.
        Feature dontUseLoopsToInitializeVariables = {
            "dont_use_loops_to_initialize_variables", FeatureCategory::OpenGLWorkarounds,
            "For loops used to initialize variables hit native GLSL compiler bugs", &members,
            "http://crbug.com/809422"};
    
        // On some NVIDIA drivers gl_FragDepth is not clamped correctly when rendering to a floating
        // point depth buffer. Clamp it in the translated shader to fix this.
        Feature clampFragDepth = {
            "clamp_frag_depth", FeatureCategory::OpenGLWorkarounds,
            "gl_FragDepth is not clamped correctly when rendering to a floating point depth buffer",
            &members};
    
        // On some NVIDIA drivers before version 397.31 repeated assignment to swizzled values inside a
        // GLSL user-defined function have incorrect results. Rewrite this type of statements to fix
        // this.
        Feature rewriteRepeatedAssignToSwizzled = {"rewrite_repeated_assign_to_swizzled",
                                                   FeatureCategory::OpenGLWorkarounds,
                                                   "Repeated assignment to swizzled values inside a "
                                                   "GLSL user-defined function have incorrect results",
                                                   &members};
    
        // On some AMD and Intel GL drivers ARB_blend_func_extended does not pass the tests.
        // It might be possible to work around the Intel bug by rewriting *FragData to *FragColor
        // instead of disabling the functionality entirely. The AMD bug looked like incorrect blending,
        // not sure if a workaround is feasible. http://anglebug.com/1085
        Feature disableBlendFuncExtended = {
            "disable_blend_func_extended", FeatureCategory::OpenGLWorkarounds,
            "ARB_blend_func_extended does not pass the tests", &members, "http://anglebug.com/1085"};
    
        // Qualcomm drivers returns raw sRGB values instead of linearized values when calling
        // glReadPixels on unsized sRGB texture formats. http://crbug.com/550292 and
        // http://crbug.com/565179
        Feature unsizedsRGBReadPixelsDoesntTransform = {
            "unsized_srgb_read_pixels_doesnt_transform", FeatureCategory::OpenGLWorkarounds,
            "Drivers returning raw sRGB values instead of linearized values when calling glReadPixels "
            "on unsized sRGB texture formats",
            &members, "http://crbug.com/565179"};
    
        // Older Qualcomm drivers generate errors when querying the number of bits in timer queries, ex:
        // GetQueryivEXT(GL_TIME_ELAPSED, GL_QUERY_COUNTER_BITS).  http://anglebug.com/3027
        Feature queryCounterBitsGeneratesErrors = {
            "query_counter_bits_generates_errors", FeatureCategory::OpenGLWorkarounds,
            "Drivers generate errors when querying the number of bits in timer queries", &members,
            "http://anglebug.com/3027"};
    
        // Re-linking a program in parallel is buggy on some Intel Windows OpenGL drivers and Android
        // platforms.
        // http://anglebug.com/3045
        Feature dontRelinkProgramsInParallel = {
            "dont_relink_programs_in_parallel", FeatureCategory::OpenGLWorkarounds,
            "Relinking a program in parallel is buggy", &members, "http://anglebug.com/3045"};
    
        // Some tests have been seen to fail using worker contexts, this switch allows worker contexts
        // to be disabled for some platforms. http://crbug.com/849576
        Feature disableWorkerContexts = {"disable_worker_contexts", FeatureCategory::OpenGLWorkarounds,
                                         "Some tests have been seen to fail using worker contexts",
                                         &members, "http://crbug.com/849576"};
    
        // Most Android devices fail to allocate a texture that is larger than 4096. Limit the caps
        // instead of generating GL_OUT_OF_MEMORY errors. Also causes system to hang on some older
        // intel mesa drivers on Linux.
        Feature limitMaxTextureSizeTo4096 = {"max_texture_size_limit_4096",
                                             FeatureCategory::OpenGLWorkarounds,
                                             "Limit max texture size to 4096 to avoid frequent "
                                             "out-of-memory errors",
                                             &members, "http://crbug.com/927470"};
    
        // Prevent excessive MSAA allocations on Android devices, various rendering bugs have been
        // observed and they tend to be high DPI anyways. http://crbug.com/797243
        Feature limitMaxMSAASamplesTo4 = {
            "max_msaa_sample_count_4", FeatureCategory::OpenGLWorkarounds,
            "Various rendering bugs have been observed when using higher MSAA counts", &members,
            "http://crbug.com/797243"};
    
        // Prefer to do the robust resource init clear using a glClear. Calls to TexSubImage2D on large
        // textures can take hundreds of milliseconds because of slow uploads on macOS. Do this only on
        // macOS because clears are buggy on other drivers.
        // https://crbug.com/848952 (slow uploads on macOS)
        // https://crbug.com/883276 (buggy clears on Android)
        Feature allowClearForRobustResourceInit = {
            "allow_clear_for_robust_resource_init", FeatureCategory::OpenGLWorkarounds,
            "Using glClear for robust resource initialization is buggy on some drivers and leads to "
            "texture corruption. Default to data uploads except on MacOS where it is very slow.",
            &members, "http://crbug.com/883276"};
    
        // Some drivers automatically handle out-of-bounds uniform array access but others need manual
        // clamping to satisfy the WebGL requirements.
        Feature clampArrayAccess = {"clamp_array_access", FeatureCategory::OpenGLWorkarounds,
                                    "Clamp uniform array access to avoid reading invalid memory.",
                                    &members, "http://anglebug.com/2978"};
    
        // Reset glTexImage2D base level to workaround pixel comparison failure above Mac OS 10.12.4 on
        // Intel Mac.
        Feature resetTexImage2DBaseLevel = {"reset_teximage2d_base_level",
                                            FeatureCategory::OpenGLWorkarounds,
                                            "Reset texture base level before calling glTexImage2D to "
                                            "work around pixel comparison failure.",
                                            &members, "https://crbug.com/705865"};
    
        // glClearColor does not always work on Intel 6xxx Mac drivers when the clear color made up of
        // all zeros and ones.
        Feature clearToZeroOrOneBroken = {
            "clear_to_zero_or_one_broken", FeatureCategory::OpenGLWorkarounds,
            "Clears when the clear color is all zeros or ones do not work.", &members,
            "https://crbug.com/710443"};
    
        // Some older Linux Intel mesa drivers will hang the system when allocating large textures. Fix
        // this by capping the max texture size.
        Feature limitMax3dArrayTextureSizeTo1024 = {
            "max_3d_array_texture_size_1024", FeatureCategory::OpenGLWorkarounds,
            "Limit max 3d texture size and max array texture layers to 1024 to avoid system hang",
            &members, "http://crbug.com/927470"};
    
        // BlitFramebuffer has issues on some platforms with large source/dest texture sizes. This
        // workaround adjusts the destination rectangle source and dest rectangle to fit within maximum
        // twice the size of the framebuffer.
        Feature adjustSrcDstRegionBlitFramebuffer = {
            "adjust_src_dst_region_for_blitframebuffer", FeatureCategory::OpenGLWorkarounds,
            "Many platforms have issues with blitFramebuffer when the parameters are large.", &members,
            "http://crbug.com/830046"};
    
        // BlitFramebuffer has issues on Mac when the source bounds aren't enclosed by the framebuffer.
        // This workaround clips the source region and adjust the dest region proportionally.
        Feature clipSrcRegionBlitFramebuffer = {
            "clip_src_region_for_blitframebuffer", FeatureCategory::OpenGLWorkarounds,
            "Issues with blitFramebuffer when the parameters don't match the framebuffer size.",
            &members, "http://crbug.com/830046"};
    
        // Mac Intel samples transparent black from GL_COMPRESSED_RGB_S3TC_DXT1_EXT
        Feature rgbDXT1TexturesSampleZeroAlpha = {
            "rgb_dxt1_textures_sample_zero_alpha", FeatureCategory::OpenGLWorkarounds,
            "Sampling BLACK texels from RGB DXT1 textures returns transparent black on Mac.", &members,
            "http://anglebug.com/3729"};
    
        // Mac incorrectly executes both sides of && and || expressions when they should short-circuit.
        Feature unfoldShortCircuits = {
            "unfold_short_circuits", FeatureCategory::OpenGLWorkarounds,
            "Mac incorrectly executes both sides of && and || expressions when they should "
            "short-circuit.",
            &members, "http://anglebug.com/482"};
    
        Feature emulatePrimitiveRestartFixedIndex = {
            "emulate_primitive_restart_fixed_index", FeatureCategory::OpenGLWorkarounds,
            "When GL_PRIMITIVE_RESTART_FIXED_INDEX is not available, emulate it with "
            "GL_PRIMITIVE_RESTART and glPrimitiveRestartIndex.",
            &members, "http://anglebug.com/3997"};
    
        Feature setPrimitiveRestartFixedIndexForDrawArrays = {
            "set_primitive_restart_fixed_index_for_draw_arrays", FeatureCategory::OpenGLWorkarounds,
            "Some drivers discard vertex data in DrawArrays calls when the fixed primitive restart "
            "index is within the number of primitives being drawn.",
            &members, "http://anglebug.com/3997"};
    
        // Dynamic indexing of swizzled l-values doesn't work correctly on various platforms.
        Feature removeDynamicIndexingOfSwizzledVector = {
            "remove_dynamic_indexing_of_swizzled_vector", FeatureCategory::OpenGLWorkarounds,
            "Dynamic indexing of swizzled l-values doesn't work correctly on various platforms.",
            &members, "http://crbug.com/709351"};
    
        // Intel Mac drivers does not treat texelFetchOffset() correctly.
        Feature preAddTexelFetchOffsets = {
            "pre_add_texel_fetch_offsets", FeatureCategory::OpenGLWorkarounds,
            "Intel Mac drivers mistakenly consider the parameter position of nagative vaule as invalid "
            "even if the sum of position and offset is in range, so we need to add workarounds by "
            "rewriting texelFetchOffset(sampler, position, lod, offset) into texelFetch(sampler, "
            "position + offset, lod).",
            &members, "http://crbug.com/642605"};
    
        // All Mac drivers do not handle struct scopes correctly. This workaround overwrites a struct
        // name with a unique prefix
        Feature regenerateStructNames = {
            "regenerate_struct_names", FeatureCategory::OpenGLWorkarounds,
            "All Mac drivers do not handle struct scopes correctly. This workaround overwrites a struct"
            "name with a unique prefix.",
            &members, "http://crbug.com/403957"};
    
        // Quite some OpenGL ES drivers don't implement readPixels for RGBA/UNSIGNED_SHORT from
        // EXT_texture_norm16 correctly
        Feature readPixelsUsingImplementationColorReadFormatForNorm16 = {
            "read_pixels_using_implementation_color_read_format", FeatureCategory::OpenGLWorkarounds,
            "Quite some OpenGL ES drivers don't implement readPixels for RGBA/UNSIGNED_SHORT from "
            "EXT_texture_norm16 correctly",
            &members, "http://anglebug.com/4214"};
    
        // Bugs exist in some Intel drivers where dependencies are incorrectly
        // tracked for textures which are copy destinations (via CopyTexImage2D, for
        // example). Flush before DeleteTexture if these entry points have been
        // called recently.
        Feature flushBeforeDeleteTextureIfCopiedTo = {
            "flush_before_delete_texture_if_copied_to", FeatureCategory::OpenGLWorkarounds,
            "Some drivers track CopyTex{Sub}Image texture dependencies incorrectly. Flush"
            " before glDeleteTextures in this case",
            &members, "http://anglebug.com/4267"};
    
        // Rewrite row-major matrices as column-major as a driver bug workaround if
        // necessary.
        Feature rewriteRowMajorMatrices = {
            "rewrite_row_major_matrices", FeatureCategory::OpenGLWorkarounds,
            "Rewrite row major matrices in shaders as column major as a driver bug workaround",
            &members, "http://anglebug.com/2273"};
    
        // Bugs exist in various OpenGL Intel drivers on Windows that produce incorrect
        // values for GL_COMPRESSED_SRGB_S3TC_DXT1_EXT format. Replace it with
        // GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT as it's the closest option allowed by
        // the WebGL extension spec.
        Feature avoidDXT1sRGBTextureFormat = {
            "avoid_dxt1_srgb_texture_format", FeatureCategory::OpenGLWorkarounds,
            "Replaces DXT1 sRGB with DXT1 sRGB Alpha as a driver bug workaround.", &members};
    
        // Bugs exist in OpenGL AMD drivers on Windows that produce incorrect pipeline state for
        // colorMaski calls.
        Feature disableDrawBuffersIndexed = {"disable_draw_buffers_indexed",
                                             FeatureCategory::OpenGLWorkarounds,
                                             "Disable OES_draw_buffers_indexed extension.", &members};
    
        // GL_EXT_semaphore_fd doesn't work properly with Mesa 19.3.4 and earlier versions.
        Feature disableSemaphoreFd = {"disable_semaphore_fd", FeatureCategory::OpenGLWorkarounds,
                                      "Disable GL_EXT_semaphore_fd extension", &members,
                                      "https://crbug.com/1046462"};
    
        // GL_EXT_disjoint_timer_query doesn't work properly with Linux VMWare drivers.
        Feature disableTimestampQueries = {
            "disable_timestamp_queries", FeatureCategory::OpenGLWorkarounds,
            "Disable GL_EXT_disjoint_timer_query extension", &members, "https://crbug.com/811661"};
    
        // Some drivers use linear blending when generating mipmaps for sRGB textures. Work around this
        // by generating mipmaps in a linear texture and copying back to sRGB.
        Feature encodeAndDecodeSRGBForGenerateMipmap = {
            "decode_encode_srgb_for_generatemipmap", FeatureCategory::OpenGLWorkarounds,
            "Decode and encode before generateMipmap for srgb format textures.", &members,
            "http://anglebug.com/4646"};
    
        Feature emulateCopyTexImage2DFromRenderbuffers = {
            "emulate_copyteximage2d_from_renderbuffers", FeatureCategory::OpenGLWorkarounds,
            "CopyTexImage2D spuriously returns errors on iOS when copying from renderbuffers.",
            &members, "https://anglebug.com/4674"};
    
        Feature disableGPUSwitchingSupport = {
            "disable_gpu_switching_support", FeatureCategory::OpenGLWorkarounds,
            "Disable GPU switching support (use only the low-power GPU) on older MacBook Pros.",
            &members, "https://crbug.com/1091824"};
    
        // KHR_parallel_shader_compile fails TSAN on Linux, so we avoid using it with this workaround.
        Feature disableNativeParallelCompile = {
            "disable_native_parallel_compile", FeatureCategory::OpenGLWorkarounds,
            "Do not use native KHR_parallel_shader_compile even when available.", &members,
            "http://crbug.com/1094869"};
    
        Feature emulatePackSkipRowsAndPackSkipPixels = {
            "emulate_pack_skip_rows_and_pack_skip_pixels", FeatureCategory::OpenGLWorkarounds,
            "GL_PACK_SKIP_ROWS and GL_PACK_SKIP_PIXELS are ignored in Apple's OpenGL driver.", &members,
            "https://anglebug.com/4849"};
    
        // Some drivers return bogus/1hz values for GetMscRate, which we may want to clamp
        Feature clampMscRate = {
            "clamp_msc_rate", FeatureCategory::OpenGLWorkarounds,
            "Some drivers return bogus values for GetMscRate, so we clamp it to 30Hz", &members,
            "https://crbug.com/1042393"};
    
        // Mac drivers generate GL_INVALID_VALUE when binding a transform feedback buffer with
        // glBindBufferRange before first binding it to some generic binding point.
        Feature bindTransformFeedbackBufferBeforeBindBufferRange = {
            "bind_transform_feedback_buffer_before_bind_buffer_range",
            FeatureCategory::OpenGLWorkarounds,
            "Bind transform feedback buffers to the generic binding point before calling "
            "glBindBufferBase or glBindBufferRange.",
            &members, "https://anglebug.com/5140"};
    
        // Speculative fix for issues on Linux/Wayland where exposing GLX_OML_sync_control renders
        // Chrome unusable
        Feature disableSyncControlSupport = {
            "disable_sync_control_support", FeatureCategory::OpenGLWorkarounds,
            "Speculative fix for issues on Linux/Wayland where exposing GLX_OML_sync_control renders "
            "Chrome unusable",
            &members, "https://crbug.com/1137851"};
    
        // Buffers need to maintain a shadow copy of data when buffer data readback is not possible
        // through the GL API
        Feature keepBufferShadowCopy = {
            "keep_buffer_shadow_copy", FeatureCategory::OpenGLWorkarounds,
            "Maintain a shadow copy of buffer data when the GL API does not permit reading data back.",
            &members};
    
        // glGenerateMipmap fails if the zero texture level is not set on some Mac drivers
        Feature setZeroLevelBeforeGenerateMipmap = {
            "set_zero_level_before_generating_mipmap", FeatureCategory::OpenGLWorkarounds,
            "glGenerateMipmap fails if the zero texture level is not set on some Mac drivers.",
            &members};
    
        // On macOS with AMD GPUs, packed color formats like RGB565 and RGBA4444 are buggy. Promote them
        // to 8 bit per channel formats.
        Feature promotePackedFormatsTo8BitPerChannel = {
            "promote_packed_formats_to_8_bit_per_channel", FeatureCategory::OpenGLWorkarounds,
            "Packed color formats are buggy on Macs with AMD GPUs", &members,
            "http://anglebug.com/5469"};
    
        // If gl_FragColor is not written by fragment shader, it may cause context lost with Adreno 42x
        // and 3xx.
        Feature initFragmentOutputVariables = {
            "init_fragment_output_variables", FeatureCategory::OpenGLWorkarounds,
            "No init gl_FragColor causes context lost", &members, "http://crbug.com/1171371"};
    
        // On macOS with Intel GPUs, instanced array with divisor > 0 is buggy when first > 0 in
        // drawArraysInstanced. Shift the attributes with extra offset to workaround.
        Feature shiftInstancedArrayDataWithExtraOffset = {
            "shift_instanced_array_data_with_offset", FeatureCategory::OpenGLWorkarounds,
            "glDrawArraysInstanced is buggy on certain new Mac Intel GPUs", &members,
            "http://crbug.com/1144207"};
    
        // ANGLE needs to support devices that have no native VAOs. Sync everything to the default VAO.
        Feature syncVertexArraysToDefault = {
            "sync_vertex_arrays_to_default", FeatureCategory::OpenGLWorkarounds,
            "Only use the default VAO because of missing support or driver bugs", &members,
            "http://anglebug.com/5577"};
    
        // On desktop Linux/AMD when using the amdgpu drivers, the precise kernel and DRM version are
        // leaked via GL_RENDERER. We workaround this to improve user privacy.
        Feature sanitizeAmdGpuRendererString = {
            "sanitize_amdgpu_renderer_string", FeatureCategory::OpenGLWorkarounds,
            "Strip precise kernel and DRM version information from amdgpu renderer strings.", &members,
            "http://crbug.com/1181193"};
    
        // Imagination GL drivers are buggy with context switching. We need to ubind fbo to workaround a
        // crash in the driver.
        Feature unbindFBOOnContextSwitch = {"unbind_fbo_before_switching_context",
                                            FeatureCategory::OpenGLWorkarounds,
                                            "Imagination GL drivers are buggy with context switching.",
                                            &members, "http://crbug.com/1181193"};
    
        Feature flushOnFramebufferChange = {"flush_on_framebuffer_change",
                                            FeatureCategory::OpenGLWorkarounds,
                                            "Switching framebuffers without a flush can lead to "
                                            "crashes on Intel 9th Generation GPU Macs.",
                                            &members, "http://crbug.com/1181068"};
    
        Feature disableMultisampledRenderToTexture = {
            "disable_mutlisampled_render_to_texture", FeatureCategory::OpenGLWorkarounds,
            "Many drivers have bugs when using GL_EXT_multisampled_render_to_texture", &members,
            "http://anglebug.com/2894"};
    
        // Mac OpenGL drivers often hang when calling glTexSubImage with >120kb of data. Instead, upload
        // the data in <120kb chunks.
        static constexpr const size_t kUploadTextureDataInChunksUploadSize = (120 * 1024) - 1;
        Feature uploadTextureDataInChunks                                  = {
            "chunked_texture_upload", FeatureCategory::OpenGLWorkarounds,
            "Upload texture data in <120kb chunks to work around Mac driver hangs and crashes.",
            &members, "http://crbug.com/1181068"};
    };
    
    inline FeaturesGL::FeaturesGL()  = default;
    inline FeaturesGL::~FeaturesGL() = default;
    
    }  // namespace angle
    
    #endif  // ANGLE_PLATFORM_FEATURESGL_H_