/**************************************************************************/
/*  metal_device_properties.cpp                                           */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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/**************************************************************************/
/*                                                                        */
/* Portions of this code were derived from MoltenVK.                      */
/*                                                                        */
/* Copyright (c) 2015-2023 The Brenwill Workshop Ltd.                     */
/* (http://www.brenwill.com)                                              */
/*                                                                        */
/* Licensed under the Apache License, Version 2.0 (the "License");        */
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#include "metal_device_properties.h"

#include "metal_utils.h"

#include "servers/rendering/renderer_rd/effects/metal_fx.h"

#include <MetalFX/MetalFX.hpp>
#include <spirv_cross.hpp>
#include <spirv_msl.hpp>

#include <unistd.h>

// Common scaling multipliers.
#define KIBI (1024)
#define MEBI (KIBI * KIBI)

#if (TARGET_OS_OSX && __MAC_OS_X_VERSION_MAX_ALLOWED < 140000) || (TARGET_OS_IPHONE && __IPHONE_OS_VERSION_MAX_ALLOWED < 170000)
constexpr MTL::GPUFamily GPUFamilyApple9 = static_cast<MTL::GPUFamily>(1009);
#else
constexpr MTL::GPUFamily GPUFamilyApple9 = MTL::GPUFamilyApple9;
#endif

API_AVAILABLE(macos(11.0), ios(14.0), tvos(14.0), visionos(1.0))
MTL::GPUFamily &operator--(MTL::GPUFamily &p_family) {
	p_family = static_cast<MTL::GPUFamily>(static_cast<int>(p_family) - 1);
	if (p_family < MTL::GPUFamilyApple1) {
		p_family = GPUFamilyApple9;
	}

	return p_family;
}

void MetalDeviceProperties::init_features(MTL::Device *p_device) {
	features = {};

	MTL::CompileOptions *opts = MTL::CompileOptions::alloc()->init();
	MTL::LanguageVersion lang_version = opts->languageVersion();
	features.msl_max_version = make_msl_version((static_cast<uint32_t>(lang_version) >> 0x10) & 0xff, (static_cast<uint32_t>(lang_version) >> 0x00) & 0xff);
	features.msl_target_version = features.msl_max_version;
	opts->release();
	if (String version = OS::get_singleton()->get_environment("GODOT_MTL_TARGET_VERSION"); !version.is_empty()) {
		if (version != "max") {
			Vector<String> parts = version.split(".", true, 2);
			if (parts.size() == 2) {
				uint32_t major = parts[0].to_int();
				uint32_t minor = parts[1].to_int();
				uint32_t msl_version = make_msl_version(major, minor);
				if (msl_version < MSL_VERSION_23 || msl_version > MSL_VERSION_40) {
					WARN_PRINT(vformat("GODOT_MTL_TARGET_VERSION: invalid MSL version '%d.%d'", major, minor));
				} else {
					print_line(vformat("Override: Targeting Metal version %d.%d", major, minor));
					features.msl_target_version = msl_version;
				}
			} else {
				WARN_PRINT("GODOT_MTL_TARGET_VERSION: invalid version string format. Expected major.minor or 'max'.");
			}
		}
	}

	features.highestFamily = MTL::GPUFamilyApple1;
	for (MTL::GPUFamily family = GPUFamilyApple9; family >= MTL::GPUFamilyApple1; --family) {
		if (p_device->supportsFamily(family)) {
			features.highestFamily = family;
			break;
		}
	}

	if (__builtin_available(macOS 11, iOS 16.4, tvOS 16.4, *)) {
		features.supportsBCTextureCompression = p_device->supportsBCTextureCompression();
	} else {
		features.supportsBCTextureCompression = false;
	}

#if TARGET_OS_OSX
	features.supportsDepth24Stencil8 = p_device->isDepth24Stencil8PixelFormatSupported();
#endif

	if (__builtin_available(macOS 11.0, iOS 14.0, tvOS 14.0, *)) {
		features.supports32BitFloatFiltering = p_device->supports32BitFloatFiltering();
		features.supports32BitMSAA = p_device->supports32BitMSAA();
	}

	if (__builtin_available(macOS 13.0, iOS 16.0, tvOS 16.0, *)) {
		features.supports_gpu_address = true;
	}

	features.hostMemoryPageSize = sysconf(_SC_PAGESIZE);

	for (SampleCount sc = SampleCount1; sc <= SampleCount64; sc <<= 1) {
		if (p_device->supportsTextureSampleCount(sc)) {
			features.supportedSampleCounts |= sc;
		}
	}

	features.layeredRendering = p_device->supportsFamily(MTL::GPUFamilyApple5);
	features.multisampleLayeredRendering = p_device->supportsFamily(MTL::GPUFamilyApple7);
	features.tessellationShader = p_device->supportsFamily(MTL::GPUFamilyApple3);
	features.imageCubeArray = p_device->supportsFamily(MTL::GPUFamilyApple3);
	features.quadPermute = p_device->supportsFamily(MTL::GPUFamilyApple4);
	features.simdPermute = p_device->supportsFamily(MTL::GPUFamilyApple6);
	features.simdReduction = p_device->supportsFamily(MTL::GPUFamilyApple7);
	features.supports_border_color = p_device->supportsFamily(MTL::GPUFamilyApple7);
	features.argument_buffers_tier = p_device->argumentBuffersSupport();
	features.supports_image_atomic_32_bit = p_device->supportsFamily(MTL::GPUFamilyApple6);
	features.supports_image_atomic_64_bit = p_device->supportsFamily(GPUFamilyApple9) || (p_device->supportsFamily(MTL::GPUFamilyApple8) && p_device->supportsFamily(MTL::GPUFamilyMac2));

	if (features.msl_target_version >= MSL_VERSION_31) {
		// Native atomics are only supported on 3.1 and above.
		if (__builtin_available(macOS 14.0, iOS 17.0, tvOS 17.0, visionOS 1.0, *)) {
			features.supports_native_image_atomics = true;
		}
	}

	if (OS::get_singleton()->get_environment("GODOT_MTL_DISABLE_IMAGE_ATOMICS") == "1") {
		features.supports_native_image_atomics = false;
	}

	if (__builtin_available(macOS 15.0, iOS 18.0, tvOS 18.0, visionOS 2.0, *)) {
		features.supports_residency_sets = true;
	} else {
		features.supports_residency_sets = false;
	}

	if (__builtin_available(macOS 13.0, iOS 16.0, tvOS 16.0, *)) {
		features.needs_arg_encoders = !(p_device->supportsFamily(MTL::GPUFamilyMetal3) && features.argument_buffers_tier == MTL::ArgumentBuffersTier2);
	}

	if (String v = OS::get_singleton()->get_environment("GODOT_MTL_DISABLE_ARGUMENT_BUFFERS"); v == "1") {
		features.use_argument_buffers = false;
	}

	if (__builtin_available(macOS 13.0, iOS 16.0, tvOS 16.0, *)) {
		features.metal_fx_spatial = MTLFX::SpatialScalerDescriptor::supportsDevice(p_device);
#ifdef METAL_MFXTEMPORAL_ENABLED
		features.metal_fx_temporal = MTLFX::TemporalScalerDescriptor::supportsDevice(p_device);
#else
		features.metal_fx_temporal = false;
#endif
	}
}

void MetalDeviceProperties::init_limits(MTL::Device *p_device) {
	using std::max;
	using std::min;

	// FST: https://developer.apple.com/metal/Metal-Feature-Set-Tables.pdf

	// FST: Maximum number of layers per 1D texture array, 2D texture array, or 3D texture.
	limits.maxImageArrayLayers = 2048;
	if (p_device->supportsFamily(MTL::GPUFamilyApple3)) {
		// FST: Maximum 2D texture width and height.
		limits.maxFramebufferWidth = 16384;
		limits.maxFramebufferHeight = 16384;
		limits.maxViewportDimensionX = 16384;
		limits.maxViewportDimensionY = 16384;
		// FST: Maximum 1D texture width.
		limits.maxImageDimension1D = 16384;
		// FST: Maximum 2D texture width and height.
		limits.maxImageDimension2D = 16384;
		// FST: Maximum cube map texture width and height.
		limits.maxImageDimensionCube = 16384;
	} else {
		// FST: Maximum 2D texture width and height.
		limits.maxFramebufferWidth = 8192;
		limits.maxFramebufferHeight = 8192;
		limits.maxViewportDimensionX = 8192;
		limits.maxViewportDimensionY = 8192;
		// FST: Maximum 1D texture width.
		limits.maxImageDimension1D = 8192;
		// FST: Maximum 2D texture width and height.
		limits.maxImageDimension2D = 8192;
		// FST: Maximum cube map texture width and height.
		limits.maxImageDimensionCube = 8192;
	}
	// FST: Maximum 3D texture width, height, and depth.
	limits.maxImageDimension3D = 2048;

	limits.maxThreadsPerThreadGroup = p_device->maxThreadsPerThreadgroup();
	// No effective limits.
	limits.maxComputeWorkGroupCount = { std::numeric_limits<uint32_t>::max(), std::numeric_limits<uint32_t>::max(), std::numeric_limits<uint32_t>::max() };
	// https://github.com/KhronosGroup/MoltenVK/blob/568cc3acc0e2299931fdaecaaa1fc3ec5b4af281/MoltenVK/MoltenVK/GPUObjects/MVKDevice.h#L85
	limits.maxBoundDescriptorSets = SPIRV_CROSS_NAMESPACE::kMaxArgumentBuffers;
	// FST: Maximum number of color render targets per render pass descriptor.
	limits.maxColorAttachments = 8;

	// Maximum number of textures the device can access, per stage, from an argument buffer.
	if (p_device->supportsFamily(MTL::GPUFamilyApple6)) {
		limits.maxTexturesPerArgumentBuffer = 1'000'000;
	} else if (p_device->supportsFamily(MTL::GPUFamilyApple4)) {
		limits.maxTexturesPerArgumentBuffer = 96;
	} else {
		limits.maxTexturesPerArgumentBuffer = 31;
	}

	// Maximum number of samplers the device can access, per stage, from an argument buffer.
	if (p_device->supportsFamily(MTL::GPUFamilyApple6)) {
		limits.maxSamplersPerArgumentBuffer = 1024;
	} else {
		limits.maxSamplersPerArgumentBuffer = 16;
	}

	// Maximum number of buffers the device can access, per stage, from an argument buffer.
	if (p_device->supportsFamily(MTL::GPUFamilyApple6)) {
		limits.maxBuffersPerArgumentBuffer = std::numeric_limits<uint64_t>::max();
	} else if (p_device->supportsFamily(MTL::GPUFamilyApple4)) {
		limits.maxBuffersPerArgumentBuffer = 96;
	} else {
		limits.maxBuffersPerArgumentBuffer = 31;
	}

	limits.minSubgroupSize = limits.maxSubgroupSize = 1;
	// These values were taken from MoltenVK.
	if (features.simdPermute) {
		limits.minSubgroupSize = 4;
		limits.maxSubgroupSize = 32;
	} else if (features.quadPermute) {
		limits.minSubgroupSize = limits.maxSubgroupSize = 4;
	}

	limits.subgroupSupportedShaderStages.set_flag(RDD::ShaderStage::SHADER_STAGE_COMPUTE_BIT);
	if (features.tessellationShader) {
		limits.subgroupSupportedShaderStages.set_flag(RDD::ShaderStage::SHADER_STAGE_TESSELATION_CONTROL_BIT);
	}
	limits.subgroupSupportedShaderStages.set_flag(RDD::ShaderStage::SHADER_STAGE_FRAGMENT_BIT);

	limits.subgroupSupportedOperations.set_flag(RDD::SubgroupOperations::SUBGROUP_BASIC_BIT);
	if (features.simdPermute || features.quadPermute) {
		limits.subgroupSupportedOperations.set_flag(RDD::SubgroupOperations::SUBGROUP_VOTE_BIT);
		limits.subgroupSupportedOperations.set_flag(RDD::SubgroupOperations::SUBGROUP_BALLOT_BIT);
		limits.subgroupSupportedOperations.set_flag(RDD::SubgroupOperations::SUBGROUP_SHUFFLE_BIT);
		limits.subgroupSupportedOperations.set_flag(RDD::SubgroupOperations::SUBGROUP_SHUFFLE_RELATIVE_BIT);
	}

	if (features.simdReduction) {
		limits.subgroupSupportedOperations.set_flag(RDD::SubgroupOperations::SUBGROUP_ARITHMETIC_BIT);
	}

	if (features.quadPermute) {
		limits.subgroupSupportedOperations.set_flag(RDD::SubgroupOperations::SUBGROUP_QUAD_BIT);
	}

	limits.maxBufferLength = p_device->maxBufferLength();

	// FST: Maximum size of vertex descriptor layout stride.
	limits.maxVertexDescriptorLayoutStride = std::numeric_limits<uint64_t>::max();

	// Maximum number of viewports.
	if (p_device->supportsFamily(MTL::GPUFamilyApple5)) {
		limits.maxViewports = 16;
	} else {
		limits.maxViewports = 1;
	}

	limits.maxPerStageBufferCount = 31;
	limits.maxPerStageSamplerCount = 16;
	if (p_device->supportsFamily(MTL::GPUFamilyApple6)) {
		limits.maxPerStageTextureCount = 128;
	} else if (p_device->supportsFamily(MTL::GPUFamilyApple4)) {
		limits.maxPerStageTextureCount = 96;
	} else {
		limits.maxPerStageTextureCount = 31;
	}

	limits.maxVertexInputAttributes = 31;
	limits.maxVertexInputBindings = 31;
	limits.maxVertexInputBindingStride = (2 * KIBI);
	limits.maxShaderVaryings = 31; // Accurate on Apple4 and above. See: https://developer.apple.com/metal/Metal-Feature-Set-Tables.pdf

	if (p_device->supportsFamily(MTL::GPUFamilyApple4)) {
		limits.maxThreadGroupMemoryAllocation = 32768;
	} else if (p_device->supportsFamily(MTL::GPUFamilyApple3)) {
		limits.maxThreadGroupMemoryAllocation = 16384;
	} else {
		limits.maxThreadGroupMemoryAllocation = 16352;
	}

#if TARGET_OS_IOS && !TARGET_OS_MACCATALYST
	limits.minUniformBufferOffsetAlignment = 64;
#endif

#if TARGET_OS_OSX
	// This is Apple Silicon specific.
	limits.minUniformBufferOffsetAlignment = 16;
#endif

	limits.maxDrawIndexedIndexValue = std::numeric_limits<uint32_t>::max() - 1;

#ifdef METAL_MFXTEMPORAL_ENABLED
	if (__builtin_available(macOS 14.0, iOS 17.0, tvOS 17.0, *)) {
		limits.temporalScalerInputContentMinScale = MTLFX::TemporalScalerDescriptor::supportedInputContentMinScale(p_device);
		limits.temporalScalerInputContentMaxScale = MTLFX::TemporalScalerDescriptor::supportedInputContentMaxScale(p_device);
	} else {
		// Defaults taken from macOS 14+
		limits.temporalScalerInputContentMinScale = 1.0;
		limits.temporalScalerInputContentMaxScale = 3.0;
	}
#else
	// Defaults taken from macOS 14+
	limits.temporalScalerInputContentMinScale = 1.0;
	limits.temporalScalerInputContentMaxScale = 3.0;
#endif
}

void MetalDeviceProperties::init_os_props() {
	NS::OperatingSystemVersion ver = NS::ProcessInfo::processInfo()->operatingSystemVersion();
	os_version = (uint32_t)ver.majorVersion * 10000 + (uint32_t)ver.minorVersion * 100 + (uint32_t)ver.patchVersion;
}

MetalDeviceProperties::MetalDeviceProperties(MTL::Device *p_device) {
	init_features(p_device);
	init_limits(p_device);
	init_os_props();
}

MetalDeviceProperties::~MetalDeviceProperties() {
}

SampleCount MetalDeviceProperties::find_nearest_supported_sample_count(RenderingDeviceCommons::TextureSamples p_samples) const {
	SampleCount supported = features.supportedSampleCounts;
	if (supported & sample_count[p_samples]) {
		return sample_count[p_samples];
	}

	SampleCount requested_sample_count = sample_count[p_samples];
	// Find the nearest supported sample count.
	while (requested_sample_count > SampleCount1) {
		if (supported & requested_sample_count) {
			return requested_sample_count;
		}
		requested_sample_count = (SampleCount)(requested_sample_count >> 1);
	}

	return SampleCount1;
}

// region static members

const SampleCount MetalDeviceProperties::sample_count[RenderingDeviceCommons::TextureSamples::TEXTURE_SAMPLES_MAX] = {
	SampleCount1,
	SampleCount2,
	SampleCount4,
	SampleCount8,
	SampleCount16,
	SampleCount32,
	SampleCount64,
};

// endregion