// This file is part of meshoptimizer library; see meshoptimizer.h for version/license details #include "meshoptimizer.h" #include #include // The block below auto-detects SIMD ISA that can be used on the target platform #ifndef MESHOPTIMIZER_NO_SIMD // The SIMD implementation requires SSSE3, which can be enabled unconditionally through compiler settings #if defined(__AVX__) || defined(__SSSE3__) #define SIMD_SSE #endif // An experimental implementation using AVX512 instructions; it's only enabled when AVX512 is enabled through compiler settings #if defined(__AVX512VBMI2__) && defined(__AVX512VBMI__) && defined(__AVX512VL__) && defined(__POPCNT__) #undef SIMD_SSE #define SIMD_AVX #endif // MSVC supports compiling SSSE3 code regardless of compile options; we use a cpuid-based scalar fallback #if !defined(SIMD_SSE) && !defined(SIMD_AVX) && defined(_MSC_VER) && !defined(__clang__) && (defined(_M_IX86) || defined(_M_X64)) #define SIMD_SSE #define SIMD_FALLBACK #endif // GCC 4.9+ and clang 3.8+ support targeting SIMD ISA from individual functions; we use a cpuid-based scalar fallback #if !defined(SIMD_SSE) && !defined(SIMD_AVX) && ((defined(__clang__) && __clang_major__ * 100 + __clang_minor__ >= 308) || (defined(__GNUC__) && __GNUC__ * 100 + __GNUC_MINOR__ >= 409)) && (defined(__i386__) || defined(__x86_64__)) #define SIMD_SSE #define SIMD_FALLBACK #define SIMD_TARGET __attribute__((target("ssse3"))) #endif // GCC/clang define these when NEON support is available #if defined(__ARM_NEON__) || defined(__ARM_NEON) #define SIMD_NEON #endif // On MSVC, we assume that ARM builds always target NEON-capable devices #if !defined(SIMD_NEON) && defined(_MSC_VER) && (defined(_M_ARM) || defined(_M_ARM64)) #define SIMD_NEON #endif // When targeting Wasm SIMD we can't use runtime cpuid checks so we unconditionally enable SIMD #if defined(__wasm_simd128__) #define SIMD_WASM #endif #ifndef SIMD_TARGET #define SIMD_TARGET #endif #endif // !MESHOPTIMIZER_NO_SIMD #ifdef SIMD_SSE #include #endif #if defined(SIMD_SSE) && defined(SIMD_FALLBACK) #ifdef _MSC_VER #include // __cpuid #else #include // __cpuid #endif #endif #ifdef SIMD_AVX #include #endif #ifdef SIMD_NEON #if defined(_MSC_VER) && defined(_M_ARM64) #include #else #include #endif #endif #ifdef SIMD_WASM #include #endif #ifndef TRACE #define TRACE 0 #endif #if TRACE #include #endif #ifdef SIMD_WASM #define wasmx_splat_v32x4(v, i) wasm_v32x4_shuffle(v, v, i, i, i, i) #define wasmx_unpacklo_v8x16(a, b) wasm_v8x16_shuffle(a, b, 0, 16, 1, 17, 2, 18, 3, 19, 4, 20, 5, 21, 6, 22, 7, 23) #define wasmx_unpackhi_v8x16(a, b) wasm_v8x16_shuffle(a, b, 8, 24, 9, 25, 10, 26, 11, 27, 12, 28, 13, 29, 14, 30, 15, 31) #define wasmx_unpacklo_v16x8(a, b) wasm_v16x8_shuffle(a, b, 0, 8, 1, 9, 2, 10, 3, 11) #define wasmx_unpackhi_v16x8(a, b) wasm_v16x8_shuffle(a, b, 4, 12, 5, 13, 6, 14, 7, 15) #define wasmx_unpacklo_v64x2(a, b) wasm_v64x2_shuffle(a, b, 0, 2) #define wasmx_unpackhi_v64x2(a, b) wasm_v64x2_shuffle(a, b, 1, 3) #endif namespace meshopt { const unsigned char kVertexHeader = 0xa0; static int gEncodeVertexVersion = 0; const size_t kVertexBlockSizeBytes = 8192; const size_t kVertexBlockMaxSize = 256; const size_t kByteGroupSize = 16; const size_t kByteGroupDecodeLimit = 24; const size_t kTailMaxSize = 32; static size_t getVertexBlockSize(size_t vertex_size) { // make sure the entire block fits into the scratch buffer size_t result = kVertexBlockSizeBytes / vertex_size; // align to byte group size; we encode each byte as a byte group // if vertex block is misaligned, it results in wasted bytes, so just truncate the block size result &= ~(kByteGroupSize - 1); return (result < kVertexBlockMaxSize) ? result : kVertexBlockMaxSize; } inline unsigned char zigzag8(unsigned char v) { return ((signed char)(v) >> 7) ^ (v << 1); } inline unsigned char unzigzag8(unsigned char v) { return -(v & 1) ^ (v >> 1); } #if TRACE struct Stats { size_t size; size_t header; size_t bitg[4]; size_t bitb[4]; }; Stats* bytestats; Stats vertexstats[256]; #endif static bool encodeBytesGroupZero(const unsigned char* buffer) { for (size_t i = 0; i < kByteGroupSize; ++i) if (buffer[i]) return false; return true; } static size_t encodeBytesGroupMeasure(const unsigned char* buffer, int bits) { assert(bits >= 1 && bits <= 8); if (bits == 1) return encodeBytesGroupZero(buffer) ? 0 : size_t(-1); if (bits == 8) return kByteGroupSize; size_t result = kByteGroupSize * bits / 8; unsigned char sentinel = (1 << bits) - 1; for (size_t i = 0; i < kByteGroupSize; ++i) result += buffer[i] >= sentinel; return result; } static unsigned char* encodeBytesGroup(unsigned char* data, const unsigned char* buffer, int bits) { assert(bits >= 1 && bits <= 8); if (bits == 1) return data; if (bits == 8) { memcpy(data, buffer, kByteGroupSize); return data + kByteGroupSize; } size_t byte_size = 8 / bits; assert(kByteGroupSize % byte_size == 0); // fixed portion: bits bits for each value // variable portion: full byte for each out-of-range value (using 1...1 as sentinel) unsigned char sentinel = (1 << bits) - 1; for (size_t i = 0; i < kByteGroupSize; i += byte_size) { unsigned char byte = 0; for (size_t k = 0; k < byte_size; ++k) { unsigned char enc = (buffer[i + k] >= sentinel) ? sentinel : buffer[i + k]; byte <<= bits; byte |= enc; } *data++ = byte; } for (size_t i = 0; i < kByteGroupSize; ++i) { if (buffer[i] >= sentinel) { *data++ = buffer[i]; } } return data; } static unsigned char* encodeBytes(unsigned char* data, unsigned char* data_end, const unsigned char* buffer, size_t buffer_size) { assert(buffer_size % kByteGroupSize == 0); unsigned char* header = data; // round number of groups to 4 to get number of header bytes size_t header_size = (buffer_size / kByteGroupSize + 3) / 4; if (size_t(data_end - data) < header_size) return 0; data += header_size; memset(header, 0, header_size); for (size_t i = 0; i < buffer_size; i += kByteGroupSize) { if (size_t(data_end - data) < kByteGroupDecodeLimit) return 0; int best_bits = 8; size_t best_size = encodeBytesGroupMeasure(buffer + i, 8); for (int bits = 1; bits < 8; bits *= 2) { size_t size = encodeBytesGroupMeasure(buffer + i, bits); if (size < best_size) { best_bits = bits; best_size = size; } } int bitslog2 = (best_bits == 1) ? 0 : (best_bits == 2) ? 1 : (best_bits == 4) ? 2 : 3; assert((1 << bitslog2) == best_bits); size_t header_offset = i / kByteGroupSize; header[header_offset / 4] |= bitslog2 << ((header_offset % 4) * 2); unsigned char* next = encodeBytesGroup(data, buffer + i, best_bits); assert(data + best_size == next); data = next; #if TRACE > 1 bytestats->bitg[bitslog2]++; bytestats->bitb[bitslog2] += best_size; #endif } #if TRACE > 1 bytestats->header += header_size; #endif return data; } static unsigned char* encodeVertexBlock(unsigned char* data, unsigned char* data_end, const unsigned char* vertex_data, size_t vertex_count, size_t vertex_size, unsigned char last_vertex[256]) { assert(vertex_count > 0 && vertex_count <= kVertexBlockMaxSize); unsigned char buffer[kVertexBlockMaxSize]; assert(sizeof(buffer) % kByteGroupSize == 0); // we sometimes encode elements we didn't fill when rounding to kByteGroupSize memset(buffer, 0, sizeof(buffer)); for (size_t k = 0; k < vertex_size; ++k) { size_t vertex_offset = k; unsigned char p = last_vertex[k]; for (size_t i = 0; i < vertex_count; ++i) { buffer[i] = zigzag8(vertex_data[vertex_offset] - p); p = vertex_data[vertex_offset]; vertex_offset += vertex_size; } #if TRACE const unsigned char* olddata = data; bytestats = &vertexstats[k]; #endif data = encodeBytes(data, data_end, buffer, (vertex_count + kByteGroupSize - 1) & ~(kByteGroupSize - 1)); if (!data) return 0; #if TRACE bytestats = 0; vertexstats[k].size += data - olddata; #endif } memcpy(last_vertex, &vertex_data[vertex_size * (vertex_count - 1)], vertex_size); return data; } #if defined(SIMD_FALLBACK) || (!defined(SIMD_SSE) && !defined(SIMD_NEON) && !defined(SIMD_AVX)) static const unsigned char* decodeBytesGroup(const unsigned char* data, unsigned char* buffer, int bitslog2) { #define READ() byte = *data++ #define NEXT(bits) enc = byte >> (8 - bits), byte <<= bits, encv = *data_var, *buffer++ = (enc == (1 << bits) - 1) ? encv : enc, data_var += (enc == (1 << bits) - 1) unsigned char byte, enc, encv; const unsigned char* data_var; switch (bitslog2) { case 0: memset(buffer, 0, kByteGroupSize); return data; case 1: data_var = data + 4; // 4 groups with 4 2-bit values in each byte READ(), NEXT(2), NEXT(2), NEXT(2), NEXT(2); READ(), NEXT(2), NEXT(2), NEXT(2), NEXT(2); READ(), NEXT(2), NEXT(2), NEXT(2), NEXT(2); READ(), NEXT(2), NEXT(2), NEXT(2), NEXT(2); return data_var; case 2: data_var = data + 8; // 8 groups with 2 4-bit values in each byte READ(), NEXT(4), NEXT(4); READ(), NEXT(4), NEXT(4); READ(), NEXT(4), NEXT(4); READ(), NEXT(4), NEXT(4); READ(), NEXT(4), NEXT(4); READ(), NEXT(4), NEXT(4); READ(), NEXT(4), NEXT(4); READ(), NEXT(4), NEXT(4); return data_var; case 3: memcpy(buffer, data, kByteGroupSize); return data + kByteGroupSize; default: assert(!"Unexpected bit length"); // unreachable since bitslog2 is a 2-bit value return data; } #undef READ #undef NEXT } static const unsigned char* decodeBytes(const unsigned char* data, const unsigned char* data_end, unsigned char* buffer, size_t buffer_size) { assert(buffer_size % kByteGroupSize == 0); const unsigned char* header = data; // round number of groups to 4 to get number of header bytes size_t header_size = (buffer_size / kByteGroupSize + 3) / 4; if (size_t(data_end - data) < header_size) return 0; data += header_size; for (size_t i = 0; i < buffer_size; i += kByteGroupSize) { if (size_t(data_end - data) < kByteGroupDecodeLimit) return 0; size_t header_offset = i / kByteGroupSize; int bitslog2 = (header[header_offset / 4] >> ((header_offset % 4) * 2)) & 3; data = decodeBytesGroup(data, buffer + i, bitslog2); } return data; } static const unsigned char* decodeVertexBlock(const unsigned char* data, const unsigned char* data_end, unsigned char* vertex_data, size_t vertex_count, size_t vertex_size, unsigned char last_vertex[256]) { assert(vertex_count > 0 && vertex_count <= kVertexBlockMaxSize); unsigned char buffer[kVertexBlockMaxSize]; unsigned char transposed[kVertexBlockSizeBytes]; size_t vertex_count_aligned = (vertex_count + kByteGroupSize - 1) & ~(kByteGroupSize - 1); for (size_t k = 0; k < vertex_size; ++k) { data = decodeBytes(data, data_end, buffer, vertex_count_aligned); if (!data) return 0; size_t vertex_offset = k; unsigned char p = last_vertex[k]; for (size_t i = 0; i < vertex_count; ++i) { unsigned char v = unzigzag8(buffer[i]) + p; transposed[vertex_offset] = v; p = v; vertex_offset += vertex_size; } } memcpy(vertex_data, transposed, vertex_count * vertex_size); memcpy(last_vertex, &transposed[vertex_size * (vertex_count - 1)], vertex_size); return data; } #endif #if defined(SIMD_SSE) || defined(SIMD_NEON) || defined(SIMD_WASM) static unsigned char kDecodeBytesGroupShuffle[256][8]; static unsigned char kDecodeBytesGroupCount[256]; #ifdef __wasm__ __attribute__((cold)) // this saves 500 bytes in the output binary - we don't need to vectorize this loop! #endif static bool decodeBytesGroupBuildTables() { for (int mask = 0; mask < 256; ++mask) { unsigned char shuffle[8]; unsigned char count = 0; for (int i = 0; i < 8; ++i) { int maski = (mask >> i) & 1; shuffle[i] = maski ? count : 0x80; count += (unsigned char)(maski); } memcpy(kDecodeBytesGroupShuffle[mask], shuffle, 8); kDecodeBytesGroupCount[mask] = count; } return true; } static bool gDecodeBytesGroupInitialized = decodeBytesGroupBuildTables(); #endif #ifdef SIMD_SSE SIMD_TARGET static __m128i decodeShuffleMask(unsigned char mask0, unsigned char mask1) { __m128i sm0 = _mm_loadl_epi64(reinterpret_cast(&kDecodeBytesGroupShuffle[mask0])); __m128i sm1 = _mm_loadl_epi64(reinterpret_cast(&kDecodeBytesGroupShuffle[mask1])); __m128i sm1off = _mm_set1_epi8(kDecodeBytesGroupCount[mask0]); __m128i sm1r = _mm_add_epi8(sm1, sm1off); return _mm_unpacklo_epi64(sm0, sm1r); } SIMD_TARGET static const unsigned char* decodeBytesGroupSimd(const unsigned char* data, unsigned char* buffer, int bitslog2) { switch (bitslog2) { case 0: { __m128i result = _mm_setzero_si128(); _mm_storeu_si128(reinterpret_cast<__m128i*>(buffer), result); return data; } case 1: { #ifdef __GNUC__ typedef int __attribute__((aligned(1))) unaligned_int; #else typedef int unaligned_int; #endif __m128i sel2 = _mm_cvtsi32_si128(*reinterpret_cast(data)); __m128i rest = _mm_loadu_si128(reinterpret_cast(data + 4)); __m128i sel22 = _mm_unpacklo_epi8(_mm_srli_epi16(sel2, 4), sel2); __m128i sel2222 = _mm_unpacklo_epi8(_mm_srli_epi16(sel22, 2), sel22); __m128i sel = _mm_and_si128(sel2222, _mm_set1_epi8(3)); __m128i mask = _mm_cmpeq_epi8(sel, _mm_set1_epi8(3)); int mask16 = _mm_movemask_epi8(mask); unsigned char mask0 = (unsigned char)(mask16 & 255); unsigned char mask1 = (unsigned char)(mask16 >> 8); __m128i shuf = decodeShuffleMask(mask0, mask1); __m128i result = _mm_or_si128(_mm_shuffle_epi8(rest, shuf), _mm_andnot_si128(mask, sel)); _mm_storeu_si128(reinterpret_cast<__m128i*>(buffer), result); return data + 4 + kDecodeBytesGroupCount[mask0] + kDecodeBytesGroupCount[mask1]; } case 2: { __m128i sel4 = _mm_loadl_epi64(reinterpret_cast(data)); __m128i rest = _mm_loadu_si128(reinterpret_cast(data + 8)); __m128i sel44 = _mm_unpacklo_epi8(_mm_srli_epi16(sel4, 4), sel4); __m128i sel = _mm_and_si128(sel44, _mm_set1_epi8(15)); __m128i mask = _mm_cmpeq_epi8(sel, _mm_set1_epi8(15)); int mask16 = _mm_movemask_epi8(mask); unsigned char mask0 = (unsigned char)(mask16 & 255); unsigned char mask1 = (unsigned char)(mask16 >> 8); __m128i shuf = decodeShuffleMask(mask0, mask1); __m128i result = _mm_or_si128(_mm_shuffle_epi8(rest, shuf), _mm_andnot_si128(mask, sel)); _mm_storeu_si128(reinterpret_cast<__m128i*>(buffer), result); return data + 8 + kDecodeBytesGroupCount[mask0] + kDecodeBytesGroupCount[mask1]; } case 3: { __m128i result = _mm_loadu_si128(reinterpret_cast(data)); _mm_storeu_si128(reinterpret_cast<__m128i*>(buffer), result); return data + 16; } default: assert(!"Unexpected bit length"); // unreachable since bitslog2 is a 2-bit value return data; } } #endif #ifdef SIMD_AVX static const __m128i decodeBytesGroupConfig[] = { _mm_set1_epi8(3), _mm_set1_epi8(15), _mm_setr_epi8(6, 4, 2, 0, 14, 12, 10, 8, 22, 20, 18, 16, 30, 28, 26, 24), _mm_setr_epi8(4, 0, 12, 8, 20, 16, 28, 24, 36, 32, 44, 40, 52, 48, 60, 56), }; static const unsigned char* decodeBytesGroupSimd(const unsigned char* data, unsigned char* buffer, int bitslog2) { switch (bitslog2) { case 0: { __m128i result = _mm_setzero_si128(); _mm_storeu_si128(reinterpret_cast<__m128i*>(buffer), result); return data; } case 1: case 2: { const unsigned char* skip = data + (bitslog2 << 2); __m128i selb = _mm_loadl_epi64(reinterpret_cast(data)); __m128i rest = _mm_loadu_si128(reinterpret_cast(skip)); __m128i sent = decodeBytesGroupConfig[bitslog2 - 1]; __m128i ctrl = decodeBytesGroupConfig[bitslog2 + 1]; __m128i selw = _mm_shuffle_epi32(selb, 0x44); __m128i sel = _mm_and_si128(sent, _mm_multishift_epi64_epi8(ctrl, selw)); __mmask16 mask16 = _mm_cmp_epi8_mask(sel, sent, _MM_CMPINT_EQ); __m128i result = _mm_mask_expand_epi8(sel, mask16, rest); _mm_storeu_si128(reinterpret_cast<__m128i*>(buffer), result); return skip + _mm_popcnt_u32(mask16); } case 3: { __m128i result = _mm_loadu_si128(reinterpret_cast(data)); _mm_storeu_si128(reinterpret_cast<__m128i*>(buffer), result); return data + 16; } default: assert(!"Unexpected bit length"); // unreachable since bitslog2 is a 2-bit value return data; } } #endif #ifdef SIMD_NEON static uint8x16_t shuffleBytes(unsigned char mask0, unsigned char mask1, uint8x8_t rest0, uint8x8_t rest1) { uint8x8_t sm0 = vld1_u8(kDecodeBytesGroupShuffle[mask0]); uint8x8_t sm1 = vld1_u8(kDecodeBytesGroupShuffle[mask1]); uint8x8_t r0 = vtbl1_u8(rest0, sm0); uint8x8_t r1 = vtbl1_u8(rest1, sm1); return vcombine_u8(r0, r1); } static void neonMoveMask(uint8x16_t mask, unsigned char& mask0, unsigned char& mask1) { static const unsigned char byte_mask_data[16] = {1, 2, 4, 8, 16, 32, 64, 128, 1, 2, 4, 8, 16, 32, 64, 128}; uint8x16_t byte_mask = vld1q_u8(byte_mask_data); uint8x16_t masked = vandq_u8(mask, byte_mask); #ifdef __aarch64__ // aarch64 has horizontal sums; MSVC doesn't expose this via arm64_neon.h so this path is exclusive to clang/gcc mask0 = vaddv_u8(vget_low_u8(masked)); mask1 = vaddv_u8(vget_high_u8(masked)); #else // we need horizontal sums of each half of masked, which can be done in 3 steps (yielding sums of sizes 2, 4, 8) uint8x8_t sum1 = vpadd_u8(vget_low_u8(masked), vget_high_u8(masked)); uint8x8_t sum2 = vpadd_u8(sum1, sum1); uint8x8_t sum3 = vpadd_u8(sum2, sum2); mask0 = vget_lane_u8(sum3, 0); mask1 = vget_lane_u8(sum3, 1); #endif } static const unsigned char* decodeBytesGroupSimd(const unsigned char* data, unsigned char* buffer, int bitslog2) { switch (bitslog2) { case 0: { uint8x16_t result = vdupq_n_u8(0); vst1q_u8(buffer, result); return data; } case 1: { uint8x8_t sel2 = vld1_u8(data); uint8x8_t sel22 = vzip_u8(vshr_n_u8(sel2, 4), sel2).val[0]; uint8x8x2_t sel2222 = vzip_u8(vshr_n_u8(sel22, 2), sel22); uint8x16_t sel = vandq_u8(vcombine_u8(sel2222.val[0], sel2222.val[1]), vdupq_n_u8(3)); uint8x16_t mask = vceqq_u8(sel, vdupq_n_u8(3)); unsigned char mask0, mask1; neonMoveMask(mask, mask0, mask1); uint8x8_t rest0 = vld1_u8(data + 4); uint8x8_t rest1 = vld1_u8(data + 4 + kDecodeBytesGroupCount[mask0]); uint8x16_t result = vbslq_u8(mask, shuffleBytes(mask0, mask1, rest0, rest1), sel); vst1q_u8(buffer, result); return data + 4 + kDecodeBytesGroupCount[mask0] + kDecodeBytesGroupCount[mask1]; } case 2: { uint8x8_t sel4 = vld1_u8(data); uint8x8x2_t sel44 = vzip_u8(vshr_n_u8(sel4, 4), vand_u8(sel4, vdup_n_u8(15))); uint8x16_t sel = vcombine_u8(sel44.val[0], sel44.val[1]); uint8x16_t mask = vceqq_u8(sel, vdupq_n_u8(15)); unsigned char mask0, mask1; neonMoveMask(mask, mask0, mask1); uint8x8_t rest0 = vld1_u8(data + 8); uint8x8_t rest1 = vld1_u8(data + 8 + kDecodeBytesGroupCount[mask0]); uint8x16_t result = vbslq_u8(mask, shuffleBytes(mask0, mask1, rest0, rest1), sel); vst1q_u8(buffer, result); return data + 8 + kDecodeBytesGroupCount[mask0] + kDecodeBytesGroupCount[mask1]; } case 3: { uint8x16_t result = vld1q_u8(data); vst1q_u8(buffer, result); return data + 16; } default: assert(!"Unexpected bit length"); // unreachable since bitslog2 is a 2-bit value return data; } } #endif #ifdef SIMD_WASM SIMD_TARGET static v128_t decodeShuffleMask(unsigned char mask0, unsigned char mask1) { v128_t sm0 = wasm_v128_load(&kDecodeBytesGroupShuffle[mask0]); v128_t sm1 = wasm_v128_load(&kDecodeBytesGroupShuffle[mask1]); v128_t sm1off = wasm_v128_load(&kDecodeBytesGroupCount[mask0]); sm1off = wasm_v8x16_shuffle(sm1off, sm1off, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0); v128_t sm1r = wasm_i8x16_add(sm1, sm1off); return wasmx_unpacklo_v64x2(sm0, sm1r); } SIMD_TARGET static void wasmMoveMask(v128_t mask, unsigned char& mask0, unsigned char& mask1) { v128_t mask_0 = wasm_v32x4_shuffle(mask, mask, 0, 2, 1, 3); uint64_t mask_1a = wasm_i64x2_extract_lane(mask_0, 0) & 0x0804020108040201ull; uint64_t mask_1b = wasm_i64x2_extract_lane(mask_0, 1) & 0x8040201080402010ull; // TODO: This can use v8x16_bitmask in the future uint64_t mask_2 = mask_1a | mask_1b; uint64_t mask_4 = mask_2 | (mask_2 >> 16); uint64_t mask_8 = mask_4 | (mask_4 >> 8); mask0 = uint8_t(mask_8); mask1 = uint8_t(mask_8 >> 32); } SIMD_TARGET static const unsigned char* decodeBytesGroupSimd(const unsigned char* data, unsigned char* buffer, int bitslog2) { unsigned char byte, enc, encv; const unsigned char* data_var; switch (bitslog2) { case 0: { v128_t result = wasm_i8x16_splat(0); wasm_v128_store(buffer, result); return data; } case 1: { v128_t sel2 = wasm_v128_load(data); v128_t rest = wasm_v128_load(data + 4); v128_t sel22 = wasmx_unpacklo_v8x16(wasm_i16x8_shr(sel2, 4), sel2); v128_t sel2222 = wasmx_unpacklo_v8x16(wasm_i16x8_shr(sel22, 2), sel22); v128_t sel = wasm_v128_and(sel2222, wasm_i8x16_splat(3)); v128_t mask = wasm_i8x16_eq(sel, wasm_i8x16_splat(3)); unsigned char mask0, mask1; wasmMoveMask(mask, mask0, mask1); v128_t shuf = decodeShuffleMask(mask0, mask1); v128_t result = wasm_v128_bitselect(wasm_v8x16_swizzle(rest, shuf), sel, mask); wasm_v128_store(buffer, result); return data + 4 + kDecodeBytesGroupCount[mask0] + kDecodeBytesGroupCount[mask1]; } case 2: { v128_t sel4 = wasm_v128_load(data); v128_t rest = wasm_v128_load(data + 8); v128_t sel44 = wasmx_unpacklo_v8x16(wasm_i16x8_shr(sel4, 4), sel4); v128_t sel = wasm_v128_and(sel44, wasm_i8x16_splat(15)); v128_t mask = wasm_i8x16_eq(sel, wasm_i8x16_splat(15)); unsigned char mask0, mask1; wasmMoveMask(mask, mask0, mask1); v128_t shuf = decodeShuffleMask(mask0, mask1); v128_t result = wasm_v128_bitselect(wasm_v8x16_swizzle(rest, shuf), sel, mask); wasm_v128_store(buffer, result); return data + 8 + kDecodeBytesGroupCount[mask0] + kDecodeBytesGroupCount[mask1]; } case 3: { v128_t result = wasm_v128_load(data); wasm_v128_store(buffer, result); return data + 16; } default: assert(!"Unexpected bit length"); // unreachable since bitslog2 is a 2-bit value return data; } } #endif #if defined(SIMD_SSE) || defined(SIMD_AVX) SIMD_TARGET static void transpose8(__m128i& x0, __m128i& x1, __m128i& x2, __m128i& x3) { __m128i t0 = _mm_unpacklo_epi8(x0, x1); __m128i t1 = _mm_unpackhi_epi8(x0, x1); __m128i t2 = _mm_unpacklo_epi8(x2, x3); __m128i t3 = _mm_unpackhi_epi8(x2, x3); x0 = _mm_unpacklo_epi16(t0, t2); x1 = _mm_unpackhi_epi16(t0, t2); x2 = _mm_unpacklo_epi16(t1, t3); x3 = _mm_unpackhi_epi16(t1, t3); } SIMD_TARGET static __m128i unzigzag8(__m128i v) { __m128i xl = _mm_sub_epi8(_mm_setzero_si128(), _mm_and_si128(v, _mm_set1_epi8(1))); __m128i xr = _mm_and_si128(_mm_srli_epi16(v, 1), _mm_set1_epi8(127)); return _mm_xor_si128(xl, xr); } #endif #ifdef SIMD_NEON static void transpose8(uint8x16_t& x0, uint8x16_t& x1, uint8x16_t& x2, uint8x16_t& x3) { uint8x16x2_t t01 = vzipq_u8(x0, x1); uint8x16x2_t t23 = vzipq_u8(x2, x3); uint16x8x2_t x01 = vzipq_u16(vreinterpretq_u16_u8(t01.val[0]), vreinterpretq_u16_u8(t23.val[0])); uint16x8x2_t x23 = vzipq_u16(vreinterpretq_u16_u8(t01.val[1]), vreinterpretq_u16_u8(t23.val[1])); x0 = vreinterpretq_u8_u16(x01.val[0]); x1 = vreinterpretq_u8_u16(x01.val[1]); x2 = vreinterpretq_u8_u16(x23.val[0]); x3 = vreinterpretq_u8_u16(x23.val[1]); } static uint8x16_t unzigzag8(uint8x16_t v) { uint8x16_t xl = vreinterpretq_u8_s8(vnegq_s8(vreinterpretq_s8_u8(vandq_u8(v, vdupq_n_u8(1))))); uint8x16_t xr = vshrq_n_u8(v, 1); return veorq_u8(xl, xr); } #endif #ifdef SIMD_WASM SIMD_TARGET static void transpose8(v128_t& x0, v128_t& x1, v128_t& x2, v128_t& x3) { v128_t t0 = wasmx_unpacklo_v8x16(x0, x1); v128_t t1 = wasmx_unpackhi_v8x16(x0, x1); v128_t t2 = wasmx_unpacklo_v8x16(x2, x3); v128_t t3 = wasmx_unpackhi_v8x16(x2, x3); x0 = wasmx_unpacklo_v16x8(t0, t2); x1 = wasmx_unpackhi_v16x8(t0, t2); x2 = wasmx_unpacklo_v16x8(t1, t3); x3 = wasmx_unpackhi_v16x8(t1, t3); } SIMD_TARGET static v128_t unzigzag8(v128_t v) { v128_t xl = wasm_i8x16_neg(wasm_v128_and(v, wasm_i8x16_splat(1))); v128_t xr = wasm_u8x16_shr(v, 1); return wasm_v128_xor(xl, xr); } #endif #if defined(SIMD_SSE) || defined(SIMD_AVX) || defined(SIMD_NEON) || defined(SIMD_WASM) SIMD_TARGET static const unsigned char* decodeBytesSimd(const unsigned char* data, const unsigned char* data_end, unsigned char* buffer, size_t buffer_size) { assert(buffer_size % kByteGroupSize == 0); assert(kByteGroupSize == 16); const unsigned char* header = data; // round number of groups to 4 to get number of header bytes size_t header_size = (buffer_size / kByteGroupSize + 3) / 4; if (size_t(data_end - data) < header_size) return 0; data += header_size; size_t i = 0; // fast-path: process 4 groups at a time, do a shared bounds check - each group reads <=24b for (; i + kByteGroupSize * 4 <= buffer_size && size_t(data_end - data) >= kByteGroupDecodeLimit * 4; i += kByteGroupSize * 4) { size_t header_offset = i / kByteGroupSize; unsigned char header_byte = header[header_offset / 4]; data = decodeBytesGroupSimd(data, buffer + i + kByteGroupSize * 0, (header_byte >> 0) & 3); data = decodeBytesGroupSimd(data, buffer + i + kByteGroupSize * 1, (header_byte >> 2) & 3); data = decodeBytesGroupSimd(data, buffer + i + kByteGroupSize * 2, (header_byte >> 4) & 3); data = decodeBytesGroupSimd(data, buffer + i + kByteGroupSize * 3, (header_byte >> 6) & 3); } // slow-path: process remaining groups for (; i < buffer_size; i += kByteGroupSize) { if (size_t(data_end - data) < kByteGroupDecodeLimit) return 0; size_t header_offset = i / kByteGroupSize; int bitslog2 = (header[header_offset / 4] >> ((header_offset % 4) * 2)) & 3; data = decodeBytesGroupSimd(data, buffer + i, bitslog2); } return data; } SIMD_TARGET static const unsigned char* decodeVertexBlockSimd(const unsigned char* data, const unsigned char* data_end, unsigned char* vertex_data, size_t vertex_count, size_t vertex_size, unsigned char last_vertex[256]) { assert(vertex_count > 0 && vertex_count <= kVertexBlockMaxSize); unsigned char buffer[kVertexBlockMaxSize * 4]; unsigned char transposed[kVertexBlockSizeBytes]; size_t vertex_count_aligned = (vertex_count + kByteGroupSize - 1) & ~(kByteGroupSize - 1); for (size_t k = 0; k < vertex_size; k += 4) { for (size_t j = 0; j < 4; ++j) { data = decodeBytesSimd(data, data_end, buffer + j * vertex_count_aligned, vertex_count_aligned); if (!data) return 0; } #if defined(SIMD_SSE) || defined(SIMD_AVX) #define TEMP __m128i #define PREP() __m128i pi = _mm_cvtsi32_si128(*reinterpret_cast(last_vertex + k)) #define LOAD(i) __m128i r##i = _mm_loadu_si128(reinterpret_cast(buffer + j + i * vertex_count_aligned)) #define GRP4(i) t0 = _mm_shuffle_epi32(r##i, 0), t1 = _mm_shuffle_epi32(r##i, 1), t2 = _mm_shuffle_epi32(r##i, 2), t3 = _mm_shuffle_epi32(r##i, 3) #define FIXD(i) t##i = pi = _mm_add_epi8(pi, t##i) #define SAVE(i) *reinterpret_cast(savep) = _mm_cvtsi128_si32(t##i), savep += vertex_size #endif #ifdef SIMD_NEON #define TEMP uint8x8_t #define PREP() uint8x8_t pi = vreinterpret_u8_u32(vld1_lane_u32(reinterpret_cast(last_vertex + k), vdup_n_u32(0), 0)) #define LOAD(i) uint8x16_t r##i = vld1q_u8(buffer + j + i * vertex_count_aligned) #define GRP4(i) t0 = vget_low_u8(r##i), t1 = vreinterpret_u8_u32(vdup_lane_u32(vreinterpret_u32_u8(t0), 1)), t2 = vget_high_u8(r##i), t3 = vreinterpret_u8_u32(vdup_lane_u32(vreinterpret_u32_u8(t2), 1)) #define FIXD(i) t##i = pi = vadd_u8(pi, t##i) #define SAVE(i) vst1_lane_u32(reinterpret_cast(savep), vreinterpret_u32_u8(t##i), 0), savep += vertex_size #endif #ifdef SIMD_WASM #define TEMP v128_t #define PREP() v128_t pi = wasm_v128_load(last_vertex + k) #define LOAD(i) v128_t r##i = wasm_v128_load(buffer + j + i * vertex_count_aligned) #define GRP4(i) t0 = wasmx_splat_v32x4(r##i, 0), t1 = wasmx_splat_v32x4(r##i, 1), t2 = wasmx_splat_v32x4(r##i, 2), t3 = wasmx_splat_v32x4(r##i, 3) #define FIXD(i) t##i = pi = wasm_i8x16_add(pi, t##i) #define SAVE(i) *reinterpret_cast(savep) = wasm_i32x4_extract_lane(t##i, 0), savep += vertex_size #endif PREP(); unsigned char* savep = transposed + k; for (size_t j = 0; j < vertex_count_aligned; j += 16) { LOAD(0); LOAD(1); LOAD(2); LOAD(3); r0 = unzigzag8(r0); r1 = unzigzag8(r1); r2 = unzigzag8(r2); r3 = unzigzag8(r3); transpose8(r0, r1, r2, r3); TEMP t0, t1, t2, t3; GRP4(0); FIXD(0), FIXD(1), FIXD(2), FIXD(3); SAVE(0), SAVE(1), SAVE(2), SAVE(3); GRP4(1); FIXD(0), FIXD(1), FIXD(2), FIXD(3); SAVE(0), SAVE(1), SAVE(2), SAVE(3); GRP4(2); FIXD(0), FIXD(1), FIXD(2), FIXD(3); SAVE(0), SAVE(1), SAVE(2), SAVE(3); GRP4(3); FIXD(0), FIXD(1), FIXD(2), FIXD(3); SAVE(0), SAVE(1), SAVE(2), SAVE(3); #undef TEMP #undef PREP #undef LOAD #undef GRP4 #undef FIXD #undef SAVE } } memcpy(vertex_data, transposed, vertex_count * vertex_size); memcpy(last_vertex, &transposed[vertex_size * (vertex_count - 1)], vertex_size); return data; } #endif #if defined(SIMD_SSE) && defined(SIMD_FALLBACK) static unsigned int getCpuFeatures() { int cpuinfo[4] = {}; #ifdef _MSC_VER __cpuid(cpuinfo, 1); #else __cpuid(1, cpuinfo[0], cpuinfo[1], cpuinfo[2], cpuinfo[3]); #endif return cpuinfo[2]; } unsigned int cpuid = getCpuFeatures(); #endif } // namespace meshopt size_t meshopt_encodeVertexBuffer(unsigned char* buffer, size_t buffer_size, const void* vertices, size_t vertex_count, size_t vertex_size) { using namespace meshopt; assert(vertex_size > 0 && vertex_size <= 256); assert(vertex_size % 4 == 0); #if TRACE memset(vertexstats, 0, sizeof(vertexstats)); #endif const unsigned char* vertex_data = static_cast(vertices); unsigned char* data = buffer; unsigned char* data_end = buffer + buffer_size; if (size_t(data_end - data) < 1 + vertex_size) return 0; int version = gEncodeVertexVersion; *data++ = (unsigned char)(kVertexHeader | version); unsigned char first_vertex[256] = {}; if (vertex_count > 0) memcpy(first_vertex, vertex_data, vertex_size); unsigned char last_vertex[256] = {}; memcpy(last_vertex, first_vertex, vertex_size); size_t vertex_block_size = getVertexBlockSize(vertex_size); size_t vertex_offset = 0; while (vertex_offset < vertex_count) { size_t block_size = (vertex_offset + vertex_block_size < vertex_count) ? vertex_block_size : vertex_count - vertex_offset; data = encodeVertexBlock(data, data_end, vertex_data + vertex_offset * vertex_size, block_size, vertex_size, last_vertex); if (!data) return 0; vertex_offset += block_size; } size_t tail_size = vertex_size < kTailMaxSize ? kTailMaxSize : vertex_size; if (size_t(data_end - data) < tail_size) return 0; // write first vertex to the end of the stream and pad it to 32 bytes; this is important to simplify bounds checks in decoder if (vertex_size < kTailMaxSize) { memset(data, 0, kTailMaxSize - vertex_size); data += kTailMaxSize - vertex_size; } memcpy(data, first_vertex, vertex_size); data += vertex_size; assert(data >= buffer + tail_size); assert(data <= buffer + buffer_size); #if TRACE size_t total_size = data - buffer; for (size_t k = 0; k < vertex_size; ++k) { const Stats& vsk = vertexstats[k]; printf("%2d: %d bytes\t%.1f%%\t%.1f bpv", int(k), int(vsk.size), double(vsk.size) / double(total_size) * 100, double(vsk.size) / double(vertex_count) * 8); #if TRACE > 1 printf("\t\thdr %d bytes\tbit0 %d (%d bytes)\tbit1 %d (%d bytes)\tbit2 %d (%d bytes)\tbit3 %d (%d bytes)", int(vsk.header), int(vsk.bitg[0]), int(vsk.bitb[0]), int(vsk.bitg[1]), int(vsk.bitb[1]), int(vsk.bitg[2]), int(vsk.bitb[2]), int(vsk.bitg[3]), int(vsk.bitb[3])); #endif printf("\n"); } #endif return data - buffer; } size_t meshopt_encodeVertexBufferBound(size_t vertex_count, size_t vertex_size) { using namespace meshopt; assert(vertex_size > 0 && vertex_size <= 256); assert(vertex_size % 4 == 0); size_t vertex_block_size = getVertexBlockSize(vertex_size); size_t vertex_block_count = (vertex_count + vertex_block_size - 1) / vertex_block_size; size_t vertex_block_header_size = (vertex_block_size / kByteGroupSize + 3) / 4; size_t vertex_block_data_size = vertex_block_size; size_t tail_size = vertex_size < kTailMaxSize ? kTailMaxSize : vertex_size; return 1 + vertex_block_count * vertex_size * (vertex_block_header_size + vertex_block_data_size) + tail_size; } void meshopt_encodeVertexVersion(int version) { assert(unsigned(version) <= 0); meshopt::gEncodeVertexVersion = version; } int meshopt_decodeVertexBuffer(void* destination, size_t vertex_count, size_t vertex_size, const unsigned char* buffer, size_t buffer_size) { using namespace meshopt; assert(vertex_size > 0 && vertex_size <= 256); assert(vertex_size % 4 == 0); const unsigned char* (*decode)(const unsigned char*, const unsigned char*, unsigned char*, size_t, size_t, unsigned char[256]) = 0; #if defined(SIMD_SSE) && defined(SIMD_FALLBACK) decode = (cpuid & (1 << 9)) ? decodeVertexBlockSimd : decodeVertexBlock; #elif defined(SIMD_SSE) || defined(SIMD_AVX) || defined(SIMD_NEON) || defined(SIMD_WASM) decode = decodeVertexBlockSimd; #else decode = decodeVertexBlock; #endif #if defined(SIMD_SSE) || defined(SIMD_NEON) || defined(SIMD_WASM) assert(gDecodeBytesGroupInitialized); (void)gDecodeBytesGroupInitialized; #endif unsigned char* vertex_data = static_cast(destination); const unsigned char* data = buffer; const unsigned char* data_end = buffer + buffer_size; if (size_t(data_end - data) < 1 + vertex_size) return -2; unsigned char data_header = *data++; if ((data_header & 0xf0) != kVertexHeader) return -1; int version = data_header & 0x0f; if (version > 0) return -1; unsigned char last_vertex[256]; memcpy(last_vertex, data_end - vertex_size, vertex_size); size_t vertex_block_size = getVertexBlockSize(vertex_size); size_t vertex_offset = 0; while (vertex_offset < vertex_count) { size_t block_size = (vertex_offset + vertex_block_size < vertex_count) ? vertex_block_size : vertex_count - vertex_offset; data = decode(data, data_end, vertex_data + vertex_offset * vertex_size, block_size, vertex_size, last_vertex); if (!data) return -2; vertex_offset += block_size; } size_t tail_size = vertex_size < kTailMaxSize ? kTailMaxSize : vertex_size; if (size_t(data_end - data) != tail_size) return -3; return 0; } #undef SIMD_NEON #undef SIMD_SSE #undef SIMD_AVX #undef SIMD_WASM #undef SIMD_FALLBACK #undef SIMD_TARGET