astc: Make IntegerEncodedValue a trivial structure

src/video_core/textures/astc.cpp

@@ -160,232 +160,198 @@ private:
 
 enum class IntegerEncoding { JustBits, Qus32, Trit };
 
-class IntegerEncodedValue {
-private:
-    IntegerEncoding m_Encoding{};
-    u32 m_NumBits = 0;
-    u32 m_BitValue = 0;
-    union {
-        u32 m_Qus32Value = 0;
-        u32 m_TritValue;
-    };
-
-public:
-    constexpr IntegerEncodedValue() = default;
-    constexpr IntegerEncodedValue(IntegerEncoding encoding, u32 numBits)
-        : m_Encoding(encoding), m_NumBits(numBits) {}
-
-    IntegerEncoding GetEncoding() const {
-        return m_Encoding;
-    }
-    u32 BaseBitLength() const {
-        return m_NumBits;
-    }
-
-    u32 GetBitValue() const {
-        return m_BitValue;
-    }
-    void SetBitValue(u32 val) {
-        m_BitValue = val;
-    }
-
-    u32 GetTritValue() const {
-        return m_TritValue;
-    }
-    void SetTritValue(u32 val) {
-        m_TritValue = val;
-    }
-
-    u32 GetQus32Value() const {
-        return m_Qus32Value;
-    }
-    void SetQus32Value(u32 val) {
-        m_Qus32Value = val;
-    }
+struct IntegerEncodedValue {
+    constexpr IntegerEncodedValue(IntegerEncoding encoding_, u32 num_bits_)
+        : encoding{encoding_}, num_bits{num_bits_} {}
 
-    bool MatchesEncoding(const IntegerEncodedValue& other) const {
-        return m_Encoding == other.m_Encoding && m_NumBits == other.m_NumBits;
+    constexpr bool MatchesEncoding(const IntegerEncodedValue& other) const {
+        return encoding == other.encoding && num_bits == other.num_bits;
     }
 
     // Returns the number of bits required to encode nVals values.
     u32 GetBitLength(u32 nVals) const {
-        u32 totalBits = m_NumBits * nVals;
-        if (m_Encoding == IntegerEncoding::Trit) {
+        u32 totalBits = num_bits * nVals;
+        if (encoding == IntegerEncoding::Trit) {
             totalBits += (nVals * 8 + 4) / 5;
-        } else if (m_Encoding == IntegerEncoding::Qus32) {
+        } else if (encoding == IntegerEncoding::Qus32) {
             totalBits += (nVals * 7 + 2) / 3;
         }
         return totalBits;
     }
 
-    // Returns a new instance of this struct that corresponds to the
-    // can take no more than maxval values
-    static IntegerEncodedValue CreateEncoding(u32 maxVal) {
-        while (maxVal > 0) {
-            u32 check = maxVal + 1;
+    IntegerEncoding encoding;
+    u32 num_bits;
+    u32 bit_value = 0;
+    union {
+        u32 qus32_value = 0;
+        u32 trit_value;
+    };
+};
 
-            // Is maxVal a power of two?
-            if (!(check & (check - 1))) {
-                return IntegerEncodedValue(IntegerEncoding::JustBits, Popcnt(maxVal));
-            }
+static void DecodeTritBlock(InputBitStream& bits, std::vector<IntegerEncodedValue>& result,
+                            u32 nBitsPerValue) {
+    // Implement the algorithm in section C.2.12
+    u32 m[5];
+    u32 t[5];
+    u32 T;
+
+    // Read the trit encoded block according to
+    // table C.2.14
+    m[0] = bits.ReadBits(nBitsPerValue);
+    T = bits.ReadBits(2);
+    m[1] = bits.ReadBits(nBitsPerValue);
+    T |= bits.ReadBits(2) << 2;
+    m[2] = bits.ReadBits(nBitsPerValue);
+    T |= bits.ReadBit() << 4;
+    m[3] = bits.ReadBits(nBitsPerValue);
+    T |= bits.ReadBits(2) << 5;
+    m[4] = bits.ReadBits(nBitsPerValue);
+    T |= bits.ReadBit() << 7;
+
+    u32 C = 0;
+
+    Bits<u32> Tb(T);
+    if (Tb(2, 4) == 7) {
+        C = (Tb(5, 7) << 2) | Tb(0, 1);
+        t[4] = t[3] = 2;
+    } else {
+        C = Tb(0, 4);
+        if (Tb(5, 6) == 3) {
+            t[4] = 2;
+            t[3] = Tb[7];
+        } else {
+            t[4] = Tb[7];
+            t[3] = Tb(5, 6);
+        }
+    }
 
-            // Is maxVal of the type 3*2^n - 1?
-            if ((check % 3 == 0) && !((check / 3) & ((check / 3) - 1))) {
-                return IntegerEncodedValue(IntegerEncoding::Trit, Popcnt(check / 3 - 1));
-            }
+    Bits<u32> Cb(C);
+    if (Cb(0, 1) == 3) {
+        t[2] = 2;
+        t[1] = Cb[4];
+        t[0] = (Cb[3] << 1) | (Cb[2] & ~Cb[3]);
+    } else if (Cb(2, 3) == 3) {
+        t[2] = 2;
+        t[1] = 2;
+        t[0] = Cb(0, 1);
+    } else {
+        t[2] = Cb[4];
+        t[1] = Cb(2, 3);
+        t[0] = (Cb[1] << 1) | (Cb[0] & ~Cb[1]);
+    }
 
-            // Is maxVal of the type 5*2^n - 1?
-            if ((check % 5 == 0) && !((check / 5) & ((check / 5) - 1))) {
-                return IntegerEncodedValue(IntegerEncoding::Qus32, Popcnt(check / 5 - 1));
-            }
+    for (std::size_t i = 0; i < 5; ++i) {
+        IntegerEncodedValue& val = result.emplace_back(IntegerEncoding::Trit, nBitsPerValue);
+        val.bit_value = m[i];
+        val.trit_value = t[i];
+    }
+}
 
-            // Apparently it can't be represented with a bounded s32eger sequence...
-            // just iterate.
-            maxVal--;
+static void DecodeQus32Block(InputBitStream& bits, std::vector<IntegerEncodedValue>& result,
+                             u32 nBitsPerValue) {
+    // Implement the algorithm in section C.2.12
+    u32 m[3];
+    u32 q[3];
+    u32 Q;
+
+    // Read the trit encoded block according to
+    // table C.2.15
+    m[0] = bits.ReadBits(nBitsPerValue);
+    Q = bits.ReadBits(3);
+    m[1] = bits.ReadBits(nBitsPerValue);
+    Q |= bits.ReadBits(2) << 3;
+    m[2] = bits.ReadBits(nBitsPerValue);
+    Q |= bits.ReadBits(2) << 5;
+
+    Bits<u32> Qb(Q);
+    if (Qb(1, 2) == 3 && Qb(5, 6) == 0) {
+        q[0] = q[1] = 4;
+        q[2] = (Qb[0] << 2) | ((Qb[4] & ~Qb[0]) << 1) | (Qb[3] & ~Qb[0]);
+    } else {
+        u32 C = 0;
+        if (Qb(1, 2) == 3) {
+            q[2] = 4;
+            C = (Qb(3, 4) << 3) | ((~Qb(5, 6) & 3) << 1) | Qb[0];
+        } else {
+            q[2] = Qb(5, 6);
+            C = Qb(0, 4);
         }
-        return IntegerEncodedValue(IntegerEncoding::JustBits, 0);
-    }
-
-    // Fills result with the values that are encoded in the given
-    // bitstream. We must know beforehand what the maximum possible
-    // value is, and how many values we're decoding.
-    static void DecodeIntegerSequence(std::vector<IntegerEncodedValue>& result,
-                                      InputBitStream& bits, u32 maxRange, u32 nValues) {
-        // Determine encoding parameters
-        IntegerEncodedValue val = IntegerEncodedValue::CreateEncoding(maxRange);
-
-        // Start decoding
-        u32 nValsDecoded = 0;
-        while (nValsDecoded < nValues) {
-            switch (val.GetEncoding()) {
-            case IntegerEncoding::Qus32:
-                DecodeQus32Block(bits, result, val.BaseBitLength());
-                nValsDecoded += 3;
-                break;
-
-            case IntegerEncoding::Trit:
-                DecodeTritBlock(bits, result, val.BaseBitLength());
-                nValsDecoded += 5;
-                break;
 
-            case IntegerEncoding::JustBits:
-                val.SetBitValue(bits.ReadBits(val.BaseBitLength()));
-                result.push_back(val);
-                nValsDecoded++;
-                break;
-            }
+        Bits<u32> Cb(C);
+        if (Cb(0, 2) == 5) {
+            q[1] = 4;
+            q[0] = Cb(3, 4);
+        } else {
+            q[1] = Cb(3, 4);
+            q[0] = Cb(0, 2);
         }
     }
 
-private:
-    static void DecodeTritBlock(InputBitStream& bits, std::vector<IntegerEncodedValue>& result,
-                                u32 nBitsPerValue) {
-        // Implement the algorithm in section C.2.12
-        u32 m[5];
-        u32 t[5];
-        u32 T;
-
-        // Read the trit encoded block according to
-        // table C.2.14
-        m[0] = bits.ReadBits(nBitsPerValue);
-        T = bits.ReadBits(2);
-        m[1] = bits.ReadBits(nBitsPerValue);
-        T |= bits.ReadBits(2) << 2;
-        m[2] = bits.ReadBits(nBitsPerValue);
-        T |= bits.ReadBit() << 4;
-        m[3] = bits.ReadBits(nBitsPerValue);
-        T |= bits.ReadBits(2) << 5;
-        m[4] = bits.ReadBits(nBitsPerValue);
-        T |= bits.ReadBit() << 7;
+    for (std::size_t i = 0; i < 3; ++i) {
+        IntegerEncodedValue& val = result.emplace_back(IntegerEncoding::Qus32, nBitsPerValue);
+        val.bit_value = m[i];
+        val.qus32_value = q[i];
+    }
+}
 
-        u32 C = 0;
+// Returns a new instance of this struct that corresponds to the
+// can take no more than maxval values
+static IntegerEncodedValue CreateEncoding(u32 maxVal) {
+    while (maxVal > 0) {
+        u32 check = maxVal + 1;
 
-        Bits<u32> Tb(T);
-        if (Tb(2, 4) == 7) {
-            C = (Tb(5, 7) << 2) | Tb(0, 1);
-            t[4] = t[3] = 2;
-        } else {
-            C = Tb(0, 4);
-            if (Tb(5, 6) == 3) {
-                t[4] = 2;
-                t[3] = Tb[7];
-            } else {
-                t[4] = Tb[7];
-                t[3] = Tb(5, 6);
-            }
+        // Is maxVal a power of two?
+        if (!(check & (check - 1))) {
+            return IntegerEncodedValue(IntegerEncoding::JustBits, Popcnt(maxVal));
         }
 
-        Bits<u32> Cb(C);
-        if (Cb(0, 1) == 3) {
-            t[2] = 2;
-            t[1] = Cb[4];
-            t[0] = (Cb[3] << 1) | (Cb[2] & ~Cb[3]);
-        } else if (Cb(2, 3) == 3) {
-            t[2] = 2;
-            t[1] = 2;
-            t[0] = Cb(0, 1);
-        } else {
-            t[2] = Cb[4];
-            t[1] = Cb(2, 3);
-            t[0] = (Cb[1] << 1) | (Cb[0] & ~Cb[1]);
+        // Is maxVal of the type 3*2^n - 1?
+        if ((check % 3 == 0) && !((check / 3) & ((check / 3) - 1))) {
+            return IntegerEncodedValue(IntegerEncoding::Trit, Popcnt(check / 3 - 1));
         }
 
-        for (u32 i = 0; i < 5; i++) {
-            IntegerEncodedValue val(IntegerEncoding::Trit, nBitsPerValue);
-            val.SetBitValue(m[i]);
-            val.SetTritValue(t[i]);
-            result.push_back(val);
+        // Is maxVal of the type 5*2^n - 1?
+        if ((check % 5 == 0) && !((check / 5) & ((check / 5) - 1))) {
+            return IntegerEncodedValue(IntegerEncoding::Qus32, Popcnt(check / 5 - 1));
         }
+
+        // Apparently it can't be represented with a bounded s32eger sequence...
+        // just iterate.
+        maxVal--;
     }
+    return IntegerEncodedValue(IntegerEncoding::JustBits, 0);
+}
 
-    static void DecodeQus32Block(InputBitStream& bits, std::vector<IntegerEncodedValue>& result,
-                                 u32 nBitsPerValue) {
-        // Implement the algorithm in section C.2.12
-        u32 m[3];
-        u32 q[3];
-        u32 Q;
-
-        // Read the trit encoded block according to
-        // table C.2.15
-        m[0] = bits.ReadBits(nBitsPerValue);
-        Q = bits.ReadBits(3);
-        m[1] = bits.ReadBits(nBitsPerValue);
-        Q |= bits.ReadBits(2) << 3;
-        m[2] = bits.ReadBits(nBitsPerValue);
-        Q |= bits.ReadBits(2) << 5;
-
-        Bits<u32> Qb(Q);
-        if (Qb(1, 2) == 3 && Qb(5, 6) == 0) {
-            q[0] = q[1] = 4;
-            q[2] = (Qb[0] << 2) | ((Qb[4] & ~Qb[0]) << 1) | (Qb[3] & ~Qb[0]);
-        } else {
-            u32 C = 0;
-            if (Qb(1, 2) == 3) {
-                q[2] = 4;
-                C = (Qb(3, 4) << 3) | ((~Qb(5, 6) & 3) << 1) | Qb[0];
-            } else {
-                q[2] = Qb(5, 6);
-                C = Qb(0, 4);
-            }
+// Fills result with the values that are encoded in the given
+// bitstream. We must know beforehand what the maximum possible
+// value is, and how many values we're decoding.
+static void DecodeIntegerSequence(std::vector<IntegerEncodedValue>& result, InputBitStream& bits,
+                                  u32 maxRange, u32 nValues) {
+    // Determine encoding parameters
+    IntegerEncodedValue val = CreateEncoding(maxRange);
+
+    // Start decoding
+    u32 nValsDecoded = 0;
+    while (nValsDecoded < nValues) {
+        switch (val.encoding) {
+        case IntegerEncoding::Qus32:
+            DecodeQus32Block(bits, result, val.num_bits);
+            nValsDecoded += 3;
+            break;
 
-            Bits<u32> Cb(C);
-            if (Cb(0, 2) == 5) {
-                q[1] = 4;
-                q[0] = Cb(3, 4);
-            } else {
-                q[1] = Cb(3, 4);
-                q[0] = Cb(0, 2);
-            }
-        }
+        case IntegerEncoding::Trit:
+            DecodeTritBlock(bits, result, val.num_bits);
+            nValsDecoded += 5;
+            break;
 
-        for (u32 i = 0; i < 3; i++) {
-            IntegerEncodedValue val(IntegerEncoding::Qus32, nBitsPerValue);
-            val.m_BitValue = m[i];
-            val.m_Qus32Value = q[i];
+        case IntegerEncoding::JustBits:
+            val.bit_value = bits.ReadBits(val.num_bits);
             result.push_back(val);
+            nValsDecoded++;
+            break;
         }
     }
-};
+}
 
 namespace ASTCC {
 
@@ -405,7 +371,7 @@ struct TexelWeightParams {
             nIdxs *= 2;
         }
 
-        return IntegerEncodedValue::CreateEncoding(m_MaxWeight).GetBitLength(nIdxs);
+        return CreateEncoding(m_MaxWeight).GetBitLength(nIdxs);
     }
 
     u32 GetNumWeightValues() const {
@@ -814,12 +780,12 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
     // figure out the max value for each of them...
     u32 range = 256;
     while (--range > 0) {
-        IntegerEncodedValue val = IntegerEncodedValue::CreateEncoding(range);
+        IntegerEncodedValue val = CreateEncoding(range);
         u32 bitLength = val.GetBitLength(nValues);
         if (bitLength <= nBitsForColorData) {
             // Find the smallest possible range that matches the given encoding
             while (--range > 0) {
-                IntegerEncodedValue newval = IntegerEncodedValue::CreateEncoding(range);
+                IntegerEncodedValue newval = CreateEncoding(range);
                 if (!newval.MatchesEncoding(val)) {
                     break;
                 }
@@ -834,7 +800,7 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
     // We now have enough to decode our s32eger sequence.
     std::vector<IntegerEncodedValue> decodedColorValues;
     InputBitStream colorStream(data);
-    IntegerEncodedValue::DecodeIntegerSequence(decodedColorValues, colorStream, range, nValues);
+    DecodeIntegerSequence(decodedColorValues, colorStream, range, nValues);
 
     // Once we have the decoded values, we need to dequantize them to the 0-255 range
     // This procedure is outlined in ASTC spec C.2.13
@@ -846,8 +812,8 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
         }
 
         const IntegerEncodedValue& val = *itr;
-        u32 bitlen = val.BaseBitLength();
-        u32 bitval = val.GetBitValue();
+        u32 bitlen = val.num_bits;
+        u32 bitval = val.bit_value;
 
         assert(bitlen >= 1);
 
@@ -855,7 +821,7 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
         // A is just the lsb replicated 9 times.
         A = Replicate(bitval & 1, 1, 9);
 
-        switch (val.GetEncoding()) {
+        switch (val.encoding) {
         // Replicate bits
         case IntegerEncoding::JustBits:
             out[outIdx++] = Replicate(bitval, bitlen, 8);
@@ -864,7 +830,7 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
         // Use algorithm in C.2.13
         case IntegerEncoding::Trit: {
 
-            D = val.GetTritValue();
+            D = val.trit_value;
 
             switch (bitlen) {
             case 1: {
@@ -915,7 +881,7 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
 
         case IntegerEncoding::Qus32: {
 
-            D = val.GetQus32Value();
+            D = val.qus32_value;
 
             switch (bitlen) {
             case 1: {
@@ -956,9 +922,9 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
             } // switch(bitlen)
         }     // case IntegerEncoding::Qus32
         break;
-        } // switch(val.GetEncoding())
+        } // switch(val.encoding)
 
-        if (val.GetEncoding() != IntegerEncoding::JustBits) {
+        if (val.encoding != IntegerEncoding::JustBits) {
             u32 T = D * C + B;
             T ^= A;
             T = (A & 0x80) | (T >> 2);
@@ -973,20 +939,20 @@ static void DecodeColorValues(u32* out, u8* data, const u32* modes, const u32 nP
 }
 
 static u32 UnquantizeTexelWeight(const IntegerEncodedValue& val) {
-    u32 bitval = val.GetBitValue();
-    u32 bitlen = val.BaseBitLength();
+    u32 bitval = val.bit_value;
+    u32 bitlen = val.num_bits;
 
     u32 A = Replicate(bitval & 1, 1, 7);
     u32 B = 0, C = 0, D = 0;
 
     u32 result = 0;
-    switch (val.GetEncoding()) {
+    switch (val.encoding) {
     case IntegerEncoding::JustBits:
         result = Replicate(bitval, bitlen, 6);
         break;
 
     case IntegerEncoding::Trit: {
-        D = val.GetTritValue();
+        D = val.trit_value;
         assert(D < 3);
 
         switch (bitlen) {
@@ -1018,7 +984,7 @@ static u32 UnquantizeTexelWeight(const IntegerEncodedValue& val) {
     } break;
 
     case IntegerEncoding::Qus32: {
-        D = val.GetQus32Value();
+        D = val.qus32_value;
         assert(D < 5);
 
         switch (bitlen) {
@@ -1044,7 +1010,7 @@ static u32 UnquantizeTexelWeight(const IntegerEncodedValue& val) {
     } break;
     }
 
-    if (val.GetEncoding() != IntegerEncoding::JustBits && bitlen > 0) {
+    if (val.encoding != IntegerEncoding::JustBits && bitlen > 0) {
         // Decode the value...
         result = D * C + B;
         result ^= A;
@@ -1562,9 +1528,8 @@ static void DecompressBlock(const u8 inBuf[16], const u32 blockWidth, const u32
     std::vector<IntegerEncodedValue> texelWeightValues;
     InputBitStream weightStream(texelWeightData);
 
-    IntegerEncodedValue::DecodeIntegerSequence(texelWeightValues, weightStream,
-                                               weightParams.m_MaxWeight,
-                                               weightParams.GetNumWeightValues());
+    DecodeIntegerSequence(texelWeightValues, weightStream, weightParams.m_MaxWeight,
+                          weightParams.GetNumWeightValues());
 
     // Blocks can be at most 12x12, so we can have as many as 144 weights
     u32 weights[2][144];