| // Copyright 2016 The SwiftShader Authors. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "ETC_Decoder.hpp" |
| |
| namespace { |
| inline unsigned char clampByte(int value) |
| { |
| return static_cast<unsigned char>((value < 0) ? 0 : ((value > 255) ? 255 : value)); |
| } |
| |
| inline signed char clampSByte(int value) |
| { |
| return static_cast<signed char>((value < -128) ? -128 : ((value > 127) ? 127 : value)); |
| } |
| |
| inline short clampEAC(int value, bool isSigned) |
| { |
| short min = isSigned ? -1023 : 0; |
| short max = isSigned ? 1023 : 2047; |
| return static_cast<short>(((value < min) ? min : ((value > max) ? max : value)) << 5); |
| } |
| |
| struct bgra8 |
| { |
| unsigned char b; |
| unsigned char g; |
| unsigned char r; |
| unsigned char a; |
| |
| inline bgra8() |
| { |
| } |
| |
| inline void set(int red, int green, int blue) |
| { |
| r = clampByte(red); |
| g = clampByte(green); |
| b = clampByte(blue); |
| } |
| |
| inline void set(int red, int green, int blue, int alpha) |
| { |
| r = clampByte(red); |
| g = clampByte(green); |
| b = clampByte(blue); |
| a = clampByte(alpha); |
| } |
| |
| const bgra8 &addA(unsigned char alpha) |
| { |
| a = alpha; |
| return *this; |
| } |
| }; |
| |
| inline int extend_4to8bits(int x) |
| { |
| return (x << 4) | x; |
| } |
| |
| inline int extend_5to8bits(int x) |
| { |
| return (x << 3) | (x >> 2); |
| } |
| |
| inline int extend_6to8bits(int x) |
| { |
| return (x << 2) | (x >> 4); |
| } |
| |
| inline int extend_7to8bits(int x) |
| { |
| return (x << 1) | (x >> 6); |
| } |
| |
| struct ETC2 |
| { |
| // Decodes unsigned single or dual channel block to bytes |
| static void DecodeBlock(const ETC2 **sources, unsigned char *dest, int nbChannels, int x, int y, int w, int h, int pitch, bool isSigned, bool isEAC) |
| { |
| if(isEAC) |
| { |
| for(int j = 0; j < 4 && (y + j) < h; j++) |
| { |
| short *sDst = reinterpret_cast<short *>(dest); |
| for(int i = 0; i < 4 && (x + i) < w; i++) |
| { |
| for(int c = nbChannels - 1; c >= 0; c--) |
| { |
| sDst[i * nbChannels + c] = clampEAC(sources[c]->getSingleChannel(i, j, isSigned, true), isSigned); |
| } |
| } |
| dest += pitch; |
| } |
| } |
| else |
| { |
| if(isSigned) |
| { |
| signed char *sDst = reinterpret_cast<signed char *>(dest); |
| for(int j = 0; j < 4 && (y + j) < h; j++) |
| { |
| for(int i = 0; i < 4 && (x + i) < w; i++) |
| { |
| for(int c = nbChannels - 1; c >= 0; c--) |
| { |
| sDst[i * nbChannels + c] = clampSByte(sources[c]->getSingleChannel(i, j, isSigned, false)); |
| } |
| } |
| sDst += pitch; |
| } |
| } |
| else |
| { |
| for(int j = 0; j < 4 && (y + j) < h; j++) |
| { |
| for(int i = 0; i < 4 && (x + i) < w; i++) |
| { |
| for(int c = nbChannels - 1; c >= 0; c--) |
| { |
| dest[i * nbChannels + c] = clampByte(sources[c]->getSingleChannel(i, j, isSigned, false)); |
| } |
| } |
| dest += pitch; |
| } |
| } |
| } |
| } |
| |
| // Decodes RGB block to bgra8 |
| void decodeBlock(unsigned char *dest, int x, int y, int w, int h, int pitch, unsigned char alphaValues[4][4], bool punchThroughAlpha) const |
| { |
| bool opaqueBit = diffbit; |
| bool nonOpaquePunchThroughAlpha = punchThroughAlpha && !opaqueBit; |
| |
| // Select mode |
| if(diffbit || punchThroughAlpha) |
| { |
| int r = (R + dR); |
| int g = (G + dG); |
| int b = (B + dB); |
| if(r < 0 || r > 31) |
| { |
| decodeTBlock(dest, x, y, w, h, pitch, alphaValues, nonOpaquePunchThroughAlpha); |
| } |
| else if(g < 0 || g > 31) |
| { |
| decodeHBlock(dest, x, y, w, h, pitch, alphaValues, nonOpaquePunchThroughAlpha); |
| } |
| else if(b < 0 || b > 31) |
| { |
| decodePlanarBlock(dest, x, y, w, h, pitch, alphaValues); |
| } |
| else |
| { |
| decodeDifferentialBlock(dest, x, y, w, h, pitch, alphaValues, nonOpaquePunchThroughAlpha); |
| } |
| } |
| else |
| { |
| decodeIndividualBlock(dest, x, y, w, h, pitch, alphaValues, nonOpaquePunchThroughAlpha); |
| } |
| } |
| |
| private: |
| struct |
| { |
| union |
| { |
| // Individual, differential, H and T modes |
| struct |
| { |
| union |
| { |
| // Individual and differential modes |
| struct |
| { |
| union |
| { |
| struct // Individual colors |
| { |
| unsigned char R2 : 4; |
| unsigned char R1 : 4; |
| unsigned char G2 : 4; |
| unsigned char G1 : 4; |
| unsigned char B2 : 4; |
| unsigned char B1 : 4; |
| }; |
| |
| struct // Differential colors |
| { |
| signed char dR : 3; |
| unsigned char R : 5; |
| signed char dG : 3; |
| unsigned char G : 5; |
| signed char dB : 3; |
| unsigned char B : 5; |
| }; |
| }; |
| |
| bool flipbit : 1; |
| bool diffbit : 1; |
| unsigned char cw2 : 3; |
| unsigned char cw1 : 3; |
| }; |
| |
| // T mode |
| struct |
| { |
| // Byte 1 |
| unsigned char TR1b : 2; |
| unsigned char TdummyB : 1; |
| unsigned char TR1a : 2; |
| unsigned char TdummyA : 3; |
| |
| // Byte 2 |
| unsigned char TB1 : 4; |
| unsigned char TG1 : 4; |
| |
| // Byte 3 |
| unsigned char TG2 : 4; |
| unsigned char TR2 : 4; |
| |
| // Byte 4 |
| unsigned char Tdb : 1; |
| bool Tflipbit : 1; |
| unsigned char Tda : 2; |
| unsigned char TB2 : 4; |
| }; |
| |
| // H mode |
| struct |
| { |
| // Byte 1 |
| unsigned char HG1a : 3; |
| unsigned char HR1 : 4; |
| unsigned char HdummyA : 1; |
| |
| // Byte 2 |
| unsigned char HB1b : 2; |
| unsigned char HdummyC : 1; |
| unsigned char HB1a : 1; |
| unsigned char HG1b : 1; |
| unsigned char HdummyB : 3; |
| |
| // Byte 3 |
| unsigned char HG2a : 3; |
| unsigned char HR2 : 4; |
| unsigned char HB1c : 1; |
| |
| // Byte 4 |
| unsigned char Hdb : 1; |
| bool Hflipbit : 1; |
| unsigned char Hda : 1; |
| unsigned char HB2 : 4; |
| unsigned char HG2b : 1; |
| }; |
| }; |
| |
| unsigned char pixelIndexMSB[2]; |
| unsigned char pixelIndexLSB[2]; |
| }; |
| |
| // planar mode |
| struct |
| { |
| // Byte 1 |
| unsigned char GO1 : 1; |
| unsigned char RO : 6; |
| unsigned char PdummyA : 1; |
| |
| // Byte 2 |
| unsigned char BO1 : 1; |
| unsigned char GO2 : 6; |
| unsigned char PdummyB : 1; |
| |
| // Byte 3 |
| unsigned char BO3a : 2; |
| unsigned char PdummyD : 1; |
| unsigned char BO2 : 2; |
| unsigned char PdummyC : 3; |
| |
| // Byte 4 |
| unsigned char RH2 : 1; |
| bool Pflipbit : 1; |
| unsigned char RH1 : 5; |
| unsigned char BO3b : 1; |
| |
| // Byte 5 |
| unsigned char BHa : 1; |
| unsigned char GH : 7; |
| |
| // Byte 6 |
| unsigned char RVa : 3; |
| unsigned char BHb : 5; |
| |
| // Byte 7 |
| unsigned char GVa : 5; |
| unsigned char RVb : 3; |
| |
| // Byte 8 |
| unsigned char BV : 6; |
| unsigned char GVb : 2; |
| }; |
| |
| // Single channel block |
| struct |
| { |
| union |
| { |
| unsigned char base_codeword; |
| signed char signed_base_codeword; |
| }; |
| |
| unsigned char table_index : 4; |
| unsigned char multiplier : 4; |
| |
| unsigned char mc1 : 2; |
| unsigned char mb : 3; |
| unsigned char ma : 3; |
| |
| unsigned char mf1 : 1; |
| unsigned char me : 3; |
| unsigned char md : 3; |
| unsigned char mc2 : 1; |
| |
| unsigned char mh : 3; |
| unsigned char mg : 3; |
| unsigned char mf2 : 2; |
| |
| unsigned char mk1 : 2; |
| unsigned char mj : 3; |
| unsigned char mi : 3; |
| |
| unsigned char mn1 : 1; |
| unsigned char mm : 3; |
| unsigned char ml : 3; |
| unsigned char mk2 : 1; |
| |
| unsigned char mp : 3; |
| unsigned char mo : 3; |
| unsigned char mn2 : 2; |
| }; |
| }; |
| }; |
| |
| void decodeIndividualBlock(unsigned char *dest, int x, int y, int w, int h, int pitch, unsigned char alphaValues[4][4], bool nonOpaquePunchThroughAlpha) const |
| { |
| int r1 = extend_4to8bits(R1); |
| int g1 = extend_4to8bits(G1); |
| int b1 = extend_4to8bits(B1); |
| |
| int r2 = extend_4to8bits(R2); |
| int g2 = extend_4to8bits(G2); |
| int b2 = extend_4to8bits(B2); |
| |
| decodeIndividualOrDifferentialBlock(dest, x, y, w, h, pitch, r1, g1, b1, r2, g2, b2, alphaValues, nonOpaquePunchThroughAlpha); |
| } |
| |
| void decodeDifferentialBlock(unsigned char *dest, int x, int y, int w, int h, int pitch, unsigned char alphaValues[4][4], bool nonOpaquePunchThroughAlpha) const |
| { |
| int b1 = extend_5to8bits(B); |
| int g1 = extend_5to8bits(G); |
| int r1 = extend_5to8bits(R); |
| |
| int r2 = extend_5to8bits(R + dR); |
| int g2 = extend_5to8bits(G + dG); |
| int b2 = extend_5to8bits(B + dB); |
| |
| decodeIndividualOrDifferentialBlock(dest, x, y, w, h, pitch, r1, g1, b1, r2, g2, b2, alphaValues, nonOpaquePunchThroughAlpha); |
| } |
| |
| void decodeIndividualOrDifferentialBlock(unsigned char *dest, int x, int y, int w, int h, int pitch, int r1, int g1, int b1, int r2, int g2, int b2, unsigned char alphaValues[4][4], bool nonOpaquePunchThroughAlpha) const |
| { |
| // Table 3.17.2 sorted according to table 3.17.3 |
| static const int intensityModifierDefault[8][4] = { |
| { 2, 8, -2, -8 }, |
| { 5, 17, -5, -17 }, |
| { 9, 29, -9, -29 }, |
| { 13, 42, -13, -42 }, |
| { 18, 60, -18, -60 }, |
| { 24, 80, -24, -80 }, |
| { 33, 106, -33, -106 }, |
| { 47, 183, -47, -183 } |
| }; |
| |
| // Table C.12, intensity modifier for non opaque punchthrough alpha |
| static const int intensityModifierNonOpaque[8][4] = { |
| { 0, 8, 0, -8 }, |
| { 0, 17, 0, -17 }, |
| { 0, 29, 0, -29 }, |
| { 0, 42, 0, -42 }, |
| { 0, 60, 0, -60 }, |
| { 0, 80, 0, -80 }, |
| { 0, 106, 0, -106 }, |
| { 0, 183, 0, -183 } |
| }; |
| |
| const int(&intensityModifier)[8][4] = nonOpaquePunchThroughAlpha ? intensityModifierNonOpaque : intensityModifierDefault; |
| |
| bgra8 subblockColors0[4]; |
| bgra8 subblockColors1[4]; |
| |
| const int i10 = intensityModifier[cw1][0]; |
| const int i11 = intensityModifier[cw1][1]; |
| const int i12 = intensityModifier[cw1][2]; |
| const int i13 = intensityModifier[cw1][3]; |
| |
| subblockColors0[0].set(r1 + i10, g1 + i10, b1 + i10); |
| subblockColors0[1].set(r1 + i11, g1 + i11, b1 + i11); |
| subblockColors0[2].set(r1 + i12, g1 + i12, b1 + i12); |
| subblockColors0[3].set(r1 + i13, g1 + i13, b1 + i13); |
| |
| const int i20 = intensityModifier[cw2][0]; |
| const int i21 = intensityModifier[cw2][1]; |
| const int i22 = intensityModifier[cw2][2]; |
| const int i23 = intensityModifier[cw2][3]; |
| |
| subblockColors1[0].set(r2 + i20, g2 + i20, b2 + i20); |
| subblockColors1[1].set(r2 + i21, g2 + i21, b2 + i21); |
| subblockColors1[2].set(r2 + i22, g2 + i22, b2 + i22); |
| subblockColors1[3].set(r2 + i23, g2 + i23, b2 + i23); |
| |
| unsigned char *destStart = dest; |
| |
| if(flipbit) |
| { |
| for(int j = 0; j < 2 && (y + j) < h; j++) |
| { |
| bgra8 *color = (bgra8 *)dest; |
| if((x + 0) < w) color[0] = subblockColors0[getIndex(0, j)].addA(alphaValues[j][0]); |
| if((x + 1) < w) color[1] = subblockColors0[getIndex(1, j)].addA(alphaValues[j][1]); |
| if((x + 2) < w) color[2] = subblockColors0[getIndex(2, j)].addA(alphaValues[j][2]); |
| if((x + 3) < w) color[3] = subblockColors0[getIndex(3, j)].addA(alphaValues[j][3]); |
| dest += pitch; |
| } |
| |
| for(int j = 2; j < 4 && (y + j) < h; j++) |
| { |
| bgra8 *color = (bgra8 *)dest; |
| if((x + 0) < w) color[0] = subblockColors1[getIndex(0, j)].addA(alphaValues[j][0]); |
| if((x + 1) < w) color[1] = subblockColors1[getIndex(1, j)].addA(alphaValues[j][1]); |
| if((x + 2) < w) color[2] = subblockColors1[getIndex(2, j)].addA(alphaValues[j][2]); |
| if((x + 3) < w) color[3] = subblockColors1[getIndex(3, j)].addA(alphaValues[j][3]); |
| dest += pitch; |
| } |
| } |
| else |
| { |
| for(int j = 0; j < 4 && (y + j) < h; j++) |
| { |
| bgra8 *color = (bgra8 *)dest; |
| if((x + 0) < w) color[0] = subblockColors0[getIndex(0, j)].addA(alphaValues[j][0]); |
| if((x + 1) < w) color[1] = subblockColors0[getIndex(1, j)].addA(alphaValues[j][1]); |
| if((x + 2) < w) color[2] = subblockColors1[getIndex(2, j)].addA(alphaValues[j][2]); |
| if((x + 3) < w) color[3] = subblockColors1[getIndex(3, j)].addA(alphaValues[j][3]); |
| dest += pitch; |
| } |
| } |
| |
| if(nonOpaquePunchThroughAlpha) |
| { |
| decodePunchThroughAlphaBlock(destStart, x, y, w, h, pitch); |
| } |
| } |
| |
| void decodeTBlock(unsigned char *dest, int x, int y, int w, int h, int pitch, unsigned char alphaValues[4][4], bool nonOpaquePunchThroughAlpha) const |
| { |
| // Table C.8, distance index fot T and H modes |
| static const int distance[8] = { 3, 6, 11, 16, 23, 32, 41, 64 }; |
| |
| bgra8 paintColors[4]; |
| |
| int r1 = extend_4to8bits(TR1a << 2 | TR1b); |
| int g1 = extend_4to8bits(TG1); |
| int b1 = extend_4to8bits(TB1); |
| |
| int r2 = extend_4to8bits(TR2); |
| int g2 = extend_4to8bits(TG2); |
| int b2 = extend_4to8bits(TB2); |
| |
| const int d = distance[Tda << 1 | Tdb]; |
| |
| paintColors[0].set(r1, g1, b1); |
| paintColors[1].set(r2 + d, g2 + d, b2 + d); |
| paintColors[2].set(r2, g2, b2); |
| paintColors[3].set(r2 - d, g2 - d, b2 - d); |
| |
| unsigned char *destStart = dest; |
| |
| for(int j = 0; j < 4 && (y + j) < h; j++) |
| { |
| bgra8 *color = (bgra8 *)dest; |
| if((x + 0) < w) color[0] = paintColors[getIndex(0, j)].addA(alphaValues[j][0]); |
| if((x + 1) < w) color[1] = paintColors[getIndex(1, j)].addA(alphaValues[j][1]); |
| if((x + 2) < w) color[2] = paintColors[getIndex(2, j)].addA(alphaValues[j][2]); |
| if((x + 3) < w) color[3] = paintColors[getIndex(3, j)].addA(alphaValues[j][3]); |
| dest += pitch; |
| } |
| |
| if(nonOpaquePunchThroughAlpha) |
| { |
| decodePunchThroughAlphaBlock(destStart, x, y, w, h, pitch); |
| } |
| } |
| |
| void decodeHBlock(unsigned char *dest, int x, int y, int w, int h, int pitch, unsigned char alphaValues[4][4], bool nonOpaquePunchThroughAlpha) const |
| { |
| // Table C.8, distance index fot T and H modes |
| static const int distance[8] = { 3, 6, 11, 16, 23, 32, 41, 64 }; |
| |
| bgra8 paintColors[4]; |
| |
| int r1 = extend_4to8bits(HR1); |
| int g1 = extend_4to8bits(HG1a << 1 | HG1b); |
| int b1 = extend_4to8bits(HB1a << 3 | HB1b << 1 | HB1c); |
| |
| int r2 = extend_4to8bits(HR2); |
| int g2 = extend_4to8bits(HG2a << 1 | HG2b); |
| int b2 = extend_4to8bits(HB2); |
| |
| const int d = distance[(Hda << 2) | (Hdb << 1) | ((r1 << 16 | g1 << 8 | b1) >= (r2 << 16 | g2 << 8 | b2) ? 1 : 0)]; |
| |
| paintColors[0].set(r1 + d, g1 + d, b1 + d); |
| paintColors[1].set(r1 - d, g1 - d, b1 - d); |
| paintColors[2].set(r2 + d, g2 + d, b2 + d); |
| paintColors[3].set(r2 - d, g2 - d, b2 - d); |
| |
| unsigned char *destStart = dest; |
| |
| for(int j = 0; j < 4 && (y + j) < h; j++) |
| { |
| bgra8 *color = (bgra8 *)dest; |
| if((x + 0) < w) color[0] = paintColors[getIndex(0, j)].addA(alphaValues[j][0]); |
| if((x + 1) < w) color[1] = paintColors[getIndex(1, j)].addA(alphaValues[j][1]); |
| if((x + 2) < w) color[2] = paintColors[getIndex(2, j)].addA(alphaValues[j][2]); |
| if((x + 3) < w) color[3] = paintColors[getIndex(3, j)].addA(alphaValues[j][3]); |
| dest += pitch; |
| } |
| |
| if(nonOpaquePunchThroughAlpha) |
| { |
| decodePunchThroughAlphaBlock(destStart, x, y, w, h, pitch); |
| } |
| } |
| |
| void decodePlanarBlock(unsigned char *dest, int x, int y, int w, int h, int pitch, unsigned char alphaValues[4][4]) const |
| { |
| int ro = extend_6to8bits(RO); |
| int go = extend_7to8bits(GO1 << 6 | GO2); |
| int bo = extend_6to8bits(BO1 << 5 | BO2 << 3 | BO3a << 1 | BO3b); |
| |
| int rh = extend_6to8bits(RH1 << 1 | RH2); |
| int gh = extend_7to8bits(GH); |
| int bh = extend_6to8bits(BHa << 5 | BHb); |
| |
| int rv = extend_6to8bits(RVa << 3 | RVb); |
| int gv = extend_7to8bits(GVa << 2 | GVb); |
| int bv = extend_6to8bits(BV); |
| |
| for(int j = 0; j < 4 && (y + j) < h; j++) |
| { |
| int ry = j * (rv - ro) + 2; |
| int gy = j * (gv - go) + 2; |
| int by = j * (bv - bo) + 2; |
| for(int i = 0; i < 4 && (x + i) < w; i++) |
| { |
| ((bgra8 *)(dest))[i].set(((i * (rh - ro) + ry) >> 2) + ro, |
| ((i * (gh - go) + gy) >> 2) + go, |
| ((i * (bh - bo) + by) >> 2) + bo, |
| alphaValues[j][i]); |
| } |
| dest += pitch; |
| } |
| } |
| |
| // Index for individual, differential, H and T modes |
| inline int getIndex(int x, int y) const |
| { |
| int bitIndex = x * 4 + y; |
| int bitOffset = bitIndex & 7; |
| int lsb = (pixelIndexLSB[1 - (bitIndex >> 3)] >> bitOffset) & 1; |
| int msb = (pixelIndexMSB[1 - (bitIndex >> 3)] >> bitOffset) & 1; |
| |
| return (msb << 1) | lsb; |
| } |
| |
| void decodePunchThroughAlphaBlock(unsigned char *dest, int x, int y, int w, int h, int pitch) const |
| { |
| for(int j = 0; j < 4 && (y + j) < h; j++) |
| { |
| for(int i = 0; i < 4 && (x + i) < w; i++) |
| { |
| if(getIndex(i, j) == 2) // msb == 1 && lsb == 0 |
| { |
| ((bgra8 *)dest)[i].set(0, 0, 0, 0); |
| } |
| } |
| dest += pitch; |
| } |
| } |
| |
| // Single channel utility functions |
| inline int getSingleChannel(int x, int y, bool isSigned, bool isEAC) const |
| { |
| int codeword = isSigned ? signed_base_codeword : base_codeword; |
| return isEAC ? ((multiplier == 0) ? (codeword * 8 + 4 + getSingleChannelModifier(x, y)) : (codeword * 8 + 4 + getSingleChannelModifier(x, y) * multiplier * 8)) : codeword + getSingleChannelModifier(x, y) * multiplier; |
| } |
| |
| inline int getSingleChannelIndex(int x, int y) const |
| { |
| switch(x * 4 + y) |
| { |
| case 0: return ma; |
| case 1: return mb; |
| case 2: return mc1 << 1 | mc2; |
| case 3: return md; |
| case 4: return me; |
| case 5: return mf1 << 2 | mf2; |
| case 6: return mg; |
| case 7: return mh; |
| case 8: return mi; |
| case 9: return mj; |
| case 10: return mk1 << 1 | mk2; |
| case 11: return ml; |
| case 12: return mm; |
| case 13: return mn1 << 2 | mn2; |
| case 14: return mo; |
| default: return mp; // 15 |
| } |
| } |
| |
| inline int getSingleChannelModifier(int x, int y) const |
| { |
| static const int modifierTable[16][8] = { { -3, -6, -9, -15, 2, 5, 8, 14 }, |
| { -3, -7, -10, -13, 2, 6, 9, 12 }, |
| { -2, -5, -8, -13, 1, 4, 7, 12 }, |
| { -2, -4, -6, -13, 1, 3, 5, 12 }, |
| { -3, -6, -8, -12, 2, 5, 7, 11 }, |
| { -3, -7, -9, -11, 2, 6, 8, 10 }, |
| { -4, -7, -8, -11, 3, 6, 7, 10 }, |
| { -3, -5, -8, -11, 2, 4, 7, 10 }, |
| { -2, -6, -8, -10, 1, 5, 7, 9 }, |
| { -2, -5, -8, -10, 1, 4, 7, 9 }, |
| { -2, -4, -8, -10, 1, 3, 7, 9 }, |
| { -2, -5, -7, -10, 1, 4, 6, 9 }, |
| { -3, -4, -7, -10, 2, 3, 6, 9 }, |
| { -1, -2, -3, -10, 0, 1, 2, 9 }, |
| { -4, -6, -8, -9, 3, 5, 7, 8 }, |
| { -3, -5, -7, -9, 2, 4, 6, 8 } }; |
| |
| return modifierTable[table_index][getSingleChannelIndex(x, y)]; |
| } |
| }; |
| } // namespace |
| |
| // Decodes 1 to 4 channel images to 8 bit output |
| bool ETC_Decoder::Decode(const unsigned char *src, unsigned char *dst, int w, int h, int dstW, int dstH, int dstPitch, int dstBpp, InputType inputType) |
| { |
| const ETC2 *sources[2]; |
| sources[0] = (const ETC2 *)src; |
| |
| unsigned char alphaValues[4][4] = { { 255, 255, 255, 255 }, { 255, 255, 255, 255 }, { 255, 255, 255, 255 }, { 255, 255, 255, 255 } }; |
| |
| switch(inputType) |
| { |
| case ETC_R_SIGNED: |
| case ETC_R_UNSIGNED: |
| for(int y = 0; y < h; y += 4) |
| { |
| unsigned char *dstRow = dst + (y * dstPitch); |
| for(int x = 0; x < w; x += 4, sources[0]++) |
| { |
| ETC2::DecodeBlock(sources, dstRow + (x * dstBpp), 1, x, y, dstW, dstH, dstPitch, inputType == ETC_R_SIGNED, true); |
| } |
| } |
| break; |
| case ETC_RG_SIGNED: |
| case ETC_RG_UNSIGNED: |
| sources[1] = sources[0] + 1; |
| for(int y = 0; y < h; y += 4) |
| { |
| unsigned char *dstRow = dst + (y * dstPitch); |
| for(int x = 0; x < w; x += 4, sources[0] += 2, sources[1] += 2) |
| { |
| ETC2::DecodeBlock(sources, dstRow + (x * dstBpp), 2, x, y, dstW, dstH, dstPitch, inputType == ETC_RG_SIGNED, true); |
| } |
| } |
| break; |
| case ETC_RGB: |
| case ETC_RGB_PUNCHTHROUGH_ALPHA: |
| for(int y = 0; y < h; y += 4) |
| { |
| unsigned char *dstRow = dst + (y * dstPitch); |
| for(int x = 0; x < w; x += 4, sources[0]++) |
| { |
| sources[0]->decodeBlock(dstRow + (x * dstBpp), x, y, dstW, dstH, dstPitch, alphaValues, inputType == ETC_RGB_PUNCHTHROUGH_ALPHA); |
| } |
| } |
| break; |
| case ETC_RGBA: |
| for(int y = 0; y < h; y += 4) |
| { |
| unsigned char *dstRow = dst + (y * dstPitch); |
| for(int x = 0; x < w; x += 4) |
| { |
| // Decode Alpha |
| ETC2::DecodeBlock(&sources[0], &(alphaValues[0][0]), 1, x, y, dstW, dstH, 4, false, false); |
| sources[0]++; // RGBA packets are 128 bits, so move on to the next 64 bit packet to decode the RGB color |
| |
| // Decode RGB |
| sources[0]->decodeBlock(dstRow + (x * dstBpp), x, y, dstW, dstH, dstPitch, alphaValues, false); |
| sources[0]++; |
| } |
| } |
| break; |
| default: |
| return false; |
| } |
| |
| return true; |
| } |
