bsnes/nall/decode/png.hpp

335 lines
9.1 KiB
C++

#ifndef NALL_DECODE_PNG_HPP
#define NALL_DECODE_PNG_HPP
#include <nall/string.hpp>
#include <nall/decode/inflate.hpp>
namespace nall { namespace Decode {
struct PNG {
struct Info {
unsigned width;
unsigned height;
unsigned bitDepth;
//colorType:
//0 = L (luma)
//2 = R,G,B
//3 = P (palette)
//4 = L,A
//6 = R,G,B,A
unsigned colorType;
unsigned compressionMethod;
unsigned filterType;
unsigned interlaceMethod;
unsigned bytesPerPixel;
unsigned pitch;
uint8_t palette[256][3];
} info;
uint8_t* data = nullptr;
unsigned size = 0;
inline bool load(const string& filename);
inline bool load(const uint8_t* sourceData, unsigned sourceSize);
inline unsigned readbits(const uint8_t*& data);
unsigned bitpos = 0;
inline PNG();
inline ~PNG();
protected:
enum class FourCC : unsigned {
IHDR = 0x49484452,
PLTE = 0x504c5445,
IDAT = 0x49444154,
IEND = 0x49454e44,
};
inline unsigned interlace(unsigned pass, unsigned index);
inline unsigned inflateSize();
inline bool deinterlace(const uint8_t*& inputData, unsigned pass);
inline bool filter(uint8_t* outputData, const uint8_t* inputData, unsigned width, unsigned height);
inline unsigned read(const uint8_t* data, unsigned length);
};
bool PNG::load(const string& filename) {
if(auto memory = file::read(filename)) {
return load(memory.data(), memory.size());
}
return false;
}
bool PNG::load(const uint8_t* sourceData, unsigned sourceSize) {
if(sourceSize < 8) return false;
if(read(sourceData + 0, 4) != 0x89504e47) return false;
if(read(sourceData + 4, 4) != 0x0d0a1a0a) return false;
uint8_t* compressedData = nullptr;
unsigned compressedSize = 0;
unsigned offset = 8;
while(offset < sourceSize) {
unsigned length = read(sourceData + offset + 0, 4);
unsigned fourCC = read(sourceData + offset + 4, 4);
unsigned checksum = read(sourceData + offset + 8 + length, 4);
if(fourCC == (unsigned)FourCC::IHDR) {
info.width = read(sourceData + offset + 8, 4);
info.height = read(sourceData + offset + 12, 4);
info.bitDepth = read(sourceData + offset + 16, 1);
info.colorType = read(sourceData + offset + 17, 1);
info.compressionMethod = read(sourceData + offset + 18, 1);
info.filterType = read(sourceData + offset + 19, 1);
info.interlaceMethod = read(sourceData + offset + 20, 1);
if(info.bitDepth == 0 || info.bitDepth > 16) return false;
if(info.bitDepth & (info.bitDepth - 1)) return false; //not a power of two
if(info.compressionMethod != 0) return false;
if(info.filterType != 0) return false;
if(info.interlaceMethod != 0 && info.interlaceMethod != 1) return false;
switch(info.colorType) {
case 0: info.bytesPerPixel = info.bitDepth * 1; break; //L
case 2: info.bytesPerPixel = info.bitDepth * 3; break; //R,G,B
case 3: info.bytesPerPixel = info.bitDepth * 1; break; //P
case 4: info.bytesPerPixel = info.bitDepth * 2; break; //L,A
case 6: info.bytesPerPixel = info.bitDepth * 4; break; //R,G,B,A
default: return false;
}
if(info.colorType == 2 || info.colorType == 4 || info.colorType == 6) {
if(info.bitDepth != 8 && info.bitDepth != 16) return false;
}
if(info.colorType == 3 && info.bitDepth == 16) return false;
info.bytesPerPixel = (info.bytesPerPixel + 7) / 8;
info.pitch = (int)info.width * info.bytesPerPixel;
}
if(fourCC == (unsigned)FourCC::PLTE) {
if(length % 3) return false;
for(unsigned n = 0, p = offset + 8; n < length / 3; n++) {
info.palette[n][0] = sourceData[p++];
info.palette[n][1] = sourceData[p++];
info.palette[n][2] = sourceData[p++];
}
}
if(fourCC == (unsigned)FourCC::IDAT) {
compressedData = (uint8_t*)realloc(compressedData, compressedSize + length);
memcpy(compressedData + compressedSize, sourceData + offset + 8, length);
compressedSize += length;
}
if(fourCC == (unsigned)FourCC::IEND) {
break;
}
offset += 4 + 4 + length + 4;
}
unsigned interlacedSize = inflateSize();
uint8_t *interlacedData = new uint8_t[interlacedSize];
bool result = inflate(interlacedData, interlacedSize, compressedData + 2, compressedSize - 6);
free(compressedData);
if(result == false) {
delete[] interlacedData;
return false;
}
size = info.width * info.height * info.bytesPerPixel;
data = new uint8_t[size];
if(info.interlaceMethod == 0) {
if(filter(data, interlacedData, info.width, info.height) == false) {
delete[] interlacedData;
delete[] data;
data = nullptr;
return false;
}
} else {
const uint8_t *passData = interlacedData;
for(unsigned pass = 0; pass < 7; pass++) {
if(deinterlace(passData, pass) == false) {
delete[] interlacedData;
delete[] data;
data = nullptr;
return false;
}
}
}
delete[] interlacedData;
return true;
}
unsigned PNG::interlace(unsigned pass, unsigned index) {
static const unsigned data[7][4] = {
//x-distance, y-distance, x-origin, y-origin
{8, 8, 0, 0},
{8, 8, 4, 0},
{4, 8, 0, 4},
{4, 4, 2, 0},
{2, 4, 0, 2},
{2, 2, 1, 0},
{1, 2, 0, 1},
};
return data[pass][index];
}
unsigned PNG::inflateSize() {
if(info.interlaceMethod == 0) {
return info.width * info.height * info.bytesPerPixel + info.height;
}
unsigned size = 0;
for(unsigned pass = 0; pass < 7; pass++) {
unsigned xd = interlace(pass, 0), yd = interlace(pass, 1);
unsigned xo = interlace(pass, 2), yo = interlace(pass, 3);
unsigned width = (info.width + (xd - xo - 1)) / xd;
unsigned height = (info.height + (yd - yo - 1)) / yd;
if(width == 0 || height == 0) continue;
size += width * height * info.bytesPerPixel + height;
}
return size;
}
bool PNG::deinterlace(const uint8_t*& inputData, unsigned pass) {
unsigned xd = interlace(pass, 0), yd = interlace(pass, 1);
unsigned xo = interlace(pass, 2), yo = interlace(pass, 3);
unsigned width = (info.width + (xd - xo - 1)) / xd;
unsigned height = (info.height + (yd - yo - 1)) / yd;
if(width == 0 || height == 0) return true;
unsigned outputSize = width * height * info.bytesPerPixel;
uint8_t* outputData = new uint8_t[outputSize];
bool result = filter(outputData, inputData, width, height);
const uint8_t* rd = outputData;
for(unsigned y = yo; y < info.height; y += yd) {
uint8_t* wr = data + y * info.pitch;
for(unsigned x = xo; x < info.width; x += xd) {
for(unsigned b = 0; b < info.bytesPerPixel; b++) {
wr[x * info.bytesPerPixel + b] = *rd++;
}
}
}
inputData += outputSize + height;
delete[] outputData;
return result;
}
bool PNG::filter(uint8_t* outputData, const uint8_t* inputData, unsigned width, unsigned height) {
uint8_t* wr = outputData;
const uint8_t* rd = inputData;
int bpp = info.bytesPerPixel, pitch = width * bpp;
for(int y = 0; y < height; y++) {
uint8_t filter = *rd++;
switch(filter) {
case 0x00: //None
for(int x = 0; x < pitch; x++) {
wr[x] = rd[x];
}
break;
case 0x01: //Subtract
for(int x = 0; x < pitch; x++) {
wr[x] = rd[x] + (x - bpp < 0 ? 0 : wr[x - bpp]);
}
break;
case 0x02: //Above
for(int x = 0; x < pitch; x++) {
wr[x] = rd[x] + (y - 1 < 0 ? 0 : wr[x - pitch]);
}
break;
case 0x03: //Average
for(int x = 0; x < pitch; x++) {
short a = x - bpp < 0 ? 0 : wr[x - bpp];
short b = y - 1 < 0 ? 0 : wr[x - pitch];
wr[x] = rd[x] + (uint8_t)((a + b) / 2);
}
break;
case 0x04: //Paeth
for(int x = 0; x < pitch; x++) {
short a = x - bpp < 0 ? 0 : wr[x - bpp];
short b = y - 1 < 0 ? 0 : wr[x - pitch];
short c = x - bpp < 0 || y - 1 < 0 ? 0 : wr[x - pitch - bpp];
short p = a + b - c;
short pa = p > a ? p - a : a - p;
short pb = p > b ? p - b : b - p;
short pc = p > c ? p - c : c - p;
uint8_t paeth = (uint8_t)((pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c);
wr[x] = rd[x] + paeth;
}
break;
default: //Invalid
return false;
}
rd += pitch;
wr += pitch;
}
return true;
}
unsigned PNG::read(const uint8_t* data, unsigned length) {
unsigned result = 0;
while(length--) result = (result << 8) | (*data++);
return result;
}
unsigned PNG::readbits(const uint8_t*& data) {
unsigned result = 0;
switch(info.bitDepth) {
case 1:
result = (*data >> bitpos) & 1;
bitpos++;
if(bitpos == 8) { data++; bitpos = 0; }
break;
case 2:
result = (*data >> bitpos) & 3;
bitpos += 2;
if(bitpos == 8) { data++; bitpos = 0; }
break;
case 4:
result = (*data >> bitpos) & 15;
bitpos += 4;
if(bitpos == 8) { data++; bitpos = 0; }
break;
case 8:
result = *data++;
break;
case 16:
result = (data[0] << 8) | (data[1] << 0);
data += 2;
break;
}
return result;
}
PNG::PNG() {
}
PNG::~PNG() {
if(data) delete[] data;
}
}}
#endif