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Added minimal PNG writer.

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This commit is contained in:
Branimir Karadžić
2017-09-16 21:11:46 -07:00
parent 0720da91d8
commit 03c53b5c9b
2 changed files with 131 additions and 2 deletions
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12
include/bimg/bimg.h
View File

@@ -450,6 +450,18 @@ namespace bimg
, bx::Error* _err = NULL
);
///
int32_t imageWritePng(
bx::WriterI* _writer
, uint32_t _width
, uint32_t _height
, uint32_t _srcPitch
, const void* _src
, bool _grayscale
, bool _yflip
, bx::Error* _err = NULL
);
///
int32_t imageWriteDds(
bx::WriterI* _writer

121
src/image.cpp
View File

@@ -4,6 +4,7 @@
*/
#include "bimg_p.h"
#include <bx/hash.h>
namespace bimg
{
@@ -3283,7 +3284,7 @@ namespace bimg
uint32_t dstPitch = _width*bpp/8;
if (_yflip)
{
uint8_t* data = (uint8_t*)_src + _srcPitch*_height - _srcPitch;
const uint8_t* data = (const uint8_t*)_src + _srcPitch*_height - _srcPitch;
for (uint32_t yy = 0; yy < _height && _err->isOk(); ++yy)
{
total += bx::write(_writer, data, dstPitch, _err);
@@ -3296,7 +3297,7 @@ namespace bimg
}
else
{
uint8_t* data = (uint8_t*)_src;
const uint8_t* data = (const uint8_t*)_src;
for (uint32_t yy = 0; yy < _height && _err->isOk(); ++yy)
{
total += bx::write(_writer, data, dstPitch, _err);
@@ -3307,6 +3308,122 @@ namespace bimg
return total;
}
template<typename Ty>
class HashWriter : public bx::WriterI
{
public:
HashWriter(bx::WriterI* _writer)
: m_writer(_writer)
{
}
void begin()
{
m_hash.begin();
}
uint32_t end()
{
return m_hash.end();
}
virtual int32_t write(const void* _data, int32_t _size, bx::Error* _err) override
{
m_hash.add(_data, _size);
return m_writer->write(_data, _size, _err);
}
private:
Ty m_hash;
bx::WriterI* m_writer;
};
int32_t imageWritePng(bx::WriterI* _writer, uint32_t _width, uint32_t _height, uint32_t _srcPitch, const void* _src, bool _grayscale, bool _yflip, bx::Error* _err)
{
BX_ERROR_SCOPE(_err);
HashWriter<bx::HashCrc32> writer(_writer);
int32_t total = 0;
total += bx::write(&writer, "\x89PNG\r\n\x1a\n", _err);
total += bx::write(&writer, bx::toBigEndian<uint32_t>(13), _err);
writer.begin();
total += bx::write(&writer, "IHDR", _err);
total += bx::write(&writer, bx::toBigEndian(_width), _err);
total += bx::write(&writer, bx::toBigEndian(_height), _err);
total += bx::write(&writer, "\x08\x06", _err);
total += bx::writeRep(&writer, 0, 3, _err);
total += bx::write(&writer, bx::toBigEndian(writer.end() ), _err);
const uint8_t* src = (const uint8_t*)_src;
const uint32_t bpp = _grayscale ? 8 : 32;
const uint32_t stride = _width*bpp/8;
const uint16_t zlen = bx::toLittleEndian<uint16_t>(stride + 1);
const uint16_t zlenC = bx::toLittleEndian<uint16_t>(~zlen);
total += bx::write(&writer, bx::toBigEndian<uint32_t>(_height*(stride+6)+6), _err);
writer.begin();
total += bx::write(&writer, "IDAT", _err);
total += bx::write(&writer, "\x78\x9c", _err);
bx::HashAdler32 chksum;
chksum.begin();
const uint8_t* data = (const uint8_t*)_src;
int32_t step = int32_t(_srcPitch);
if (_yflip)
{
data += _srcPitch*_height - _srcPitch;
step = -step;
}
for (uint32_t ii = 0; ii < _height && _err->isOk(); ++ii)
{
chksum.add(0);
chksum.add(&src[ii*_srcPitch], stride);
total += bx::write(&writer, uint8_t(ii == _height-1 ? 1 : 0), _err);
total += bx::write(&writer, zlen, _err);
total += bx::write(&writer, zlenC, _err);
total += bx::write(&writer, uint8_t(0), _err);
if (_grayscale)
{
total += bx::write(&writer, data, stride, _err);
}
else
{
for (uint32_t xx = 0; xx < _width; ++xx)
{
const uint8_t* bgra = &data[xx*4];
const uint8_t bb = bgra[0];
const uint8_t gg = bgra[1];
const uint8_t rr = bgra[2];
const uint8_t aa = bgra[3];
total += bx::write(&writer, rr, _err);
total += bx::write(&writer, gg, _err);
total += bx::write(&writer, bb, _err);
total += bx::write(&writer, aa, _err);
}
}
data += step;
}
total += bx::write(&writer, bx::toBigEndian(chksum.end() ), _err);
total += bx::write(&writer, bx::toBigEndian(writer.end() ), _err);
writer.begin();
total += bx::write(&writer, uint32_t(0), _err);
total += bx::write(&writer, "IEND", _err);
total += bx::write(&writer, bx::toBigEndian(writer.end() ), _err);
return total;
}
static int32_t imageWriteDdsHeader(bx::WriterI* _writer, TextureFormat::Enum _format, bool _cubeMap, uint32_t _width, uint32_t _height, uint32_t _depth, uint8_t _numMips, bx::Error* _err)
{
BX_ERROR_SCOPE(_err);