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Respect the Exif orientation data when loading images
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@hughsando
hughsando committed Apr 10, 2024
1 parent 2357044 commit 20fc2bd
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Showing 3 changed files with 151 additions and 10 deletions.
8 changes: 8 additions & 0 deletions project/src/common/ExternalInterface.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -55,6 +55,7 @@ namespace nme
{
void InitCamera();
void GetGLStats(int *statsArray, int n);
extern bool gRespectExifOrientation;

// Not static
int _id_id=0;
Expand Down Expand Up @@ -4363,6 +4364,13 @@ int nme_bitmap_data_get_format(value inHandle)
DEFINE_PRIME1(nme_bitmap_data_get_format);


void nme_bitmap_data_set_respect_exif_orientation(bool respect)
{
gRespectExifOrientation = respect;
}
DEFINE_PRIME1v(nme_bitmap_data_set_respect_exif_orientation);


value nme_bitmap_data_from_bytes(value inRGBBytes, value inAlphaBytes, value inOnAppData)
{
ByteData bytes;
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146 changes: 136 additions & 10 deletions project/src/common/SurfaceIO.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -117,6 +117,8 @@ struct MySrcManager

namespace nme {

bool gRespectExifOrientation = true;

static bool isLittleEndian()
{
unsigned short val = 0;
Expand Down Expand Up @@ -195,6 +197,73 @@ bool SoftwareDecodeJPeg(unsigned char *inDest, int inWidth, int inHeight, const
}
}

// Returns requiured CW quardant rotation
static int parseExif(const uint8 *data, int inLen)
{
//printf("parseExif %d %c%c%c%c\n",inLen, data[0], data[1], data[2], data[3]);
int rotation = 0;

#define NEXT_SHORT (exif[msb]<<8) | exif[1-msb]; exif+=2
#define NEXT_INT big ? (exif[0]<<24) | (exif[1]<<16) | (exif[2]<<8) | exif[3] : \
(exif[3]<<24) | (exif[2]<<16) | (exif[1]<<8) | exif[0]; \
exif+=4;

if (inLen>10 && data[0]=='E' && data[1]=='x' && data[2]=='i' && data[3]=='f')
{
const uint8 *exif = data + 6;
const uint8 *end = data + inLen;

bool little = exif[0]==0x49 && exif[1]==0x49;
bool big = exif[0]==0x4D && exif[1]==0x4D;
if (!little && !big)
return rotation;
exif += 2;
int msb = big ? 0 : 1;
int test = NEXT_SHORT;
if (test!=42)
return rotation;

int offset = NEXT_INT;
if (offset>=8 && exif+(offset-8)+2 <= end )
{
exif += offset-8;
int entries = NEXT_SHORT;
//printf("Found exif entries:%d\n", entries);
for(int e=0; e<entries && exif+12<end; e++)
{
int tag = NEXT_SHORT;
int type = NEXT_SHORT;
int vpos = NEXT_INT;
int val = NEXT_SHORT;
exif += 2;
//printf(" tag:%d, type:%d val:%d\n", tag, type, val );
// Orientation/short
if (tag==274 && type==3)
{
//printf("Found rotation: %d\n", val);
switch(val)
{
case 1: return 0; // normal - no rotation
case 3: return 2; // 180 rotation
case 6: return 1; // must rotate 90 cw
case 8: return 3; // must rotate 270 cw (90 acw)
default:
//printf(" unknown rotation: %d\n", val);
// Mirror cases - not handled
return 0;
}
}
}

}
}

return rotation;
}

static const int APP0 = 0xe0;
static const int COM = 0xfe;

static Surface *TryJPEG(FILE *inFile,const uint8 *inData, int inDataLen, IAppDataCallback *onAppData=nullptr)
{
struct jpeg_decompress_struct cinfo;
Expand Down Expand Up @@ -232,38 +301,95 @@ static Surface *TryJPEG(FILE *inFile,const uint8 *inData, int inDataLen, IAppDat
cinfo.src = &manager.pub;
}

if (onAppData)
if (onAppData || gRespectExifOrientation)
{
const int APP0 = 0xe0;
const int COM = 0xfe;

cinfo.client_data = onAppData;
unsigned int bufSize = inDataLen>0 ? inDataLen : 1<<20;
jpeg_save_markers(&cinfo, COM, bufSize);
for(int i=0;i<15;i++)
jpeg_save_markers(&cinfo, APP0 + i, bufSize);
if (onAppData)
{
jpeg_save_markers(&cinfo, COM, bufSize);
for(int i=0;i<15;i++)
jpeg_save_markers(&cinfo, APP0 + i, bufSize);
}
else
{
jpeg_save_markers(&cinfo, APP0 + 1, bufSize);
}
}

// Read file parameters with jpeg_read_header().
if (jpeg_read_header(&cinfo, TRUE)!=JPEG_HEADER_OK)
return 0;

int rotation = 0;
if (gRespectExifOrientation)
{
jpeg_saved_marker_ptr marker = cinfo.marker_list;
while(marker)
{
if (marker->marker==APP0+1)
{
rotation = parseExif(marker->data, marker->data_length);
if (rotation)
break;
}
marker = marker->next;
}
}

cinfo.out_color_space = JCS_RGB;

// Start decompressor.
jpeg_start_decompress(&cinfo);

result = new SimpleSurface(cinfo.output_width, cinfo.output_height, pfRGB);
int imageW = rotation==1 || rotation==3 ? cinfo.output_height : cinfo.output_width;
int imageH = rotation==1 || rotation==3 ? cinfo.output_width : cinfo.output_height;
result = new SimpleSurface(imageW, imageH, pfRGB);
result->IncRef();


RenderTarget target = result->BeginRender(Rect(cinfo.output_width, cinfo.output_height));
std::vector<RGB> rowBuf;
if (rotation!=0)
rowBuf.resize(cinfo.output_width);


RenderTarget target = result->BeginRender(Rect(imageW, imageH));


while (cinfo.output_scanline < cinfo.output_height)
{
uint8 * dest = target.Row(cinfo.output_scanline);
int y = cinfo.output_scanline;
uint8 * dest = rotation==0 ? target.Row(y) : (uint8 *)&rowBuf[0];
jpeg_read_scanlines(&cinfo, &dest, 1);

if (rotation==1)
{
// 90 CW. First row starts at the right and goes down
RGB *col = ((RGB *)target.Row(0)) + imageW - 1 - y;
for(int x=0; x<imageH; x++)
{
*col = rowBuf[x];
col += imageW;
}
}
else if (rotation==2)
{
// 180 CW. First row starts at the bottom-right and goes left
RGB *row = ((RGB *)target.Row(imageH-1-y)) + imageW - 1;
for(int x=0; x<imageW; x++)
row[-x] = rowBuf[x];
}
else if (rotation==3)
{
// 90 ACW. First row starts at the bottom-left and goes up
RGB *col = ((RGB *)target.Row(imageH-1)) + y;
for(int x=0; x<imageH; x++)
{
*col = rowBuf[x];
col -= imageW;
}
}

}
result->EndRender();

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7 changes: 7 additions & 0 deletions src/nme/display/BitmapData.hx
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Original file line number Diff line number Diff line change
Expand Up @@ -68,6 +68,7 @@ class BitmapData implements IBitmapDrawable
public var nmeHandle:NativeHandle;
public var data(get,null):UInt8Array;
public var mipmaps(get, set):Bool;
public static var respectExifOrientation(null, set):Bool;


public function new(inWidth:Int, inHeight:Int, inTransparent:Bool = true, ?inFillARGB:Int, inPixelFormat:Int = -1)
Expand Down Expand Up @@ -482,6 +483,11 @@ class BitmapData implements IBitmapDrawable

public static inline function extractColor(v:Int):Int { return v & 0xFFFFFF; }

static function set_respectExifOrientation(val:Bool)
{
nme_bitmap_data_set_respect_exif_orientation(val);
return val;
}

static inline function sameValue(a:Int, b:Int)
{
Expand Down Expand Up @@ -857,6 +863,7 @@ class BitmapData implements IBitmapDrawable
private static var nme_bitmap_data_get_uints8 = PrimeLoader.load("nme_bitmap_data_get_uints8", "ooiiiiv");
private static var nme_bitmap_data_set_uints8 = PrimeLoader.load("nme_bitmap_data_set_uints8", "ooiiiiv");
private static var nme_bitmap_data_get_data_handle = PrimeLoader.load("nme_bitmap_data_get_data_handle", "oo");
private static var nme_bitmap_data_set_respect_exif_orientation = PrimeLoader.load("nme_bitmap_data_set_respect_exif_orientation", "bv");
}


Expand Down

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