ns/releases/3.1.1/source/ui/loadpng.cpp
puzl 8ec7b4bf0b made a copy
git-svn-id: https://unknownworlds.svn.cloudforge.com/ns1@352 67975925-1194-0748-b3d5-c16f83f1a3a1
2005-11-18 02:38:19 +00:00

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2.8 KiB
C++

#include "png.h"
#include "loadpng.h"
#include "cl_dll/wrect.h"
#include "cl_dll/cl_dll.h"
#include "MemoryInputStream.h"
//alternate read function for libpng
void png_read_vgui_stream(png_structp png_ptr, png_bytep data, png_size_t length);
//conversion util to change from libpng format to raw bitmap
void convertToUChar(png_infop png_info, png_bytepp rows, uchar* data);
BitmapPNG* LoadPNG(char const *pFilename)
{
int length;
uchar* data = gEngfuncs.COM_LoadFile((char*)pFilename, 5, &length);
if( !data ) { return NULL; }
MemoryInputStream stream(data,length);
BitmapPNG* pRet = LoadPNG(stream);
gEngfuncs.COM_FreeFile(data);
return pRet;
}
BitmapPNG* LoadPNG(uchar* data, int length)
{
if( !data ) { return NULL; }
MemoryInputStream stream(data,length);
return LoadPNG(stream);
}
BitmapPNG* LoadPNG(vgui::InputStream& stream)
{
//allocate structures for read
png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr)
return NULL;
png_infop info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
png_destroy_read_struct(&png_ptr,
(png_infopp)NULL, (png_infopp)NULL);
return NULL;
}
//set up our alternate read function
png_set_read_fn(png_ptr,&stream,png_read_vgui_stream);
//read the image
png_read_png(png_ptr,info_ptr,PNG_TRANSFORM_PACKING | PNG_TRANSFORM_STRIP_16,NULL);
png_bytepp rows = png_get_rows(png_ptr, info_ptr);
png_read_image(png_ptr,rows);
//we now have the information in row format, it needs to be converted to a single array
//of 32bit pixel values specified as a uchar* so that we can create the image object
uchar* data = new uchar[info_ptr->width*info_ptr->height*4];
convertToUChar(info_ptr,rows,data);
//create the BitmpPNG that we are going to return
BitmapPNG* returnVal = new BitmapPNG(info_ptr->width,info_ptr->height,data);
//read the information after the image for completeness
png_read_end(png_ptr,NULL);
//free up png structures and other memory we've used
delete[] data;
png_destroy_read_struct(&png_ptr,&info_ptr,(png_infopp)NULL);
return returnVal;
}
//implementation of alternate read function
void png_read_vgui_stream(png_structp png_ptr, png_bytep data, png_size_t length)
{
vgui::InputStream* stream = static_cast<vgui::InputStream*>(png_get_io_ptr(png_ptr));
bool success = true;
stream->readUChar(data,(int)length,success);
}
//implementation of conversion function
void convertToUChar(png_infop png_info, png_bytepp rows, uchar* data)
{
int offset = 0;
int offset_amnt = png_info->width*4;
for(size_t counter = 0; counter < png_info->height; ++counter)
{
memcpy(&data[offset],rows[counter],offset_amnt);
offset += offset_amnt;
}
}