I am struggling with Windows and FreeType2. I am following the tutorial and the following is shown as example code:
FT_Library library; /* handle to library */
FT_Face face; /* handle to face object */
error = FT_Init_FreeType( &library );
if ( error ) { ... }
error = FT_New_Face(library, "/usr/share/fonts/truetype/arial.ttf", 0, &face ); // <-- this does not exist...
if ( error == FT_Err_Unknown_File_Format )
{
... the font file could be opened and read, but it appears
... that its font format is unsupported
}
else if ( error )
{
... another error code means that the font file could not
... be opened or read, or simply that it is broken...
}
This /usr/share/fonts/truetype/arial.ttf just simply does not exist, how can I get the Arial font to work with this.
It varies from system to system. Check FOLDERID_Fonts.
Related
I am using pHash and that library uses libpng. I am having issues running my program because libpng fails loading a PNG file.
Version of libpng: 1.4.19
Platform: Windows 10
Environment: Visual Studio 2015
Trivial
Just if you came up with the following questions...
Is the path to image correct? Yes
Is the image a valid PNG file? Yes
Code details
Library pHash uses CImg, the version of CImg they are using is a bit old I think:
#define cimg_version 148 // In CImg.h
I have debugged the library and the problems occurs in CImg.h (contained in the pHash VC++ project):
CImg<T>& _load_png(std::FILE *const file, const char *const filename) {
if (!file && !filename)
throw CImgArgumentException(_cimg_instance
"load_png() : Specified filename is (null).",
cimg_instance);
// Open file and check for PNG validity
if (Buffer) strcat(Buffer, "Checking PNG availability\r\n");
const char *volatile nfilename = filename; // two 'volatile' here to remove a g++ warning due to 'setjmp'.
std::FILE *volatile nfile = file?file:cimg::fopen(nfilename,"rb");
unsigned char pngCheck[8] = { 0 };
cimg::fread(pngCheck,8,(std::FILE*)nfile);
if (png_sig_cmp(pngCheck,0,8)) {
if (!file) cimg::fclose(nfile);
throw CImgIOException(_cimg_instance
"load_png() : Invalid PNG file '%s'.",
cimg_instance,
nfilename?nfilename:"(FILE*)");
}
// Setup PNG structures for read
png_voidp user_error_ptr = 0;
png_error_ptr user_error_fn = 0, user_warning_fn = 0;
png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,user_error_ptr,user_error_fn,user_warning_fn);
if (!png_ptr) { // <-- PROBLEM HERE
if (!file) cimg::fclose(nfile);
throw CImgIOException(_cimg_instance
"load_png() : Failed to initialize 'png_ptr' structure for file '%s'.",
cimg_instance,
nfilename?nfilename:"(FILE*)");
...
}
The snippet shows the first part of CImg<T>& _load_png(std::FILE *const file, const char *const filename) which is called by the CImg library used by pHash.
Runtime issue
The code compiles fine but I get this error at runtime which I can see in the debugger:
CImgIOException: Failed to initialize 'png_ptr'...
In the point indicated in the code. I don't know why, it fails loading the image. The failure occurs when calling png_create_read_struct in CImg.h. That code is a bit obscure as defined through preprocessor directives. It is not clear why it is failing.
Any ideas?
Either if you are including libpng yourself or if another library is including and using libpng there are a few things to be aware of.
Which ever version of Visual Studio you are using, the libpng (dll or lib) files must be built from the same version of Visual Studio that your solution is linking against.
The platform you are using 32bit or 64bit is of concern.
Project settings when building the png library must match the build types of your current project. (Code Generation -> Runtime Library) must match. Your character set should match as well.
It is a little to difficult to tell what exactly is causing the problem but these are a few things to have a look at.
One thing I would suggest is to go to the website that provides the newest version of libpng and download it. Set a folder on your computer and create "system environment variable through windows" to point to your library. Open the solution to this library in the current version of VS you are using, build it out for both a static lib and dynamic lib (two different solutions) and build them both out for 32 bit and 64 bit saving the generated files into separated folders. Then go into the other library that depends on this and try to switch the dlls or libs and link against the new ones if possible. Also the other 3rd party library you should try to open its solution in the same version of VS and try to do a clean build from there. Then make sure you link everything properly. You may have to also modify the props file.
EDIT
I am not familiar with pHash or CImg, but I am familiar with libpng.
Here is a function in one of my projects to load in a png into a texture structure. Now this is a part of a class object that relies on many other classes, but you should be able to see from this snippet that I am successfully using libpng.
// ----------------------------------------------------------------------------
// loadPng()
bool TextureFileReader::loadPng( Texture* pTexture ) {
struct PngFile {
FILE* fp;
png_struct* pStruct;
png_info* pInfo;
// --------------------------------------------------------------------
PngFile() :
fp( NULL ),
pStruct( NULL ),
pInfo( NULL )
{} // PngFile
// --------------------------------------------------------------------
~PngFile() {
if ( NULL != fp ) {
fclose( fp );
}
if ( NULL != pStruct ) {
if ( NULL != pInfo ) {
png_destroy_read_struct( &pStruct, &pInfo, NULL );
} else {
png_destroy_read_struct( &pStruct, NULL, NULL );
}
}
} // ~PngFile
} png;
// Error Message Handling
std::ostringstream strStream;
strStream << __FUNCTION__ << " ";
if ( fopen_s( &png.fp, m_strFilenameWithPath.c_str(), "rb" ) != 0 ) {
strStream << "can not open file for reading";
throwError( strStream );
}
// Test If File Is Actually A PNG Image
const int NUM_HEADER_BYTES = 8;
png_byte headerBytes[NUM_HEADER_BYTES];
// Read The File Header
if ( fread( headerBytes, 1, NUM_HEADER_BYTES, png.fp ) != NUM_HEADER_BYTES ) {
strStream << "error reading header";
return false;
}
// Test Header
if ( png_sig_cmp( headerBytes, 0, NUM_HEADER_BYTES ) != 0 ) {
return false; // Not A PNG FILE
}
// Init PNG Read Structure - Test PNG Version Compatibility
png.pStruct = png_create_read_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL );
if ( NULL == png.pStruct ) {
strStream << "can not create struct for PNG file";
throwError( strStream );
}
// Init PNG Info Structure - Allocate Memory For Image Info
png.pInfo = png_create_info_struct( png.pStruct );
if ( NULL == png.pInfo ) {
strStream << "can not create info for PNG file";
throwError( strStream );
}
// Prepare For Error Handling
if ( setjmp( png_jmpbuf( png.pStruct ) ) ) {
strStream << "can not init error handling for PNG file";
throwError( strStream );
}
// Tell libPng Where The File Data Is
png_init_io( png.pStruct, png.fp );
// Tell libPng That You Have Already Read The Header Bytes
png_set_sig_bytes( png.pStruct, NUM_HEADER_BYTES );
// Read Image Data From The File
png_read_png( png.pStruct, png.pInfo, PNG_TRANSFORM_STRIP_16 | PNG_TRANSFORM_PACKING | PNG_TRANSFORM_EXPAND | PNG_TRANSFORM_GRAY_TO_RGB, NULL );
// Show Image Attributes
png_byte colorType = png_get_color_type( png.pStruct, png.pInfo );
switch( colorType ) {
case PNG_COLOR_TYPE_RGB:
case PNG_COLOR_TYPE_RGBA: {
break;
}
default: {
strStream << "PNG is saved in an unsupported color type (" << colorType << ")";
throwError( strStream );
}
}
unsigned uHeight = png_get_image_height( png.pStruct, png.pInfo );
unsigned uBytesPerRow = png_get_rowbytes( png.pStruct, png.pInfo );
if ( 0 == uHeight || 0 == uBytesPerRow ) {
strStream << "invalid image size. Height(" << uHeight << "), Bytes per row(" << uBytesPerRow << ")";
throwError( strStream );
}
// Make Room For All Pixel Data
unsigned uTotalNumBytes = uHeight * uBytesPerRow;
pTexture->vPixelData.resize( uTotalNumBytes );
// Get All Pixel Data From PNG Image
png_bytepp ppPixelRow = png_get_rows( png.pStruct, png.pInfo );
for ( unsigned int r = 0; r < uHeight; ++r ) {
memcpy( &pTexture->vPixelData[ uBytesPerRow * ( uHeight - 1 - r ) ], ppPixelRow[r], uBytesPerRow );
}
// Store Other Values In Texture
pTexture->uWidth = png_get_image_width( png.pStruct, png.pInfo );
pTexture->uHeight = uHeight;
pTexture->hasAlphaChannel = ( colorType == PNG_COLOR_TYPE_RGBA );
return true;
} // loadPng
Looking through the source code for png_create_read_struct_2(), there are only 2 failure modes: inability to allocate memory, which is unlikely to be the problem, and a library version conflict.
If you are using a precompiled build of the pHash library, you must ensure that the copy of the libpng DLL that gets linked dynamically at runtime is the same version of the library that pHash was compiled against. The latest Windows build on pHash.org ships with libpng12.dll in the "Release" subdirectory, which is probably incompatible the version that you mentioned in the question, namely 1.4.19.
If you are building pHash from source, make sure that the libpng include files that are being used in your build process match the version being loaded at runtime.
If you're unsure exactly which DLLs are being loaded at runtime, the surest way I know to determine it would be to use Process Monitor.
Some Background
Originally made a project on mac, now I want to use my Linux machine for the same project. The settings folder relied on:
#include <QJsonObject>
#include <QJsonDocument>
#include <QJsonArray>
#include <QJsonParseError>
These weren't included in my qt-devel install for SL5 - it uses QT v4. So I downloaded QJson from Sourceforge and installed using cmake. Some example output:
--Installing: /usr/include/qjson/parser.h
--Installing /usr/lib/libqjson.so
That's fine. So I added to my .pro:
LIBS += -L/usr/lib/ -lqjson
INCLUDEPATH += /usr/include/qjson/
The Actual Problem
Now I have the task of translating my old settings.cpp file to parse data in this slightly new method.
{
"HwDescription": {
"ConnectionsName": "file://settings/connections.xml",
"ShelveId": 0,
"BeBoard": {
"Id": 10,
"connectionId": "board0",
"boardType": "GLIB"
}, // + more boring stuff
So now I have this json above in a QString, just as I did for my old working method, then I try to parse as per the instructions given to me. I used: #include <qjson/parser.h> and I don't think I need any forward declarations here.
QJson::Parser parser;
bool ok;
QVariantMap result = parser.parse (raw_json, &ok).toMap(); //where raw_json is a QString - this is where I get an error
if (!ok)
{
qFatal("An error occured during parsing");
exit (1);
}
The error I get:
error: no matching function to call to 'Qjson::Parser:parse(QString&, bool)
If I remove the include, the error says:
QJson has not been declared
So it must be finding the libraries at least. Any ideas on what's going wrong?
Comments aren't parsed by default in QJson.
Here is a small adaptation I made on my QJson logic to handle comments. Notice the simple Regex to remove comments.
QFile file( filename );
//File can't be opened!
if ( !file.open( QFile::ReadOnly ) )
{
qDebug("Couldn't load config file: %s", filename.toLatin1().data());
return;
}
//Strip out comments
QStringList list = QString( file.readAll() ).split('\n');
for ( int i = 0; i < list.size(); i++ )
list[i].replace( QRegExp("//[^\"]*$"), "" );
//Load the file, converting into an object file
QJsonParseError e;
QJsonObject json =
QJsonDocument::fromJson( list.join('\n').toLatin1(), &e ).object();
//Was there an error?
if ( e.error != QJsonParseError::NoError )
{
qDebug( "Json parse error: %s", e.errorString().toLatin1().data() );
return;
}
I am trying to write PNG file (saving an image in png format) from pixel data read by glReadPixels in openGL using following piece of code (copied from here):
bool writePNGFileFromBuffer(const char *filename, unsigned char *pixels, int w, int h)
{
png_structp png = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);//8
if (!png)
return false;
png_infop info = png_create_info_struct(png);//7
if (!info) {
png_destroy_write_struct(&png, &info);//
return false;
}
FILE *fp = fopen(filename, "wb");
if (!fp) {
png_destroy_write_struct(&png, &info);//
return false;
}
png_init_io(png, fp);//9
png_set_IHDR(png, info, w, h, 8 /* depth */, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);//10
png_colorp palette = (png_colorp)png_malloc(png, PNG_MAX_PALETTE_LENGTH * sizeof(png_color));//4
if (!palette) {
fclose(fp);
png_destroy_write_struct(&png, &info);//
return false;
}
png_set_PLTE(png, info, palette, PNG_MAX_PALETTE_LENGTH);//12
png_write_info(png, info);//1
png_set_packing(png);//5
png_bytepp rows = (png_bytepp)png_malloc(png, h * sizeof(png_bytep));//
for (int i = 0; i < h; ++i)
rows[i] = (png_bytep)(pixels + (h - i) * w * 3);
png_write_image(png, rows);//2
png_write_end(png, info);//6
png_free(png, palette);//11
png_destroy_write_struct(&png, &info);//3
fclose(fp);
delete[] rows;
return true;
}
I linked the libpng and zlib libraries in the additional dependencies. But when I compile the code it gives following error:
Error 77 error LNK2001: unresolved external symbol png_write_info
It gives this error at about 12 instances marked in the code snippet above. I am clear that it is not able to find the definitions of the functions but I do not know why?
Any help would be appreciated. Thanks
Edit: I looked into the header file "png.h" and it contains declarations for all the functions. Functions are defined in "pngwrite.c" and I think it should take it from the linked library.
Edit2: After hitting around for couple of days, I found that when I change the output type of my project (in which I am using libpng.lib) to Static Lib (.lib), everything works and the code compiles well but with .dll output it throws the above specified error.
And my problem is, I have to use .dll output because that I use in another huge project which I cant change to accept .lib.
Any help on this?
You may be missing "pnglibconf.h" which you must copy from
scripts/pnglibconf.h.prebuilt to pnglibconf.h in your source directory.
I'm struggling with creating a window with the GLFW 3 function, glfwCreateWindow.
I have set an error callback function, that pretty much just prints out the error number and description, and according to that the GLFW library have not been initialized, even though the glfwInit function just returned success?
Here's an outtake from my code
// Error callback function prints out any errors from GFLW to the console
static void error_callback( int error, const char *description )
{
cout << error << '\t' << description << endl;
}
bool Base::Init()
{
// Set error callback
/*!
* According to the documentation this can be use before glfwInit,
* and removing won't change anything anyway
*/
glfwSetErrorCallback( error_callback );
// Initialize GLFW
/*!
* This return succesfull, but...
*/
if( !glfwInit() )
{
cout << "INITIALIZER: Failed to initialize GLFW!" << endl;
return false;
}
else
{
cout << "INITIALIZER: GLFW Initialized successfully!" << endl;
}
// Create window
/*!
* When this is called, or any other glfw functions, I get a
* "65537 The GLFW library is not initialized" in the console, through
* the error_callback function
*/
window = glfwCreateWindow( 800,
600,
"GLFW Window",
NULL,
NULL );
if( !window )
{
cout << "INITIALIZER: Failed to create window!" << endl;
glfwTerminate();
return false;
}
// Set window to current context
glfwMakeContextCurrent( window );
...
return true;
}
And here's what's printed out in the console
INITIALIZER: GLFW Initialized succesfully!
65537 The GLFW library is not initialized
INITIALIZER: Failed to create window!
I think I'm getting the error because of the setup isn't entirely correct, but I've done the best I can with what I could find around the place
I downloaded the windows 32 from glfw.org and stuck the 2 includes files from it into minGW/include/GLFW, the 2 .a files (from the lib-mingw folder) into minGW/lib and the dll, also from the lib-mingw folder, into Windows/System32
In code::blocks I have, from build options -> linker settings, linked the 2 .a files from the download. I believe I need to link more things, but I can figure out what, or where I should get those things from.
I tried reinstalling codeblocks and mingw, which solved the issue.
Seems like GLFW3 doesn't like having previous versions installed at the same time for some reason, so if anyone else is having a similar problem, you might want to try that.
I experienced similar problems in Cocos 3.8.1 and 3.10.
I have never installed codeblocks or mingw, so it did not make sense to install them for me.
The GLFW.lib file in the cocos directory is out of date.
http://www.glfw.org/download.html, and replace the lib file in your project with the latest one, and it may resolve your error.
I would like to load image to my application, but I have an error:
http://img510.imageshack.us/img510/5814/blad07864.png
This is a code of this application:
#include <stdio.h>
#include <stdlib.h>
#undef _UNICODE
#include "il.h"
#pragma comment( lib, "DevIL.lib" )
// Wow. DevIL is amazing.
// From http://gpwiki.org/index.php/DevIL:Tutorials:Basics
// The library consists of three sub-libraries:
// * IL - main DevIL library. It allows you to load and save images to files. Every function in this library have 'il' prefixed to their name.
// * ILU - this library contains functions for altering images. Every function in this library have 'ilu' prefixed to their name.
// * ILUT - this library connects DevIL with OpenGL. Every function in this library have 'ilut' prefixed to their name.
int main()
{
ilInit();
printf("DevIL has been initialized\n");
// Loading an image
ILboolean result = ilLoadImage( "tex1.png" ) ;
if( result == true )
{
printf("the image loaded successfully\n");
}
else
{
printf("The image failed to load\n" ) ;
ILenum err = ilGetError() ;
printf( "the error %d\n", err );
printf( "string is %s\n", ilGetString( err ) );
}
int size = ilGetInteger( IL_IMAGE_SIZE_OF_DATA ) ;
printf("Data size: %d\n", size );
ILubyte * bytes = ilGetData() ;
for( int i = 0 ; i < size; i++ )
{
// see we should see the byte data of the image now.
printf( "%d\n", bytes[ i ] );
}
}
I found code from this site: http://bobobobo.wordpress.com/2009/03/02/how-to-load-a-png-image-in-c/
Can you help me?
According to this post, 1290 means the image path wasn't found. Try using an absolute file path and see if it can load then.