SDL undeclared filename and apply_surface not working

SDL Development
1

I’ve recently dived into some SDL tutorials, but am having difficulty compiling this one in particular using DevC++ with the SDL library: http://lazyfoo.net/SDL_tutorials/lesson05/index.php

I am getting this particular error: `filename’ undeclared (first use this function) and it points to the filename.c_str() ); area of the code, as well as a few others listed in the compile log. I’d like to also investigate the “apply_surface” not being recognized as well. I have included the following headers:

Code:

#include
#include
#include
#include
#include “SDL/SDL.h”
#include “quickcg.h”
#include “SDL/SDL_mixer.h”
#include “SDL/SDL_image.h”
#include “SDL/SDL_ttf.h”

using namespace QuickCG;

Linker options include suggestions based on other threads I’ve found with the same issue, it appears I’m not alone but I haven’t quite found the solution that applies to my code yet:

Code:

-lmingw32
-mwindows
-lSDLmain
-lSDL
-lSDL_mixer
-lSDL_image
-lSDL_ttf
-lstdc++

CODE SNIPPET:

Code:

int main(int /argc/, char /argv/[])
{
{
SDL_Surface title = NULL;
SDL_Surface* hud = NULL;
SDL_Surface* screen = NULL;
SDL_Surface* loadedImage = NULL;
SDL_Surface* optimizedImage = NULL;

loadedImage = IMG_Load( filename.c_str() );

if (loadedImage != NULL)
{
    optimizedImage = SDL_DisplayFormat( loadedImage );
    SDL_FreeSurface( loadedImage );
    if( optimizedImage != NULL)

etc etc

COMPILE LOG:

Code:

Compiler: Default compiler
Building Makefile: “D:\Coding\Raycaster\Makefile.win"
Executing make…
make.exe -f “D:\Coding\Raycaster\Makefile.win” all
g++.exe -c raycaster.cpp -o raycaster.o -I"D:/Coding/Dev-Cpp/lib/gcc/mingw32/3.4.2
/include” -I"D:/Coding/Dev-Cpp/include/c++/3.4.2/backward" -I"D:/Coding/Dev-Cpp
/include/c++/3.4.2/mingw32" -I"D:/Coding/Dev-Cpp/include/c++/3.4.2" -I"D:/Coding
/Dev-Cpp/include" -fexpensive-optimizations -O3 -mwindows

raycaster.cpp: In function int SDL_main(int, char**)': raycaster.cpp:117: error:filename’ undeclared (first use this function)
raycaster.cpp:117: error: (Each undeclared identifier is reported only once for
each function it appears in.)

raycaster.cpp:130: error: invalid conversion from SDL_Surface*' toint’
raycaster.cpp:133: error: apply_surface' undeclared (first use this function) raycaster.cpp:134: error:hud’ undeclared (first use this function)

make.exe: *** [raycaster.o] Error 1

Execution terminated

Any suggestions or advice would be greatly appreciated. I’m yet another newbie to the whole C++ scene, but this is more of a learning experiment than anything else.

2

Looks like filename is not declared. Try adding :-

Code:
std::string filename = “some_image_file.png”;

Just above the IMG_Load().

3

I’ve recently dived into some SDL tutorials, but am having difficulty
compiling this one in particular using DevC++ with the SDL library:
http://lazyfoo.net/SDL_tutorials/lesson05/index.php

I am getting this particular error: `filename’ undeclared (first use this
function) and it points to the filename.c_str() ); area of the code, as
well as a few others listed in the compile log. I’d like to also
investigate the “apply_surface” not being recognized as well. I have

You are answering your own question, filename is undeclared meaning that it
has no value before you use c_str().

SDL_Surface* optimizedImage = NULL;

loadedImage = IMG_Load( filename.c_str() );

Here, you use filename.c_str() without it actually being defined as a string
before converting it to a const char*
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URL: http://lists.libsdl.org/pipermail/sdl-libsdl.org/attachments/20140401/662fa2ec/attachment.pgpOn Tuesday, April 01, 2014 04:53:47 Blackmantis wrote:

4

No problems, thanks for getting back to me guys, I have it working now. I was just a bit surprised that the source code for the tutorial did not include that part from lesson 02.