Setting Visual Studio Project with SDL and GLEW - c++

Question

I'm new to using Visual Studio and the libraries OpenGL and SDL.
I'm having trouble setting up my program and keep running into errors when I try to build it.
Can anyone help me solve the following -
Error 1 error LNK2019: unresolved external symbol __imp__glewInit#0 referenced in function _SDL_main
Error 2 error LNK2019: unresolved external symbol __imp__glewGetErrorString#4 referenced in function _SDL_main
Error 3 error LNK2001: unresolved external symbol __imp____GLEW_VERSION_3_0
Error 4 error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup
Error 5 error LNK1120: 4 unresolved externals
6 IntelliSense: identifier "GLuint" is undefined
7 IntelliSense: identifier "GLuint" is undefined
This is my code -
main.c
#include<SDL.h>
#include<GL\glew.h>
#include <stdio.h>
char shouldExit = 0;
int main(void)
{
/* Initialize SDL *l
if( SDL_Init( SDL_INIT_VIDEO ) < 0 ) {
return 1;
}
/* Create the window, OpenGL context */
SDL_GL_SetAttribute(SDL_GL_BUFFER_SIZE, 32);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_Window* window = SDL_CreateWindow(
"TestSDL",
SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
640, 480,
SDL_WINDOW_OPENGL);
if (!window) {
fprintf(stderr, "Could not create window.ErrorCode = %s\n", SDL_GetError());
SDL_Quit();
return 1;
}
SDL_GL_CreateContext(window);
/* Make sure we have a recent version of OpenGL */
GLenum glewError = glewInit();
if (glewError != GLEW_OK) {
fprintf(stderr, "Could not initialize glew.ErrorCode = %s\n", glewGetErrorString(glewError));
SDL_Quit();
return 1;
}
if (!GLEW_VERSION_3_0) {
fprintf(stderr, "OpenGL max supported version is too low.\n");
SDL_Quit();
return 1;
}
/* Setup OpenGL state */
glViewport(0, 0, 640, 480);
glMatrixMode(GL_PROJECTION);
glOrtho(0, 640, 480, 0, 0, 100);
glEnable(GL_TEXTURE_2D);
/* The game loop */
while (!shouldExit) {
// Handle OS message pump
SDL_Event event;
while (SDL_PollEvent(&event)) {
switch (event.type) {
case SDL_QUIT:
shouldExit = 1;
}
}
glClearColor(0, 0, 0, 1);
glClear(GL_COLOR_BUFFER_BIT);
/* Game logic goes here */
SDL_GL_SwapWindow(window);
}
SDL_Quit();
return 0;
}
DrawUtils.c
/***********************************************************************
Utilities for loading and drawing sprites.
*/
#include<GL/glew.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<assert.h>
/* Load a file into an OpenGL texture, and return that texture. */
GLuint glTexImageTGAFile( const char* filename, int* outWidth, int* outHeight )
{
const int BPP = 4;
/* open the file */
FILE* file = fopen( filename, "rb" );
if( file == NULL ) {
fprintf( stderr, "File: %s -- Could not open for reading.\n", filename );
return 0;
}
/* skip first two bytes of data we don't need */
fseek( file, 2, SEEK_CUR );
/* read in the image type. For our purposes the image type should
* be either a 2 or a 3. */
unsigned char imageTypeCode;
fread( &imageTypeCode, 1, 1, file );
if( imageTypeCode != 2 && imageTypeCode != 3 ) {
fclose( file );
fprintf( stderr, "File: %s -- Unsupported TGA type: %d\n", filename, imageTypeCode );
return 0;
}
/* skip 9 bytes of data we don't need */
fseek( file, 9, SEEK_CUR );
/* read image dimensions */
int imageWidth = 0;
int imageHeight = 0;
int bitCount = 0;
fread( &imageWidth, sizeof( short ), 1, file );
fread( &imageHeight, sizeof( short ), 1, file );
fread( &bitCount, sizeof( unsigned char ), 1, file );
fseek( file, 1, SEEK_CUR );
/* allocate memory for image data and read it in */
unsigned char* bytes = (unsigned char*)calloc( imageWidth * imageHeight * BPP, 1 );
/* read in data */
if( bitCount == 32 ) {
int it;
for( it = 0; it != imageWidth * imageHeight; ++it ) {
bytes[ it * BPP + 0 ] = fgetc( file );
bytes[ it * BPP + 1 ] = fgetc( file );
bytes[ it * BPP + 2 ] = fgetc( file );
bytes[ it * BPP + 3 ] = fgetc( file );
}
} else {
int it;
for( it = 0; it != imageWidth * imageHeight; ++it ) {
bytes[ it * BPP + 0 ] = fgetc( file );
bytes[ it * BPP + 1 ] = fgetc( file );
bytes[ it * BPP + 2 ] = fgetc( file );
bytes[ it * BPP + 3 ] = 255;
}
}
fclose( file );
/* load into OpenGL */
GLuint tex;
glGenTextures( 1, &tex );
glBindTexture( GL_TEXTURE_2D, tex );
glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, imageWidth, imageHeight, 0,
GL_BGRA, GL_UNSIGNED_BYTE, bytes );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
free( bytes );
if( outWidth ) {
*outWidth = imageWidth;
}
if( outHeight ) {
*outHeight = imageHeight;
}
return tex;
}
/* Draw the sprite */
void glDrawSprite( GLuint tex, int x, int y, int w, int h )
{
glBindTexture( GL_TEXTURE_2D, tex );
glBegin( GL_QUADS );
{
glColor3ub( 255, 255, 255 );
glTexCoord2f( 0, 1 );
glVertex2i( x, y );
glTexCoord2f( 1, 1 );
glVertex2i( x + w, y );
glTexCoord2f( 1, 0 );
glVertex2i( x + w, y + h );
glTexCoord2f( 0, 0 );
glVertex2i( x, y + h );
}
glEnd();
}
DrawUtils.h
#ifndef DRAWUTILS_H
#define DRAWUTILS_H
#ifdef __cplusplus
extern "C" {
#endif
GLuint glTexImageTGAFile( const char* filename, int* outWidth, int* outHeight );
void glDrawSprite( GLuint tex, int x, int y, int w, int h );
#ifdef __cplusplus
}
#endif
#endif
Am I missing an #include?

Answer 1

No, you're missing a library. You're including the GLEW header file(s):
#include<GL\glew.h>
However, header files only define the function prototypes (such as glewInit()) - the actual implementations of those functions will be stored in a .lib (or .a) file, which you must link with in order to build your project.
It's been a while since I used Visual Studio, but I'd think that you would normally set up linker options as part of your project configuration. However, it is possible to specify linker options within your code, if you must:
#pragma comment(lib, "glew/glew32s.lib")
Note that the #pragma method is MSVC-specific and probably won't work on other compilers.
If you can't be bothered fiddling around with linker options, you could always just add glew.c to your project instead.
One other thing: You're using GLuint in DrawUtils.h without including either gl.h or glew.h:
GLuint glTexImageTGAFile( const char* filename, int* outWidth, int* outHeight );
void glDrawSprite( GLuint tex, int x, int y, int w, int h );

Answer 2

Regarding Visual Studio 2017, OpenGL, SDL2 and GLEW, I recommend this webpage.
I copy and paste text only.
Part A - Downloading SDL and GLEW
A1 Create a folder OpenGL. In directory (disk) C:, create (by right click > New > Folder) a new folder with name OpenGL.
A2 Download the SDL2-devel-2.0.8-VC.zip (Visual C++ 32/64-bit). It can be found at https://www.libsdl.org/download-2.0.php. Scroll to the bottom of the page and find Development Libraries.
A2a Download the version for Visual C++. It is the SDL2-devel-2.0.8-VC.zip (Visual C++ 32/64-bit). Navigate (always by double click) to C: > OpenGL.
A2b Drag (or, by right click, copy and paste) folder SDL2-2.0.8 from the window where it is downloaded, into folder OpenGL.
A2c If the folder SDL2-devel-2.0.8-VC is downloaded, double click it to get SDL2-2.0.8.
A3 Download the GLEW. At http://glew.sourceforge.net/ below Downloads click Windows 32-bit and 64-bit. Navigate to C: > OpenGL. Drag (or, by right click, copy and paste) folder glew-2.1.0 from the window where it is downloaded, into folder *OpenGL.
A3a If folder glew-2.1.0-win32 is downloaded, double click it for get glew-2.1.0.
Part B - Creating a Visual Studio Project
B1 Create an empty project.
B1a At the Visual Studio main menu, click File. Then go to New > Project…
B1b In the left part of the New Project window, click Visual C++ if it is not clicked.
B1c In the center of the screen click Empty Project.
B1d Below that, find the Name text box, type Project-0.
B1e Next to Location text box, click Browse... and navigate to C: > OpenGL.
B1f Click Select a folder. The Location in New Project window is C:\OpenGL.
B1g Make sure the Create directory for solution box is not checked.
B1h Click OK.
B2 Add your source file to the Project.
B2a In the Solution Explorer window (at the left side of the screen), right click the Source Files folder (the last one).
B2b Click Add > New Item…
B2c In the Add New Item - Project-0 window, click C++ File (.cpp) (the first one) from the middle of the window. In Name text box type Main.cpp.
B2d. The Location is C:\OpenGL\Project-0.
B2e Click the Add button. The file will open in the main text editor but leave the file blank for now.
Part C - Installing SDL and GLEW on a Project
C1 Add the Include folders.
C1a Configure the Additional Include Directories: In Solution Explorer right click on the name of your project, that is Project-0, and select Properties.
C1b Add SDL's include folder: Open the C/C++ drop-down menu. Click General > Additional Include Directories > down arrow at the right of the field > Edit in the drop down menu.
C1c In Additional Include Directories, click the first icon > copy and paste, C:\OpenGL\SDL2-2.0.8\include
C1d Add GLEW's include folder: Click again the first icon > copy and paste: C:\OpenGL\glew-2.1.0\include Click OK on Additional Include Directories window.
C2 Add the x86 and Win32 folders.
C2a Configure the linker Additional Library Directories: Open the Linker drop-down menu, and click General.
C2b Add the x86 folder: Click Additional Library Directories entry, and click the down arrow at the right of the field. Click Edit in the drop-down menu.
C2c In Additional Library Directories click the first icon > copy and paste, C:\OpenGL\SDL2-2.0.8\lib\x86
C2d Add the Win32 folder: Click the first icon > copy and paste, C:\OpenGL\glew-2.1.0\lib\Release\Win32 Click OK.
C3 Add the four library files.
C3a Configure the linker Additional Dependencies: In the Linker drop-down menu, click Input. Click the Additional Dependencies entry > the down arrow at the right of the field > Edit in the drop-down menu.
C3b On the top-most text box of the Additional Dependencies window, copy and paste, SDL2.lib; SDL2main.lib; glew32.lib; opengl32.lib Click OK in the Additional Dependencies window.
C4 Configure the linker subsystem to console.
C4a In the Linker drop-down menu, click System > SubSystem. Click the down arrw and select Console(/SUBSYSTEM:CONSOLE) from the dropdown menu. Click Apply, then OK on the Project Property Pages window.
C5 Copy SDL2.dll file from x86 folder, and paste to Project-0 folder.
C5a Navigate to C: > OpenGL > SDL2-2.0.8 > lib > x86. Inside x86 folder click SDL2.dll file > right-click > Copy.
C5b Navigate to C: > OpenGL > Project-0. Right-click an empty area in Project-0 folder, and select Paste.
C5c The SDL2.dll file should now be in your project directory along with your Main.cpp file and a few other files created by Visual Studio.
C6 Copy the glew32.dll file from Win32 and paste to Project folder.
C6a Navigate to C: > OpenGL > glew-2.1.0 > bin > Release > Win32. Click glew32.dll > right-click > Copy.
C6b Navigate to C: > OpenGL > Project-0. Right-click an empty area in Project-0 folder, and select Paste.
C6c The glew32.dll file should now be in Project-0 folder along with Main.cpp, SDL2.dll, and a few other files created by Visual Studio.
Part D - Testing and Debugging Your Project
D1 Download the code: Click http://lazyfoo.net/tutorials/SDL/51_SDL_and_modern_opengl/index.php > Scroll down and find Download the media and source code for this tutorial here. Click here and download 51_SDL_and_modern_opengl.cpp folder. Double click it > double click file of same name. Its code will appear in Visual Studio by the side of Main.cpp file. Copy the code (413 lines) and paste on Main.cpp code area. On V.S. main menu click the green arrow Local Windows Debugger and wait... If everything went well two windows appear: one black and one with title: SDL Tutorial and inside a white square with black background. If there is any problem try fix the error(s). If you fail, repeat above steps.
Part E - Creating a Project with OpenGL-SDL-GLEW Template in Visual Studio 2017
E1 Create a project template: Go to Visual Studio main menu and, while Project-0 is open, click Project > Export Template.... On Export template Wizard check Project Template, if it's not checked. Click Next >. On Select Template Options, in Template name text box type: OpenGL-SDL-GLEW. Click Finish. Template has been created.
E2 Create OpenGL-SDL-GLEW project with created Template
E2a On V.S. main menu click File > New > Project.... On the New Project window, click template: OpenGL-SDL-GLEW. In Name text field, type: Project-1. Be sure Create directory for solution is unchecked. Click OK.
E2b On Solution Explorer, double click Source Files. Click Main.cpp > right click > click Exclude From Project.
E2c Right click Source Files > Add > New Item.... On Add New Item - Project-1 window, click C++ File (.cpp). In Name: text box type: Main.cpp. The Location should be C:\OpenGL\Project-1. Click Add. Now on Solution Explore, below Source Files, you have the new Main.cpp file.
E3 Add SDL2.dll file to project-folder
E3a Navigate to C: > OpenGL > Project-0 > click file SDL2.dll > right click > click Copy.
E3b Navigate to C: > OpenGL > Project-1 > click on empty area > right click > click Paste.
E3c Now file SDL2.dll is in folder Project-1 among Main.cpp and other 4 files.
E4 Add glew32.dll file to project-folder
E4a Navigate to C: > OpenGL > Project-0 > click file glew32.dll > right click > click Copy.
E4b Navigate to C: > OpenGL > Project-1 > click on empty area > right click > click Paste.
E4c Now file glew32.dll is in folder Project-1 among SDL2.dll, Main.cpp and other 4 files.
E5 Test your project as above. Good job.
Tip
Remember the 3 extra steps you have to take: Creating project with OpenGL-SDL-GLEW Template in Visual Studio 2017 is like creating an ordinary C++ project, but with three more steps:
1 In Solution Explorer, Source Files, the source file (Main.cpp in the example above) of the template project (Project-0, in the example) should be excluded from new project (Project-1 in example).
2 The file SDL2.dll should be copied from a previous project and pasted into new project.
3 The file glew32.dll should be copied from a previous project and pasted into new project.