https://github.com/tsherif/simple-opengl-loader

An extensible, cross-platform, single-header C/C++ OpenGL loader library.
https://github.com/tsherif/simple-opengl-loader

linux opengl opengl-loader single-header-lib win32 windows x11

Last synced: about 2 months ago
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An extensible, cross-platform, single-header C/C++ OpenGL loader library.

• Host: GitHub
• URL: https://github.com/tsherif/simple-opengl-loader
• Owner: tsherif
• License: mit
• Created: 2020-12-29T14:37:55.000Z (over 3 years ago)
• Default Branch: master
• Last Pushed: 2022-08-26T10:50:14.000Z (about 2 years ago)
• Last Synced: 2024-05-15T14:39:59.092Z (5 months ago)
• Topics: linux, opengl, opengl-loader, single-header-lib, win32, windows, x11
• Language: C
• Homepage:
• Size: 587 KB
• Stars: 85
• Watchers: 3
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

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README

        
Simple OpenGL Loader

====================

An extensible, cross-platform, single-header C/C++ OpenGL loader library.

Usage

-----

For Windows Win32 or Linux X11 applications, the simplest usage involves defining `SOGL_MAJOR_VERSION`, `SOGL_MINOR_VERSION`and either `SOGL_IMPLEMENTATION_WIN32` or `SOGL_IMPLEMENTATION_X11` before including the `simple-opengl-loader.h` header file, and then calling `sogl_loadOpenGL()` after setting up an OpenGL context.

```C

    #define SOGL_MAJOR_VERSION 4

    #define SOGL_MINOR_VERSION 5

    #define SOGL_IMPLEMENTATION_WIN32 /* or SOGL_IMPLEMENTATION_X11 */

    #include "simple-opengl-loader.h"

    int main() {

        /* Set up OpenGL context */

        

        sogl_loadOpenGL();

        /* Use OpenGL functions */

    }

```

It is recommended that `simple-opengl-loader.h` be the first include to prevent other OpenGL headers from setting up their own definitions. 

Platform support is included for Windows Win32 and Linux X11 applications by defining the `SOGL_IMPLEMENTATION_WIN32` or `SOGL_IMPLEMENTATION_X11` constants, respectively. The `SOGL_IMPLEMENTATION_X11` implementation requires the application be linked against `libdl`. See below to implement support for other platforms.

OpenGL extensions can be loaded by defining a constant of the format `SOGL_` before including the `simple-opengl-loader.h` header.

```C

    #define SOGL_MAJOR_VERSION 4

    #define SOGL_MINOR_VERSION 5

    #define SOGL_OVR_multiview

    #define SOGL_KHR_parallel_shader_compile

    #define SOGL_IMPLEMENTATION_WIN32

    #include "simple-opengl-loader.h"

```

Note that the loader makes no guarantees about OpenGL version or extension support. `sogl_loadOpenGL()` returns a boolean value indicating whether it was able to load all requested functions, and the function `sogl_getFailures` returns a null-terminated array of the names of the functions that failed to load (up to a maximum defined by `SOGL_MAX_REPORTED_FAILURES`). 

```C

    if (!sogl_loadOpenGL()) {

        const char **failures = sogl_getFailures();

        int i = 1;

        while (*failures) {

            fprintf(stderr, "Failed to load function %s\n", *failures);

            failures++;

        }

    }

```

Platform Support

----------------

Platform-specific logic is encapsulated in two functions `sogl_loadOpenGLFunction()` which takes the name of an OpenGL function as a null-terminated ASCII string and returns a pointer to the appropriate function, and `sogl_cleanup()`, which should perform any cleanup necessary after loading is complete, e.g. freeing library handles.

```C

void *sogl_loadOpenGLFunction(const char *name);

void sogl_cleanup();

```

Implementations for these functions are provided out-of-the-box for Windows Win32 and Linux X11 applications (see above). Support for other platforms simply requires implementing these two functions for the target platform and defining the constant `SOGL_IMPLEMENTATION` instead of either of the platform-specific implementation constants.

```C

    #define SOGL_MAJOR_VERSION 4

    #define SOGL_MINOR_VERSION 5

    #define SOGL_IMPLEMENTATION

    #include "simple-opengl-loader.h"

    void *sogl_loadOpenGLFunction(const char *name) {

        /* Custom function loader implementation */

    }

    

    void sogl_cleanup() {

        /* Custom cleanup implementation */ 

    }

```