gle_loader.h

#ifdef _WIN32
#include <windows.h>
#include <GL/gl.h>
#define GL_CALL APIENTRY
#else
#include "GL/gl.h"
#define GL_CALL
#endif//_WIN32

// This loader code is inspired by Bink GL extension loader
// Acquired from https://www.khronos.org/registry/OpenGL/api/GL/glext.h
#define GL_ARRAY_BUFFER                   0x8892
#define GL_ELEMENT_ARRAY_BUFFER           0x8893
#define GL_VERTEX_SHADER                  0x8B31
#define GL_FRAGMENT_SHADER                0x8B30
#define GL_COMPILE_STATUS                 0x8B81
#define GL_LINK_STATUS                    0x8B82
#define GL_CURRENT_PROGRAM                0x8B8D
#define GL_STATIC_DRAW                    0x88E4
#define GL_STREAM_DRAW                    0x88E0
#define GL_FUNC_ADD                       0x8006
#define GL_ACTIVE_TEXTURE                 0x84E0
#define GL_TEXTURE0                       0x84C0
#define GL_TEXTURE1                       0x84C1
#define GL_TEXTURE2                       0x84C2
#define GL_TEXTURE3                       0x84C3
#define GL_TEXTURE4                       0x84C4
#define GL_TEXTURE5                       0x84C5
#define GL_TEXTURE6                       0x84C6
#define GL_TEXTURE7                       0x84C7
#define GL_TEXTURE8                       0x84C8
#define GL_TEXTURE9                       0x84C9
#define GL_TEXTURE10                      0x84CA
#define GL_TEXTURE11                      0x84CB
#define GL_TEXTURE12                      0x84CC
#define GL_TEXTURE13                      0x84CD
#define GL_TEXTURE14                      0x84CE
#define GL_TEXTURE15                      0x84CF
#define GL_TEXTURE16                      0x84D0
#define GL_ARRAY_BUFFER_BINDING           0x8894
#define GL_ELEMENT_ARRAY_BUFFER_BINDING   0x8895
#define GL_VERTEX_ARRAY_BINDING           0x85B5
#define GL_BLEND_SRC_RGB                  0x80C9
#define GL_BLEND_DST_RGB                  0x80C8
#define GL_BLEND_DST_ALPHA                0x80CA
#define GL_BLEND_SRC_ALPHA                0x80CB
#define GL_BLEND_EQUATION_RGB             0x8009
#define GL_BLEND_EQUATION_ALPHA           0x883D
typedef char GLchar;
typedef ptrdiff_t GLsizeiptr;
typedef ptrdiff_t GLintptr;

typedef void (GL_CALL *GLDEBUGPROCARB)(GLenum source, GLenum type, GLuint id,
                                       GLenum severity, GLsizei length,
                                       const GLchar *message, const void *userParam);

#define GL_LIST \
    GLE(void,   BlendEquation,           GLenum mode) \
    GLE(void,   BlendEquationSeparate,   GLenum modeRGB, GLenum modeAlpha) \
    GLE(void,   BlendFuncSeparate,       GLenum srcRGB, GLenum dstRGB, GLenum srcAlpha, GLenum dstAlpha) \
    GLE(GLuint, CreateShader,            GLenum type) \
    GLE(void,   ShaderSource,            GLuint shader, GLsizei count, const GLchar* const*string, const GLint* length) \
    GLE(void,   CompileShader,           GLuint shader) \
    GLE(void,   GetShaderiv,             GLuint shader, GLenum pname, GLint* params) \
    GLE(void,   GetShaderInfoLog,        GLuint shader, GLsizei bufSize, GLsizei *length, GLchar *infoLog) \
    GLE(GLuint, CreateProgram,           void) \
    GLE(void,   AttachShader,            GLuint program, GLuint shader) \
    GLE(void,   LinkProgram,             GLuint program) \
    GLE(void,   GetProgramiv,            GLuint program, GLenum pname, GLint *params) \
    GLE(void,   GetProgramInfoLog,       GLuint program, GLsizei bufSize, GLsizei *length, GLchar *infoLog) \
    GLE(void,   DeleteProgram,           GLuint program) \
    GLE(void,   DeleteShader,            GLuint shader) \
    GLE(void,   GenVertexArrays,         GLsizei n, GLuint *arrays) \
    GLE(void,   GenBuffers,              GLsizei n, GLuint *buffers) \
    GLE(void,   DeleteVertexArrays,      GLsizei n, const GLuint *arrays) \
    GLE(void,   DeleteBuffers,           GLsizei n, const GLuint *buffers) \
    GLE(void,   BindVertexArray,         GLuint array) \
    GLE(void,   BindBuffer,              GLenum target, GLuint buffer) \
    GLE(void,   BufferData,              GLenum target, GLsizeiptr size, const void *data, GLenum usage) \
    GLE(void,   VertexAttribPointer,     GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const void *pointer) \
    GLE(void,   EnableVertexAttribArray, GLuint index) \
    GLE(void,   DisableVertexAttribArray, GLuint index) \
    GLE(void,   UseProgram,              GLuint program) \
    GLE(void,   GenerateMipmap,          GLenum target) \
    GLE(GLint,  GetUniformLocation,      GLuint program, const GLchar *name) \
    GLE(GLint,  GetAttribLocation,       GLuint program, const GLchar *name) \
    GLE(void,   ActiveTexture,           GLenum texture) \
    GLE(void,   Uniform1i,               GLint location, GLint v0) \
    GLE(void,   Uniform3f,               GLint location, GLfloat v0, GLfloat v1, GLfloat v2) \
    GLE(void,   Uniform4fv,              GLint location, GLsizei count, const GLfloat *value) \
    GLE(void,   UniformMatrix4fv,        GLint location, GLsizei count, GLboolean transpose, const GLfloat *value) \
    GLE(void,   DebugMessageCallbackARB, GLDEBUGPROCARB callback, const void* userParam)

#define GLE(ret, name, ...) typedef ret name##Func(__VA_ARGS__); \
    extern name##Func* gl##name;
GL_LIST
#undef GLE

b32 gl_load_extensions();