learning opengl using Glad https://github.com/Dav1dde/glad/blob/master/example/c/simple.c

opengltest.ec

import "ecere"
#include <glad/glad.h>
#define property _property
#include <GL/glut.h>
#undef property
// GLAD_DEBUG is only defined if the c-debug generator was used
#ifdef GLAD_DEBUG
// logs every gl call to the console
   void pre_gl_call(const char *name, void *funcptr, int len_args, ...)
   {
      printf("Calling: %s (%d arguments)\n", name, len_args);
   }
#endif

class HelloApp : Application
   {
      int width;
      width = 600;
      int height;
      height = 600;

      void (*display)(void);
      void (*reshape)(int , int);

      void display(void)
         {
            glClearColor(1.0f, 0.2f, 0.7f, 1.0f);
            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
            glutSwapBuffers();
            glutPostRedisplay();
         }

      void ::reshape(int w, int h)
         {
            width = w > 1 ? w : 1;
            height = h > 1 ? h : 1;
            glViewport(0, 0, width, height);
            glClearDepth(1.0);
            glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
            glEnable(GL_DEPTH_TEST);
         }

      void Main()
         {
            char *myargv [1];
            int myargc=1;
            PrintLn("Hello, World!!");
            if(gladLoadGL())
               {
                  // you need an OpenGL context before loading glad
                  printf("I did load GL with no context!\n");
                  //exit(-1);
               }

            PrintLn("initializing");
            myargv [0]=strdup ("Myappname");
            glutInit(&myargc, myargv);
            PrintLn("SUCCESS!");
            glutInitDisplayMode(GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE);
            glutInitWindowSize(600, 600);
            glutCreateWindow("cookie");
            PrintLn("reshape callback");
            glutReshapeFunc( this.reshape);
            PrintLn("display callback");
            glutDisplayFunc( this.display);
            PrintLn("did we load?");
            if(!gladLoadGL())
               {
                  printf("Something went wrong!\n");
                  //exit(-1);
               }
            #ifdef GLAD_DEBUG
               // before every opengl call call pre_gl_call
               glad_set_pre_callback(pre_gl_call);
               // don't use the callback for glClear
               // (glClear could be replaced with your own function)
               glad_debug_glClear = glad_glClear;
            #endif

            // gladLoadGLLoader(&glutGetProcAddress);
            printf("OpenGL %d.%d\n", GLVersion.major, GLVersion.minor);
            if (GLVersion.major < 2)
               {
                  printf("Your system doesn't support OpenGL >= 2!\n");
                  //return -1;
               }

            printf("OpenGL %s, GLSL %s\n", glGetString(GL_VERSION),
            glGetString(GL_SHADING_LANGUAGE_VERSION));

            glutMainLoop();

            //return 0;
          }
   }