glgetattachedshaders.c

/*
 * Copyright 2013 The Emscripten Authors.  All rights reserved.
 * Emscripten is available under two separate licenses, the MIT license and the
 * University of Illinois/NCSA Open Source License.  Both these licenses can be
 * found in the LICENSE file.
 */

#include <GLES2/gl2.h>
#include <EGL/egl.h>
#include <stdio.h>
#include <stdlib.h>

static void die(const char *msg) {
  printf("%s\n", msg);
  abort();
}

static void create_context(void) {
  EGLint num_config;
  EGLContext g_egl_ctx;
  EGLDisplay g_egl_dpy;
  EGLConfig g_config;

  static const EGLint attribute_list[] = {
    EGL_RED_SIZE, 8,
    EGL_GREEN_SIZE, 8,
    EGL_BLUE_SIZE, 8,
    EGL_ALPHA_SIZE, 8,
    EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
    EGL_NONE
  };

  static const EGLint context_attributes[] = {
    EGL_CONTEXT_CLIENT_VERSION, 2,
    EGL_NONE
  };

  g_egl_dpy = eglGetDisplay(EGL_DEFAULT_DISPLAY);
  if (!g_egl_dpy)
    die("failed to create display");

  if (!eglInitialize(g_egl_dpy, NULL, NULL))
    die("failed to initialize egl");

  if (!eglChooseConfig(g_egl_dpy, attribute_list, &g_config, 1, &num_config))
    die("failed to choose config");

  g_egl_ctx = eglCreateContext(g_egl_dpy, g_config, EGL_NO_CONTEXT, context_attributes);
  if (!g_egl_ctx)
    die("failed to create context");

  EGLNativeWindowType dummyWindow;
  EGLSurface surface = eglCreateWindowSurface(g_egl_dpy, g_config, dummyWindow, NULL);
  if (!surface)
    die("failed to create window surface");

  if (!eglMakeCurrent(g_egl_dpy, surface, surface, g_egl_ctx))
    die("failed to activate context");
}

int main(int argc, char *argv[]) {
  unsigned i;

  create_context();

  GLuint prog = glCreateProgram();
  if (glGetError())
    die("failed to create program");

  GLuint vertex = glCreateShader(GL_VERTEX_SHADER);
  if (glGetError())
    die("failed to create vertex shader");
  glAttachShader(prog, vertex);

  GLuint fragment = glCreateShader(GL_FRAGMENT_SHADER);
  if (glGetError())
    die("failed to create fragment shader");
  glAttachShader(prog, fragment);

  GLuint shaders[2];
  GLsizei count;

  glGetAttachedShaders(prog, 2, &count, shaders);
  if (glGetError())
    die("failed to get attached shaders");
  if (count != 2)
    die("unknown number of shaders returned");
  if (shaders[0] == shaders[1])
    die("returned identical shaders");

  for (i = 0; i < count; i++) {
    if (shaders[i] == 0)
      die("returned 0");
    if (shaders[i] != vertex && shaders[i] != fragment)
      die("unknown shader returned");
  }

  REPORT_RESULT(1);

  return 0;
}