+/**************************************************************************
+ * Copyright 2012 Intel corporation
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ **************************************************************************/
+
+#include <stdio.h>
+
+#include <X11/Xlib.h>
+#include <GL/glew.h>
+#include <GL/gl.h>
+#include <GL/glx.h>
+
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+
+int width = 64;
+int height = 64;
+
+#ifdef __GNUC__
+#define UNUSED __attribute__((unused))
+#else
+#define UNUSED
+#endif
+
+static void
+set_2d_projection (void)
+{
+ glMatrixMode (GL_PROJECTION);
+ glLoadIdentity ();
+ glOrtho (0, width, height, 0, 0, 1);
+ glMatrixMode (GL_MODELVIEW);
+}
+
+static void
+draw (Display *dpy, Window window, int width, int height)
+{
+ GLenum glew_err;
+ int visual_attr[] = {
+ GLX_RGBA,
+ GLX_RED_SIZE, 8,
+ GLX_GREEN_SIZE, 8,
+ GLX_BLUE_SIZE, 8,
+ GLX_ALPHA_SIZE, 8,
+ GLX_DOUBLEBUFFER,
+ GLX_DEPTH_SIZE, 24,
+ GLX_STENCIL_SIZE, 8,
+ GLX_X_VISUAL_TYPE, GLX_DIRECT_COLOR,
+ None
+ };
+
+ /* Window and context setup. */
+ XVisualInfo *visual_info = glXChooseVisual(dpy, 0, visual_attr);
+ GLXContext ctx = glXCreateContext(dpy, visual_info, NULL, True);
+ glXMakeCurrent(dpy, window, ctx);
+
+ glew_err = glewInit();
+ if (glew_err != GLEW_OK)
+ {
+ fprintf (stderr, "glewInit failed: %s\n",
+ glewGetErrorString(glew_err));
+ exit (1);
+ }
+
+ glViewport(0, 0, width, height);
+
+ set_2d_projection ();
+
+ /* Frame 1. Perform a few operations, most without side effects. */
+ {
+ GLint line_width UNUSED, logic_op UNUSED;
+ GLboolean blend_enabled UNUSED;
+
+ glGetIntegerv(GL_LINE_WIDTH, &line_width);
+ glGetIntegerv(GL_LOGIC_OP_MODE, &logic_op);
+
+ blend_enabled = glIsEnabled(GL_BLEND);
+
+ glEnable(GL_BLEND);
+
+ blend_enabled = glIsEnabled(GL_BLEND);
+
+ glDisable(GL_BLEND);
+ }
+
+ glXSwapBuffers (dpy, window);
+ /* Frame 2. Again, more operations, most with side effects. */
+ {
+ GLint line_width UNUSED, logic_op UNUSED;
+ GLboolean blend_enabled UNUSED;
+
+ glGetIntegerv(GL_LINE_WIDTH, &line_width);
+ glGetIntegerv(GL_LOGIC_OP_MODE, &logic_op);
+
+ blend_enabled = glIsEnabled(GL_BLEND);
+
+ glEnable(GL_BLEND);
+
+ blend_enabled = glIsEnabled(GL_BLEND);
+
+ glDisable(GL_BLEND);
+ }
+
+ /* Cleanup */
+ glXDestroyContext (dpy, ctx);
+}
+
+static void
+handle_events(Display *dpy, Window window, int width, int height)
+{
+ XEvent xev;
+ KeyCode quit_code = XKeysymToKeycode (dpy, XStringToKeysym("Q"));
+
+ XNextEvent (dpy, &xev);
+
+ while (1) {
+ XNextEvent (dpy, &xev);
+ switch (xev.type) {
+ case KeyPress:
+ if (xev.xkey.keycode == quit_code) {
+ return;
+ }
+ break;
+ case ConfigureNotify:
+ width = xev.xconfigure.width;
+ height = xev.xconfigure.height;
+ break;
+ case Expose:
+ if (xev.xexpose.count == 0) {
+ draw (dpy, window, width, height);
+ return;
+ }
+ break;
+ }
+ }
+}
+
+int
+main (void)
+{
+ Display *dpy;
+ Window window;
+
+ dpy = XOpenDisplay (NULL);
+
+ if (dpy == NULL) {
+ fprintf(stderr, "Failed to open display %s\n",
+ XDisplayName(NULL));
+ return 1;
+ }
+
+ window = XCreateSimpleWindow(dpy, DefaultRootWindow (dpy),
+ 0, 0, width, height, 0,
+ BlackPixel (dpy, DefaultScreen (dpy)),
+ BlackPixel (dpy, DefaultScreen (dpy)));
+
+ XSelectInput(dpy, window,
+ KeyPressMask | StructureNotifyMask | ExposureMask);
+
+ XMapWindow (dpy, window);
+
+ handle_events (dpy, window, width, height);
+
+ XDestroyWindow (dpy, window);
+ XCloseDisplay (dpy);
+
+ return 0;
+}