github.com/acrespo/mobile@v0.0.0-20190107162257-dc0771356504/app/x11.c (about)

     1  // Copyright 2014 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // +build linux,!android
     6  
     7  #include "_cgo_export.h"
     8  #include <EGL/egl.h>
     9  #include <GLES2/gl2.h>
    10  #include <X11/Xlib.h>
    11  #include <stdio.h>
    12  #include <stdlib.h>
    13  
    14  static Atom wm_delete_window;
    15  
    16  static Window
    17  new_window(Display *x_dpy, EGLDisplay e_dpy, int w, int h, EGLContext *ctx, EGLSurface *surf) {
    18  	static const EGLint attribs[] = {
    19  		EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
    20  		EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
    21  		EGL_BLUE_SIZE, 8,
    22  		EGL_GREEN_SIZE, 8,
    23  		EGL_RED_SIZE, 8,
    24  		EGL_DEPTH_SIZE, 16,
    25  		EGL_CONFIG_CAVEAT, EGL_NONE,
    26  		EGL_NONE
    27  	};
    28  	EGLConfig config;
    29  	EGLint num_configs;
    30  	if (!eglChooseConfig(e_dpy, attribs, &config, 1, &num_configs)) {
    31  		fprintf(stderr, "eglChooseConfig failed\n");
    32  		exit(1);
    33  	}
    34  	EGLint vid;
    35  	if (!eglGetConfigAttrib(e_dpy, config, EGL_NATIVE_VISUAL_ID, &vid)) {
    36  		fprintf(stderr, "eglGetConfigAttrib failed\n");
    37  		exit(1);
    38  	}
    39  
    40  	XVisualInfo visTemplate;
    41  	visTemplate.visualid = vid;
    42  	int num_visuals;
    43  	XVisualInfo *visInfo = XGetVisualInfo(x_dpy, VisualIDMask, &visTemplate, &num_visuals);
    44  	if (!visInfo) {
    45  		fprintf(stderr, "XGetVisualInfo failed\n");
    46  		exit(1);
    47  	}
    48  
    49  	Window root = RootWindow(x_dpy, DefaultScreen(x_dpy));
    50  	XSetWindowAttributes attr;
    51  
    52  	attr.colormap = XCreateColormap(x_dpy, root, visInfo->visual, AllocNone);
    53  	if (!attr.colormap) {
    54  		fprintf(stderr, "XCreateColormap failed\n");
    55  		exit(1);
    56  	}
    57  
    58  	attr.event_mask = StructureNotifyMask | ExposureMask |
    59  		ButtonPressMask | ButtonReleaseMask | ButtonMotionMask;
    60  	Window win = XCreateWindow(
    61  		x_dpy, root, 0, 0, w, h, 0, visInfo->depth, InputOutput,
    62  		visInfo->visual, CWColormap | CWEventMask, &attr);
    63  	XFree(visInfo);
    64  
    65  	XSizeHints sizehints;
    66  	sizehints.width  = w;
    67  	sizehints.height = h;
    68  	sizehints.flags = USSize;
    69  	XSetNormalHints(x_dpy, win, &sizehints);
    70  	XSetStandardProperties(x_dpy, win, "App", "App", None, (char **)NULL, 0, &sizehints);
    71  
    72  	static const EGLint ctx_attribs[] = {
    73  		EGL_CONTEXT_CLIENT_VERSION, 2,
    74  		EGL_NONE
    75  	};
    76  	*ctx = eglCreateContext(e_dpy, config, EGL_NO_CONTEXT, ctx_attribs);
    77  	if (!*ctx) {
    78  		fprintf(stderr, "eglCreateContext failed\n");
    79  		exit(1);
    80  	}
    81  	*surf = eglCreateWindowSurface(e_dpy, config, win, NULL);
    82  	if (!*surf) {
    83  		fprintf(stderr, "eglCreateWindowSurface failed\n");
    84  		exit(1);
    85  	}
    86  	return win;
    87  }
    88  
    89  Display *x_dpy;
    90  EGLDisplay e_dpy;
    91  EGLContext e_ctx;
    92  EGLSurface e_surf;
    93  Window win;
    94  
    95  void
    96  createWindow(void) {
    97  	x_dpy = XOpenDisplay(NULL);
    98  	if (!x_dpy) {
    99  		fprintf(stderr, "XOpenDisplay failed\n");
   100  		exit(1);
   101  	}
   102  	e_dpy = eglGetDisplay(x_dpy);
   103  	if (!e_dpy) {
   104  		fprintf(stderr, "eglGetDisplay failed\n");
   105  		exit(1);
   106  	}
   107  	EGLint e_major, e_minor;
   108  	if (!eglInitialize(e_dpy, &e_major, &e_minor)) {
   109  		fprintf(stderr, "eglInitialize failed\n");
   110  		exit(1);
   111  	}
   112  	eglBindAPI(EGL_OPENGL_ES_API);
   113  	win = new_window(x_dpy, e_dpy, 600, 800, &e_ctx, &e_surf);
   114  
   115  	wm_delete_window = XInternAtom(x_dpy, "WM_DELETE_WINDOW", True);
   116  	if (wm_delete_window != None) {
   117  		XSetWMProtocols(x_dpy, win, &wm_delete_window, 1);
   118  	}
   119  
   120  	XMapWindow(x_dpy, win);
   121  	if (!eglMakeCurrent(e_dpy, e_surf, e_surf, e_ctx)) {
   122  		fprintf(stderr, "eglMakeCurrent failed\n");
   123  		exit(1);
   124  	}
   125  
   126  	// Window size and DPI should be initialized before starting app.
   127  	XEvent ev;
   128  	while (1) {
   129  		if (XCheckMaskEvent(x_dpy, StructureNotifyMask, &ev) == False) {
   130  			continue;
   131  		}
   132  		if (ev.type == ConfigureNotify) {
   133  			onResize(ev.xconfigure.width, ev.xconfigure.height);
   134  			break;
   135  		}
   136  	}
   137  }
   138  
   139  void
   140  processEvents(void) {
   141  	while (XPending(x_dpy)) {
   142  		XEvent ev;
   143  		XNextEvent(x_dpy, &ev);
   144  		switch (ev.type) {
   145  		case ButtonPress:
   146  			onTouchBegin((float)ev.xbutton.x, (float)ev.xbutton.y);
   147  			break;
   148  		case ButtonRelease:
   149  			onTouchEnd((float)ev.xbutton.x, (float)ev.xbutton.y);
   150  			break;
   151  		case MotionNotify:
   152  			onTouchMove((float)ev.xmotion.x, (float)ev.xmotion.y);
   153  			break;
   154  		case ConfigureNotify:
   155  			onResize(ev.xconfigure.width, ev.xconfigure.height);
   156  			break;
   157  		case ClientMessage:
   158  			if (wm_delete_window != None && (Atom)ev.xclient.data.l[0] == wm_delete_window) {
   159  				onStop();
   160  				return;
   161  			}
   162  			break;
   163  		}
   164  	}
   165  }
   166  
   167  void
   168  swapBuffers(void) {
   169  	if (eglSwapBuffers(e_dpy, e_surf) == EGL_FALSE) {
   170  		fprintf(stderr, "eglSwapBuffer failed\n");
   171  		exit(1);
   172  	}
   173  }