simple-egl: Add support for using a 16 bpp EGLConfig

diff --git a/clients/simple-egl.c b/clients/simple-egl.c
index 1fd4137..f23243f 100644 (file)
--- a/clients/simple-egl.c
+++ b/clients/simple-egl.c
@@ -92,7 +92,7 @@ struct window {
        struct wl_shell_surface *shell_surface;
        EGLSurface egl_surface;
        struct wl_callback *callback;
-       int fullscreen, configured, opaque;
+       int fullscreen, configured, opaque, buffer_size;
 };
 
 static const char *vert_shader_text =
@@ -115,7 +115,7 @@ static const char *frag_shader_text =
 static int running = 1;
 
 static void
-init_egl(struct display *display, int opaque)
+init_egl(struct display *display, struct window *window)
 {
        static const EGLint context_attribs[] = {
                EGL_CONTEXT_CLIENT_VERSION, 2,
@@ -128,15 +128,15 @@ init_egl(struct display *display, int opaque)
                EGL_RED_SIZE, 1,
                EGL_GREEN_SIZE, 1,
                EGL_BLUE_SIZE, 1,
-               EGL_ALPHA_SIZE, 1,
                EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
                EGL_NONE
        };
 
-       EGLint major, minor, n;
+       EGLint major, minor, n, count, i, size;
+       EGLConfig *configs;
        EGLBoolean ret;
 
-       if (opaque)
+       if (window->opaque || window->buffer_size == 16)
                config_attribs[9] = 0;
 
        display->egl.dpy = eglGetDisplay(display->display);
@@ -147,9 +147,30 @@ init_egl(struct display *display, int opaque)
        ret = eglBindAPI(EGL_OPENGL_ES_API);
        assert(ret == EGL_TRUE);
 
+       if (!eglGetConfigs(display->egl.dpy, NULL, 0, &count) || count < 1)
+               assert(0);
+
+       configs = calloc(count, sizeof *configs);
+       assert(configs);
+
        ret = eglChooseConfig(display->egl.dpy, config_attribs,
-                             &display->egl.conf, 1, &n);
-       assert(ret && n == 1);
+                             configs, count, &n);
+       assert(ret && n >= 1);
+
+       for (i = 0; i < n; i++) {
+               eglGetConfigAttrib(display->egl.dpy,
+                                  configs[i], EGL_BUFFER_SIZE, &size);
+               if (window->buffer_size == size) {
+                       display->egl.conf = configs[i];
+                       break;
+               }
+       }
+       free(configs);
+       if (display->egl.conf == NULL) {
+               fprintf(stderr, "did not find config with buffer size %d\n",
+                       window->buffer_size);
+               exit(EXIT_FAILURE);
+       }
 
        display->egl.ctx = eglCreateContext(display->egl.dpy,
                                            display->egl.conf,
@@ -705,6 +726,7 @@ usage(int error_code)
        fprintf(stderr, "Usage: simple-egl [OPTIONS]\n\n"
                "  -f\tRun in fullscreen mode\n"
                "  -o\tCreate an opaque surface\n"
+               "  -s\tUse a 16 bpp EGL config\n"
                "  -h\tThis help text\n\n");
 
        exit(error_code);
@@ -722,12 +744,15 @@ main(int argc, char **argv)
        display.window = &window;
        window.window_size.width  = 250;
        window.window_size.height = 250;
+       window.buffer_size = 32;
 
        for (i = 1; i < argc; i++) {
                if (strcmp("-f", argv[i]) == 0)
                        window.fullscreen = 1;
                else if (strcmp("-o", argv[i]) == 0)
                        window.opaque = 1;
+               else if (strcmp("-s", argv[i]) == 0)
+                       window.buffer_size = 16;
                else if (strcmp("-h", argv[i]) == 0)
                        usage(EXIT_SUCCESS);
                else
@@ -743,7 +768,7 @@ main(int argc, char **argv)
 
        wl_display_dispatch(display.display);
 
-       init_egl(&display, window.opaque);
+       init_egl(&display, &window);
        create_surface(&window);
        init_gl(&window);