Add attr info printers for EGL config

wayland.c

@@ -8,9 +8,7 @@
 
 struct wl_compositor *compositor = NULL;
 struct wl_registry *registry = NULL;
-struct wl_shell *shell = NULL;
 struct wl_surface *surface = NULL;
-struct wl_shm *shm = NULL;
 EGLBoolean errcode = 0;
 
 void registry_handle_global(void *data, struct wl_registry *registry,
@@ -23,12 +21,6 @@ void registry_handle_global(void *data, struct wl_registry *registry,
         fprintf(stdout, "Registering compositor...\n");
         compositor = wl_registry_bind(registry, name, &wl_compositor_interface, 1);
     }
-
-    if (!strcmp(interface, wl_shell_interface.name))
-    {
-        fprintf(stdout, "Getting shell interface...\n");
-        shell = wl_registry_bind(registry, name, &wl_shell_interface, 1);
-    }
 }
 
 
@@ -106,7 +98,7 @@ int main()
       ;
       break;
     }
-    
+
     EGLConfig *configs = calloc(config_count, sizeof(EGLConfig));
 
     EGLint attr_list[] = {
@@ -114,11 +106,10 @@ int main()
 	EGL_RED_SIZE, 8,
 	EGL_GREEN_SIZE, 8,
 	EGL_BLUE_SIZE, 8,
-	EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
+	EGL_RENDERABLE_TYPE, (EGL_OPENGL_BIT | EGL_OPENGL_ES_BIT | EGL_OPENGL_ES2_BIT), // better be safe than sorry with our compatibility bitmask
 	EGL_NONE
     };
     int chosen_config_count;
-    
     errcode = eglChooseConfig(egl_display, attr_list, configs, config_count * sizeof(EGLConfig), &chosen_config_count);
     switch (errcode)
     {
@@ -133,7 +124,74 @@ int main()
       break;
     }
 
-    EGLSurface egl_surface = eglCreateWindowSurface(egl_display, configs[0], (EGLNativeWindowType)window, NULL);
+    int chosen_config_id = 0;
+    EGLConfig *chosen_config = configs[0];
+
+    fprintf(stdout, "Found %d possible configurations:\n", chosen_config_count);
+    for (int i = 0; i < chosen_config_count; ++i)
+    {
+        fprintf(stdout, "\tCONFIG %d:\n", i);
+        int attr;
+#define PRINT_ATTR(attr_name)                                                     \
+        errcode = eglGetConfigAttrib(egl_display, configs[i], attr_name, &attr);  \
+        [[maybe_unused]] int attr_##attr_name = -1;                               \
+        do {                                                                      \
+            if (errcode == EGL_TRUE) {                                            \
+                fprintf(stdout, "\t\t" #attr_name ": %d (%#0x)\n", attr, attr);   \
+                attr_##attr_name = attr;                                          \
+            }                                                                     \
+        } while (0)
+
+
+        PRINT_ATTR(EGL_ALPHA_SIZE);
+        PRINT_ATTR(EGL_ALPHA_MASK_SIZE);
+        PRINT_ATTR(EGL_BIND_TO_TEXTURE_RGB);
+        PRINT_ATTR(EGL_BIND_TO_TEXTURE_RGBA);
+        PRINT_ATTR(EGL_BLUE_SIZE);
+        PRINT_ATTR(EGL_BUFFER_SIZE);
+        PRINT_ATTR(EGL_COLOR_BUFFER_TYPE);
+        PRINT_ATTR(EGL_CONFIG_CAVEAT);
+        PRINT_ATTR(EGL_CONFIG_ID);
+        PRINT_ATTR(EGL_CONFORMANT);
+        PRINT_ATTR(EGL_DEPTH_SIZE);
+        PRINT_ATTR(EGL_GREEN_SIZE);
+        PRINT_ATTR(EGL_LEVEL);
+        PRINT_ATTR(EGL_LUMINANCE_SIZE);
+        PRINT_ATTR(EGL_MAX_PBUFFER_WIDTH);
+        PRINT_ATTR(EGL_MAX_PBUFFER_HEIGHT);
+        PRINT_ATTR(EGL_MAX_PBUFFER_PIXELS);
+        PRINT_ATTR(EGL_MAX_SWAP_INTERVAL);
+        PRINT_ATTR(EGL_NATIVE_RENDERABLE);
+        PRINT_ATTR(EGL_NATIVE_VISUAL_ID);
+        PRINT_ATTR(EGL_NATIVE_VISUAL_TYPE);
+        PRINT_ATTR(EGL_RED_SIZE);
+        PRINT_ATTR(EGL_RENDERABLE_TYPE);
+        PRINT_ATTR(EGL_SAMPLE_BUFFERS);
+        PRINT_ATTR(EGL_SAMPLES);
+        PRINT_ATTR(EGL_STENCIL_SIZE);
+        PRINT_ATTR(EGL_SURFACE_TYPE);
+        PRINT_ATTR(EGL_TRANSPARENT_TYPE);
+        PRINT_ATTR(EGL_TRANSPARENT_RED_VALUE);
+        PRINT_ATTR(EGL_TRANSPARENT_GREEN_VALUE);
+        PRINT_ATTR(EGL_TRANSPARENT_BLUE_VALUE);
+
+        // Try to at least choose an RGBA 32bit config
+        if (attr_EGL_ALPHA_SIZE        == 8 &&
+            attr_EGL_BLUE_SIZE         == 8 &&
+            attr_EGL_RED_SIZE          == 8 &&
+            attr_EGL_GREEN_SIZE        == 8 &&
+            attr_EGL_BUFFER_SIZE       == 32 &&
+            attr_EGL_COLOR_BUFFER_TYPE == EGL_RGB_BUFFER &&
+            attr_EGL_SAMPLE_BUFFERS    == 0) // with no multisampling
+        {
+            chosen_config_id = i;
+        }
+    }
+#undef PRINT_ATTR
+
+    chosen_config = configs[chosen_config_id];
+    fprintf(stdout, "Chosen config #%d\n", chosen_config_id);
+    EGLSurface egl_surface = eglCreateWindowSurface(egl_display, chosen_config, (EGLNativeWindowType)window, NULL);
 
     switch ((intptr_t)egl_surface)
     {
@@ -155,7 +213,9 @@ int main()
     static const EGLint context_attribs[] = {
       EGL_CONTEXT_MAJOR_VERSION, 3,
       EGL_CONTEXT_MINOR_VERSION, 2,
+#ifdef DEBUG
       EGL_CONTEXT_OPENGL_DEBUG, EGL_TRUE,
+#endif
       EGL_NONE
     };
 
@@ -169,7 +229,7 @@ int main()
       break;
     }
 
-    EGLContext egl_context = eglCreateContext(egl_display, configs[0], EGL_NO_CONTEXT, context_attribs);
+    EGLContext egl_context = eglCreateContext(egl_display, chosen_config, EGL_NO_CONTEXT, context_attribs);
 
     errcode = eglMakeCurrent(egl_display, egl_surface, egl_surface, egl_context);
     switch (errcode)
@@ -186,7 +246,7 @@ int main()
       fprintf(stderr, "Could not make EGL context current\n");
       break;
     }
-    
+
     struct wl_region *region = wl_compositor_create_region(compositor);
     wl_region_add(region, 0, 0, 480, 360);
     wl_surface_set_opaque_region(surface, region);
@@ -194,7 +254,7 @@ int main()
     // Main event loop
     while (1)
     {
-        //wl_display_dispatch_pending(display);
+        wl_display_dispatch_pending(display);
         fprintf(stdout, "Dispatching event...\n");
         glClearColor(0.5, 0.3, 0.0, 1.0);
         glClear(GL_COLOR_BUFFER_BIT);