Fix[gl_bridge]: provide implementation for gl4es_getMainFBSize (#6284)

- Fixes broken main framebuffer blits in gl4es, thus fixing 1.21.2+

app_pojavlauncher/src/main/jni/ctxbridges/egl_loader.c

@@ -25,6 +25,10 @@ EGLint (*eglGetError_p) (void);
 EGLContext (*eglCreateContext_p) (EGLDisplay dpy, EGLConfig config, EGLContext share_list, const EGLint *attrib_list);
 EGLBoolean (*eglSwapInterval_p) (EGLDisplay dpy, EGLint interval);
 EGLSurface (*eglGetCurrentSurface_p) (EGLint readdraw);
+EGLBoolean (*eglQuerySurface_p)( 	EGLDisplay display,
+                                           EGLSurface surface,
+                                           EGLint attribute,
+                                           EGLint * value);
 __eglMustCastToProperFunctionPointerType (*eglGetProcAddress_p) (const char *procname);
 
 bool dlsym_EGL() {
@@ -53,5 +57,6 @@ bool dlsym_EGL() {
     eglSwapInterval_p = (void*) eglGetProcAddress_p("eglSwapInterval");
     eglTerminate_p = (void*) eglGetProcAddress_p("eglTerminate");
     eglGetCurrentSurface_p = (void*) eglGetProcAddress_p("eglGetCurrentSurface");
+    eglQuerySurface_p = (void*) eglGetProcAddress_p("eglQuerySurface");
     return true;
 }

app_pojavlauncher/src/main/jni/ctxbridges/egl_loader.h

@@ -24,6 +24,10 @@ extern EGLint (*eglGetError_p) (void);
 extern EGLContext (*eglCreateContext_p) (EGLDisplay dpy, EGLConfig config, EGLContext share_list, const EGLint *attrib_list);
 extern EGLBoolean (*eglSwapInterval_p) (EGLDisplay dpy, EGLint interval);
 extern EGLSurface (*eglGetCurrentSurface_p) (EGLint readdraw);
+extern EGLBoolean (*eglQuerySurface_p)( 	EGLDisplay display,
+                                      EGLSurface surface,
+                                      EGLint attribute,
+                                      EGLint * value);
 extern __eglMustCastToProperFunctionPointerType (*eglGetProcAddress_p) (const char *procname);
 
 bool dlsym_EGL();

app_pojavlauncher/src/main/jni/ctxbridges/gl_bridge.c

@@ -39,6 +39,41 @@ gl_render_window_t* gl_get_current() {
     return currentBundle;
 }
 
+static void gl4esi_get_display_dimensions(int* width, int* height) {
+    if(currentBundle == NULL) goto zero;
+    EGLSurface surface = currentBundle->surface;
+    // Fetch dimensions from the EGL surface - the most reliable way
+    EGLBoolean result_width = eglQuerySurface_p(g_EglDisplay, surface, EGL_WIDTH, width);
+    EGLBoolean result_height = eglQuerySurface_p(g_EglDisplay, surface, EGL_HEIGHT, height);
+    if(!result_width || !result_height) goto zero;
+    return;
+
+    zero:
+    // No idea what to do, but feeding gl4es incorrect or non-initialized dimensions may be
+    // a bad idea. Set to zero in case of errors.
+    *width = 0;
+    *height = 0;
+}
+
+static bool already_initialized = false;
+static void gl_init_gl4es_internals() {
+    if(already_initialized) return;
+    already_initialized = true;
+    void* gl4es = dlopen("libgl4es_114.so", RTLD_NOLOAD);
+    if(gl4es == NULL) return;
+    void (*set_getmainfbsize)(void (*new_getMainFBSize)(int* width, int* height));
+    set_getmainfbsize = dlsym(gl4es, "set_getmainfbsize");
+    if(set_getmainfbsize == NULL) goto warn;
+    set_getmainfbsize(gl4esi_get_display_dimensions);
+    goto cleanup;
+
+    warn:
+    printf("gl4esinternals warning: gl4es was found but internals not initialized. expect rendering issues.\n");
+    cleanup:
+    // dlclose just decreases a ref counter, so this is fine
+    dlclose(gl4es);
+}
+
 gl_render_window_t* gl_init_context(gl_render_window_t *share) {
     gl_render_window_t* bundle = malloc(sizeof(gl_render_window_t));
     memset(bundle, 0, sizeof(gl_render_window_t));
@@ -110,6 +145,11 @@ void gl_swap_surface(gl_render_window_t* bundle) {
 }
 
 void gl_make_current(gl_render_window_t* bundle) {
+    // Perform initialization here as the renderer may not be loaded when gl_init or gl_init_context is called.
+    // Yes, even though it is dlopened on MC startup by Pojav, due to linker namespacing weirdness
+    // on API 29/MIUI it may not be loaded at the point of the gl_init call in the current namespace.
+    gl_init_gl4es_internals();
+
     if(bundle == NULL) {
         if(eglMakeCurrent_p(g_EglDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT)) {
             currentBundle = NULL;