Codex

#include <EGL/egl.h>
#include <GLES2/gl2.h>
#include <android/log.h>
#include <dlfcn.h>
#include <atomic>

#define LOG_TAG "Qwanwin"
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO,  LOG_TAG, __VA_ARGS__)
#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)

static std::atomic<int> gW{0}, gH{0};

using PFN_eglSwapBuffers = EGLBoolean (*)(EGLDisplay, EGLSurface);

static PFN_eglSwapBuffers orig_eglSwapBuffers = nullptr;
static thread_local bool tls_in_hook = false;


extern "C" EGLBoolean _eglSwapBuffers(EGLDisplay dpy, EGLSurface surface) {
    if (tls_in_hook) {
        return orig_eglSwapBuffers ? orig_eglSwapBuffers(dpy, surface) : EGL_FALSE;
    }
    tls_in_hook = true;

    if (dpy != EGL_NO_DISPLAY && surface != EGL_NO_SURFACE) {
        EGLint w = 0, h = 0;
        if (eglQuerySurface(dpy, surface, EGL_WIDTH, &w) == EGL_TRUE &&
            eglQuerySurface(dpy, surface, EGL_HEIGHT, &h) == EGL_TRUE &&
            w > 0 && h > 0) {
            gW.store((int)w, std::memory_order_relaxed);
            gH.store((int)h, std::memory_order_relaxed);
        } else {
            // fallback
            GLint vp[4] = {0,0,0,0};
            glGetIntegerv(GL_VIEWPORT, vp); // [x,y,w,h]
            if (vp[2] > 0 && vp[3] > 0) {
                gW.store(vp[2], std::memory_order_relaxed);
                gH.store(vp[3], std::memory_order_relaxed);
            }
        }
    }

    EGLBoolean ret = orig_eglSwapBuffers ? orig_eglSwapBuffers(dpy, surface) : EGL_FALSE;
    tls_in_hook = false;
    return ret;
}

static void* Qwanwin_eglSwapBuffers() {
    
    void* sym = dlsym(RTLD_NEXT, "eglSwapBuffers");
    if (sym) return sym;
    
    void* h = dlopen("libEGL.so", RTLD_NOW);
    if (!h) return nullptr;
    sym = dlsym(h, "eglSwapBuffers");
    return sym;
}

extern "C" void QwanEglSwapHook_Easy() {
    if (orig_eglSwapBuffers) return; 
    void* target = Qwanwin_eglSwapBuffers();
    if (!target) {
        LOGE("Failed to eglSwapBuffers");
        return;
    }

    
    if (Tools::Hook((void*)target, (void*)_eglSwapBuffers, (void**)&orig_eglSwapBuffers)) {
        LOGI("Hooked eglSwapBuffers successfully");
    } else {
        LOGE("Hook failed");
    }
}

/*
extern "C" int eglhook_get_w() { return gW.load(std::memory_order_relaxed); }
extern "C" int eglhook_get_h() { return gH.load(std::memory_order_relaxed); }*/

__attribute__((constructor))
static void on_load() { QwanEglSwapHook_Easy(); }