From d7dd2f7e3dc913f3eb14577539d9b4a797acff0b Mon Sep 17 00:00:00 2001
From: Jonathan Schwender <jonathan.schwender@huawei.com>
Date: Thu, 29 Aug 2024 13:07:32 +0800
Subject: [PATCH] ohos: dynamically link eglGetNativeClientBufferANDROID

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>
---
 src/platform/egl/ohos_ffi.rs             | 18 ++++++++++++++++++
 src/platform/egl/surface/ohos_surface.rs | 14 +++-----------
 2 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/src/platform/egl/ohos_ffi.rs b/src/platform/egl/ohos_ffi.rs
index 0d335709..88a17364 100644
--- a/src/platform/egl/ohos_ffi.rs
+++ b/src/platform/egl/ohos_ffi.rs
@@ -3,6 +3,13 @@
 #![allow(non_snake_case)]
 #![allow(unused)]
 
+use std::ffi::c_void;
+
+/// From `eglext.h` on OpenHarmony.
+pub(crate) const EGL_NATIVE_BUFFER_OHOS: u32 = 0x34E1;
+
+use crate::egl::types::EGLClientBuffer;
+
 #[repr(C)]
 pub struct NativeWindow {
     _unused: [u8; 0],
@@ -46,6 +53,17 @@ extern "C" {
     ) -> i32;
 }
 
+#[link(name = "EGL")]
+extern "C" {
+    /// Get the native Client buffer
+    ///
+    /// The extension function `eglGetNativeClientBufferANDROID` is available starting with OpenHarmony 5.0.
+    /// Its availability is documented here: https://docs.openharmony.cn/pages/v5.0/en/application-dev/reference/native-lib/egl-symbol.md
+    /// However it is not available in `EGL_EXTENSION_FUNCTIONS`, since `eglGetProcAddress()` does not find
+    /// the function and returns NULL.
+    pub(crate) fn eglGetNativeClientBufferANDROID(buffer: *const c_void) -> EGLClientBuffer;
+}
+
 // Bindings to `native_buffer` components we use. Official Documentation:
 // https://docs.openharmony.cn/pages/v5.0/en/application-dev/graphics/native-buffer-guidelines.md
 
diff --git a/src/platform/egl/surface/ohos_surface.rs b/src/platform/egl/surface/ohos_surface.rs
index f2d14d73..0c767d51 100644
--- a/src/platform/egl/surface/ohos_surface.rs
+++ b/src/platform/egl/surface/ohos_surface.rs
@@ -14,12 +14,12 @@ use crate::egl::types::{EGLSurface, EGLint};
 use crate::gl;
 use crate::gl::types::{GLenum, GLuint};
 use crate::gl_utils;
+use crate::platform::egl::ohos_ffi::{eglGetNativeClientBufferANDROID, EGL_NATIVE_BUFFER_OHOS};
 use crate::platform::generic;
 use crate::platform::generic::egl::device::EGL_FUNCTIONS;
 use crate::platform::generic::egl::ffi::EGLImageKHR;
 use crate::platform::generic::egl::ffi::EGL_EXTENSION_FUNCTIONS;
 use crate::platform::generic::egl::ffi::EGL_IMAGE_PRESERVED_KHR;
-use crate::platform::generic::egl::ffi::EGL_NATIVE_BUFFER_ANDROID;
 use crate::platform::generic::egl::ffi::EGL_NO_IMAGE_KHR;
 use crate::renderbuffers::Renderbuffers;
 use crate::{Error, SurfaceAccess, SurfaceID, SurfaceInfo, SurfaceType};
@@ -252,14 +252,6 @@ impl Device {
         _: &Context,
         hardware_buffer: *mut OH_NativeBuffer,
     ) -> EGLImageKHR {
-        // Get the native client buffer.
-        // Note: `eglGetNativeClientBufferANDROID` is available starting with OpenHarmony 5.0.
-        // Its availability is documented here: https://docs.openharmony.cn/pages/v5.0/en/application-dev/reference/native-lib/egl-symbol.md
-        let eglGetNativeClientBufferANDROID =
-            EGL_EXTENSION_FUNCTIONS.GetNativeClientBufferANDROID.expect(
-                "Where's the `EGL_ANDROID_get_native_client_buffer` \
-                                            extension?",
-            );
         let client_buffer = eglGetNativeClientBufferANDROID(hardware_buffer as *const _);
         assert!(!client_buffer.is_null());
 
@@ -273,8 +265,8 @@ impl Device {
         let egl_image = (EGL_EXTENSION_FUNCTIONS.CreateImageKHR)(
             self.egl_display,
             egl::NO_CONTEXT,
-            EGL_NATIVE_BUFFER_ANDROID,
-            client_buffer,
+            EGL_NATIVE_BUFFER_OHOS,
+            client_buffer.cast_mut().cast(),
             egl_image_attributes.as_ptr(),
         );
         assert_ne!(egl_image, EGL_NO_IMAGE_KHR);