Route RTT framebuffer binding through renderer GL

src/renderer_gl/opengl_capabilities.cpp

@@ -684,6 +684,36 @@ pp::foundation::Status readback_opengl_framebuffer(
     return pp::foundation::Status::success();
 }
 
+pp::foundation::Result<OpenGlFramebufferBindingState> bind_opengl_framebuffer_for_draw_read(
+    std::uint32_t framebuffer,
+    OpenGlFramebufferBindDispatch dispatch) noexcept
+{
+    if (dispatch.get_integer == nullptr || dispatch.bind_framebuffer == nullptr) {
+        return pp::foundation::Result<OpenGlFramebufferBindingState>::failure(
+            pp::foundation::Status::invalid_argument("OpenGL framebuffer bind dispatch callbacks must not be null"));
+    }
+
+    OpenGlFramebufferBindingState binding {};
+    dispatch.get_integer(draw_framebuffer_binding_query(), &binding.draw_framebuffer);
+    dispatch.get_integer(read_framebuffer_binding_query(), &binding.read_framebuffer);
+    dispatch.bind_framebuffer(draw_framebuffer_target(), framebuffer);
+    dispatch.bind_framebuffer(read_framebuffer_target(), framebuffer);
+    return pp::foundation::Result<OpenGlFramebufferBindingState>::success(binding);
+}
+
+pp::foundation::Status restore_opengl_framebuffer_binding(
+    OpenGlFramebufferBindingState binding,
+    OpenGlFramebufferRestoreDispatch dispatch) noexcept
+{
+    if (dispatch.bind_framebuffer == nullptr) {
+        return pp::foundation::Status::invalid_argument("OpenGL framebuffer restore dispatch callback must not be null");
+    }
+
+    dispatch.bind_framebuffer(draw_framebuffer_target(), static_cast<std::uint32_t>(binding.draw_framebuffer));
+    dispatch.bind_framebuffer(read_framebuffer_target(), static_cast<std::uint32_t>(binding.read_framebuffer));
+    return pp::foundation::Status::success();
+}
+
 std::uint32_t extension_count_query() noexcept
 {
     return gl_num_extensions;

src/renderer_gl/opengl_capabilities.h

@@ -167,6 +167,11 @@ struct OpenGlFramebufferReadback {
     void* pixels = nullptr;
 };
 
+struct OpenGlFramebufferBindingState {
+    std::int32_t draw_framebuffer = 0;
+    std::int32_t read_framebuffer = 0;
+};
+
 struct OpenGlWindowsWglContextConfig {
     std::array<std::int32_t, 9> context_attributes {};
     std::array<std::int32_t, 15> pixel_format_attributes {};
@@ -381,6 +386,15 @@ struct OpenGlFramebufferReadbackDispatch {
     OpenGlReadPixelsFn read_pixels = nullptr;
 };
 
+struct OpenGlFramebufferBindDispatch {
+    OpenGlGetIntegerFn get_integer = nullptr;
+    OpenGlBindFramebufferFn bind_framebuffer = nullptr;
+};
+
+struct OpenGlFramebufferRestoreDispatch {
+    OpenGlBindFramebufferFn bind_framebuffer = nullptr;
+};
+
 [[nodiscard]] OpenGlCapabilities detect_opengl_capabilities(
     std::span<const std::string_view> extensions,
     OpenGlRuntime runtime) noexcept;
@@ -437,6 +451,12 @@ struct OpenGlFramebufferReadbackDispatch {
 [[nodiscard]] pp::foundation::Status readback_opengl_framebuffer(
     OpenGlFramebufferReadback readback,
     OpenGlFramebufferReadbackDispatch dispatch) noexcept;
+[[nodiscard]] pp::foundation::Result<OpenGlFramebufferBindingState> bind_opengl_framebuffer_for_draw_read(
+    std::uint32_t framebuffer,
+    OpenGlFramebufferBindDispatch dispatch) noexcept;
+[[nodiscard]] pp::foundation::Status restore_opengl_framebuffer_binding(
+    OpenGlFramebufferBindingState binding,
+    OpenGlFramebufferRestoreDispatch dispatch) noexcept;
 
 [[nodiscard]] std::uint32_t extension_count_query() noexcept;
 [[nodiscard]] std::uint32_t extension_string_name() noexcept;

src/rtt.cpp

@@ -24,26 +24,6 @@ namespace {
     return static_cast<GLenum>(pp::renderer::gl::framebuffer_target());
 }
 
-[[nodiscard]] GLenum draw_framebuffer_target() noexcept
-{
-    return static_cast<GLenum>(pp::renderer::gl::draw_framebuffer_target());
-}
-
-[[nodiscard]] GLenum read_framebuffer_target() noexcept
-{
-    return static_cast<GLenum>(pp::renderer::gl::read_framebuffer_target());
-}
-
-[[nodiscard]] GLenum draw_framebuffer_binding_query() noexcept
-{
-    return static_cast<GLenum>(pp::renderer::gl::draw_framebuffer_binding_query());
-}
-
-[[nodiscard]] GLenum read_framebuffer_binding_query() noexcept
-{
-    return static_cast<GLenum>(pp::renderer::gl::read_framebuffer_binding_query());
-}
-
 void query_opengl_integer(std::uint32_t name, std::int32_t* value) noexcept
 {
     glGetIntegerv(static_cast<GLenum>(name), reinterpret_cast<GLint*>(value));
@@ -437,10 +417,19 @@ void RTT::bindFramebuffer()
 #endif
     }
 #endif // _DEBUG
-    glGetIntegerv(draw_framebuffer_binding_query(), &oldDFboID);
-    glGetIntegerv(read_framebuffer_binding_query(), &oldRFboID);
-    glBindFramebuffer(draw_framebuffer_target(), fboID);
-    glBindFramebuffer(read_framebuffer_target(), fboID);
+    const auto binding = pp::renderer::gl::bind_opengl_framebuffer_for_draw_read(
+        static_cast<std::uint32_t>(fboID),
+        pp::renderer::gl::OpenGlFramebufferBindDispatch {
+            .get_integer = query_opengl_integer,
+            .bind_framebuffer = bind_opengl_framebuffer,
+        });
+    if (!binding.ok()) {
+        LOG("RTT::bindFramebuffer() failed because: %s", binding.status().message);
+        return;
+    }
+
+    oldDFboID = static_cast<GLint>(binding.value().draw_framebuffer);
+    oldRFboID = static_cast<GLint>(binding.value().read_framebuffer);
     bound = true;
 }
 
@@ -449,8 +438,19 @@ void RTT::unbindFramebuffer()
     assert(App::I->is_render_thread());
     if (!bound)
         return;
-    glBindFramebuffer(draw_framebuffer_target(), oldDFboID);
-    glBindFramebuffer(read_framebuffer_target(), oldRFboID);
+    const auto status = pp::renderer::gl::restore_opengl_framebuffer_binding(
+        pp::renderer::gl::OpenGlFramebufferBindingState {
+            .draw_framebuffer = oldDFboID,
+            .read_framebuffer = oldRFboID,
+        },
+        pp::renderer::gl::OpenGlFramebufferRestoreDispatch {
+            .bind_framebuffer = bind_opengl_framebuffer,
+        });
+    if (!status.ok()) {
+        LOG("RTT::unbindFramebuffer() failed because: %s", status.message);
+        return;
+    }
+
     oldRFboID = 0;
     oldDFboID = 0;
     bound = false;