Route RTT utility clears through GL backend

src/renderer_gl/opengl_capabilities.cpp

@@ -464,6 +464,45 @@ pp::foundation::Status clear_panopainter_default_target(OpenGlClearDispatch disp
     return pp::foundation::Status::success();
 }
 
+pp::foundation::Status clear_opengl_render_target(
+    OpenGlDefaultClear clear,
+    OpenGlClearDispatch dispatch) noexcept
+{
+    if (dispatch.clear_color == nullptr || dispatch.clear == nullptr) {
+        return pp::foundation::Status::invalid_argument("OpenGL render-target clear dispatch callbacks must not be null");
+    }
+
+    if (clear.mask == 0U) {
+        return pp::foundation::Status::invalid_argument("OpenGL render-target clear mask is invalid");
+    }
+
+    dispatch.clear_color(clear.color[0], clear.color[1], clear.color[2], clear.color[3]);
+    dispatch.clear(clear.mask);
+    return pp::foundation::Status::success();
+}
+
+pp::foundation::Status clear_opengl_color_buffer_with_write_mask(
+    OpenGlColorMaskedClear clear,
+    OpenGlColorMaskedClearDispatch dispatch) noexcept
+{
+    if (dispatch.get_boolean == nullptr
+        || dispatch.color_mask == nullptr
+        || dispatch.clear_color == nullptr
+        || dispatch.clear == nullptr) {
+        return pp::foundation::Status::invalid_argument(
+            "OpenGL color-masked clear dispatch callbacks must not be null");
+    }
+
+    std::array<std::uint8_t, 4> old_mask {};
+    dispatch.get_boolean(color_write_mask_query(), old_mask.data());
+
+    dispatch.color_mask(clear.mask.r, clear.mask.g, clear.mask.b, clear.mask.a);
+    dispatch.clear_color(clear.color[0], clear.color[1], clear.color[2], clear.color[3]);
+    dispatch.clear(framebuffer_color_buffer_mask());
+    dispatch.color_mask(old_mask[0], old_mask[1], old_mask[2], old_mask[3]);
+    return pp::foundation::Status::success();
+}
+
 pp::foundation::Status apply_opengl_viewport(
     OpenGlViewportRect viewport,
     OpenGlViewportDispatch dispatch) noexcept