[GPU/D3D12] Letterboxing cropping to action-safe area

src/xenia/gpu/draw_util.h

@@ -272,6 +272,14 @@ bool GetResolveInfo(const RegisterFile& regs, const Memory& memory,
                     TraceWriter& trace_writer, uint32_t resolution_scale,
                     bool edram_16_as_minus_1_to_1, ResolveInfo& info_out);
 
+// Taking user configuration - stretching or letterboxing, overscan region to
+// crop to fill while maintaining the aspect ratio - into account, returns the
+// area where the frame should be presented in the host window.
+void GetPresentArea(uint32_t source_width, uint32_t source_height,
+                    uint32_t window_width, uint32_t window_height,
+                    int32_t& target_x_out, int32_t& target_y_out,
+                    uint32_t& target_width_out, uint32_t& target_height_out);
+
 }  // namespace draw_util
 }  // namespace gpu
 }  // namespace xe