video_core/opengl: Add FSR upscaling filter to the OpenGL renderer

src/video_core/fsr.h

@@ -0,0 +1,19 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "common/bit_cast.h"
+#include "common/common_types.h"
+
+namespace FSR {
+// Reimplementations of the constant generating functions in ffx_fsr1.h
+// GCC generated a lot of warnings when using the official header.
+void FsrEasuConOffset(u32 con0[4], u32 con1[4], u32 con2[4], u32 con3[4],
+                      f32 inputViewportInPixelsX, f32 inputViewportInPixelsY,
+                      f32 inputSizeInPixelsX, f32 inputSizeInPixelsY, f32 outputSizeInPixelsX,
+                      f32 outputSizeInPixelsY, f32 inputOffsetInPixelsX, f32 inputOffsetInPixelsY);
+
+void FsrRcasCon(u32* con, f32 sharpness);
+
+} // namespace FSR