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++ // Copyright (C) 2023 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
++
++ void MAIN()
++ {
++ float u = UV1.x * 2.0 - 1.0;
++ float v = UV1.y * 2.0 - 1.0;
++
++ // For D3D, GL, Metal. Not for Vulkan.
++ if (FRAMEBUFFER_Y_UP != NDC_Y_UP)
++ v *= -1.0;
++
++ POSITION = vec4(u, v, 0.0, 1.0);
++ }