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The open source OpenXR runtime
c/render: Add timewarp to mesh shader
Currently disabled.
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src/xrt/compositor/render/render_interface.h
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src/xrt/compositor/render/render_interface.h
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struct render_gfx_mesh_ubo_data
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{
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struct xrt_matrix_2x2 vertex_rot;
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struct xrt_normalized_rect post_transform;
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struct xrt_normalized_rect post_transform;
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// Only used for timewarp.
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struct xrt_normalized_rect pre_transform;
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struct xrt_matrix_4x4 transform;
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};
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/*!
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src/xrt/compositor/shaders/mesh.vert
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src/xrt/compositor/shaders/mesh.vert
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// Copyright 2019-2021, Collabora, Ltd.
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// Copyright 2019-2023, Collabora, Ltd.
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// SPDX-License-Identifier: BSL-1.0
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// Author: Lubosz Sarnecki <lubosz.sarnecki@collabora.com>
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// Author: Pete Black <pete.black@collabora.com>
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#version 450
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// Should we do timewarp.
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layout(constant_id = 0) const bool do_timewarp = false;
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layout (binding = 1, std140) uniform Config
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{
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vec4 vertex_rot;
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vec4 post_transform;
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// Only used for timewarp.
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vec4 pre_transform;
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mat4 transform;
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} ubo;
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layout (location = 0) in vec4 in_pos_ruv;
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};
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vec2 transform_uv(vec2 uv)
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vec2 transform_uv_subimage(vec2 uv)
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{
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vec2 values = uv;
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···
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// Ready to be used.
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return values.xy;
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}
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vec2 transform_uv_timewarp(vec2 uv)
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{
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vec4 values = vec4(uv, -1, 1);
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// From uv to tan angle (tangent space).
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values.xy = fma(values.xy, ubo.pre_transform.zw, ubo.pre_transform.xy);
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values.y = -values.y; // Flip to OpenXR coordinate system.
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// Timewarp.
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values = ubo.transform * values;
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values.xy = values.xy * (1.0 / max(values.w, 0.00001));
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// From [-1, 1] to [0, 1]
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values.xy = values.xy * 0.5 + 0.5;
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// To deal with OpenGL flip and sub image view.
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values.xy = fma(values.xy, ubo.post_transform.zw, ubo.post_transform.xy);
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// Done.
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return values.xy;
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}
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vec2 transform_uv(vec2 uv)
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{
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if (do_timewarp) {
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return transform_uv_timewarp(uv);
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} else {
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return transform_uv_subimage(uv);
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}
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}
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void main()