/**************************************************************************/ /* openxr_util.cpp */ /**************************************************************************/ /* This file is part of: */ /* GODOT ENGINE */ /* https://godotengine.org */ /**************************************************************************/ /* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */ /* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */ /* */ /* Permission is hereby granted, free of charge, to any person obtaining */ /* a copy of this software and associated documentation files (the */ /* "Software"), to deal in the Software without restriction, including */ /* without limitation the rights to use, copy, modify, merge, publish, */ /* distribute, sublicense, and/or sell copies of the Software, and to */ /* permit persons to whom the Software is furnished to do so, subject to */ /* the following conditions: */ /* */ /* The above copyright notice and this permission notice shall be */ /* included in all copies or substantial portions of the Software. */ /* */ /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */ /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */ /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */ /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */ /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */ /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */ /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /**************************************************************************/ #include "openxr_util.h" #include #include #define XR_ENUM_CASE_STR(name, val) \ case name: \ return #name; #define XR_ENUM_SWITCH(enumType, var) \ switch (var) { \ XR_LIST_ENUM_##enumType(XR_ENUM_CASE_STR) default : return "Unknown " #enumType ": " + String::num_int64(int64_t(var)); \ } String OpenXRUtil::get_view_configuration_name(XrViewConfigurationType p_view_configuration){ XR_ENUM_SWITCH(XrViewConfigurationType, p_view_configuration) } String OpenXRUtil::get_reference_space_name(XrReferenceSpaceType p_reference_space){ XR_ENUM_SWITCH(XrReferenceSpaceType, p_reference_space) } String OpenXRUtil::get_structure_type_name(XrStructureType p_structure_type){ XR_ENUM_SWITCH(XrStructureType, p_structure_type) } String OpenXRUtil::get_session_state_name(XrSessionState p_session_state){ XR_ENUM_SWITCH(XrSessionState, p_session_state) } String OpenXRUtil::get_action_type_name(XrActionType p_action_type){ XR_ENUM_SWITCH(XrActionType, p_action_type) } String OpenXRUtil::get_environment_blend_mode_name(XrEnvironmentBlendMode p_blend_mode) { XR_ENUM_SWITCH(XrEnvironmentBlendMode, p_blend_mode); } String OpenXRUtil::make_xr_version_string(XrVersion p_version) { String version; version += String::num_int64(XR_VERSION_MAJOR(p_version)); version += String("."); version += String::num_int64(XR_VERSION_MINOR(p_version)); version += String("."); version += String::num_int64(XR_VERSION_PATCH(p_version)); return version; } // Copied from OpenXR xr_linear.h private header, so we can still link against // system-provided packages without relying on our `thirdparty` code. // Copyright (c) 2017 The Khronos Group Inc. // Copyright (c) 2016 Oculus VR, LLC. // // SPDX-License-Identifier: Apache-2.0 // Creates a projection matrix based on the specified dimensions. // The projection matrix transforms -Z=forward, +Y=up, +X=right to the appropriate clip space for the graphics API. // The far plane is placed at infinity if farZ <= nearZ. // An infinite projection matrix is preferred for rasterization because, except for // things *right* up against the near plane, it always provides better precision: // "Tightening the Precision of Perspective Rendering" // Paul Upchurch, Mathieu Desbrun // Journal of Graphics Tools, Volume 16, Issue 1, 2012 void OpenXRUtil::XrMatrix4x4f_CreateProjection(XrMatrix4x4f *result, GraphicsAPI graphicsApi, const float tanAngleLeft, const float tanAngleRight, const float tanAngleUp, float const tanAngleDown, const float nearZ, const float farZ) { const float tanAngleWidth = tanAngleRight - tanAngleLeft; // Set to tanAngleDown - tanAngleUp for a clip space with positive Y down (Vulkan). // Set to tanAngleUp - tanAngleDown for a clip space with positive Y up (OpenGL / D3D / Metal). const float tanAngleHeight = graphicsApi == GRAPHICS_VULKAN ? (tanAngleDown - tanAngleUp) : (tanAngleUp - tanAngleDown); // Set to nearZ for a [-1,1] Z clip space (OpenGL / OpenGL ES). // Set to zero for a [0,1] Z clip space (Vulkan / D3D / Metal). const float offsetZ = (graphicsApi == GRAPHICS_OPENGL || graphicsApi == GRAPHICS_OPENGL_ES) ? nearZ : 0; if (farZ <= nearZ) { // place the far plane at infinity result->m[0] = 2.0f / tanAngleWidth; result->m[4] = 0.0f; result->m[8] = (tanAngleRight + tanAngleLeft) / tanAngleWidth; result->m[12] = 0.0f; result->m[1] = 0.0f; result->m[5] = 2.0f / tanAngleHeight; result->m[9] = (tanAngleUp + tanAngleDown) / tanAngleHeight; result->m[13] = 0.0f; result->m[2] = 0.0f; result->m[6] = 0.0f; result->m[10] = -1.0f; result->m[14] = -(nearZ + offsetZ); result->m[3] = 0.0f; result->m[7] = 0.0f; result->m[11] = -1.0f; result->m[15] = 0.0f; } else { // normal projection result->m[0] = 2.0f / tanAngleWidth; result->m[4] = 0.0f; result->m[8] = (tanAngleRight + tanAngleLeft) / tanAngleWidth; result->m[12] = 0.0f; result->m[1] = 0.0f; result->m[5] = 2.0f / tanAngleHeight; result->m[9] = (tanAngleUp + tanAngleDown) / tanAngleHeight; result->m[13] = 0.0f; result->m[2] = 0.0f; result->m[6] = 0.0f; result->m[10] = -(farZ + offsetZ) / (farZ - nearZ); result->m[14] = -(farZ * (nearZ + offsetZ)) / (farZ - nearZ); result->m[3] = 0.0f; result->m[7] = 0.0f; result->m[11] = -1.0f; result->m[15] = 0.0f; } } // Creates a projection matrix based on the specified FOV. void OpenXRUtil::XrMatrix4x4f_CreateProjectionFov(XrMatrix4x4f *result, GraphicsAPI graphicsApi, const XrFovf fov, const float nearZ, const float farZ) { const float tanLeft = tanf(fov.angleLeft); const float tanRight = tanf(fov.angleRight); const float tanDown = tanf(fov.angleDown); const float tanUp = tanf(fov.angleUp); XrMatrix4x4f_CreateProjection(result, graphicsApi, tanLeft, tanRight, tanUp, tanDown, nearZ, farZ); }