XR_ANDROID_depth_texture OpenXR 扩展

typedef struct XrSystemDepthTrackingPropertiesANDROID {  XrStructureType type;  const void* next;  XrBool32 supportsDepthTracking; } XrSystemDepthTrackingPropertiesANDROID; 

XrResult xrEnumerateDepthResolutionsANDROID(  XrSession session,  uint32_t resolutionCapacityInput,  uint32_t* resolutionCountOutput,  XrDepthCameraResolutionANDROID* resolutions); 

typedef enum XrDepthCameraResolutionANDROID {  XR_DEPTH_CAMERA_RESOLUTION_80x80_ANDROID = 0,  XR_DEPTH_CAMERA_RESOLUTION_160x160_ANDROID = 1,  XR_DEPTH_CAMERA_RESOLUTION_320x320_ANDROID = 2  } XrDepthCameraResolutionANDROID; 

XR_DEFINE_HANDLE(XrDepthSwapchainANDROID) 

XrResult xrCreateDepthSwapchainANDROID(  XrSession session,  const XrDepthSwapchainCreateInfoANDROID* createInfo,  XrDepthSwapchainANDROID* swapchain); 

typedef struct XrDepthSwapchainCreateInfoANDROID {  XrStructureType type;  const void* next;  XrDepthCameraResolutionANDROID resolution;  XrDepthSwapchainCreateFlagsANDROID createFlags; } XrDepthSwapchainCreateInfoANDROID; 

typedef XrFlags64 XrDepthSwapchainCreateFlagsANDROID; 

// Flag bits for XrDepthSwapchainCreateFlagsANDROID static const XrDepthSwapchainCreateFlagsANDROID XR_DEPTH_SWAPCHAIN_CREATE_SMOOTH_DEPTH_IMAGE_BIT_ANDROID = 0x00000001; static const XrDepthSwapchainCreateFlagsANDROID XR_DEPTH_SWAPCHAIN_CREATE_SMOOTH_CONFIDENCE_IMAGE_BIT_ANDROID = 0x00000002; static const XrDepthSwapchainCreateFlagsANDROID XR_DEPTH_SWAPCHAIN_CREATE_RAW_DEPTH_IMAGE_BIT_ANDROID = 0x00000004; static const XrDepthSwapchainCreateFlagsANDROID XR_DEPTH_SWAPCHAIN_CREATE_RAW_CONFIDENCE_IMAGE_BIT_ANDROID = 0x00000008; 

XrResult xrDestroyDepthSwapchainANDROID(  XrDepthSwapchainANDROID swapchain); 

XrResult xrEnumerateDepthSwapchainImagesANDROID( XrDepthSwapchainANDROID depthSwapchain, uint32_t depthImageCapacityInput, uint32_t* depthImageCountOutput, XrDepthSwapchainImageANDROID* depthImages); 

typedef struct XrDepthSwapchainImageANDROID {  XrStructureType type;  void* next;  const float* rawDepthImage;  const uint8_t* rawDepthConfidenceImage;  const float* smoothDepthImage;  const uint8_t* smoothDepthConfidenceImage; } XrDepthSwapchainImageANDROID; 

XrResult xrAcquireDepthSwapchainImagesANDROID(  XrDepthSwapchainANDROID depthSwapchain,  const XrDepthAcquireInfoANDROID* acquireInfo,  XrDepthAcquireResultANDROID* acquireResult); 

typedef struct XrDepthAcquireInfoANDROID {  XrStructureType type;  const void* next;  XrSpace space;  XrTime displayTime; } XrDepthAcquireInfoANDROID; 

typedef struct XrDepthAcquireResultANDROID {  XrStructureType type;  const void* next;  uint32_t acquiredIndex;  XrTime exposureTimestamp;  XrDepthViewANDROID views[2]; } XrDepthAcquireResultANDROID; 

typedef struct XrDepthViewANDROID {  XrStructureType type;  const void* next;  XrFovf fov;  XrPosef pose; } XrDepthViewANDROID; 

XrInstance instance; // previously initialized XrSystemId systemId; // previously initialized XrSession session; // previously initialized XrSpace stageSpace; // space created for XR_REFERENCE_SPACE_TYPE_STAGE. // The function pointers are previously initialized using xrGetInstanceProcAddr. PFN_xrCreateDepthSwapchainANDROID xrCreateDepthSwapchainANDROID; // previously initialized PFN_xrDestroyDepthSwapchainANDROID xrDestroyDepthSwapchainANDROID; // previously initialized PFN_xrEnumerateDepthSwapchainImagesANDROID xrEnumerateDepthSwapchainImagesANDROID; // previously initialized PFN_xrEnumerateDepthResolutionsANDROID xrEnumerateDepthResolutionsANDROID; // previously initialized PFN_xrAcquireDepthSwapchainImagesANDROID xrAcquireDepthSwapchainImagesANDROID; // previously initialized // Inspect system capability XrSystemProperties properties{XR_TYPE_SYSTEM_PROPERTIES}; XrSystemDepthTrackingPropertiesANDROID depthTrackingProperties{XR_TYPE_SYSTEM_DEPTH_TRACKING_PROPERTIES_ANDROID}; properties.next = &depthTrackingProperties; CHK_XR(xrGetSystemProperties(instance, systemId, &properties)); if (!depthTrackingProperties.supportsDepthTracking) {  // depth tracking is not supported.  return; } // Query the supported depth resolution. XrDepthCameraResolutionANDROID supportedDepthResolution; uint32_t supportedResolutionCount = 0; CHK_XR(xrEnumerateDepthResolutionsANDROID(  session, 1, &supportedResolutionCount, &supportedDepthResolution)); // Define metadata to access the raw and smooth depth along with confidences. XrDepthSwapchainCreateInfoANDROID swapchainCreateInfo = {  .type = XR_TYPE_DEPTH_SWAPCHAIN_CREATE_INFO_ANDROID,  .next = nullptr,  .createFlags =  XR_DEPTH_SWAPCHAIN_CREATE_SMOOTH_DEPTH_IMAGE_BIT_ANDROID |  XR_DEPTH_SWAPCHAIN_CREATE_SMOOTH_CONFIDENCE_IMAGE_BIT_ANDROID |  XR_DEPTH_SWAPCHAIN_CREATE_RAW_DEPTH_IMAGE_BIT_ANDROID |  XR_DEPTH_SWAPCHAIN_CREATE_RAW_CONFIDENCE_IMAGE_BIT_ANDROID,  // Use the resolution supported by the runtime.  .resolution = supportedDepthResolution, }; XrDepthSwapchainANDROID depthSwapchain; CHK_XR(xrCreateDepthSwapchainANDROID(  session, &swapchainCreateInfo, &depthSwapchain)); // Enumerate depth images. uint32_t imageCountOutput = 0; CHK_XR(xrEnumerateDepthSwapchainImagesANDROID(  depthSwapchain, 0, &imageCountOutput, nullptr)); std::vector<XrDepthSwapchainImageANDROID> depthImages(imageCountOutput); for (int i = 0; i < imageCountOutput; i++) {  depthImages[i].type = XR_TYPE_DEPTH_SWAPCHAIN_IMAGE_ANDROID; } CHK_XR(xrEnumerateDepthSwapchainImagesANDROID(  depthSwapchain, imageCountOutput, &imageCountOutput, depthImages.data())); while (1) {  // ...  // For every frame in frame loop  // ...  XrFrameState frameState; // previously returned from xrWaitFrame  const XrTime time = frameState.predictedDisplayTime;  XrDepthAcquireInfoANDROID acquireInfo = {  .type = XR_TYPE_DEPTH_ACQUIRE_INFO_ANDROID,  .space = stageSpace,  .displayTime = time};  XrDepthAcquireResultANDROID acquireResult = {  .type = XR_TYPE_DEPTH_ACQUIRE_RESULT_ANDROID,  };  CHK_XR(xrAcquireDepthImagesANDROID(  depthSwapchain, &acquireInfo, &acquireResult));  // Each value in a depth image corresponds to a point in the real world.  // The sample code in this section shows how to find the stageSpace position  // of the point corresponding to a particular value in the depth image.  // For this sample code, assume we are using a right handed coordinate system  // with +X to the right, +Y up and -Z forward.  XrDepthSwapchainImageANDROID *image =  &depthImages[acquireResult.acquireIndex];  // Assume supported resolution is XR_DEPTH_CAMERA_RESOLUTION_160x160_ANDROID.  const int imageResolution = 160;  int imageY = // value in [0, imageResolution)  int imageX = // value in [0, imageResolution)  // Get depth value from left eye.  // A right depth value would be obtained with the following expression:  // depthR = image->rawDepthImage[imageResolution*imageResolution+i*imageResolution+j]  float depthL = image->rawDepthImage[imageY*imageResolution + imageX];  XrDepthViewANDROID viewL = acquireResult.views[0];  float tanL = tanf(viewL.fov.angleLeft);  float tanR = tanf(viewL.fov.angleRight);  float tanU = tanf(viewL.fov.angleUp);  float tanD = tanf(viewL.fov.angleDown);  float s = (imageX + 0.5f) / (float)imageResolution;  float t = (imageY + 0.5f) / (float)imageResolution;  // Calculate the depth camera space position of the point  // corresponding to this depth value.  XrVector3f posInCameraSpace;  posInCameraSpace.z = -depthL;  posInCameraSpace.x = (tanL + (tanR - tanL)*s)*depthL;  posInCameraSpace.y = (tanB + (tanU - tanB)*t)*depthL;  XrPosef depthCameraPoseL = viewL.pose;  // Transform posInCameraSpace by depthCameraPoseL  // ...  // Finish frame loop  // ... }