Rust VR开发库openxr的使用：跨平台OpenXR标准实现与虚拟现实应用开发

基本示例

以下是使用openxr进行VR开发的基本示例：

use openxr as xr;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // 初始化OpenXR实例
    let entry = xr::Entry::linked()?;
    let extensions = xr::ExtensionSet::default();
    let instance = entry.create_instance(
        &xr::ApplicationInfo {
            application_name: "OpenXR Rust Demo",
            application_version: 1,
            engine_name: "No Engine",
            engine_version: 0,
        },
        &extensions,
        &[],
    )?;
    
    // 获取系统信息
    let system = instance.system(xr::FormFactor::HEAD_MOUNTED_DISPLAY)?;
    let system_properties = instance.system_properties(system)?;
    println!("System properties: {:?}", system_properties);
    
    // 创建会话
    let graphics_requirements = xr::VulkanRequirements::new();
    let session = unsafe {
        instance.create_session(
            system,
            &xr::VulkanGraphicsRequirements::new(),
            None,
        )
    }?;
    
    // 主循环
    loop {
        let event = instance.poll_event()?;
        match event {
            Some(xr::Event::SessionStateChanged(e)) => {
                println!("Session state changed to {:?}", e.state);
                if e.state == xr::SessionState::STOPPING {
                    break;
                }
            }
            None => break,
            _ => {}
        }
    }
    
    Ok(())
}

完整Vulkan渲染示例

use openxr as xr;
use ash::{vk, Entry as AshEntry, Instance as AshInstance};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // 1. 初始化OpenXR
    let xr_entry = xr::Entry::linked()?;
    let extensions = xr::ExtensionSet::default();
    let xr_instance = xr_entry.create_instance(
        &xr::ApplicationInfo {
            application_name: "Vulkan OpenXR Demo",
            application_version: 1,
            engine_name: "No Engine",
            engine_version: 0,
        },
        &extensions,
        &[],
    )?;
    
    // 2. 初始化Vulkan
    let ash_entry = AshEntry::linked()?;
    let ash_instance = unsafe {
        ash_entry.create_instance(
            &vk::InstanceCreateInfo::builder()
                .application_info(&vk::ApplicationInfo {
                    application_name: b"Vulkan OpenXR Demo\0".as_ptr() as *const i8,
                    application_version: 1,
                    engine_name: b"No Engine\0".as_ptr() as *const i8,
                    engine_version: 0,
                    api_version: vk::make_api_version(0, 1, 0, 0),
                }),
            None,
        )
    }?;
    
    // 3. 创建OpenXR系统
    let system = xr_instance.system(xr::FormFactor::HEAD_MOUNTED_DISPLAY)?;
    
    // 4. 创建OpenXR会话
    let session = unsafe {
        xr_instance.create_session(
            system,
            &xr::VulkanGraphicsRequirements::new(),
            Some(&vk::PhysicalDevice::default()),
        )
    }?;
    
    // 5. 创建交换链
    let swapchain = unsafe {
        session.create_swapchain(&xr::SwapchainCreateInfo {
            create_flags: xr::SwapchainCreateFlags::EMPTY,
            usage_flags: xr::SwapchainUsageFlags::COLOR_ATTACHMENT,
            format: vk::Format::R8G8B8A8_SRGB as i32,
            sample_count: 1,
            width: 1920,
            height: 1080,
            face_count: 1,
            array_size: 1,
            mip_count: 1,
        })
    }?;
    
    // 6. 渲染循环
    session.begin(xr::ViewConfigurationType::PRIMARY_STEREO)?;
    
    loop {
        let event = xr_instance.poll_event()?;
        match event {
            Some(xr::Event::SessionStateChanged(e)) => {
                if e.state == xr::SessionState::STOPPING {
                    break;
                }
            }
            None => break,
            _ => {}
        }
        
        // 渲染逻辑...
    }
    
    Ok(())
}