1use anyhow::Context as _;
 2use blade_graphics as gpu;
 3use std::sync::Arc;
 4use util::ResultExt;
 5
 6#[cfg_attr(target_os = "macos", derive(Clone))]
 7pub struct BladeContext {
 8    pub(super) gpu: Arc<gpu::Context>,
 9}
10
11impl BladeContext {
12    pub fn new() -> anyhow::Result<Self> {
13        let device_id_forced = match std::env::var("ZED_DEVICE_ID") {
14            Ok(val) => parse_pci_id(&val)
15                .context("Failed to parse device ID from `ZED_DEVICE_ID` environment variable")
16                .log_err(),
17            Err(std::env::VarError::NotPresent) => None,
18            err => {
19                err.context("Failed to read value of `ZED_DEVICE_ID` environment variable")
20                    .log_err();
21                None
22            }
23        };
24        let gpu = Arc::new(
25            unsafe {
26                gpu::Context::init(gpu::ContextDesc {
27                    presentation: true,
28                    validation: false,
29                    device_id: device_id_forced.unwrap_or(0),
30                    ..Default::default()
31                })
32            }
33            .map_err(|e| anyhow::anyhow!("{e:?}"))?,
34        );
35        Ok(Self { gpu })
36    }
37
38    #[allow(dead_code)]
39    pub fn supports_dual_source_blending(&self) -> bool {
40        self.gpu.capabilities().dual_source_blending
41    }
42}
43
44fn parse_pci_id(id: &str) -> anyhow::Result<u32> {
45    let mut id = id.trim();
46
47    if id.starts_with("0x") || id.starts_with("0X") {
48        id = &id[2..];
49    }
50    let is_hex_string = id.chars().all(|c| c.is_ascii_hexdigit());
51    let is_4_chars = id.len() == 4;
52    anyhow::ensure!(
53        is_4_chars && is_hex_string,
54        "Expected a 4 digit PCI ID in hexadecimal format"
55    );
56
57    u32::from_str_radix(id, 16).context("parsing PCI ID as hex")
58}
59
60#[cfg(test)]
61mod tests {
62    use super::parse_pci_id;
63
64    #[test]
65    fn test_parse_device_id() {
66        assert!(parse_pci_id("0xABCD").is_ok());
67        assert!(parse_pci_id("ABCD").is_ok());
68        assert!(parse_pci_id("abcd").is_ok());
69        assert!(parse_pci_id("1234").is_ok());
70        assert!(parse_pci_id("123").is_err());
71        assert_eq!(
72            parse_pci_id(&format!("{:x}", 0x1234)).unwrap(),
73            parse_pci_id(&format!("{:X}", 0x1234)).unwrap(),
74        );
75
76        assert_eq!(
77            parse_pci_id(&format!("{:#x}", 0x1234)).unwrap(),
78            parse_pci_id(&format!("{:#X}", 0x1234)).unwrap(),
79        );
80        assert_eq!(
81            parse_pci_id(&format!("{:#x}", 0x1234)).unwrap(),
82            parse_pci_id(&format!("{:#X}", 0x1234)).unwrap(),
83        );
84    }
85}