fix(capture): replay the projection used by world geometry

apps/fparkan-game/src/camera_capture.rs

@@ -0,0 +1,251 @@
+use super::{CapturedViewport, PreviewCameraFrame};
+use fparkan_render::{LegacyD3d7Projection, RawCameraTransform};
+use serde::Deserialize;
+
+#[derive(Clone, Debug, Deserialize, PartialEq)]
+pub(super) struct LegacyCameraCapture {
+    pub(super) schema: String,
+    pub(super) render_input_usable: Option<bool>,
+    pub(super) selector0_words: [u32; 16],
+    pub(super) parented_camera: Option<bool>,
+    pub(super) effective_world_matrix_space: Option<String>,
+    pub(super) effective_world_matrix_words: Option<[u32; 16]>,
+    pub(super) viewport: [i32; 4],
+    pub(super) near_plane: f32,
+    pub(super) far_plane: f32,
+    pub(super) field_of_view_radians: f32,
+    pub(super) atmosphere_seconds: Option<f32>,
+    pub(super) geometry_projection: Option<GeometryProjection>,
+}
+
+#[derive(Clone, Debug, Deserialize, PartialEq)]
+pub(super) struct GeometryProjection {
+    verified: bool,
+    viewport: [i32; 4],
+    near_plane: f32,
+    far_plane: f32,
+    field_of_view_radians: f32,
+}
+
+pub(super) fn selected_atmosphere_seconds(
+    command_line: Option<f32>,
+    capture: Option<&LegacyCameraCapture>,
+) -> Option<f32> {
+    command_line.or_else(|| capture.and_then(|capture| capture.atmosphere_seconds))
+}
+
+impl LegacyCameraCapture {
+    pub(super) fn preview_matrix_words(&self) -> Result<[u32; 16], String> {
+        match (
+            self.effective_world_matrix_space.as_deref(),
+            self.effective_world_matrix_words,
+        ) {
+            (Some("world"), Some(words)) => Ok(words),
+            (Some(_), _) => Err(
+                "legacy camera effective_world_matrix_space must be 'world'".to_string(),
+            ),
+            (None, Some(_)) => Err(
+                "legacy camera effective_world_matrix_words requires an explicit world-space marker"
+                    .to_string(),
+            ),
+            (None, None) if self.parented_camera == Some(true) => Err(
+                "parented legacy camera requires an effective world-space matrix".to_string(),
+            ),
+            (None, None) => Ok(self.selector0_words),
+        }
+    }
+
+    pub(super) fn captured_viewport(&self) -> Result<CapturedViewport, String> {
+        let width = self.viewport[2]
+            .checked_sub(self.viewport[0])
+            .filter(|width| *width > 0)
+            .ok_or_else(|| "legacy camera capture has an invalid viewport width".to_string())?;
+        let height = self.viewport[3]
+            .checked_sub(self.viewport[1])
+            .filter(|height| *height > 0)
+            .ok_or_else(|| "legacy camera capture has an invalid viewport height".to_string())?;
+        Ok(CapturedViewport {
+            rect: self.viewport,
+            extent: [
+                u32::try_from(width)
+                    .map_err(|_| "legacy camera viewport width exceeds u32".to_string())?,
+                u32::try_from(height)
+                    .map_err(|_| "legacy camera viewport height exceeds u32".to_string())?,
+            ],
+        })
+    }
+
+    pub(super) fn preview_camera_frame(&self) -> Result<PreviewCameraFrame, String> {
+        let projection = if let Some(geometry) = &self.geometry_projection {
+            if !geometry.verified || geometry.viewport != self.viewport {
+                return Err(
+                    "legacy camera geometry projection is unverified or has a different viewport"
+                        .to_string(),
+                );
+            }
+            LegacyD3d7Projection {
+                viewport: geometry.viewport,
+                near_plane: geometry.near_plane,
+                far_plane: geometry.far_plane,
+                field_of_view_radians: geometry.field_of_view_radians,
+            }
+        } else {
+            LegacyD3d7Projection {
+                viewport: self.viewport,
+                near_plane: self.near_plane,
+                far_plane: self.far_plane,
+                field_of_view_radians: self.field_of_view_radians,
+            }
+        };
+        let frame = PreviewCameraFrame::from_legacy_d3d7(
+            RawCameraTransform {
+                words: self.preview_matrix_words()?,
+            },
+            projection,
+        )
+        .ok_or_else(|| "legacy camera capture contains an invalid D3D7 camera".to_string())?;
+        self.captured_viewport()?;
+        Ok(frame)
+    }
+}
+
+pub(super) fn load_legacy_camera_capture(
+    path: &std::path::Path,
+) -> Result<LegacyCameraCapture, String> {
+    let bytes = std::fs::read(path).map_err(|err| format!("{}: {err}", path.display()))?;
+    let capture =
+        parse_legacy_camera_capture(&bytes).map_err(|err| format!("{}: {err}", path.display()))?;
+    if capture.geometry_projection.is_none() {
+        eprintln!("render_coverage captured_projection_unverified=1 (capture has no geometry_projection; using the recorded camera boundary, which can clip nearby surfaces)");
+    }
+    Ok(capture)
+}
+
+pub(super) fn parse_legacy_camera_capture(bytes: &[u8]) -> Result<LegacyCameraCapture, String> {
+    // Windows PowerShell 5.1 writes redirected text as UTF-16LE with a BOM.
+    // `capture-original-camera.ps1` intentionally emits plain JSON, so accept
+    // that normal hand-off format as well as UTF-8 without making the caller
+    // re-encode a read-only capture file.
+    let json = decode_legacy_camera_capture_json(bytes)?;
+    let capture: LegacyCameraCapture =
+        serde_json::from_str(&json).map_err(|err| format!("invalid legacy camera JSON: {err}"))?;
+    if capture.schema != "fparkan-legacy-camera-v1" {
+        return Err("unsupported legacy camera capture schema".to_string());
+    }
+    if capture.effective_world_matrix_space.is_some()
+        != capture.effective_world_matrix_words.is_some()
+    {
+        return Err(
+            "effective_world_matrix_space and effective_world_matrix_words must be supplied together"
+                .to_string(),
+        );
+    }
+    if capture.render_input_usable == Some(false) {
+        return Err("legacy camera capture is marked render_input_usable=false".to_string());
+    }
+    if capture
+        .atmosphere_seconds
+        .is_some_and(|seconds| !seconds.is_finite() || seconds < 0.0)
+    {
+        return Err(
+            "legacy camera capture atmosphere_seconds must be finite and non-negative".to_string(),
+        );
+    }
+    capture.preview_camera_frame()?;
+    Ok(capture)
+}
+
+fn decode_legacy_camera_capture_json(bytes: &[u8]) -> Result<String, String> {
+    let decode_utf16 = |words: Vec<u16>| {
+        String::from_utf16(&words)
+            .map_err(|err| format!("invalid UTF-16 legacy camera JSON: {err}"))
+    };
+    match bytes {
+        [0xff, 0xfe, rest @ ..] => {
+            let chunks = rest.chunks_exact(2);
+            if !chunks.remainder().is_empty() {
+                return Err("invalid UTF-16LE legacy camera JSON length".to_string());
+            }
+            decode_utf16(
+                chunks
+                    .map(|chunk| u16::from_le_bytes([chunk[0], chunk[1]]))
+                    .collect(),
+            )
+        }
+        [0xfe, 0xff, rest @ ..] => {
+            let chunks = rest.chunks_exact(2);
+            if !chunks.remainder().is_empty() {
+                return Err("invalid UTF-16BE legacy camera JSON length".to_string());
+            }
+            decode_utf16(
+                chunks
+                    .map(|chunk| u16::from_be_bytes([chunk[0], chunk[1]]))
+                    .collect(),
+            )
+        }
+        [0xef, 0xbb, 0xbf, rest @ ..] => std::str::from_utf8(rest)
+            .map(str::to_owned)
+            .map_err(|err| format!("invalid UTF-8 legacy camera JSON: {err}")),
+        _ => std::str::from_utf8(bytes)
+            .map(str::to_owned)
+            .map_err(|err| format!("invalid UTF-8 legacy camera JSON: {err}")),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn json() -> serde_json::Value {
+        let words = [
+            1.0_f32, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0,
+        ]
+        .map(f32::to_bits);
+        serde_json::json!({
+            "schema": "fparkan-legacy-camera-v1", "selector0_words": words,
+            "viewport": [0, 0, 1280, 1024], "near_plane": 5.0, "far_plane": 700.0,
+            "field_of_view_radians": 1.3,
+            "geometry_projection": {
+                "verified": true, "viewport": [0, 0, 1280, 1024],
+                "near_plane": 0.5, "far_plane": 700.0, "field_of_view_radians": 1.3,
+            }
+        })
+    }
+
+    #[test]
+    fn geometry_projection_preserves_surfaces_closer_than_restored_camera_near() {
+        let mut json = json();
+        let captured = parse_legacy_camera_capture(&serde_json::to_vec(&json).unwrap()).unwrap();
+        let camera = captured.preview_camera_frame().unwrap();
+        let point = [1.0, 0.0, 0.0, 1.0];
+        let depth = |matrix: [f32; 16]| {
+            (0..4)
+                .map(|row| point[row] * matrix[row * 4 + 2])
+                .sum::<f32>()
+        };
+        assert_eq!(camera.near_plane, 0.5);
+        assert!(depth(camera.clip_from_world) > 0.0);
+        json.as_object_mut().unwrap().remove("geometry_projection");
+        let old = parse_legacy_camera_capture(&serde_json::to_vec(&json).unwrap()).unwrap();
+        let old_camera = old.preview_camera_frame().unwrap();
+        assert_eq!(old_camera.near_plane, 5.0);
+        assert!(depth(old_camera.clip_from_world) < 0.0);
+    }
+
+    #[test]
+    fn geometry_projection_rejects_unverified_mismatched_or_invalid_input() {
+        for (field, value) in [
+            ("verified", serde_json::json!(false)),
+            ("viewport", serde_json::json!([0, 0, 640, 480])),
+            ("near_plane", serde_json::json!(0.0)),
+            ("far_plane", serde_json::json!(0.25)),
+        ] {
+            let mut json = json();
+            json["geometry_projection"][field] = value;
+            assert!(
+                parse_legacy_camera_capture(&serde_json::to_vec(&json).unwrap()).is_err(),
+                "{field}"
+            );
+        }
+    }
+}