Function test_batch

perro_source/render_stack/perro_graphics/src/three_d/gpu.rs:1793–1851

(
        order_index: u32,
        draw_on_top: bool,
        alpha_mode: u8,
        mesh_blend: bool,
        texture_slot: u32,
        mesh_index_start: u32,
    )

}

#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
enum RenderBatchKind {
    Opaque,
    Alpha,
    MeshBlend,
    Overlay,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
struct RenderStateKey {
    pipeline_key: u64,
    texture_slot: u64,
    mesh_index_start: u32,
    mesh_base_vertex: i32,
    batch_kind: RenderBatchKind,
}

#[derive(Clone, Copy, Debug, Default)]
struct RenderPerfCounters {
    pipeline_switches: u32,
    texture_bind_group_switches: u32,
    camera_bind_group_switches: u32,
    draw_batches: u32,
    // Triangles the main mesh pass submits (index_count/3 x instance_count,
    // summed over every batch it walks). GPU-culled batches still count their
    // full instance range, so this is an upper bound, not a rasterized count.
    triangles: u64,
}

// Pass-structure counters. Written every frame by `render_pass` /
// `mesh_blend_screen_pass`, read by the render-pass structure tests and by
// `Gpu::render`, which folds them into `RenderGpuTiming` for the frame CSV.
// Main-view only: camera streams own separate `Gpu3D` instances with their own
// counters.
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
pub(crate) struct PassCounters {
    // Render passes `render_pass` encodes for this frame.
    pub(crate) render_passes: u32,
    // Sky fullscreen triangles drawn inside the mesh pass.
    pub(crate) sky_draws: u32,
    // Seam passes and scene-color copies `mesh_blend_screen_pass` encodes.
    pub(crate) mesh_blend_seam_passes: u32,
    pub(crate) mesh_blend_scene_copies: u32,
    // Pixels covered by the seam scene copy (0 when the copy is skipped).
    pub(crate) mesh_blend_copy_pixels: u32,
    // Per-source receiver depth passes the vertex mesh-blend loop encodes, and
    // the sources that reused depth already resident in the shared target
    // (an earlier source's pass, or the frame's global blend-depth pass).
    pub(crate) mesh_blend_source_depth_passes: u32,
    pub(crate) mesh_blend_source_depth_reuses: u32,
    // Full-res scene-depth copies encoded for the 3D water pass.
    pub(crate) water_depth_copies: u32,
    // Depth clears encoded for the 3D water pass's private depth target (the
    // copy's replacement at 1 sample).
    pub(crate) water_depth_clears: u32,
    // Shadow depth layers actually re-rendered this frame (cached-valid layers
    // are skipped and do not count).
    pub(crate) shadow_layer_renders: u32,