Merge pull request #47 from roteiro-gis/ian/pr3

Add Gaussian and rotated grids and GRIB2 product templates 4.2–4.15

Author: i-norden

CHANGELOG.md

@@ -20,6 +20,20 @@
   expand bitmap gaps a byte at a time
 - locate GRIB messages with substring search instead of testing every byte
   offset
+- decode rotated latitude/longitude and regular Gaussian grids while rejecting
+  quasi-regular geometry with a typed error
+- preserve GRIB2 generating-process and data-cutoff metadata and decode signed
+  forecast offsets without unsigned wraparound
+- decode derived-ensemble, probability, and percentile forecasts with typed
+  probability thresholds for product templates 4.2, 4.5, and 4.6
+- write product templates 4.2, 4.5, and 4.6 and compare their Section 4
+  metadata with ecCodes in the parity suite
+- decode interval probability, percentile, and derived-ensemble templates 4.9,
+  4.10, and 4.12 through one shared statistical-interval model
+- write interval product templates 4.9, 4.10, and 4.12 and verify their
+  timestamps, time ranges, thresholds, and ensemble metadata against ecCodes
+- decode and write spatially processed product template 4.15 and verify its
+  process type, spatial method, and source-point count against ecCodes
 - raise the workspace MSRV to Rust 1.87 for the coordinated breaking release
 
 ## 0.6.0 - 2026-06-25

README.md

@@ -132,14 +132,14 @@ let product = ProductDefinition {
     parameter_category: 0,
     parameter_number: 0,
     template: ProductDefinitionTemplate::AnalysisOrForecast(AnalysisOrForecastTemplate {
-        generating_process: 2,
+        type_of_generating_process: 2,
+        background_generating_process_identifier: 0,
+        generating_process_identifier: 0,
+        hours_after_data_cutoff: Some(0),
+        minutes_after_data_cutoff: Some(0),
         forecast_time_unit: 1,
         forecast_time: 6,
-        first_surface: Some(FixedSurface {
-            surface_type: 103,
-            scale_factor: 0,
-            scaled_value: 850,
-        }),
+        first_surface: Some(FixedSurface::with_value(103, 0, 850)),
         second_surface: None,
     }),
 };
@@ -163,6 +163,8 @@ GribWriter::new(&mut bytes).write_grib2_message([field])?;
 - Logical field indexing for multi-field GRIB2 messages
 - GRIB2 Section 2 access and same-message bitmap reuse through indicator 254
 - Regular latitude/longitude grids for GRIB1 and GRIB2
+- Reader GRIB2 rotated latitude/longitude template 3.1 and regular Gaussian
+  template 3.40, with explicit typed rejection of quasi-regular grids
 - Reader GRIB2 Mercator grid template 3.10, polar stereographic grid template
   3.20, Lambert conformal grid template 3.30, and Albers equal-area grid
   template 3.31 metadata, projected coordinate offsets, and flat data decode
@@ -174,7 +176,10 @@ GribWriter::new(&mut bytes).write_grib2_message([field])?;
 - Typed metadata access for reference time, parameter identity, product metadata, grid geometry, and lat/lon coordinates
 - Explicit north-up decode methods in addition to reader order that preserves
   the encoded i/j scan directions
-- Reader and writer GRIB2 product definition templates 4.0, 4.1, 4.8, and 4.11
+- Reader GRIB2 product definition templates 4.0, 4.1, 4.2, 4.5, 4.6, 4.8,
+  4.9, 4.10, 4.11, 4.12, and 4.15
+- Writer GRIB2 product definition templates 4.0, 4.1, 4.2, 4.5, 4.6, 4.8,
+  4.9, 4.10, 4.11, 4.12, and 4.15
 - Forecast valid-time helpers for supported fixed-width GRIB1/GRIB2 time units
 - `GribFile::builder()` for strict or tolerant scanning and allocation limits
 - Bitmap application with missing values surfaced as `NaN`
@@ -194,11 +199,16 @@ GribWriter::new(&mut bytes).write_grib2_message([field])?;
 
 ## Not Yet Supported
 
-- Remaining GRIB2 grid templates beyond 3.0, 3.10, 3.20, 3.30, and 3.31
-- Remaining GRIB2 product definition templates beyond 4.0, 4.1, 4.8, and 4.11
+- Remaining GRIB2 grid templates beyond 3.0, 3.1, 3.10, 3.20, 3.30, 3.31,
+  and 3.40
+- Remaining reader GRIB2 product definition templates beyond 4.0, 4.1, 4.2,
+  4.5, 4.6, 4.8, 4.9, 4.10, 4.11, 4.12, and 4.15
+- Remaining writer GRIB2 product definition templates beyond 4.0, 4.1, 4.2,
+  4.5, 4.6, 4.8, 4.9, 4.10, 4.11, 4.12, and 4.15
 - Writer GRIB2 row-by-row complex packing
 
-Unsupported cases fail explicitly with typed errors.
+Unsupported decode and encode operations fail explicitly with typed errors;
+unknown GRIB2 product templates remain indexable with their raw bytes preserved.
 Calendar-dependent forecast units such as months and years are exposed through
 raw metadata but currently return `None` from `valid_time()`.
 

grib-core/src/error.rs

@@ -29,6 +29,18 @@ pub enum Error {
     #[error("unsupported grid definition template: {0}")]
     UnsupportedGridTemplate(u16),
 
+    #[error("unsupported quasi-regular grid definition template: {template}")]
+    UnsupportedQuasiRegularGrid { template: u16 },
+
+    #[error(
+        "grid template {template} uses unsupported angular unit {basic_angle}/{subdivisions} degrees"
+    )]
+    UnsupportedGridAngularUnit {
+        template: u16,
+        basic_angle: u32,
+        subdivisions: u32,
+    },
+
     #[error("unsupported data representation template: {0}")]
     UnsupportedDataTemplate(u16),