Allow reading block-size of Rasters

Cargo.toml

@@ -12,6 +12,7 @@ documentation = "https://georust.github.io/gdal/"
 
 [features]
 bindgen = ["gdal-sys/bindgen"]
+gdal_2_2 = ["gdal-sys/min_gdal_version_2_2"]
 array = ["ndarray"]
 
 [dependencies]

src/raster/rasterband.rs

@@ -26,8 +26,6 @@ impl <'a> RasterBand<'a> {
     }
 
     /// Get block size from a 'Dataset'.
-    /// # Arguments
-    /// * band_index - the band_index
     pub fn block_size(&self) -> (usize, usize) {
         let mut size_x = 0;
         let mut size_y = 0;
@@ -42,6 +40,31 @@ impl <'a> RasterBand<'a> {
         (size_x as usize, size_y as usize)
     }
 
+    /// Get x-size of the band
+    pub fn x_size(&self) -> usize {
+        let out;
+        unsafe {
+            out = gdal_sys::GDALGetRasterBandXSize(self.c_rasterband);
+        }
+        out as usize
+    }
+
+    /// Get y-size of the band
+    pub fn y_size(&self) -> usize {
+        let out;
+        unsafe {
+            out = gdal_sys::GDALGetRasterBandYSize(self.c_rasterband)
+        }
+        out as usize
+    }
+
+    /// Get dimensions of the band.
+    /// Note that this may not be the same as `size` on the
+    /// `owning_dataset` due to scale.
+    pub fn size(&self) -> (usize, usize) {
+        (self.x_size(), self.y_size())
+    }
+
     /// Read a 'Buffer<T>' from a 'Dataset'. T implements 'GdalType'
     /// # Arguments
     /// * band_index - the band_index
@@ -251,6 +274,26 @@ impl <'a> RasterBand<'a> {
         }
         None
     }
+
+    /// Get actual block size (at the edges) when block size
+    /// does not divide band size.
+    #[cfg(feature = "gdal_2_2")]
+    pub fn actual_block_size(&self, offset: (isize, isize))
+                             -> Result<(usize, usize)>{
+        let mut block_size_x = 0;
+        let mut block_size_y = 0;
+        let rv = unsafe { gdal_sys::GDALGetActualBlockSize(
+            self.c_rasterband,
+            offset.0 as libc::c_int,
+            offset.1 as libc::c_int,
+            &mut block_size_x,
+            &mut block_size_y,
+        )};
+        if rv != CPLErr::CE_None {
+            Err(_last_cpl_err(rv))?;
+        }
+        Ok((block_size_x as usize, block_size_y as usize))
+    }
 }
 
 impl<'a> MajorObject for RasterBand<'a> {

src/raster/tests.rs

@@ -365,3 +365,29 @@ fn test_get_offset() {
     let offset = rasterband.offset();
     assert_eq!(offset, Some(0.0));
 }
+
+
+#[test]
+fn test_get_rasterband_size() {
+    let dataset = Dataset::open(fixture!("tinymarble.png")).unwrap();
+    let rasterband = dataset.rasterband(1).unwrap();
+    let size = rasterband.size();
+    assert_eq!(size, (100, 50));
+}
+
+#[test]
+fn test_get_rasterband_block_size() {
+    let dataset = Dataset::open(fixture!("tinymarble.png")).unwrap();
+    let rasterband = dataset.rasterband(1).unwrap();
+    let size = rasterband.block_size();
+    assert_eq!(size, (100, 1));
+}
+
+#[test]
+#[cfg(feature = "gdal_2_2")]
+fn test_get_rasterband_actual_block_size() {
+    let dataset = Dataset::open(fixture!("tinymarble.png")).unwrap();
+    let rasterband = dataset.rasterband(1).unwrap();
+    let size = rasterband.actual_block_size((0,40));
+    assert_eq!(size.unwrap(), (100, 1));
+}

src/vector/dataset.rs

@@ -8,7 +8,7 @@ use gdal_major_object::MajorObject;
 use metadata::Metadata;
 use gdal_sys::{self, GDALMajorObjectH, OGRDataSourceH, OGRLayerH, OGRwkbGeometryType};
 use utils::_last_null_pointer_err;
-
+use spatial_ref::SpatialRef;
 
 use errors::*;
 
@@ -98,6 +98,34 @@ impl Dataset {
         self._child_layer(c_layer);
         Ok(self.layers.last_mut().unwrap()) // TODO: is this safe?
     }
+
+    /// Create a new layer with name, spatial ref. and type.
+    pub fn create_layer_ext(
+        &mut self,
+        name: &str,
+        srs: Option<&SpatialRef>,
+        ty: OGRwkbGeometryType::Type,
+    ) -> Result<&mut Layer> {
+        let c_name = CString::new(name)?;
+        let c_srs = match srs {
+            Some(srs) => srs.to_c_hsrs(),
+            None => null_mut(),
+        };
+
+        let c_layer = unsafe { gdal_sys::OGR_DS_CreateLayer(
+            self.c_dataset,
+            c_name.as_ptr(),
+            c_srs,
+            ty,
+            null_mut(),
+        ) };
+        if c_layer.is_null() {
+            Err(_last_null_pointer_err("OGR_DS_CreateLayer"))?;
+        };
+        self._child_layer(c_layer);
+        Ok(self.layers.last_mut().unwrap()) // TODO: is this safe?
+
+    }
 }