Basic API in place, some tests working

Reading an image, getting its dimensions, and resizing are working.

cargo test passes

src/lib.rs

@@ -26,6 +26,10 @@
 
 extern crate libc;
 
+use std::ffi::CString;
+use libc::{c_uint, size_t, c_double};
+use filters::FilterType;
+
 mod bindings;
 
 /// MagickWand is a Rustic wrapper to the Rust bindings to ImageMagick.
@@ -43,16 +47,65 @@ impl MagickWand {
         }
     }
 
-// wand-of-rust wrapper around MagickResizeImage
-// pub fn resize_image(&self, width: uint, height: uint,
-//                     filter: FilterType, blur_factor: f64) {
-//     unsafe {
-//         bindings::MagickResizeImage(
-//             self.wand, width as size_t, height as size_t,
-//             filter as c_uint, blur_factor as c_double
-//         );
-//     }
-// }
+    /// Read the image data from the named file.
+    pub fn read_image(&self, path: &str) -> Result<(), &'static str> {
+        let c_name = CString::new(path).unwrap();
+        let result = unsafe {
+            bindings::MagickReadImage(self.wand, c_name.as_ptr())
+        };
+        match result {
+            bindings::MagickTrue => Ok(()),
+            _ => Err("failed to read image")
+        }
+    }
+
+    // TODO: make a Rustic wrapper for reading a blob from bytes
+    // pub fn MagickReadImageBlob(arg1: *mut MagickWand,
+    //                            arg2: *const ::libc::c_void, arg3: size_t)
+    //  -> MagickBooleanType;
+
+    /// Retrieve the width of the image.
+    pub fn get_image_width(&self) -> usize {
+        unsafe {
+            bindings::MagickGetImageWidth(self.wand) as usize
+        }
+    }
+
+    /// Retrieve the height of the image.
+    pub fn get_image_height(&self) -> usize {
+        unsafe {
+            bindings::MagickGetImageHeight(self.wand) as usize
+        }
+    }
+
+    /// Resize the image to the specified width and height, using the
+    /// specified filter type with the specified blur / sharpness factor.
+    ///
+    /// blur_factor values greater than 1 create blurriness, while values
+    /// less than 1 create sharpness.
+    pub fn resize_image(&self, width: usize, height: usize,
+                        filter: FilterType, blur_factor: f64) {
+        unsafe {
+            bindings::MagickResizeImage(
+                self.wand, width as size_t, height as size_t,
+                filter as c_uint, blur_factor as c_double
+            );
+        }
+    }
+
+    // TODO: get the image from the wand somehow (maybe GetImageFromMagickWand())
+
+    /// Write the current image to the provided path.
+    pub fn write_image(&self, path: &str) -> Result<(), &'static str> {
+        let c_name = CString::new(path).unwrap();
+        let result = unsafe {
+            bindings::MagickWriteImage(self.wand, c_name.as_ptr())
+        };
+        match result {
+            bindings::MagickTrue => Ok(()),
+            _ => Err("failed to write image")
+        }
+    }
 }
 
 // Automate safe cleanup for MagickWand instances.
@@ -68,27 +121,63 @@ impl Drop for MagickWand {
 }
 
 /// This function must be called before any other ImageMagick operations
-/// are attempted.
+/// are attempted. This function is safe to be called repeatedly.
 pub fn magick_wand_genesis() {
     unsafe {
-        bindings::MagickWandGenesis();
+        match bindings::IsMagickWandInstantiated() {
+            bindings::MagickTrue => (),
+            _ => bindings::MagickWandGenesis()
+        }
     }
 }
 
 /// This function should be called when ImageMagick is no longer needed.
+/// This function is safe to be called repeatedly.
 pub fn magick_wand_terminus() {
     unsafe {
-        bindings::MagickWandTerminus();
+        match bindings::IsMagickWandInstantiated() {
+            bindings::MagickTrue => bindings::MagickWandTerminus(),
+            _ => ()
+        }
     }
 }
 
-#[cfg(test)]
-mod test {
+pub mod filters {
 
-    use super::{MagickWand};
+    use bindings;
 
-    #[test]
-    fn test_new_drop() {
-        MagickWand::new();
+    pub enum FilterType {
+        UndefinedFilter = bindings::UndefinedFilter as isize,
+        PointFilter = bindings::PointFilter as isize,
+        BoxFilter = bindings::BoxFilter as isize,
+        TriangleFilter = bindings::TriangleFilter as isize,
+        HermiteFilter = bindings::HermiteFilter as isize,
+        HanningFilter = bindings::HanningFilter as isize,
+        HammingFilter = bindings::HammingFilter as isize,
+        BlackmanFilter = bindings::BlackmanFilter as isize,
+        GaussianFilter = bindings::GaussianFilter as isize,
+        QuadraticFilter = bindings::QuadraticFilter as isize,
+        CubicFilter = bindings::CubicFilter as isize,
+        CatromFilter = bindings::CatromFilter as isize,
+        MitchellFilter = bindings::MitchellFilter as isize,
+        JincFilter = bindings::JincFilter as isize,
+        SincFilter = bindings::SincFilter as isize,
+        SincFastFilter = bindings::SincFastFilter as isize,
+        KaiserFilter = bindings::KaiserFilter as isize,
+        WelshFilter = bindings::WelshFilter as isize,
+        ParzenFilter = bindings::ParzenFilter as isize,
+        BohmanFilter = bindings::BohmanFilter as isize,
+        BartlettFilter = bindings::BartlettFilter as isize,
+        LagrangeFilter = bindings::LagrangeFilter as isize,
+        LanczosFilter = bindings::LanczosFilter as isize,
+        LanczosSharpFilter = bindings::LanczosSharpFilter as isize,
+        Lanczos2Filter = bindings::Lanczos2Filter as isize,
+        Lanczos2SharpFilter = bindings::Lanczos2SharpFilter as isize,
+        RobidouxFilter = bindings::RobidouxFilter as isize,
+        RobidouxSharpFilter = bindings::RobidouxSharpFilter as isize,
+        CosineFilter = bindings::CosineFilter as isize,
+        SplineFilter = bindings::SplineFilter as isize,
+        LanczosRadiusFilter = bindings::LanczosRadiusFilter as isize,
+        SentinelFilter = bindings::SentinelFilter as isize
     }
 }