Merge pull request servo#57 from zarazek/master

Handle 16-bit chennels by stripping them to 8-bit.
lambdacat · Jan 28, 2015 · ade2143 · ade2143
2 parents 9b2445d + a09c33b
commit ade2143
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diff --git a/src/ffi.rs b/src/ffi.rs
@@ -84,4 +84,5 @@ extern {
     pub fn RUST_png_set_add_alpha(png_ptr: *mut png_struct, val: u32, flag: c_int);
     pub fn RUST_png_set_filler(png_ptr: *mut png_struct, val: u32, flag: c_int);
     pub fn RUST_png_set_interlace_handling(png_ptr: *mut png_struct);
+    pub fn RUST_png_set_strip_16(png_ptr: *mut png_struct);
 }
diff --git a/src/lib.rs b/src/lib.rs
@@ -106,6 +106,7 @@ pub fn load_png_from_memory(image: &[u8]) -> Result<Image,String> {
         let width = ffi::RUST_png_get_image_width(png_ptr, info_ptr) as usize;
         let height = ffi::RUST_png_get_image_height(png_ptr, info_ptr) as usize;
         let color_type = ffi::RUST_png_get_color_type(png_ptr, info_ptr);
+        let bit_depth = ffi::RUST_png_get_bit_depth(png_ptr, info_ptr);
 
         // convert palette and grayscale to rgb
         match color_type as c_int {
@@ -118,6 +119,11 @@ pub fn load_png_from_memory(image: &[u8]) -> Result<Image,String> {
             _ => {}
         }
 
+        // convert 16-bit channels to 8-bit
+        if bit_depth == 16 {
+            ffi::RUST_png_set_strip_16(png_ptr);
+        }
+
         // add alpha channels
         ffi::RUST_png_set_add_alpha(png_ptr, 0xff, ffi::FILLER_AFTER);
         if ffi::RUST_png_get_valid(png_ptr, info_ptr, ffi::INFO_tRNS as u32) != 0 {