add png loading tests

ggdt/src/graphics/bitmap/png.rs

@@ -220,7 +220,7 @@ impl PixelReader<u8> for PixelDecoder<u8> {
 			ColorFormat::IndexedColor => {
 				Ok(reader.read_u8()?)
 			}
-			_ => return Err(PngError::BadFile(format!("Unsupported color format: {:?}", self.header.format))),
+			_ => return Err(PngError::BadFile(format!("Unsupported color format for this PixelReader: {:?}", self.header.format))),
 		}
 	}
 }
@@ -249,7 +249,7 @@ impl PixelReader<u32> for PixelDecoder<u32> {
 				let a = reader.read_u8()?;
 				Ok(to_argb32(a, r, g, b))
 			}
-			_ => return Err(PngError::BadFile(format!("Unsupported color format: {:?}", self.header.format))),
+			_ => return Err(PngError::BadFile(format!("Unsupported color format for this PixelReader: {:?}", self.header.format))),
 		}
 	}
 }
@@ -468,11 +468,176 @@ impl RgbaBitmap {
 
 #[cfg(test)]
 pub mod tests {
+	use std::io::Read;
+	use std::path::PathBuf;
+
+	use byteorder::LittleEndian;
+	use claim::*;
+
 	use super::*;
 
+	const BASE_PATH: &str = "./test-assets/png/";
+
+	fn path_to_file(file: &Path) -> PathBuf {
+		PathBuf::from(BASE_PATH).join(file)
+	}
+
+	fn load_raw_indexed(bin_file: &Path) -> Result<Box<[u8]>, io::Error> {
+		let f = File::open(bin_file)?;
+		let mut reader = BufReader::new(f);
+		let mut buffer = Vec::new();
+		reader.read_to_end(&mut buffer)?;
+		Ok(buffer.into_boxed_slice())
+	}
+
+	fn load_raw_argb(bin_file: &Path) -> Result<Box<[u32]>, io::Error> {
+		let f = File::open(bin_file)?;
+		let mut reader = BufReader::new(f);
+		let mut buffer = Vec::new();
+		loop {
+			buffer.push(match reader.read_u32::<LittleEndian>() {
+				Ok(value) => value,
+				Err(err) if err.kind() == io::ErrorKind::UnexpectedEof => break,
+				Err(err) => return Err(err),
+			});
+		}
+		Ok(buffer.into_boxed_slice())
+	}
+
 	#[test]
-	pub fn foo() -> Result<(), PngError> {
-		let _ = IndexedBitmap::load_png_file(Path::new("./test-assets/test_indexed.png"))?;
+	pub fn loads_indexed_256_color() -> Result<(), PngError> {
+		let ref_bytes = load_raw_indexed(path_to_file(Path::new("indexed_8.bin")).as_path())?;
+		let (bmp, palette) = IndexedBitmap::load_png_file(path_to_file(Path::new("indexed_8.png")).as_path())?;
+		assert!(palette.is_some());
+		assert_eq!(ref_bytes, bmp.pixels);
+		Ok(())
+	}
+
+	#[test]
+	pub fn loads_indexed_256_color_to_rgba_destination() -> Result<(), PngError> {
+		let ref_bytes = load_raw_argb(path_to_file(Path::new("indexed_8_rgba.bin")).as_path())?;
+		let (bmp, palette) = RgbaBitmap::load_png_file(path_to_file(Path::new("indexed_8.png")).as_path())?;
+		assert!(palette.is_some());
+		assert_eq!(ref_bytes, bmp.pixels);
+		Ok(())
+	}
+
+	#[test]
+	pub fn loads_rgb_color() -> Result<(), PngError> {
+		let ref_bytes = load_raw_argb(path_to_file(Path::new("rgb.bin")).as_path())?;
+		let (bmp, palette) = RgbaBitmap::load_png_file(path_to_file(Path::new("rgb.png")).as_path())?;
+		assert!(palette.is_none());
+		assert_eq!(ref_bytes, bmp.pixels);
+		Ok(())
+	}
+
+	#[test]
+	pub fn loads_rgba_color() -> Result<(), PngError> {
+		let ref_bytes = load_raw_argb(path_to_file(Path::new("rgba.bin")).as_path())?;
+		let (bmp, palette) = RgbaBitmap::load_png_file(path_to_file(Path::new("rgba.png")).as_path())?;
+		assert!(palette.is_none());
+		assert_eq!(ref_bytes, bmp.pixels);
+		Ok(())
+	}
+
+	#[test]
+	pub fn loads_filter_0() -> Result<(), PngError> {
+		let ref_bytes = load_raw_argb(path_to_file(Path::new("filter_0_rgb.bin")).as_path())?;
+		let (bmp, palette) = RgbaBitmap::load_png_file(path_to_file(Path::new("filter_0_rgb.png")).as_path())?;
+		assert!(palette.is_none());
+		assert_eq!(ref_bytes, bmp.pixels);
+		Ok(())
+	}
+
+	#[test]
+	pub fn loads_filter_1() -> Result<(), PngError> {
+		let ref_bytes = load_raw_argb(path_to_file(Path::new("filter_1_rgb.bin")).as_path())?;
+		let (bmp, palette) = RgbaBitmap::load_png_file(path_to_file(Path::new("filter_1_rgb.png")).as_path())?;
+		assert!(palette.is_none());
+		assert_eq!(ref_bytes, bmp.pixels);
+		Ok(())
+	}
+
+	#[test]
+	pub fn loads_filter_2() -> Result<(), PngError> {
+		let ref_bytes = load_raw_argb(path_to_file(Path::new("filter_2_rgb.bin")).as_path())?;
+		let (bmp, palette) = RgbaBitmap::load_png_file(path_to_file(Path::new("filter_2_rgb.png")).as_path())?;
+		assert!(palette.is_none());
+		assert_eq!(ref_bytes, bmp.pixels);
+		Ok(())
+	}
+
+	#[test]
+	pub fn loads_filter_3() -> Result<(), PngError> {
+		let ref_bytes = load_raw_argb(path_to_file(Path::new("filter_3_rgb.bin")).as_path())?;
+		let (bmp, palette) = RgbaBitmap::load_png_file(path_to_file(Path::new("filter_3_rgb.png")).as_path())?;
+		assert!(palette.is_none());
+		assert_eq!(ref_bytes, bmp.pixels);
+		Ok(())
+	}
+
+	#[test]
+	pub fn loads_filter_4() -> Result<(), PngError> {
+		let ref_bytes = load_raw_argb(path_to_file(Path::new("filter_4_rgb.bin")).as_path())?;
+		let (bmp, palette) = RgbaBitmap::load_png_file(path_to_file(Path::new("filter_4_rgb.png")).as_path())?;
+		assert!(palette.is_none());
+		assert_eq!(ref_bytes, bmp.pixels);
+		Ok(())
+	}
+
+	#[test]
+	pub fn loads_larger_indexed_256color_images() -> Result<(), PngError> {
+		let ref_bytes = load_raw_indexed(path_to_file(Path::new("large_1_indexed.bin")).as_path())?;
+		let (bmp, palette) = IndexedBitmap::load_png_file(path_to_file(Path::new("large_1_indexed.png")).as_path())?;
+		assert!(palette.is_some());
+		assert_eq!(ref_bytes, bmp.pixels);
+
+		let ref_bytes = load_raw_indexed(path_to_file(Path::new("large_2_indexed.bin")).as_path())?;
+		let (bmp, palette) = IndexedBitmap::load_png_file(path_to_file(Path::new("large_2_indexed.png")).as_path())?;
+		assert!(palette.is_some());
+		assert_eq!(ref_bytes, bmp.pixels);
+
+		Ok(())
+	}
+
+	#[test]
+	pub fn loads_larger_rgb_images() -> Result<(), PngError> {
+		let ref_bytes = load_raw_argb(path_to_file(Path::new("large_1_rgba.bin")).as_path())?;
+		let (bmp, palette) = RgbaBitmap::load_png_file(path_to_file(Path::new("large_1_rgb.png")).as_path())?;
+		assert!(palette.is_none());
+		assert_eq!(ref_bytes, bmp.pixels);
+
+		let ref_bytes = load_raw_argb(path_to_file(Path::new("large_2_rgba.bin")).as_path())?;
+		let (bmp, palette) = RgbaBitmap::load_png_file(path_to_file(Path::new("large_2_rgb.png")).as_path())?;
+		assert!(palette.is_none());
+		assert_eq!(ref_bytes, bmp.pixels);
+
+		Ok(())
+	}
+
+	#[test]
+	pub fn load_fails_on_unsupported_formats() -> Result<(), PngError> {
+		assert_matches!(
+			RgbaBitmap::load_png_file(path_to_file(Path::new("unsupported_alpha_8bit.png")).as_path()),
+			Err(PngError::BadFile(..))
+		);
+		assert_matches!(
+			RgbaBitmap::load_png_file(path_to_file(Path::new("unsupported_greyscale_8bit.png")).as_path()),
+			Err(PngError::BadFile(..))
+		);
+		assert_matches!(
+			RgbaBitmap::load_png_file(path_to_file(Path::new("unsupported_indexed_16col.png")).as_path()),
+			Err(PngError::BadFile(..))
+		);
+		assert_matches!(
+			RgbaBitmap::load_png_file(path_to_file(Path::new("unsupported_rgb_16bit.png")).as_path()),
+			Err(PngError::BadFile(..))
+		);
+		assert_matches!(
+			RgbaBitmap::load_png_file(path_to_file(Path::new("unsupported_rgba_16bit.png")).as_path()),
+			Err(PngError::BadFile(..))
+		);
+
 		Ok(())
 	}
 }