Merge pull request #46 from firefly-zero/image-v2

New image format (v2)

Author: orsinium

src/graphics_canvas.mbt

@@ -10,7 +10,7 @@ struct Canvas(FixedArray[Byte]) derive(Default)
 ///|
 /// Create a new blank canvas.
 pub fn Canvas::new(size : Size) -> Canvas {
-  Canvas(Image::new(size, bpp=4).0)
+  Canvas(Image::new(size).0)
 }
 
 ///|

src/graphics_image.mbt

@@ -6,50 +6,25 @@ struct Image(FixedArray[Byte]) derive(Default)
 
 ///|
 /// Create a new blank image.
-///
-/// By default the image uses 4 bits-per-pixel (`bpp`).
-/// The `bpp` must be either 1, 2, or 4.
-pub fn Image::new(size : Size, bpp? : Byte = 4) -> Image {
-  guard bpp == 1 || bpp == 2 || bpp == 4 else { panic() }
-  let header_size = 5 + bpp.to_int() * 2
-  let body_size = size.w * size.h * bpp.to_int() / 8
+pub fn Image::new(size : Size) -> Image {
+  let header_size = 4
+  let body_size = size.w * size.h / 2
   let arr = FixedArray::make(header_size + body_size, Byte::default())
-  arr[0] = 0x21 // magic number
-  arr[1] = bpp
-  arr[2] = size.w.to_byte()
-  arr[3] = (size.w >> 8).to_byte()
-  arr[4] = 255 // transparency
-  for i in 0..<(2 * bpp.to_int()) {
-    arr[5 + i] = (((i * 2) << 4) | (i * 2 + 1)).to_byte()
-  }
+  arr[0] = 0x22 // magic number
+  arr[1] = size.w.to_byte()
+  arr[2] = (size.w >> 8).to_byte()
+  arr[3] = 0xff // no transparency
   Image(arr)
 }
 
-///|
-test "new image has correct bpp" {
-  inspect(Image::new(Size::new(20, 10), bpp=1).bpp(), content="1")
-  inspect(Image::new(Size::new(20, 10), bpp=2).bpp(), content="2")
-  inspect(Image::new(Size::new(20, 10), bpp=4).bpp(), content="4")
-}
-
 ///|
 test "new image has correct size" {
-  inspect(Image::new(Size::new(20, 10), bpp=1).size(), content="{w: 20, h: 10}")
-  inspect(Image::new(Size::new(20, 10), bpp=2).size(), content="{w: 20, h: 10}")
-  inspect(Image::new(Size::new(20, 10), bpp=4).size(), content="{w: 20, h: 10}")
+  inspect(Image::new(Size::new(20, 10)).size(), content="{w: 20, h: 10}")
 }
 
 ///|
 test "new image has correct pixel count" {
-  inspect(Image::new(Size::new(20, 10), bpp=1).pixels(), content="200")
-  inspect(Image::new(Size::new(20, 10), bpp=2).pixels(), content="200")
-  inspect(Image::new(Size::new(20, 10), bpp=4).pixels(), content="200")
-}
-
-///|
-/// Convert the `Image` to a `File`.
-pub fn Image::as_file(self : Image) -> File {
-  File(self.0)
+  inspect(Image::new(Size::new(20, 10)).pixels(), content="200")
 }
 
 ///|
@@ -74,16 +49,10 @@ pub fn Image::sub(self : Image, point : Point, size : Size) -> SubImage {
   }
 }
 
-///|
-/// Bits per pixel. One of: 1, 2, or 4
-pub fn Image::bpp(self : Image) -> Int {
-  self.0[1].to_int()
-}
-
 ///|
 /// The color used for transparency. If no transparency, returns `None`
 pub fn Image::transparency(self : Image) -> Color {
-  match self.0[4] {
+  match self.0[3] {
     _..<15 as c => Color::from_byte(c + 1)
     _ => Color::None
   }
@@ -103,14 +72,14 @@ pub fn Image::set_transparency(self : Image, color : Color) -> Unit {
 ///|
 /// Returns the number of pixels the image has
 pub fn Image::pixels(self : Image) -> Int {
-  let header_size = 5 + self.bpp() * 2
-  (self.0.length() - header_size) * 8 / self.bpp()
+  let header_size = 4
+  (self.0.length() - header_size) * 2
 }
 
 ///|
 /// Returns the width of the image (in pixels).
 pub fn Image::width(self : Image) -> Int {
-  self.0[2].to_int() | (self.0[3].to_int() << 8)
+  self.0[1].to_int() | (self.0[2].to_int() << 8)
 }
 
 ///|
@@ -130,61 +99,3 @@ pub fn Image::size(self : Image) -> Size {
     _ as width => Size::new(width, self.pixels() / width)
   }
 }
-
-///|
-/// Get a color from the image color palette.
-///
-/// Palette index must be between 0-15 (includesive),
-/// otherwise this function returns `Color::None`
-pub fn Image::get_color(self : Image, index : Byte) -> Color {
-  if index > 15 {
-    return Color::None
-  }
-  let mut val = self.0[5 + index.to_int() / 2]
-  if index % 2 == 0 {
-    val = val >> 4
-  }
-  val = val & 0b1111
-  let transparentColor = self.0[4]
-  if val == transparentColor {
-    Color::None
-  } else {
-    Color::from_byte(val + 1)
-  }
-}
-
-///|
-/// Set color in the image color palette.
-///
-/// Palette index must be between 0-15 (includesive),
-/// otherwise this function is a no-op.
-pub fn Image::set_color(self : Image, index : Byte, color : Color) -> Unit {
-  // ngl, this implementation looks kinda fishy.
-  // needs testing, 'cause I ain't believing this is working
-  if index > 15 || color is Color::None {
-    return
-  }
-  let byte_index = 5 + index.to_int() / 2
-  let mut val = self.0[byte_index]
-  let color_val = color.to_byte() - 1
-  if index % 2 == 0 {
-    val = (color_val << 4) | (val & 0b1111)
-  } else {
-    val = color_val | (val & 0b1111_0000)
-  }
-  self.0[byte_index] = val
-}
-
-///|
-/// Replace one color in the image's color palette with another.
-pub fn Image::replace_color(
-  self : Image,
-  old_color : Color,
-  new_color : Color,
-) -> Unit {
-  for index = (0 : Byte); index < 16; index = index + 1 {
-    if self.get_color(index) == old_color {
-      self.set_color(index, new_color)
-    }
-  }
-}