textium: significant improvements in texture abstraction

textium/src/texture.rs

@@ -1,16 +1,93 @@
 use std::borrow::Cow;
+use std::slice::Chunks;
 
 use glium::texture::{RawImage2d, Texture2dDataSource};
 pub use glium::texture::PixelValue;
 
+/// A CPU RAM-based 2d buffer.
+pub trait Buffer2d: Sized {
+    type Pixel;
 
-pub struct Texture2dData<T> where T: Clone {
+    fn width(&self) -> usize;
+    fn height(&self) -> usize;
+    fn dimensions(&self) -> (usize, usize) {(self.width(), self.height())}
+
+    fn get(&self, x: usize, y: usize) -> Option<Self::Pixel>;
+    fn set(&mut self, x: usize, y: usize, v: Self::Pixel);
+
+    fn patch<B>(&mut self, x: usize, y: usize, buf: &B)
+        where B: Buffer2d<Pixel=Self::Pixel>
+    {
+        let (w, h) = buf.dimensions();
+
+        // TODO: can this be optimized by performing an unsafe memcpy of some sort?
+        for sy in 0..h {
+            for sx in 0..w {
+                match buf.get(sx, sy) {
+                    Some(v) => self.set(x+sx, y+sy, v),
+                    _ => (),
+                }
+            }
+        }
+    }
+}
+
+pub trait ResizeableBuffer2d: Buffer2d {
+    fn resize(&mut self, width: usize, height: usize);
+}
+
+pub struct Bitmap<T> {
     pub data: Vec<T>,
-    pub width: u32,
-    pub height: u32,
+    pub width: usize,
+    pub height: usize,
+}
+
+impl<T> Bitmap<T> where T: Clone + Default {
+    pub fn new(w: usize, h: usize) -> Bitmap<T> {
+        Bitmap {
+            data: vec![Default::default(); w*h],
+            width: w,
+            height: h,
+        }
+    }
+
+    pub fn lines(&self) -> Chunks<T> {
+        self.data.chunks(self.width)
+    }
+}
+
+impl<T> Buffer2d for Bitmap<T> where T: Clone {
+    type Pixel = T;
+
+    fn width(&self) -> usize {self.width}
+    fn height(&self) -> usize {self.height}
+
+    fn get(&self, x: usize, y: usize) -> Option<Self::Pixel> {
+        self.data.get(x + self.width * y).cloned()
+    }
+
+    fn set(&mut self, x: usize, y: usize, v: Self::Pixel) {
+        if let Some(p) = self.data.get_mut(x + self.width * y) {
+            *p = v;
+        }
+    }
+}
+
+impl<T> ResizeableBuffer2d for Bitmap<T> where T: Clone + Default {
+    fn resize(&mut self, width: usize, height: usize) {
+        assert!(self.width() <= width && self.height() <= height,
+                "resizable buffers cannot shrink!");
+
+        // create new, larger buffer
+        let mut new: Bitmap<T> = Bitmap::new(width as usize, height as usize);
+        // copy the existing buffer into it
+        new.patch(0, 0, self);
+        // overwrite the current buffer with the new buffer
+        *self = new;
+    }
 }
 
-impl<'a, P> Texture2dDataSource<'a> for &'a Texture2dData<P>
+impl<'a, P> Texture2dDataSource<'a> for &'a Bitmap<P>
     where P: Clone + PixelValue
 {
     type Data = P;
@@ -18,8 +95,8 @@ impl<'a, P> Texture2dDataSource<'a> for &'a Texture2dData<P>
     fn into_raw(self) -> RawImage2d<'a, P> {
         RawImage2d {
             data: Cow::Borrowed(&self.data),
-            width: self.width,
-            height: self.height,
+            width: self.width as u32,
+            height: self.height as u32,
             format: <P as PixelValue>::get_format(),
         }
     }