textium: Add render_atlas example (packs atlas, exports as png)

textium/Cargo.toml

@@ -6,3 +6,6 @@ authors = ["Erin <erin@hashbang.sh>"]
 [dependencies]
 glium = "0.17"
 rusttype = "0.2.1"
+
+[dev-dependencies]
+image = "0.15"

textium/examples/render_atlas.rs

@@ -1,10 +1,13 @@
+extern crate image;
 extern crate textium;
 extern crate rusttype;
 
+use std::path::Path;
 use rusttype::{FontCollection};
+use textium::texture::Buffer2d;
+use image::{ImageBuffer, Luma};
 
-/// An array of all of the ascii printable characters.
-pub const ASCII: &'static [char] = &[
+const ASCII: &'static [char] = &[
     ' ', '!', '"', '#', '$', '%', '&', '\'', '(', ')', '*', '+', ',', '-', '.', '/',
     ':', ';', '<', '=', '>', '?', '[', ']', '\\', '|', '{', '}', '^', '~', '_', '@',
     '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
@@ -14,24 +17,14 @@ pub const ASCII: &'static [char] = &[
 ];
 
 fn main() {
-    let font_data = include_bytes!("Gudea-Regular.ttf");
+    let font_data = include_bytes!("Px437_IBM_VGA8.ttf");
     let font = FontCollection::from_bytes(font_data as &[u8])
         .into_font().unwrap();
     let font = textium::Font::new(font);
 
-    let chrs = ASCII.iter().cloned();
-    let (atlas, bitmap, line_height) = font.make_atlas(chrs, 40.0, 1, 64, 64);
+    let chrs = ASCII.iter().cloned().chain(ASCII.iter().cloned());
+    let (_, bitmap, _) = font.make_atlas(chrs, 20.0, 1, 256, 128);
 
-    // println!("{:?}", atlas.glyph_data);
-    for line in bitmap.lines() {
-        print!("{:03} ", line.len());
-        for &pixel in line {
-            if pixel == 0 {
-                print!(" ");
-            } else {
-                print!("#");
-            }
-        }
-        println!("");
-    }
+    let img: ImageBuffer<Luma<u8>, _> = ImageBuffer::from_raw(bitmap.width() as u32, bitmap.height() as u32, bitmap.raw()).unwrap();
+    let _ = img.save(&Path::new("atlas.png"));
 }