Optimize rendering

This moves some logic that was previously being done per-character into
the vertex shader. At this time, we've traded CPU computation for
additional gl::Uniform2f calls. This is only a marginal improvement.
However, this patch positions the renderer well for instanced drawing,
and that will be a huge performance win.

1 files changed, 10 insertions, 8 deletions

diff --git a/src/text.rs b/src/text.rs
index 2a04c4be..5086a3a4 100644
--- a/src/text.rs
+++ b/src/text.rs
@@ -108,10 +108,11 @@ impl Rasterizer {
         }
 
         RasterizedGlyph {
-            top: glyph.bitmap_top() as usize,
-            left: glyph.bitmap_left() as usize,
-            width: glyph.bitmap().width() as usize / 3,
-            height: glyph.bitmap().rows() as usize,
+            c: c,
+            top: glyph.bitmap_top(),
+            left: glyph.bitmap_left(),
+            width: glyph.bitmap().width() / 3,
+            height: glyph.bitmap().rows(),
             buf: packed,
         }
     }
@@ -119,10 +120,11 @@ impl Rasterizer {
 
 #[derive(Debug)]
 pub struct RasterizedGlyph {
-    pub width: usize,
-    pub height: usize,
-    pub top: usize,
-    pub left: usize,
+    pub c: char,
+    pub width: i32,
+    pub height: i32,
+    pub top: i32,
+    pub left: i32,
     pub buf: Vec<u8>,
 }