--- a/content/blog/2016/12/chip8-graphics.markdown Wed Dec 21 11:53:34 2016 -0500
+++ b/content/blog/2016/12/chip8-graphics.markdown Wed Dec 21 12:00:08 2016 -0500
@@ -87,6 +87,13 @@
a multidimensional array to make the indexing a bit nicer, but by using a simple
flat array we'll be able to pass it directly to OpenGL later.
+OpenGL is going to want this array to be in "X-major" order, so the array will
+need to look like:
+
+ [(x₀, y₀), (x₁, y₀), (x₂, y₀), ...,
+ (x₀, y₁), (x₁, y₁), (x₂, y₁), ...,
+ ...]
+
We'll add a couple of helper functions to make the indexing of this array a bit
less painful:
@@ -99,7 +106,8 @@
new-value))
```
-Now we can simply say `(vref chip 5 15)` to get the pixel at (5, 15).
+Now we can simply say `(vref chip 5 15)` to get the pixel at (5, 15) instead of
+manually calculating out the `aref`.
We'll add one more field to `chip` before moving on, a "dirty" flag: