From dd57eb3dc38be03670ccfd254654ec774149786a Mon Sep 17 00:00:00 2001
From: Rekai Musuka <rekai@musuka.dev>
Date: Wed, 22 Jun 2022 19:20:01 -0300
Subject: [PATCH] feat: implement selection between 4bpp and 8bpp sprites

---
 src/sprite2d/main.zig | 51 +++++++++++++++++++++++++++++++++----------
 1 file changed, 40 insertions(+), 11 deletions(-)

diff --git a/src/sprite2d/main.zig b/src/sprite2d/main.zig
index d80bccb..e68f395 100644
--- a/src/sprite2d/main.zig
+++ b/src/sprite2d/main.zig
@@ -8,38 +8,60 @@ const Input = @import("gba").Input;
 
 const sprites = @import("sprites.zig");
 
-const sprite_attrs = [12]OAM.Attribute{
+const sprite_attrs = [24]OAM.Attribute{
     sprites.square.d2.bpp4.Sprite8x8.getAttribute(),
     sprites.square.d2.bpp4.Sprite16x16.getAttribute(),
     sprites.square.d2.bpp4.Sprite32x32.getAttribute(),
     sprites.square.d2.bpp4.Sprite64x64.getAttribute(),
-
     sprites.horizontal.d2.bpp4.Sprite16x8.getAttribute(),
     sprites.horizontal.d2.bpp4.Sprite32x8.getAttribute(),
     sprites.horizontal.d2.bpp4.Sprite32x16.getAttribute(),
     sprites.horizontal.d2.bpp4.Sprite64x32.getAttribute(),
-
     sprites.vertical.d2.bpp4.Sprite8x16.getAttribute(),
     sprites.vertical.d2.bpp4.Sprite8x32.getAttribute(),
     sprites.vertical.d2.bpp4.Sprite16x32.getAttribute(),
     sprites.vertical.d2.bpp4.Sprite32x64.getAttribute(),
+
+    sprites.square.d2.bpp8.Sprite8x8.getAttribute(),
+    sprites.square.d2.bpp8.Sprite16x16.getAttribute(),
+    sprites.square.d2.bpp8.Sprite32x32.getAttribute(),
+    sprites.square.d2.bpp8.Sprite64x64.getAttribute(),
+    sprites.horizontal.d2.bpp8.Sprite16x8.getAttribute(),
+    sprites.horizontal.d2.bpp8.Sprite32x8.getAttribute(),
+    sprites.horizontal.d2.bpp8.Sprite32x16.getAttribute(),
+    sprites.horizontal.d2.bpp8.Sprite64x32.getAttribute(),
+    sprites.vertical.d2.bpp8.Sprite8x16.getAttribute(),
+    sprites.vertical.d2.bpp8.Sprite8x32.getAttribute(),
+    sprites.vertical.d2.bpp8.Sprite16x32.getAttribute(),
+    sprites.vertical.d2.bpp8.Sprite32x64.getAttribute(),
 };
 
-const sprite_load_fns = [12]fn () void{
+const sprite_load_fns = [24]fn () void{
     sprites.square.d2.bpp4.Sprite8x8.load,
     sprites.square.d2.bpp4.Sprite16x16.load,
     sprites.square.d2.bpp4.Sprite32x32.load,
     sprites.square.d2.bpp4.Sprite64x64.load,
-
     sprites.horizontal.d2.bpp4.Sprite16x8.load,
     sprites.horizontal.d2.bpp4.Sprite32x8.load,
     sprites.horizontal.d2.bpp4.Sprite32x16.load,
     sprites.horizontal.d2.bpp4.Sprite64x32.load,
-
     sprites.vertical.d2.bpp4.Sprite8x16.load,
     sprites.vertical.d2.bpp4.Sprite8x32.load,
     sprites.vertical.d2.bpp4.Sprite16x32.load,
     sprites.vertical.d2.bpp4.Sprite32x64.load,
+
+    sprites.square.d2.bpp8.Sprite8x8.load,
+    sprites.square.d2.bpp8.Sprite16x16.load,
+    sprites.square.d2.bpp8.Sprite32x32.load,
+    sprites.square.d2.bpp8.Sprite64x64.load,
+    sprites.horizontal.d2.bpp8.Sprite16x8.load,
+    sprites.horizontal.d2.bpp8.Sprite32x8.load,
+    sprites.horizontal.d2.bpp8.Sprite32x16.load,
+    sprites.horizontal.d2.bpp8.Sprite64x32.load,
+    sprites.vertical.d2.bpp8.Sprite8x16.load,
+    sprites.vertical.d2.bpp8.Sprite8x32.load,
+    sprites.vertical.d2.bpp8.Sprite16x32.load,
+    sprites.vertical.d2.bpp8.Sprite32x64.load,
 };
 
 // TODO: ZigGBA should support spaces, slashes, underscores, etc. in ROM Title
@@ -73,6 +95,7 @@ pub fn main() noreturn {
 
     var size_idx: u2 = 0;
     var shape_idx: u2 = 0;
+    var is_4bpp: bool = true;
 
     while (true) {
         LCD.naiveVSync();
@@ -80,14 +103,18 @@ pub fn main() noreturn {
 
         const shoulder = @truncate(u2, @bitCast(u32, Input.getShoulderJustPressed()));
 
+        if (Input.isKeyJustPressed(Input.Keys.Start)) is_4bpp = !is_4bpp;
         if (Input.isKeyJustPressed(Input.Keys.A)) shape_idx +%= 1;
         if (Input.isKeyJustPressed(Input.Keys.B)) shape_idx -%= 1;
 
-        if (shoulder != 0 or Input.isKeyJustPressed(Input.Keys.A) or Input.isKeyJustPressed(Input.Keys.B)) {
+        const input_cond =
+            Input.isKeyJustPressed(Input.Keys.A) or Input.isKeyJustPressed(Input.Keys.B) or Input.isKeyJustPressed(Input.Keys.Start);
+
+        if (shoulder != 0 or input_cond) {
             size_idx +%= shoulder;
             shape_idx %= 3;
 
-            loadSprite(shape_idx, size_idx, &sprite);
+            loadSprite(is_4bpp, shape_idx, size_idx, &sprite);
         }
 
         x += Input.getHorizontal() * 2;
@@ -98,9 +125,11 @@ pub fn main() noreturn {
     }
 }
 
-fn loadSprite(shape: usize, size: usize, sprite: *OAM.Attribute) void {
+fn loadSprite(is_4bpp: bool, shape: usize, size: usize, sprite: *OAM.Attribute) void {
     GBA.memset32(GBA.SPRITE_VRAM, 0, 0x8000); // Clear Sprite VRAM
 
-    sprite.* = sprite_attrs[shape * 4 + size];
-    sprite_load_fns[shape * 4 + size]();
+    const idx = @as(usize, 12) * @boolToInt(is_4bpp) + 4 * shape + size;
+
+    sprite.* = sprite_attrs[idx];
+    sprite_load_fns[idx]();
 }