chore: add some type definitions for sprites

src/bus/dma.zig

@@ -107,8 +107,8 @@ pub fn DmaController(comptime id: u2) type {
             }
 
             switch (sad_adj) {
-                .Increment => self._sad += offset,
+                .Increment => self._sad +%= offset,
-                .Decrement => self._sad -= offset,
+                .Decrement => self._sad -%= offset,
                 .Fixed => {},
 
                 // TODO: Figure out correct behaviour on Illegal Source Addr Control Type
@@ -116,14 +116,16 @@ pub fn DmaController(comptime id: u2) type {
             }
 
             switch (dad_adj) {
-                .Increment, .IncrementReload => self._dad += offset,
+                .Increment, .IncrementReload => self._dad +%= offset,
-                .Decrement => self._dad -= offset,
+                .Decrement => self._dad -%= offset,
                 .Fixed => {},
             }
 
             self._word_count -= 1;
 
             if (self._word_count == 0) {
+                if (!self.cnt.repeat.read()) {
+                    // If we're not repeating, Fire the IRQs and disable the DMA
                     if (self.cnt.irq.read()) {
                         switch (id) {
                             0 => bus.io.irq.dma0.set(),
@@ -132,8 +134,12 @@ pub fn DmaController(comptime id: u2) type {
                             3 => bus.io.irq.dma0.set(),
                         }
                     }
-
                     self.cnt.enabled.unset();
+                }
+
+                // We want to disable our internal enabled flag regardless of repeat
+                // because we only want to step A DMA that repeats during it's specific
+                // timing window
                 self.enabled = false;
             }
 
@@ -153,6 +159,13 @@ pub fn DmaController(comptime id: u2) type {
                 .VBlank => self.enabled = self.cnt.enabled.read() and self.cnt.start_timing.read() == 0b01,
                 .Immediate, .Special => {},
             }
+
+            if (self.cnt.repeat.read() and self.enabled) {
+                self._word_count = if (self.word_count == 0) std.math.maxInt(@TypeOf(self._word_count)) else self.word_count;
+
+                const dad_adj = std.meta.intToEnum(Adjustment, self.cnt.dad_adj.read()) catch unreachable;
+                if (dad_adj == .IncrementReload) self._dad = self.dad;
+            }
         }
     };
 }