start implementing PPU

1 files changed, 15 insertions, 0 deletions

diff --git a/ppu.c b/ppu.c
new file mode 100644
index 0000000..4ae0162
--- /dev/null
+++ b/ppu.c
@@ -0,0 +1,15 @@
+#include "ppu.h"
+
+struct ppu ppu = {0};
+
+void
+ppu_tick(void)
+{
+        ppu.cycles++;
+        if (ppu.cycles >= 341) {
+                ppu.cycles -= 341;
+                ppu.scanlines++;
+        }
+        if (ppu.scanlines >= 262)
+                ppu.scanlines -= 262;
+}