chore: stub vram, start work on ppu, fix set_register bug

2020-12-23 21:24:27 -06:00
parent 2a234f4d14
commit 677a584ba7
4 changed files with 104 additions and 9 deletions
--- a/src/ppu.rs
+++ b/src/ppu.rs
@@ -0,0 +1,42 @@
+struct PPU {
+    lcdc: LCDControl,
+}
+
+struct LCDControl {
+    lcd_enable: bool, // Bit 7
+    window_tile_map_select: bool,
+    window_enable: bool,
+    tile_data_select: bool,
+    bg_tile_map_select: bool,
+    sprite_size: bool,
+    sprite_enable: bool,
+    display_priority: bool, // Bit 0
+}
+
+impl From<u8> for LCDControl {
+    fn from(byte: u8) -> Self {
+        Self {
+            lcd_enable: (byte >> 7) == 0x01,
+            window_tile_map_select: ((byte >> 6) & 0x01) == 0x01,
+            window_enable: ((byte >> 5) & 0x01) == 0x01,
+            tile_data_select: ((byte >> 4) & 0x01) == 0x01,
+            bg_tile_map_select: ((byte >> 3) & 0x01) == 0x01,
+            sprite_size: ((byte >> 2) & 0x01) == 0x01,
+            sprite_enable: ((byte >> 1) & 0x01) == 0x01,
+            display_priority: (byte & 0x01) == 0x01,
+        }
+    }
+}
+
+impl From<LCDControl> for u8 {
+    fn from(lcdc: LCDControl) -> Self {
+        (lcdc.lcd_enable as u8) << 7
+            | (lcdc.window_tile_map_select as u8) << 6
+            | (lcdc.window_enable as u8) << 5
+            | (lcdc.tile_data_select as u8) << 4
+            | (lcdc.bg_tile_map_select as u8) << 3
+            | (lcdc.sprite_size as u8) << 2
+            | (lcdc.sprite_enable as u8) << 1
+            | lcdc.display_priority as u8
+    }
+}