Get all the code lined up

examples-bak/light_cycle.rs

@@ -1,61 +0,0 @@
-#![no_std]
-#![feature(start)]
-#![forbid(unsafe_code)]
-
-use gba::{
-  io::{
-    display::{spin_until_vblank, spin_until_vdraw, DisplayControlSetting, DisplayMode, DISPCNT},
-    keypad::read_key_input,
-  },
-  vram::bitmap::Mode3,
-  Color,
-};
-
-#[panic_handler]
-fn panic(_info: &core::panic::PanicInfo) -> ! {
-  loop {}
-}
-
-#[start]
-fn main(_argc: isize, _argv: *const *const u8) -> isize {
-  const SETTING: DisplayControlSetting = DisplayControlSetting::new().with_mode(DisplayMode::Mode3).with_bg2(true);
-  DISPCNT.write(SETTING);
-
-  let mut px = Mode3::WIDTH / 2;
-  let mut py = Mode3::HEIGHT / 2;
-  let mut color = Color::from_rgb(31, 0, 0);
-
-  loop {
-    // read the input for this frame
-    let this_frame_keys = read_key_input();
-
-    // adjust game state and wait for vblank
-    px = px.wrapping_add(2 * this_frame_keys.column_direction() as usize);
-    py = py.wrapping_add(2 * this_frame_keys.row_direction() as usize);
-    spin_until_vblank();
-
-    // draw the new game and wait until the next frame starts.
-    const BLACK: Color = Color::from_rgb(0, 0, 0);
-    if px >= Mode3::WIDTH || py >= Mode3::HEIGHT {
-      // out of bounds, reset the screen and position.
-      Mode3::clear_to(BLACK);
-      color = color.rotate_left(5);
-      px = Mode3::WIDTH / 2;
-      py = Mode3::HEIGHT / 2;
-    } else {
-      let color_here = Mode3::read(px, py);
-      if color_here != Some(BLACK) {
-        // crashed into our own line, reset the screen
-        Mode3::dma_clear_to(BLACK);
-        color = color.rotate_left(5);
-      } else {
-        // draw the new part of the line
-        Mode3::write(px, py, color);
-        Mode3::write(px, py + 1, color);
-        Mode3::write(px + 1, py, color);
-        Mode3::write(px + 1, py + 1, color);
-      }
-    }
-    spin_until_vdraw();
-  }
-}

examples/hello_world.rs

@@ -4,11 +4,13 @@
 
 use gba::{
   fatal,
-  io::display::{DisplayControlSetting, DisplayMode, DISPCNT},
+  io::{
+    display::{DisplayControlSetting, DisplayMode, DISPCNT, VBLANK_SCANLINE, VCOUNT},
+    keypad::read_key_input,
+  },
   vram::bitmap::Mode3,
   Color,
 };
-use gba::io::keypad::read_key_input;
 
 #[panic_handler]
 fn panic(info: &core::panic::PanicInfo) -> ! {
@@ -33,9 +35,51 @@ fn main(_argc: isize, _argv: *const *const u8) -> isize {
     // read our keys for this frame
     let this_frame_keys = read_key_input();
 
-    gba::io::display::spin_until_vblank();
-    Mode5::dma_clear_to(Page::Zero, Color(111));
-    Mode5::draw_line(Page::Zero, 5, 5, 100, 100, Color(0b0_11111_11111_11111));
-    gba::io::display::spin_until_vdraw();
+    // adjust game state and wait for vblank
+    px = px.wrapping_add(2 * this_frame_keys.x_tribool() as usize);
+    py = py.wrapping_add(2 * this_frame_keys.y_tribool() as usize);
+    if this_frame_keys.l() {
+      color = Color(color.0.rotate_left(5));
+    }
+    if this_frame_keys.r() {
+      color = Color(color.0.rotate_right(5));
+    }
+
+    // now we wait
+    spin_until_vblank();
+
+    // draw the new game and wait until the next frame starts.
+    const BLACK: Color = Color::from_rgb(0, 0, 0);
+    if px >= Mode3::WIDTH || py >= Mode3::HEIGHT {
+      // out of bounds, reset the screen and position.
+      Mode3::dma_clear_to(BLACK);
+      px = Mode3::WIDTH / 2;
+      py = Mode3::HEIGHT / 2;
+    } else {
+      // draw the new part of the line
+      Mode3::write(px, py, color);
+      Mode3::write(px, py + 1, color);
+      Mode3::write(px + 1, py, color);
+      Mode3::write(px + 1, py + 1, color);
+    }
+
+    // now we wait again
+    spin_until_vdraw();
   }
 }
+
+/// Performs a busy loop until VBlank starts.
+///
+/// This is very inefficient, and please keep following the lessons until we
+/// cover how interrupts work!
+pub fn spin_until_vblank() {
+  while VCOUNT.read() < VBLANK_SCANLINE {}
+}
+
+/// Performs a busy loop until VDraw starts.
+///
+/// This is very inefficient, and please keep following the lessons until we
+/// cover how interrupts work!
+pub fn spin_until_vdraw() {
+  while VCOUNT.read() >= VBLANK_SCANLINE {}
+}

examples/irq.rs

@@ -26,7 +26,8 @@ fn panic(_info: &core::panic::PanicInfo) -> ! {
 
 fn start_timers() {
   let init_val: u16 = u32::wrapping_sub(0x1_0000, 64) as u16;
-  const TIMER_SETTINGS: TimerControlSetting = TimerControlSetting::new().with_overflow_irq(true).with_enabled(true);
+  const TIMER_SETTINGS: TimerControlSetting =
+    TimerControlSetting::new().with_overflow_irq(true).with_enabled(true);
 
   TM0CNT_L.write(init_val);
   TM0CNT_H.write(TIMER_SETTINGS.with_tick_rate(TimerTickRate::CPU1024));
@@ -90,8 +91,8 @@ static mut PIXEL: usize = 0;
 
 fn write_pixel(color: Color) {
   unsafe {
-    Mode3::write_pixel(PIXEL, 0, color);
-    PIXEL = (PIXEL + 1) % Mode3::SCREEN_PIXEL_COUNT;
+    Mode3::write(PIXEL, 0, color);
+    PIXEL = (PIXEL + 1) % (Mode3::WIDTH * Mode3::HEIGHT);
   }
 }
 

src/io/display.rs

@@ -127,37 +127,6 @@ pub const VCOUNT: ROVolAddress<u16> = unsafe { ROVolAddress::new(0x400_0006) };
 /// If the `VCOUNT` register reads equal to or above this then you're in vblank.
 pub const VBLANK_SCANLINE: u16 = 160;
 
-/// Obtains the current `VCOUNT` value.
-pub fn vcount() -> u16 {
-  VCOUNT.read()
-}
-
-/// Performs a busy loop until VBlank starts.
-///
-/// NOTE: This method isn't very power efficient, since it is equivalent to
-/// calling "halt" repeatedly. The recommended way to wait for a VBlank or VDraw
-/// is to set an IRQ handler with
-/// [`io::irq::set_irq_handler`](`io::irq::set_irq_handler`) and using
-/// [`bios::vblank_intr_wait`](bios::vblank_interrupt_wait) to sleep the CPU
-/// until a VBlank IRQ is generated. See the [`io::irq`](io::irq) module for
-/// more details.
-pub fn spin_until_vblank() {
-  while vcount() < VBLANK_SCANLINE {}
-}
-
-/// Performs a busy loop until VDraw starts.
-///
-/// NOTE: This method isn't very power efficient, since it is equivalent to
-/// calling "halt" repeatedly. The recommended way to wait for a VBlank or VDraw
-/// is to set an IRQ handler with
-/// [`io::irq::set_irq_handler`](`io::irq::set_irq_handler`) and using
-/// [`bios::vblank_intr_wait`](bios::vblank_interrupt_wait) to sleep the CPU
-/// until a VBlank IRQ is generated. See the [`io::irq`](io::irq) module for
-/// more details.
-pub fn spin_until_vdraw() {
-  while vcount() >= VBLANK_SCANLINE {}
-}
-
 /// Global mosaic effect control. Write-only.
 pub const MOSAIC: VolAddress<MosaicSetting> = unsafe { VolAddress::new(0x400_004C) };
 

src/io/keypad.rs

@@ -50,9 +50,10 @@ impl KeyInput {
     KeyInput(self.0 ^ other.0)
   }
 
-  /// Gives the arrow pad value as a tribool, with Plus being increased column
-  /// value (right).
-  pub fn column_direction(self) -> TriBool {
+  /// Right/left tribool.
+  ///
+  /// Right is Plus and Left is Minus
+  pub fn x_tribool(self) -> TriBool {
     if self.right() {
       TriBool::Plus
     } else if self.left() {
@@ -62,9 +63,10 @@ impl KeyInput {
     }
   }
 
-  /// Gives the arrow pad value as a tribool, with Plus being increased row
-  /// value (down).
-  pub fn row_direction(self) -> TriBool {
+  /// Up/down tribool.
+  ///
+  /// Down is Plus and Up is Minus
+  pub fn y_tribool(self) -> TriBool {
     if self.down() {
       TriBool::Plus
     } else if self.up() {

src/lib.rs

@@ -71,13 +71,6 @@ impl Color {
   pub const fn from_rgb(r: u16, g: u16, b: u16) -> Color {
     Color(b << 10 | g << 5 | r)
   }
-
-  /// Does a left rotate of the bits.
-  ///
-  /// This has no particular meaning but is a wild way to cycle colors.
-  pub const fn rotate_left(self, n: u32) -> Color {
-    Color(self.0.rotate_left(n))
-  }
 }
 
 //