cgb refactor + double speed groundwork

lib/src/processor/memory.rs

@@ -5,9 +5,10 @@ use self::{
     addresses::{Address, AddressMarker, CgbIoAddress, IoAddress},
     mmio::{
         apu::ApuSaveState,
+        cgb::{DoubleSpeed, Infrared, VramDma},
         gpu::{Colour, GpuSaveState},
         serial::SerialSaveState,
-        Apu, Gpu, Infrared, Joypad, OamDma, Serial, Timer, VramDma,
+        Apu, Gpu, Joypad, OamDma, Serial, Timer,
     },
     rom::RomSaveState,
 };
@@ -84,6 +85,7 @@ impl Wram {
 struct CgbPeripherals {
     vram_dma: VramDma,
     infrared: Infrared,
+    double_speed: DoubleSpeed,
 }
 
 pub struct Memory<ColourFormat, R, C>
@@ -361,7 +363,7 @@ where
             IoAddress::Cgb(address) => {
                 if let WramBanks::Cgb { banks: _, selected } = &self.ram.banks && let Some(cgb_peripherals) = &self.cgb_peripherals {
                     match address {
-                        CgbIoAddress::PrepareSpeed => todo!(),
+                        CgbIoAddress::PrepareSpeed => cgb_peripherals.double_speed.get(),
                         CgbIoAddress::VramBank => self.gpu.vram.get_vram_bank(),
                         CgbIoAddress::VramDma(address) => cgb_peripherals.vram_dma.get_register(address),
                         CgbIoAddress::Infrared => cgb_peripherals.infrared.get(),
@@ -420,7 +422,7 @@ where
             IoAddress::Cgb(address) => {
                 if let WramBanks::Cgb { banks: _, selected } = &mut self.ram.banks && let Some(cgb_peripherals) = &mut self.cgb_peripherals {
                     match address {
-                        CgbIoAddress::PrepareSpeed => todo!(),
+                        CgbIoAddress::PrepareSpeed => cgb_peripherals.double_speed.set(data),
                         CgbIoAddress::VramBank => self.gpu.vram.set_vram_bank(data),
                         CgbIoAddress::VramDma(address) => cgb_peripherals.vram_dma.set_register(address, data),
                         CgbIoAddress::Infrared => cgb_peripherals.infrared.set(data),

lib/src/processor/memory/mmio/cgb/double_speed.rs

@@ -0,0 +1,50 @@
+use crate::{
+    connect::{PocketCamera, Renderer},
+    processor::memory::{mmio::gpu::Colour, Memory},
+};
+use serde::{Deserialize, Serialize};
+
+#[derive(Default, Serialize, Deserialize, Clone, Copy)]
+pub(crate) struct DoubleSpeed {
+    prepared: bool,
+    current: bool,
+}
+
+impl DoubleSpeed {
+    pub(crate) fn get(&self) -> u8 {
+        0b01111110 | if self.current { 0b1 << 7 } else { 0 } | if self.prepared { 0b1 } else { 0 }
+    }
+
+    pub(crate) fn set(&mut self, data: u8) {
+        self.prepared = data & 0b1 == 0b1;
+    }
+}
+
+impl<ColourFormat, R, C> Memory<ColourFormat, R, C>
+where
+    ColourFormat: From<Colour> + Clone,
+    R: Renderer<ColourFormat>,
+    C: PocketCamera + Send + 'static,
+{
+    pub(crate) fn is_double_speed(&self) -> bool {
+        self.cgb_peripherals
+            .as_ref()
+            .map_or(false, |v| v.double_speed.current)
+    }
+
+    pub(crate) fn should_switch_speed(&mut self) -> bool {
+        if let Some(cgb_peripherals) = &mut self.cgb_peripherals {
+            if cgb_peripherals.double_speed.prepared && !cgb_peripherals.double_speed.current {
+                cgb_peripherals.double_speed.current = true;
+                cgb_peripherals.double_speed.prepared = false;
+                return true;
+            } else if cgb_peripherals.double_speed.prepared && cgb_peripherals.double_speed.current
+            {
+                cgb_peripherals.double_speed.current = false;
+                cgb_peripherals.double_speed.prepared = false;
+                return true;
+            }
+        }
+        false
+    }
+}

lib/src/processor/memory/mmio/cgb/mod.rs

@@ -0,0 +1,7 @@
+mod double_speed;
+mod ir;
+mod vram_dma;
+
+pub(crate) use double_speed::DoubleSpeed;
+pub(crate) use ir::Infrared;
+pub(crate) use vram_dma::VramDma;

lib/src/processor/memory/mmio/cgb/vram_dma.rs

@@ -1,9 +1,9 @@
-use super::gpu::{Colour, DrawMode};
 use crate::{
     connect::{PocketCamera, Renderer},
     processor::{
         memory::{
             addresses::{AddressMarker, VramDmaAddress},
+            mmio::gpu::{Colour, DrawMode},
             Memory,
         },
         SplitRegister,

lib/src/processor/memory/mmio/mod.rs

@@ -1,16 +1,13 @@
 pub(crate) mod apu;
+pub(crate) mod cgb;
 pub(crate) mod gpu;
-mod ir;
 pub(crate) mod joypad;
 mod oam_dma;
 pub(crate) mod serial;
 mod timer;
-mod vram_dma;
 pub use apu::Apu;
 pub use gpu::Gpu;
-pub use ir::Infrared;
 pub use joypad::Joypad;
 pub use oam_dma::OamDma;
 pub use serial::Serial;
 pub use timer::Timer;
-pub use vram_dma::VramDma;