fix error colour being dmg zero in cgb mode

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

@@ -3,8 +3,8 @@ use self::{
     cgb::CgbData,
     tile_window::TileWindow,
     types::{
-        BgAttributes, ColourInner, GpuInterrupts, Lcdc, Oam, ObjPalette, ObjSize, Object,
-        ObjectFlags, Palette, Stat, TiledataArea, TilemapArea, Vram, VramBank,
+        rgb_from_bytes, BgAttributes, ColourInner, GpuInterrupts, Lcdc, Oam, ObjPalette, ObjSize,
+        Object, ObjectFlags, Palette, Stat, TiledataArea, TilemapArea, Vram, VramBank,
     },
 };
 use crate::{
@@ -61,7 +61,14 @@ where
     pub fn new(cgb: bool, window: R, tile_window_renderer: Option<R>) -> Self {
         let tile_window = tile_window_renderer
             .map(|tile_window_renderer| TileWindow::new(tile_window_renderer, cgb));
-        let buffer = vec![ColourInner::Error.rgb_bytes(None, false).into(); WIDTH * HEIGHT];
+        let buffer = vec![
+            if cgb {
+                rgb_from_bytes(0xFFFF).into()
+            } else {
+                ColourInner::Error.rgb_bytes(None).into()
+            };
+            WIDTH * HEIGHT
+        ];
 
         Self {
             buffer,
@@ -217,7 +224,7 @@ where
         } else {
             for x in 0..WIDTH {
                 self.buffer[(scanline as usize * WIDTH) + x] = ColourInner::Error
-                    .rgb_bytes(None, self.cgb_data.is_some())
+                    .rgb_bytes(self.cgb_data.as_ref().map(|d| (&d.palettes.bg, 0_u8)))
                     .into();
             }
         }
@@ -362,7 +369,7 @@ where
                 {
                     let cgb_data = self.cgb_data.as_ref().map(|v| {
                         (
-                            v.palettes.obj,
+                            &v.palettes.obj,
                             if self.is_cgb_mode() {
                                 object.flags.cgb_palette
                             } else {
@@ -371,8 +378,7 @@ where
                         )
                     });
 
-                    self.buffer[buffer_index] =
-                        colour.rgb_bytes(cgb_data, self.cgb_data.is_some()).into();
+                    self.buffer[buffer_index] = colour.rgb_bytes(cgb_data).into();
                 }
             }
         }
@@ -451,10 +457,9 @@ where
             let cgb_data = self
                 .cgb_data
                 .as_ref()
-                .map(|v| (v.palettes.bg, attributes.palette));
+                .map(|v| (&v.palettes.bg, attributes.palette));
 
-            self.buffer[(scanline as usize * WIDTH) + x] =
-                colour.rgb_bytes(cgb_data, self.cgb_data.is_some()).into();
+            self.buffer[(scanline as usize * WIDTH) + x] = colour.rgb_bytes(cgb_data).into();
         }
     }
 

lib/src/processor/memory/mmio/gpu/tile_window.rs

@@ -33,7 +33,7 @@ where
         window.prepare(current_width, TILE_WINDOW_HEIGHT);
         Self {
             sprite_buffer: vec![
-                ColourInner::Error.rgb_bytes(None, false).into();
+                ColourInner::Error.rgb_bytes(None).into();
                 current_width * TILE_WINDOW_HEIGHT
             ],
             sprite_renderer: window,
@@ -56,10 +56,8 @@ where
             };
             self.sprite_renderer
                 .resize(current_width, TILE_WINDOW_HEIGHT);
-            self.sprite_buffer = vec![
-                ColourInner::Error.rgb_bytes(None, false).into();
-                current_width * TILE_WINDOW_HEIGHT
-            ];
+            self.sprite_buffer =
+                vec![ColourInner::Error.rgb_bytes(None).into(); current_width * TILE_WINDOW_HEIGHT];
         }
         for (tile_y, data_begin) in (0x8000..0xA000).step_by(0x10 * 16).enumerate() {
             self.draw_row(tile_y, data_begin, palette, memory, is_cgb_mode);
@@ -150,7 +148,7 @@ where
 
                     let addr = offset + real_px_x + (real_px_y * line_width);
                     if addr < self.sprite_buffer.len() {
-                        self.sprite_buffer[addr] = colour.rgb_bytes(None, is_cgb_mode).into();
+                        self.sprite_buffer[addr] = colour.rgb_bytes(None).into();
                     }
                 }
             }

lib/src/processor/memory/mmio/gpu/types.rs

@@ -117,7 +117,7 @@ impl From<Colour> for [u8; 4] {
     }
 }
 
-fn rgb_from_bytes(bytes: u16) -> Colour {
+pub(super) fn rgb_from_bytes(bytes: u16) -> Colour {
     let b = (bytes & (0b11111 << 10)) >> 10;
     let g = (bytes & (0b11111 << 5)) >> 5;
     let r = bytes & 0b11111;
@@ -139,16 +139,19 @@ fn rgb_from_bytes(bytes: u16) -> Colour {
 }
 
 impl ColourInner {
-    pub(super) fn rgb_bytes(
-        &self,
-        cgb_data: Option<(CgbPalette, u8)>,
-        is_cgb_mode: bool,
-    ) -> Colour {
+    pub(super) fn rgb_bytes(&self, cgb_data: Option<(&CgbPalette, u8)>) -> Colour {
         if let Some((cgb_palette, pallete_num)) = cgb_data {
-            if *self == ColourInner::Error {
-                return ERROR_COLOUR;
-            }
-            let offset: usize = (pallete_num as usize * 2 * 4) + (*self as usize * 2);
+            let offset: usize = (pallete_num as usize * 2 * 4)
+                + (if *self == ColourInner::Error {
+                    if cfg!(debug_assertions) {
+                        return ERROR_COLOUR;
+                    } else {
+                        ColourInner::Zero
+                    }
+                } else {
+                    *self
+                } as usize
+                    * 2);
 
             rgb_from_bytes(*from_bytes(&cgb_palette.data[offset..=offset + 1]))
         } else {
@@ -160,8 +163,6 @@ impl ColourInner {
                 ColourInner::Error => {
                     if cfg!(debug_assertions) {
                         ERROR_COLOUR
-                    } else if is_cgb_mode {
-                        rgb_from_bytes(0xFFFF)
                     } else {
                         dmg_colours::ZERO
                     }