From cb47d23233f28594d029abd647847e14e54849ba Mon Sep 17 00:00:00 2001
From: transistor <trans@jabberwocky.ca>
Date: Tue, 23 Nov 2021 11:45:44 -0800
Subject: [PATCH] Fixed issue with colour 0 being the mask colour

For systems that legitimately use 0 for black, this causes a
problem, so I instead use 0xFFFFFFFF for the mask colour which
corresponds to transparent white in ARGB format, which minifb
doesn't support anyways
---
 src/host/gfx.rs                   | 9 +++++----
 src/peripherals/genesis/ym7101.rs | 6 ++----
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/host/gfx.rs b/src/host/gfx.rs
index 3bf5d6e..a1c6841 100644
--- a/src/host/gfx.rs
+++ b/src/host/gfx.rs
@@ -22,7 +22,7 @@ impl BlitableSurface for Frame {
         for y in pos_y..(pos_y + height) {
             for x in pos_x..(pos_x + width) {
                 match bitmap.next().unwrap() {
-                    0 => { },
+                    0xFFFFFFFF => { },
                     value if x < self.width && y < self.height => { self.bitmap[(x + (y * self.width)) as usize] = value; },
                     _ => { },
                 }
@@ -31,6 +31,7 @@ impl BlitableSurface for Frame {
     }
 
     fn clear(&mut self, value: u32) {
+        let value = if value == 0xFFFFFFFF { 0 } else { value };
         for i in 0..((self.width as usize) * (self.height as usize)) {
             self.bitmap[i] = value;
         }
@@ -40,14 +41,14 @@ impl BlitableSurface for Frame {
 
 pub struct FrameSwapper {
     pub current: Frame,
-    pub previous: Frame,
+    //pub previous: Frame,
 }
 
 impl FrameSwapper {
     pub fn new(width: u32, height: u32) -> FrameSwapper {
         FrameSwapper {
             current: Frame { width, height, bitmap: vec![0; (width * height) as usize] },
-            previous: Frame { width, height, bitmap: vec![0; (width * height) as usize] },
+            //previous: Frame { width, height, bitmap: vec![0; (width * height) as usize] },
         }
     }
 
@@ -66,7 +67,7 @@ impl WindowUpdater for FrameSwapper {
     }
 
     fn update_frame(&mut self, width: u32, _height: u32, bitmap: &mut [u32]) {
-        std::mem::swap(&mut self.current, &mut self.previous);
+        //std::mem::swap(&mut self.current, &mut self.previous);
 
         for y in 0..self.current.height {
             for x in 0..self.current.width {
diff --git a/src/peripherals/genesis/ym7101.rs b/src/peripherals/genesis/ym7101.rs
index 37707b9..1fe7d76 100644
--- a/src/peripherals/genesis/ym7101.rs
+++ b/src/peripherals/genesis/ym7101.rs
@@ -209,7 +209,7 @@ impl Ym7101State {
 
     pub fn get_palette_colour(&self, palette: u8, colour: u8) -> u32 {
         if colour == 0 {
-            return 0;
+            return 0xFFFFFFFF;
         }
         let rgb = read_beu16(&self.cram[(((palette * 16) + colour) * 2) as usize..]);
         (((rgb & 0xF00) as u32) >> 4) | (((rgb & 0x0F0) as u32) << 8) | (((rgb & 0x00F) as u32) << 20)
@@ -259,9 +259,7 @@ impl Ym7101State {
 
     pub fn draw_background(&mut self, frame: &mut Frame) {
         let bg_colour = self.get_palette_colour((self.regs[REG_BACKGROUND] & 0x30) >> 4, self.regs[REG_BACKGROUND] & 0x0f);
-        for i in 0..(frame.width as usize * frame.height as usize) {
-            frame.bitmap[i] = bg_colour;
-        }
+        frame.clear(bg_colour);
     }
 
     pub fn draw_cell_table(&mut self, frame: &mut Frame, cell_table: u32) {