From 97491a4ab37f624810ee0af5a20f89f6879b12bf Mon Sep 17 00:00:00 2001
From: Thomas <thomas@thomasw.dev>
Date: Thu, 8 Feb 2024 20:06:06 +0100
Subject: [PATCH] Add PPU mode 5 and 6

---
 src/snes/ppu/render.rs | 41 ++++++++++++++++++++++++++++++++++++-----
 src/snes/ppu/state.rs  |  9 +++++++++
 2 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/src/snes/ppu/render.rs b/src/snes/ppu/render.rs
index 89a5538..e6f8cee 100644
--- a/src/snes/ppu/render.rs
+++ b/src/snes/ppu/render.rs
@@ -416,6 +416,41 @@ impl PPUState {
                 // BG2 tiles with priority 0
                 self.render_scanline_bglayer(scanline, 1, &mut state, false);
             }
+            5 => {
+                // 2 layers, bg1: 4bpp (16 colors)
+                // bg2: 2bpp (4 colors)
+                // Sprites with priority 3
+                self.render_scanline_sprites(scanline, &mut state, 3);
+                // BG1 tiles with priority 1
+                self.render_scanline_bglayer(scanline, 0, &mut state, true);
+                // Sprites with priority 2
+                self.render_scanline_sprites(scanline, &mut state, 2);
+                // BG2 tiles with priority 1
+                self.render_scanline_bglayer(scanline, 1, &mut state, true);
+                // Sprites with priority 1
+                self.render_scanline_sprites(scanline, &mut state, 1);
+                // BG1 tiles with priority 0
+                self.render_scanline_bglayer(scanline, 0, &mut state, false);
+                // Sprites with priority 0
+                self.render_scanline_sprites(scanline, &mut state, 0);
+                // BG2 tiles with priority 0
+                self.render_scanline_bglayer(scanline, 1, &mut state, false);
+            }
+            6 => {
+                // 1 layer, bg1: 4bpp (16 colors)
+                // Sprites with priority 3
+                self.render_scanline_sprites(scanline, &mut state, 3);
+                // BG1 tiles with priority 1
+                self.render_scanline_bglayer(scanline, 0, &mut state, true);
+                // Sprites with priority 2
+                self.render_scanline_sprites(scanline, &mut state, 2);
+                // Sprites with priority 1
+                self.render_scanline_sprites(scanline, &mut state, 1);
+                // BG1 tiles with priority 0
+                self.render_scanline_bglayer(scanline, 0, &mut state, false);
+                // Sprites with priority 0
+                self.render_scanline_sprites(scanline, &mut state, 0);
+            }
             7 => {
                 // TODO extbg
                 // Sprites with priority 3
@@ -429,11 +464,7 @@ impl PPUState {
                 // Sprites with priority 0
                 self.render_scanline_sprites(scanline, &mut state, 0);
             }
-            _ => println!(
-                "TODO unimplemented PPU mode {} at scanline {}",
-                self.get_screen_mode(),
-                scanline
-            ),
+            _ => unreachable!(),
         }
 
         state
diff --git a/src/snes/ppu/state.rs b/src/snes/ppu/state.rs
index 746c714..f8c846a 100644
--- a/src/snes/ppu/state.rs
+++ b/src/snes/ppu/state.rs
@@ -370,6 +370,15 @@ impl PPUState {
                 1 => BPP::Two,
                 _ => unreachable!(),
             },
+            5 => match bg {
+                0 => BPP::Four,
+                1 => BPP::Two,
+                _ => unreachable!(),
+            },
+            6 => match bg {
+                0 => BPP::Four,
+                _ => unreachable!(),
+            },
             _ => todo!(),
         }
     }