From bec5a0c3d60ba14579b8dd276a7484cc4b18f8b5 Mon Sep 17 00:00:00 2001
From: Alex Janka <alex@alexjanka.com>
Date: Mon, 6 Feb 2023 12:14:02 +1100
Subject: [PATCH] window renders + it all works kind of almost ish

---
 src/processor/gpu.rs | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/src/processor/gpu.rs b/src/processor/gpu.rs
index cb6a3e2..875a6ca 100644
--- a/src/processor/gpu.rs
+++ b/src/processor/gpu.rs
@@ -225,9 +225,10 @@ impl CPU {
 
     fn render_scanline(&mut self, scanline: u8, lcdc: &LCDC) {
         if lcdc.bg_window_enable {
-            self.render_scanline_bg(scanline, lcdc);
+            let palette = byte_to_palette(self.memory.get(0xFF47));
+            self.render_scanline_bg(scanline, lcdc, palette);
             if lcdc.window_enable {
-                self.render_scanline_window(scanline, lcdc);
+                self.render_scanline_window(scanline, lcdc, palette);
             }
         }
         if lcdc.obj_enable {
@@ -235,10 +236,9 @@ impl CPU {
         }
     }
 
-    fn render_scanline_bg(&mut self, scanline: u8, lcdc: &LCDC) {
+    fn render_scanline_bg(&mut self, scanline: u8, lcdc: &LCDC, palette: Palette) {
         let scroll_y = self.memory.get(0xFF42);
         let scroll_x = self.memory.get(0xFF43);
-        let palette = byte_to_palette(self.memory.get(0xFF47));
         self.render_tiles(
             scanline,
             &lcdc.bg_tilemap,
@@ -249,12 +249,19 @@ impl CPU {
         );
     }
 
-    fn render_scanline_window(&mut self, _scanline: u8, _lcdc: &LCDC) {
+    fn render_scanline_window(&mut self, scanline: u8, lcdc: &LCDC, palette: Palette) {
         let pos_y = self.memory.get(0xFF4A);
         // subtracting 7 to get the Real Number...
         let pos_x = self.memory.get(0xFF4B).wrapping_sub(7);
         if pos_y < 143 && pos_x < 166 {
-            // within range!! render here
+            self.render_tiles(
+                scanline,
+                &lcdc.window_tilemap,
+                &lcdc.tile_area,
+                palette,
+                pos_x,
+                pos_y,
+            )
         }
     }
 
@@ -266,7 +273,7 @@ impl CPU {
         tilemap: &TilemapArea,
         tiledata: &TiledataArea,
         palette: Palette,
-        offset_x: u8,
+        _offset_x: u8,
         offset_y: u8,
     ) {
         let tile_line = (scanline as usize) + (offset_y as usize);
@@ -280,8 +287,8 @@ impl CPU {
             let lsbs = self.memory.get(tile_addr);
             let msbs = self.memory.get(tile_addr + 1);
             for px_x in 0..8 {
-                let lsb = get_bit(lsbs, px_x);
-                let msb = get_bit(msbs, px_x);
+                let lsb = get_bit(lsbs, 7 - px_x);
+                let msb = get_bit(msbs, 7 - px_x);
                 let colour = bits_to_mapped_colour(lsb, msb, palette);
                 let x_coord = ((x * 8) + (px_x as u16)) as usize;
                 if x_coord < WIDTH {