From 805ae0c8172ceb3187924a3fffa422f634a04e2a Mon Sep 17 00:00:00 2001
From: Alex Janka <alex@alexjanka.com>
Date: Mon, 6 Feb 2023 12:14:51 +1100
Subject: [PATCH] draw window with tiledata

---
 src/processor/gpu.rs             | 36 +++++++++++++++++++++--
 src/processor/gpu/tile_window.rs | 50 ++++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+), 3 deletions(-)
 create mode 100644 src/processor/gpu/tile_window.rs

diff --git a/src/processor/gpu.rs b/src/processor/gpu.rs
index 875a6ca..d139ae2 100644
--- a/src/processor/gpu.rs
+++ b/src/processor/gpu.rs
@@ -1,6 +1,10 @@
+use minifb::{Window, WindowOptions};
+
 use crate::{FACTOR, HEIGHT, WIDTH};
 
-use super::{as_signed, clear_bit, get_bit, set_bit, set_or_clear_bit, CPU};
+use super::{as_signed, get_bit, set_bit, set_or_clear_bit, CPU};
+
+mod tile_window;
 
 #[derive(PartialEq)]
 enum DrawMode {
@@ -32,8 +36,8 @@ enum TiledataArea {
 impl TiledataArea {
     fn get_addr(&self, addr: u8) -> u16 {
         match self {
-            TiledataArea::D8000 => 0x8000 + (addr as u16),
-            TiledataArea::D9000 => 0x9000_u16.wrapping_add_signed(as_signed(addr) as i16),
+            TiledataArea::D8000 => 0x8000 + ((addr as u16) * 16),
+            TiledataArea::D9000 => 0x9000_u16.wrapping_add_signed((as_signed(addr) as i16) * 16),
         }
     }
 }
@@ -86,22 +90,44 @@ struct Palette {
     three: Colour,
 }
 
+const TILE_WINDOW_EDGE_LENGTH: usize = 16 * 8;
+const TILE_WINDOW_EDGE_LENGTH_SCALED: usize = TILE_WINDOW_EDGE_LENGTH * FACTOR;
+
 pub struct GPU {
     pub buffer: Vec<u32>,
     scaled_buffer: Vec<u32>,
     mode: DrawMode,
     mode_clock: usize,
     scanline: u8,
+    sprite_buffer: Vec<u32>,
+    sprite_buffer_scaled: Vec<u32>,
+    sprite_window: Window,
 }
 
 impl Default for GPU {
     fn default() -> Self {
+        let window = Window::new(
+            "Tiles",
+            TILE_WINDOW_EDGE_LENGTH_SCALED,
+            TILE_WINDOW_EDGE_LENGTH_SCALED,
+            WindowOptions::default(),
+        )
+        .unwrap_or_else(|e| {
+            panic!("{}", e);
+        });
         Self {
             buffer: vec![0; WIDTH * HEIGHT],
             scaled_buffer: vec![0; WIDTH * HEIGHT * 4],
             mode: DrawMode::Mode2,
             mode_clock: 0,
             scanline: 0,
+            sprite_buffer: vec![0; TILE_WINDOW_EDGE_LENGTH * TILE_WINDOW_EDGE_LENGTH],
+            sprite_buffer_scaled: vec![
+                0;
+                TILE_WINDOW_EDGE_LENGTH_SCALED
+                    * TILE_WINDOW_EDGE_LENGTH_SCALED
+            ],
+            sprite_window: window,
         }
     }
 }
@@ -201,6 +227,10 @@ impl CPU {
     fn exit_vblank(&mut self) {
         self.gpu.mode = DrawMode::Mode2;
         self.gpu.scanline = 0;
+        self.draw_sprite_window(
+            TiledataArea::D8000,
+            byte_to_palette(self.memory.get(0xFF47)),
+        );
         // self.memory
         //     .set(0xFF0F, clear_bit(self.memory.get(0xFF0F), 0));
     }
diff --git a/src/processor/gpu/tile_window.rs b/src/processor/gpu/tile_window.rs
new file mode 100644
index 0000000..deb6f9f
--- /dev/null
+++ b/src/processor/gpu/tile_window.rs
@@ -0,0 +1,50 @@
+use crate::{
+    processor::{get_bit, CPU},
+    FACTOR,
+};
+
+use super::{
+    bits_to_mapped_colour, scale_buffer, Palette, TiledataArea, TILE_WINDOW_EDGE_LENGTH,
+    TILE_WINDOW_EDGE_LENGTH_SCALED,
+};
+
+impl CPU {
+    pub(super) fn draw_sprite_window(&mut self, area: TiledataArea, palette: Palette) {
+        for tile_y in 0..16 {
+            for tile_x in 0..16 {
+                let tile_num = (tile_y * 16) + tile_x;
+                let data_begin = area.get_addr(tile_num);
+                for px_y in 0..8 {
+                    let lsbs = self.memory.get((px_y * 2) + data_begin);
+                    let msbs = self.memory.get((px_y * 2) + data_begin + 1);
+                    for px_x in 0..8 {
+                        let real_px_y = (tile_y as usize * 8) + px_y as usize;
+                        let real_px_x = (tile_x as usize * 8) + px_x as usize;
+                        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);
+
+                        // if buself.gpu.b
+                        self.gpu.sprite_buffer[real_px_x + (real_px_y * TILE_WINDOW_EDGE_LENGTH)] =
+                            colour.to_rgb();
+                    }
+                }
+            }
+        }
+
+        self.gpu.sprite_buffer_scaled = scale_buffer(
+            &self.gpu.sprite_buffer,
+            TILE_WINDOW_EDGE_LENGTH,
+            TILE_WINDOW_EDGE_LENGTH,
+            FACTOR,
+        );
+        self.gpu
+            .sprite_window
+            .update_with_buffer(
+                &self.gpu.sprite_buffer_scaled,
+                TILE_WINDOW_EDGE_LENGTH_SCALED,
+                TILE_WINDOW_EDGE_LENGTH_SCALED,
+            )
+            .unwrap();
+    }
+}