Start drawing objects

src/window/vram/utils.rs

@@ -2,21 +2,53 @@ use egui::{Color32, Image, ImageSource, Response, Sense, TextureOptions, Ui, Wid
 
 pub const GENERIC_PALETTE: [u8; 4] = [0, 64, 128, 255];
 
-pub fn parse_palette(palette: u8, brts: &[u8]) -> [u8; 4] {
+pub fn shade(brt: u8, color: Color32) -> Color32 {
+    color.gamma_multiply(brt as f32 / 255.0)
+}
+
+pub fn generic_palette(color: Color32) -> [Color32; 4] {
+    GENERIC_PALETTE.map(|brt| shade(brt, color))
+}
+
+pub fn parse_palette(palette: u8, brts: &[u8], color: Color32) -> [Color32; 4] {
     let shades = [
-        0,
-        brts[0],
-        brts[2],
-        brts[0].saturating_add(brts[2]).saturating_add(brts[4]),
+        Color32::BLACK,
+        shade(brts[0], color),
+        shade(brts[2], color),
+        shade(
+            brts[0].saturating_add(brts[2]).saturating_add(brts[4]),
+            color,
+        ),
     ];
     [
-        0,
+        Color32::BLACK,
         shades[(palette >> 2) as usize & 0x03],
         shades[(palette >> 4) as usize & 0x03],
         shades[(palette >> 6) as usize & 0x03],
     ]
 }
 
+pub fn parse_cell(cell: u16) -> (usize, bool, bool, usize) {
+    let char_index = (cell & 0x7ff) as usize;
+    let vflip = cell & 0x1000 != 0;
+    let hflip = cell & 0x2000 != 0;
+    let palette_index = (cell >> 14) as usize;
+    (char_index, vflip, hflip, palette_index)
+}
+
+pub fn read_char_row(
+    char: &[u16],
+    hflip: bool,
+    vflip: bool,
+    row: usize,
+) -> impl Iterator<Item = u8> {
+    let pixels = if vflip { char[7 - row] } else { char[row] };
+    (0..16).step_by(2).map(move |i| {
+        let pixel = if hflip { 14 - i } else { i };
+        ((pixels >> pixel) & 0x3) as u8
+    })
+}
+
 pub struct CharacterGrid<'a> {
     source: ImageSource<'a>,
     scale: f32,
@@ -71,7 +103,6 @@ impl Widget for CharacterGrid<'_> {
     fn ui(self, ui: &mut Ui) -> Response {
         let image = Image::new(self.source)
             .fit_to_original_size(self.scale)
-            .tint(Color32::RED)
             .texture_options(TextureOptions::NEAREST)
             .sense(Sense::click());
         let res = ui.add(image);