attempt to fix charset rendering (no success)

This commit is contained in:
2023-07-10 21:43:01 -05:00
parent 703e819e80
commit 265da3470f
+50 -13
View File
@@ -61,21 +61,58 @@ fn render_background(bgdebug: &mut BgDebug, registers: &PPURegisters) {
fn render_background_char_2bpp(bgdebug: &mut BgDebug, registers: &PPURegisters) { fn render_background_char_2bpp(bgdebug: &mut BgDebug, registers: &PPURegisters) {
let vram_base_address = registers.get_bg_char_base_address(bgdebug.background) as usize; let vram_base_address = registers.get_bg_char_base_address(bgdebug.background) as usize;
let vram = registers.vram(); let vram = registers.vram();
let width = 8 * 16; let width: usize = 8 * 16;
let height = 8 * 8; let height: usize = 8 * 8;
for x in 0..width { for y in 0..height {
for y in 0..height { for x in 0..width {
let current_char = (x / 8) + ((y / 8) * 16);
let current_char_column = x.rem_euclid(8);
let current_char_row = y.rem_euclid(8);
// 8x8 pixels, 2 bitplanes, each word (16bit) holds 8 pixels
// so 1 char is 8 bytes x 2
let char_base_vram_address = current_char * 8 * 2;
let vram_address = vram_base_address + (
char_base_vram_address + (current_char_row * 2)
);
let current_pixel = x + (y * width); let current_pixel = x + (y * width);
let vram_address = vram_base_address + (current_pixel / 4);
let byte = vram[vram_address]; let lsb_bitplane= vram[vram_address];
let msb_bitplane= vram[vram_address + 1];
let pixels = [ let pixels = [
(byte >> 6) & 0b11, (
(byte >> 4) & 0b11, (lsb_bitplane >> 7) |
(byte >> 2) & 0b11, ((msb_bitplane >> 7) << 1)
byte & 0b11, ),
(
((lsb_bitplane >> 6) & 1) |
(((msb_bitplane >> 6) & 1) << 1)
),
(
((lsb_bitplane >> 5) & 1) |
(((msb_bitplane >> 5) & 1) << 1)
),
(
((lsb_bitplane >> 4) & 1) |
(((msb_bitplane >> 4) & 1) << 1)
),
(
((lsb_bitplane >> 3) & 1) |
(((msb_bitplane >> 3) & 1) << 1)
),
(
((lsb_bitplane >> 2) & 1) |
(((msb_bitplane >> 2) & 1) << 1)
),
(
((lsb_bitplane >> 1) & 1) |
(((msb_bitplane >> 1) & 1) << 1)
),
(
(lsb_bitplane & 1) |
((msb_bitplane & 1) << 1)
),
]; ];
let pixel_index = current_pixel.rem_euclid(4); let effective_pixel = pixels[current_char_column];
let effective_pixel = pixels[pixel_index];
let fb_index = current_pixel * 4; let fb_index = current_pixel * 4;
let r = fb_index; let r = fb_index;
@@ -130,7 +167,7 @@ pub fn background_window(bgdebug: &mut BgDebug, registers: &PPURegisters, ui: &i
.opened(&mut bgdebug.is_enabled) .opened(&mut bgdebug.is_enabled)
.build(ui, || { .build(ui, || {
ui.text("Charset:"); ui.text("Charset:");
let charset_image = imgui::Image::new(char_texture_id, [16.0 * 8.0, 8.0 * 8.0]); let charset_image = imgui::Image::new(char_texture_id, [16.0 * 8.0 * 2.0, 8.0 * 8.0 * 2.0]);
charset_image.build(&ui); charset_image.build(&ui);
ui.separator(); ui.separator();
ui.text("Background:"); ui.text("Background:");