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No commits in common. "e4bbd33a4968fcd37762a1545823c8cdfa14b808" and "4eb0d469b355872b15abc95d8b8cbc3c0c77034d" have entirely different histories.
e4bbd33a49
...
4eb0d469b3
205
src/ppu.zig
205
src/ppu.zig
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@ -96,7 +96,7 @@ pub const Ppu = struct {
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const attr0 = @bitCast(Attr0, self.oam.read(u16, i));
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const attr0 = @bitCast(Attr0, self.oam.read(u16, i));
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// Only consider enabled Sprites
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// Only consider enabled Sprites
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if (attr0.is_affine.read() or !attr0.disabled.read()) {
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if (!attr0.disabled.read()) {
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const attr1 = @bitCast(Attr1, self.oam.read(u16, i + 2));
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const attr1 = @bitCast(Attr1, self.oam.read(u16, i + 2));
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// When fetching sprites we only care about ones that could be rendered
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// When fetching sprites we only care about ones that could be rendered
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@ -126,115 +126,79 @@ pub const Ppu = struct {
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}
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}
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}
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}
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fn drawSprites(self: *Self, layer: u2) void {
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/// Draw all relevant sprites on a scanline
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fn drawSprites(self: *Self, prio: u2) void {
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const char_base = 0x4000 * 4;
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const y = @bitCast(i8, self.vcount.scanline.read());
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// Loop over every fetched sprite
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// Loop over every fetched sprite
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for (self.scanline_sprites) |maybe_sprite| {
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sprite_loop: for (self.scanline_sprites) |maybe_sprites| {
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if (maybe_sprite) |sprite| {
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if (maybe_sprites) |sprite| {
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// Skip this sprite if it isn't on the current priority
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// Move on to the next sprite If its of a different priority
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if (sprite.priority() != layer) continue;
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if (sprite.priority() != prio) continue :sprite_loop;
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if (sprite.attr0.is_affine.read()) self.drawAffineSprite(AffineSprite.from(sprite)) else self.drawSprite(sprite);
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if (sprite.attr0.is_affine.read()) continue :sprite_loop; // TODO: Affine Sprites
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var i: u9 = 0;
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px_loop: while (i < sprite.width) : (i += 1) {
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const x = (sprite.x() +% i) % 240;
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const ix = @bitCast(i9, x);
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// If We've already rendered a pixel here don't overwrite it
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if (self.scanline_buf[x] != null) continue :px_loop;
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const start = sprite.x();
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const istart = @bitCast(i9, start);
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const end = start +% sprite.width;
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const iend = @bitCast(i9, end);
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// By comparing with both signed and unsigned values we ensure that sprites
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// are displayed in all valid (AFAIK) configuration
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if ((start <= x and x < end) or (istart <= ix and ix < iend)) {
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self.drawSpritePixel(char_base, sprite, ix, y);
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}
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}
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} else break;
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} else break;
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}
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}
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}
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}
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fn drawAffineSprite(self: *Self, sprite: AffineSprite) void {
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/// Draw a Pixel of a Sprite Tile
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const iy = @bitCast(i8, self.vcount.scanline.read());
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fn drawSpritePixel(self: *Self, char_base: u32, sprite: Sprite, x: i9, y: i8) void {
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// FIXME: We branch on this condition quite a lot
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const is_8bpp = sprite.is_8bpp();
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const is_8bpp = sprite.is8bpp();
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const tile_id: u32 = sprite.tileId();
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const obj_mapping = self.dispcnt.obj_mapping.read();
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const tile_row_offset: u32 = if (is_8bpp) 8 else 4;
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const tile_len: u32 = if (is_8bpp) 0x40 else 0x20;
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const char_base = 0x4000 * 4;
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var i: u9 = 0;
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while (i < sprite.width) : (i += 1) {
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const x = (sprite.x() +% i) % width;
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const ix = @bitCast(i9, x);
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if (self.scanline_buf[x] != null) continue;
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const sprite_start = sprite.x();
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const isprite_start = @bitCast(i9, sprite_start);
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const sprite_end = sprite_start +% sprite.width;
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const isprite_end = @bitCast(i9, sprite_end);
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const condition = (sprite_start <= x and x < sprite_end) or (isprite_start <= ix and ix < isprite_end);
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if (!condition) continue;
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// Sprite is within bounds and therefore should be rendered
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// std.math.absInt is branchless
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// std.math.absInt is branchless
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const tile_x = @bitCast(u9, std.math.absInt(ix - @bitCast(i9, sprite.x())) catch unreachable);
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const x_diff = @bitCast(u9, std.math.absInt(x - @bitCast(i9, sprite.x())) catch unreachable);
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const tile_y = @bitCast(u8, std.math.absInt(iy -% @bitCast(i8, sprite.y())) catch unreachable);
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const y_diff = @bitCast(u8, std.math.absInt(y -% @bitCast(i8, sprite.y())) catch unreachable);
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const row = @truncate(u3, tile_y);
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const col = @truncate(u3, tile_x);
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// TODO: Finish that 2D Sprites Test ROM
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const tile_base = char_base + (tile_id * 0x20) + (row * tile_row_offset) + if (is_8bpp) col else col >> 1;
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const mapping_offset = if (obj_mapping) sprite.width >> 3 else if (is_8bpp) @as(u32, 0x10) else 0x20;
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const tile_offset = (tile_x >> 3) * tile_len + (tile_y >> 3) * tile_len * mapping_offset;
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const tile = self.vram.buf[tile_base + tile_offset];
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const pal_id: u16 = if (!is_8bpp) get4bppTilePalette(sprite.palBank(), col, tile) else tile;
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// Sprite Palette starts at 0x0500_0200
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if (pal_id != 0) self.scanline_buf[x] = self.palette.read(u16, 0x200 + pal_id * 2);
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}
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}
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fn drawSprite(self: *Self, sprite: Sprite) void {
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const iy = @bitCast(i8, self.vcount.scanline.read());
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const is_8bpp = sprite.is8bpp();
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const tile_id: u32 = sprite.tileId();
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const obj_mapping = self.dispcnt.obj_mapping.read();
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const tile_row_offset: u32 = if (is_8bpp) 8 else 4;
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const tile_len: u32 = if (is_8bpp) 0x40 else 0x20;
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const char_base = 0x4000 * 4;
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var i: u9 = 0;
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while (i < sprite.width) : (i += 1) {
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const x = (sprite.x() +% i) % width;
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const ix = @bitCast(i9, x);
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if (self.scanline_buf[x] != null) continue;
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const sprite_start = sprite.x();
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const isprite_start = @bitCast(i9, sprite_start);
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const sprite_end = sprite_start +% sprite.width;
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const isprite_end = @bitCast(i9, sprite_end);
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const condition = (sprite_start <= x and x < sprite_end) or (isprite_start <= ix and ix < isprite_end);
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if (!condition) continue;
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// Sprite is within bounds and therefore should be rendered
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// std.math.absInt is branchless
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const x_diff = @bitCast(u9, std.math.absInt(ix - @bitCast(i9, sprite.x())) catch unreachable);
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const y_diff = @bitCast(u8, std.math.absInt(iy -% @bitCast(i8, sprite.y())) catch unreachable);
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// Note that we flip the tile_pos not the (tile_pos % 8) like we do for
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// Note that we flip the tile_pos not the (tile_pos % 8) like we do for
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// Background Tiles. By doing this we mirror the entire sprite instead of
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// Background Tiles. By doing this we mirror the entire sprite instead of
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// just a specific tile (see how sprite.width and sprite.height are involved)
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// just a specific tile (see how sprite.width and sprite.height are involved)
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const tile_y = y_diff ^ if (sprite.vFlip()) (sprite.height - 1) else 0;
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const tile_y = y_diff ^ if (sprite.v_flip()) (sprite.height - 1) else 0;
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const tile_x = x_diff ^ if (sprite.hFlip()) (sprite.width - 1) else 0;
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const tile_x = x_diff ^ if (sprite.h_flip()) (sprite.width - 1) else 0;
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const row = @truncate(u3, tile_y);
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// Like in the background Tiles are 8x8 groups of pixels in 8bpp or 4bpp formats
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const tile_id = sprite.tile_id();
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const tile_row_offset: u32 = if (is_8bpp) 8 else 4;
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const tile_len: u32 = if (is_8bpp) 0x40 else 0x20;
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const row = tile_y & 7;
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const col = @truncate(u3, tile_x);
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const col = @truncate(u3, tile_x);
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// TODO: Finish that 2D Sprites Test ROM
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// When calcualting the inital address, the first entry is always 0x20 * tile_id, even if it is 8bpp
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const tile_base = char_base + (tile_id * 0x20) + (row * tile_row_offset) + if (is_8bpp) col else col >> 1;
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const tile_base = char_base + (0x20 * @as(u32, tile_id)) + (tile_row_offset * row) + if (is_8bpp) col else col >> 1;
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const mapping_offset = if (obj_mapping) sprite.width >> 3 else if (is_8bpp) @as(u32, 0x10) else 0x20;
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const tile_offset = (tile_x >> 3) * tile_len + (tile_y >> 3) * tile_len * mapping_offset;
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// TODO: Finish that 2D Sprites Test ROM
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const offset_base = (tile_x >> 3) * tile_len;
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const offset_offset = (tile_y >> 3) * tile_len * if (self.dispcnt.obj_mapping.read()) sprite.width >> 3 else if (is_8bpp) @as(u32, 0x10) else 0x20;
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const tile_offset = offset_base + offset_offset;
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const tile = self.vram.buf[tile_base + tile_offset];
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const tile = self.vram.buf[tile_base + tile_offset];
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const pal_id: u16 = if (!is_8bpp) get4bppTilePalette(sprite.palBank(), col, tile) else tile;
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const pal_id: u16 = if (!is_8bpp) get4bppTilePalette(sprite.pal_bank(), col, tile) else tile;
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// Sprite Palette starts at 0x0500_0200
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// Sprite Palette starts at 0x0500_0200
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if (pal_id != 0) self.scanline_buf[x] = self.palette.read(u16, 0x200 + pal_id * 2);
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if (pal_id != 0) self.scanline_buf[@bitCast(u9, x)] = self.palette.read(u16, 0x200 + pal_id * 2);
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}
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}
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}
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fn drawAffineBackground(self: *Self, comptime n: u3) void {
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fn drawAffineBackground(self: *Self, comptime n: u3) void {
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@ -807,23 +771,31 @@ const Sprite = struct {
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return self.attr0.y.read();
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return self.attr0.y.read();
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}
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}
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fn is8bpp(self: *const Self) bool {
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fn is_8bpp(self: *const Self) bool {
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return self.attr0.is_8bpp.read();
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return self.attr0.is_8bpp.read();
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}
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}
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fn tileId(self: *const Self) u10 {
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fn shape(self: *const Self) u2 {
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return self.attr0.shape.read();
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}
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fn size(self: *const Self) u2 {
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return self.attr1.size.read();
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}
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fn tile_id(self: *const Self) u10 {
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return self.attr2.tile_id.read();
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return self.attr2.tile_id.read();
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}
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}
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fn palBank(self: *const Self) u4 {
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fn pal_bank(self: *const Self) u4 {
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return self.attr2.pal_bank.read();
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return self.attr2.pal_bank.read();
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}
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}
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fn hFlip(self: *const Self) bool {
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fn h_flip(self: *const Self) bool {
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return self.attr1.h_flip.read();
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return self.attr1.h_flip.read();
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}
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}
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fn vFlip(self: *const Self) bool {
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fn v_flip(self: *const Self) bool {
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return self.attr1.v_flip.read();
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return self.attr1.v_flip.read();
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}
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}
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@ -842,39 +814,17 @@ const AffineSprite = struct {
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width: u8,
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width: u8,
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height: u8,
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height: u8,
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fn from(sprite: Sprite) AffineSprite {
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fn init(attr0: AffineAttr0, attr1: AffineAttr1, attr2: Attr2) Self {
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const d = spriteDimensions(attr0.shape.read(), attr1.size.read());
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return .{
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return .{
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.attr0 = .{ .raw = sprite.attr0.raw },
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.attr0 = attr0,
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.attr1 = .{ .raw = sprite.attr1.raw },
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.attr1 = attr1,
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.attr2 = sprite.attr2,
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.attr2 = attr2,
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.width = sprite.width,
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.width = d[0],
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.height = sprite.height,
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.height = d[1],
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};
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};
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}
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}
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fn x(self: *const Self) u9 {
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return self.attr1.x.read();
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}
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fn y(self: *const Self) u8 {
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return self.attr0.y.read();
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}
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fn is8bpp(self: *const Self) bool {
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return self.attr0.is_8bpp.read();
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}
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fn tileId(self: *const Self) u10 {
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return self.attr2.tile_id.read();
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}
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fn palBank(self: *const Self) u4 {
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return self.attr2.pal_bank.read();
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}
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fn matrixId(self: *const Self) u5 {
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return self.attr1.aff_sel.read();
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}
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};
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};
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const Attr0 = extern union {
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const Attr0 = extern union {
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@ -918,7 +868,6 @@ const Attr2 = extern union {
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tile_id: Bitfield(u16, 0, 10),
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tile_id: Bitfield(u16, 0, 10),
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rel_prio: Bitfield(u16, 10, 2),
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rel_prio: Bitfield(u16, 10, 2),
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pal_bank: Bitfield(u16, 12, 4),
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pal_bank: Bitfield(u16, 12, 4),
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raw: u16,
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};
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};
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fn spriteDimensions(shape: u2, size: u2) [2]u8 {
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fn spriteDimensions(shape: u2, size: u2) [2]u8 {
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Reference in New Issue