zba/src/core/ppu/Oam.zig

45 lines
1.1 KiB
Zig

const std = @import("std");
const Allocator = std.mem.Allocator;
const buf_len = 0x400;
const Self = @This();
buf: []u8,
allocator: Allocator,
pub fn read(self: *const Self, comptime T: type, address: usize) T {
const addr = address & 0x3FF;
return switch (T) {
u32, u16, u8 => std.mem.readIntSliceLittle(T, self.buf[addr..][0..@sizeOf(T)]),
else => @compileError("OAM: Unsupported read width"),
};
}
pub fn write(self: *Self, comptime T: type, address: usize, value: T) void {
const addr = address & 0x3FF;
switch (T) {
u32, u16 => std.mem.writeIntSliceLittle(T, self.buf[addr..][0..@sizeOf(T)], value),
u8 => return, // 8-bit writes are explicitly ignored
else => @compileError("OAM: Unsupported write width"),
}
}
pub fn init(allocator: Allocator) !Self {
const buf = try allocator.alloc(u8, buf_len);
@memset(buf, 0);
return Self{ .buf = buf, .allocator = allocator };
}
pub fn reset(self: *Self) void {
@memset(self.buf, 0);
}
pub fn deinit(self: *Self) void {
self.allocator.free(self.buf);
self.* = undefined;
}