zba/src/ppu.zig

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2022-01-04 01:47:26 +00:00
const std = @import("std");
const Allocator = std.mem.Allocator;
pub const Ppu = struct {
vram: Vram,
pub fn init(alloc: Allocator) !@This() {
return @This(){
.vram = try Vram.init(alloc),
};
}
};
const Vram = struct {
buf: []u8,
fn init(alloc: Allocator) !@This() {
return @This(){
.buf = try alloc.alloc(u8, 0x18000),
};
}
pub inline fn get32(self: *const @This(), idx: usize) u32 {
return (@as(u32, self.buf[idx + 3]) << 24) | (@as(u32, self.buf[idx + 2]) << 16) | (@as(u32, self.buf[idx + 1]) << 8) | (@as(u32, self.buf[idx]));
}
pub inline fn set32(self: *@This(), idx: usize, word: u32) void {
self.buf[idx + 3] = @truncate(u8, word >> 24);
self.buf[idx + 2] = @truncate(u8, word >> 16);
self.buf[idx + 1] = @truncate(u8, word >> 8);
self.buf[idx] = @truncate(u8, word);
}
pub inline fn get16(self: *const @This(), idx: usize) u16 {
return (@as(u16, self.buf[idx + 1]) << 8) | @as(u16, self.buf[idx]);
}
pub inline fn set16(self: *@This(), idx: usize, halfword: u16) void {
self.buf[idx + 1] = @truncate(u8, halfword >> 8);
self.buf[idx] = @truncate(u8, halfword);
}
pub inline fn get8(self: *const @This(), idx: usize) u8 {
return self.buf[idx];
}
};