zba/src/platform.zig

303 lines
12 KiB
Zig

const std = @import("std");
const SDL = @import("sdl2");
const gl = @import("gl");
const emu = @import("core/emu.zig");
const config = @import("config.zig");
const Apu = @import("core/apu.zig").Apu;
const Arm7tdmi = @import("core/cpu.zig").Arm7tdmi;
const Scheduler = @import("core/scheduler.zig").Scheduler;
const FpsTracker = @import("util.zig").FpsTracker;
const span = @import("util.zig").span;
const pitch = @import("core/ppu.zig").framebuf_pitch;
const gba_width = @import("core/ppu.zig").width;
const gba_height = @import("core/ppu.zig").height;
const default_title: []const u8 = "ZBA";
pub const Gui = struct {
const Self = @This();
const SDL_GLContext = *anyopaque; // SDL.SDL_GLContext is a ?*anyopaque
const log = std.log.scoped(.Gui);
// zig fmt: off
const vertices: [32]f32 = [_]f32{
// Positions // Colours // Texture Coords
1.0, -1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 1.0, // Top Right
1.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, // Bottom Right
-1.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, // Bottom Left
-1.0, -1.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0, // Top Left
};
const indices: [6]u32 = [_]u32{
0, 1, 3, // First Triangle
1, 2, 3, // Second Triangle
};
// zig fmt: on
window: *SDL.SDL_Window,
ctx: SDL_GLContext,
title: []const u8,
audio: Audio,
program_id: gl.GLuint,
pub fn init(title: *const [12]u8, apu: *Apu, width: i32, height: i32) Self {
if (SDL.SDL_Init(SDL.SDL_INIT_VIDEO | SDL.SDL_INIT_EVENTS | SDL.SDL_INIT_AUDIO) < 0) panic();
if (SDL.SDL_GL_SetAttribute(SDL.SDL_GL_CONTEXT_PROFILE_MASK, SDL.SDL_GL_CONTEXT_PROFILE_CORE) < 0) panic();
if (SDL.SDL_GL_SetAttribute(SDL.SDL_GL_CONTEXT_MAJOR_VERSION, 3) < 0) panic();
if (SDL.SDL_GL_SetAttribute(SDL.SDL_GL_CONTEXT_MAJOR_VERSION, 3) < 0) panic();
const win_scale = @intCast(c_int, config.config().host.win_scale);
const window = SDL.SDL_CreateWindow(
default_title.ptr,
SDL.SDL_WINDOWPOS_CENTERED,
SDL.SDL_WINDOWPOS_CENTERED,
@as(c_int, width * win_scale),
@as(c_int, height * win_scale),
SDL.SDL_WINDOW_OPENGL | SDL.SDL_WINDOW_SHOWN,
) orelse panic();
const ctx = SDL.SDL_GL_CreateContext(window) orelse panic();
if (SDL.SDL_GL_MakeCurrent(window, ctx) < 0) panic();
gl.load(ctx, Self.glGetProcAddress) catch @panic("gl.load failed");
if (SDL.SDL_GL_SetSwapInterval(@boolToInt(config.config().host.vsync)) < 0) panic();
const program_id = compileShaders();
return Self{
.window = window,
.title = span(title),
.ctx = ctx,
.program_id = program_id,
.audio = Audio.init(apu),
};
}
fn compileShaders() gl.GLuint {
// TODO: Panic on Shader Compiler Failure + Error Message
const vert_shader = @embedFile("shader/pixelbuf.vert");
const frag_shader = @embedFile("shader/pixelbuf.frag");
const vs = gl.createShader(gl.VERTEX_SHADER);
defer gl.deleteShader(vs);
gl.shaderSource(vs, 1, &[_][*c]const u8{vert_shader}, 0);
gl.compileShader(vs);
const fs = gl.createShader(gl.FRAGMENT_SHADER);
defer gl.deleteShader(fs);
gl.shaderSource(fs, 1, &[_][*c]const u8{frag_shader}, 0);
gl.compileShader(fs);
const program = gl.createProgram();
gl.attachShader(program, vs);
gl.attachShader(program, fs);
gl.linkProgram(program);
return program;
}
// Returns the VAO ID since it's used in run()
fn generateBuffers() [3]c_uint {
var vao_id: c_uint = undefined;
var vbo_id: c_uint = undefined;
var ebo_id: c_uint = undefined;
gl.genVertexArrays(1, &vao_id);
gl.genBuffers(1, &vbo_id);
gl.genBuffers(1, &ebo_id);
gl.bindVertexArray(vao_id);
gl.bindBuffer(gl.ARRAY_BUFFER, vbo_id);
gl.bufferData(gl.ARRAY_BUFFER, @sizeOf(@TypeOf(vertices)), &vertices, gl.STATIC_DRAW);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, ebo_id);
gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, @sizeOf(@TypeOf(indices)), &indices, gl.STATIC_DRAW);
// Position
gl.vertexAttribPointer(0, 3, gl.FLOAT, gl.FALSE, 8 * @sizeOf(f32), @intToPtr(?*anyopaque, 0)); // lmao
gl.enableVertexAttribArray(0);
// Colour
gl.vertexAttribPointer(1, 3, gl.FLOAT, gl.FALSE, 8 * @sizeOf(f32), @intToPtr(?*anyopaque, (3 * @sizeOf(f32))));
gl.enableVertexAttribArray(1);
// Texture Coord
gl.vertexAttribPointer(2, 2, gl.FLOAT, gl.FALSE, 8 * @sizeOf(f32), @intToPtr(?*anyopaque, (6 * @sizeOf(f32))));
gl.enableVertexAttribArray(2);
return .{ vao_id, vbo_id, ebo_id };
}
fn generateTexture(buf: []const u8) c_uint {
var tex_id: c_uint = undefined;
gl.genTextures(1, &tex_id);
gl.bindTexture(gl.TEXTURE_2D, tex_id);
// gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
// gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gba_width, gba_height, 0, gl.RGBA, gl.UNSIGNED_INT_8_8_8_8, buf.ptr);
// gl.generateMipmap(gl.TEXTURE_2D); // TODO: Remove?
return tex_id;
}
pub fn run(self: *Self, cpu: *Arm7tdmi, scheduler: *Scheduler) !void {
var quit = std.atomic.Atomic(bool).init(false);
var tracker = FpsTracker.init();
const thread = try std.Thread.spawn(.{}, emu.run, .{ &quit, scheduler, cpu, &tracker });
defer thread.join();
var title_buf: [0x100]u8 = [_]u8{0} ** 0x100;
const vao_id = Self.generateBuffers()[0];
_ = Self.generateTexture(cpu.bus.ppu.framebuf.get(.Renderer));
emu_loop: while (true) {
var event: SDL.SDL_Event = undefined;
while (SDL.SDL_PollEvent(&event) != 0) {
switch (event.type) {
SDL.SDL_QUIT => break :emu_loop,
SDL.SDL_KEYDOWN => {
const io = &cpu.bus.io;
const key_code = event.key.keysym.sym;
switch (key_code) {
SDL.SDLK_UP => io.keyinput.up.unset(),
SDL.SDLK_DOWN => io.keyinput.down.unset(),
SDL.SDLK_LEFT => io.keyinput.left.unset(),
SDL.SDLK_RIGHT => io.keyinput.right.unset(),
SDL.SDLK_x => io.keyinput.a.unset(),
SDL.SDLK_z => io.keyinput.b.unset(),
SDL.SDLK_a => io.keyinput.shoulder_l.unset(),
SDL.SDLK_s => io.keyinput.shoulder_r.unset(),
SDL.SDLK_RETURN => io.keyinput.start.unset(),
SDL.SDLK_RSHIFT => io.keyinput.select.unset(),
else => {},
}
},
SDL.SDL_KEYUP => {
const io = &cpu.bus.io;
const key_code = event.key.keysym.sym;
switch (key_code) {
SDL.SDLK_UP => io.keyinput.up.set(),
SDL.SDLK_DOWN => io.keyinput.down.set(),
SDL.SDLK_LEFT => io.keyinput.left.set(),
SDL.SDLK_RIGHT => io.keyinput.right.set(),
SDL.SDLK_x => io.keyinput.a.set(),
SDL.SDLK_z => io.keyinput.b.set(),
SDL.SDLK_a => io.keyinput.shoulder_l.set(),
SDL.SDLK_s => io.keyinput.shoulder_r.set(),
SDL.SDLK_RETURN => io.keyinput.start.set(),
SDL.SDLK_RSHIFT => io.keyinput.select.set(),
SDL.SDLK_i => log.err("Sample Count: {}", .{@intCast(u32, SDL.SDL_AudioStreamAvailable(cpu.bus.apu.stream)) / (2 * @sizeOf(u16))}),
SDL.SDLK_j => log.err("Scheduler Capacity: {} | Scheduler Event Count: {}", .{ scheduler.queue.capacity(), scheduler.queue.count() }),
SDL.SDLK_k => {
// Dump IWRAM to file
log.info("PC: 0x{X:0>8}", .{cpu.r[15]});
log.info("LR: 0x{X:0>8}", .{cpu.r[14]});
// const iwram_file = try std.fs.cwd().createFile("iwram.bin", .{});
// defer iwram_file.close();
// try iwram_file.writeAll(cpu.bus.iwram.buf);
},
else => {},
}
},
else => {},
}
}
// Emulator has an internal Double Buffer
const framebuf = cpu.bus.ppu.framebuf.get(.Renderer);
gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, gba_width, gba_height, gl.RGBA, gl.UNSIGNED_INT_8_8_8_8, framebuf.ptr);
gl.useProgram(self.program_id);
gl.bindVertexArray(vao_id);
gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_INT, null);
SDL.SDL_GL_SwapWindow(self.window);
const dyn_title = std.fmt.bufPrint(&title_buf, "ZBA | {s} [Emu: {}fps] ", .{ self.title, tracker.value() }) catch unreachable;
SDL.SDL_SetWindowTitle(self.window, dyn_title.ptr);
}
quit.store(true, .SeqCst); // Terminate Emulator Thread
}
pub fn deinit(self: *Self) void {
self.audio.deinit();
// TODO: Buffer deletions
gl.deleteProgram(self.program_id);
SDL.SDL_GL_DeleteContext(self.ctx);
SDL.SDL_DestroyWindow(self.window);
SDL.SDL_Quit();
self.* = undefined;
}
fn glGetProcAddress(ctx: SDL.SDL_GLContext, proc: [:0]const u8) ?*anyopaque {
_ = ctx;
return SDL.SDL_GL_GetProcAddress(proc.ptr);
}
};
const Audio = struct {
const Self = @This();
const log = std.log.scoped(.PlatformAudio);
const sample_rate = @import("core/apu.zig").host_sample_rate;
device: SDL.SDL_AudioDeviceID,
fn init(apu: *Apu) Self {
var have: SDL.SDL_AudioSpec = undefined;
var want: SDL.SDL_AudioSpec = std.mem.zeroes(SDL.SDL_AudioSpec);
want.freq = sample_rate;
want.format = SDL.AUDIO_U16;
want.channels = 2;
want.samples = 0x100;
want.callback = Self.callback;
want.userdata = apu;
const device = SDL.SDL_OpenAudioDevice(null, 0, &want, &have, 0);
if (device == 0) panic();
SDL.SDL_PauseAudioDevice(device, 0); // Unpause Audio
return .{ .device = device };
}
fn deinit(self: *Self) void {
SDL.SDL_CloseAudioDevice(self.device);
self.* = undefined;
}
export fn callback(userdata: ?*anyopaque, stream: [*c]u8, len: c_int) void {
const apu = @ptrCast(*Apu, @alignCast(@alignOf(*Apu), userdata));
// TODO: Find a better way to mute this
if (!config.config().host.mute) {
_ = SDL.SDL_AudioStreamGet(apu.stream, stream, len);
} else {
// FIXME: I don't think this hack to remove DC Offset is acceptable :thinking:
std.mem.set(u8, stream[0..@intCast(usize, len)], 0x40);
}
// If we don't write anything, play silence otherwise garbage will be played
// if (written == 0) std.mem.set(u8, stream[0..@intCast(usize, len)], 0x40);
}
};
fn panic() noreturn {
const str = @as(?[*:0]const u8, SDL.SDL_GetError()) orelse "unknown error";
@panic(std.mem.sliceTo(str, 0));
}