zba/src/platform.zig

501 lines
18 KiB
Zig

const std = @import("std");
const SDL = @import("sdl2");
const gl = @import("gl");
const zgui = @import("zgui");
const emu = @import("core/emu.zig");
const config = @import("config.zig");
const imgui = @import("imgui.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 Channel = @import("zba-util").Channel(emu.Message, 0x100);
const KeyInput = @import("core/bus/io.zig").KeyInput;
const gba_width = @import("core/ppu.zig").width;
const gba_height = @import("core/ppu.zig").height;
const GLuint = gl.GLuint;
const GLsizei = gl.GLsizei;
const SDL_GLContext = *anyopaque;
const Allocator = std.mem.Allocator;
pub const Dimensions = struct { width: u32, height: u32 };
const default_dim: Dimensions = .{ .width = 1280, .height = 720 };
pub const sample_rate = 1 << 15;
pub const sample_format = SDL.AUDIO_U16;
const window_title = "ZBA";
pub const Gui = struct {
const Self = @This();
const log = std.log.scoped(.Gui);
window: *SDL.SDL_Window,
ctx: SDL_GLContext,
audio: Audio,
state: imgui.State,
allocator: Allocator,
pub fn init(allocator: Allocator, apu: *Apu, title_opt: ?*const [12]u8) !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 window = SDL.SDL_CreateWindow(
window_title,
SDL.SDL_WINDOWPOS_CENTERED,
SDL.SDL_WINDOWPOS_CENTERED,
default_dim.width,
default_dim.height,
SDL.SDL_WINDOW_OPENGL | SDL.SDL_WINDOW_SHOWN | SDL.SDL_WINDOW_RESIZABLE,
) 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 {};
if (SDL.SDL_GL_SetSwapInterval(@boolToInt(config.config().host.vsync)) < 0) panic();
zgui.init(allocator);
zgui.plot.init();
zgui.backend.init(window, ctx, "#version 330 core");
// zgui.io.setIniFilename(null);
return Self{
.window = window,
.ctx = ctx,
.audio = Audio.init(apu),
.allocator = allocator,
.state = try imgui.State.init(allocator, title_opt),
};
}
pub fn deinit(self: *Self) void {
self.audio.deinit();
self.state.deinit(self.allocator);
zgui.backend.deinit();
zgui.plot.deinit();
zgui.deinit();
SDL.SDL_GL_DeleteContext(self.ctx);
SDL.SDL_DestroyWindow(self.window);
SDL.SDL_Quit();
self.* = undefined;
}
const RunOptions = struct {
ch: Channel.Sender,
tracker: ?*FpsTracker = null,
cpu: *Arm7tdmi,
scheduler: *Scheduler,
};
const RunMode = enum { Standard, Debug };
pub fn run(self: *Self, comptime mode: RunMode, opt: RunOptions) !void {
const cpu = opt.cpu;
const tracker = opt.tracker;
const ch = opt.ch;
const objects = opengl_impl.createObjects();
defer gl.deleteBuffers(3, @as(*const [3]GLuint, &.{ objects.vao, objects.vbo, objects.ebo }));
const emu_tex = opengl_impl.createScreenTexture(cpu.bus.ppu.framebuf.get(.Renderer));
const out_tex = opengl_impl.createOutputTexture();
defer gl.deleteTextures(2, &[_]GLuint{ emu_tex, out_tex });
const fbo_id = try opengl_impl.createFrameBuffer(out_tex);
defer gl.deleteFramebuffers(1, &fbo_id);
// TODO: Support dynamically switching shaders?
const prog_id = try opengl_impl.compileShaders();
defer gl.deleteProgram(prog_id);
var win_dim: Dimensions = default_dim;
emu_loop: while (true) {
// Outside of `SDL.SDL_QUIT` below, the DearImgui UI might signal that the program
// should exit, in which case we should also handle this
if (self.state.should_quit) break :emu_loop;
var event: SDL.SDL_Event = undefined;
while (SDL.SDL_PollEvent(&event) != 0) {
_ = zgui.backend.processEvent(&event);
switch (event.type) {
SDL.SDL_QUIT => break :emu_loop,
SDL.SDL_KEYDOWN => {
// TODO: Make use of compare_and_xor?
const key_code = event.key.keysym.sym;
var keyinput: KeyInput = .{ .raw = 0x0000 };
switch (key_code) {
SDL.SDLK_UP => keyinput.up.set(),
SDL.SDLK_DOWN => keyinput.down.set(),
SDL.SDLK_LEFT => keyinput.left.set(),
SDL.SDLK_RIGHT => keyinput.right.set(),
SDL.SDLK_x => keyinput.a.set(),
SDL.SDLK_z => keyinput.b.set(),
SDL.SDLK_a => keyinput.shoulder_l.set(),
SDL.SDLK_s => keyinput.shoulder_r.set(),
SDL.SDLK_RETURN => keyinput.start.set(),
SDL.SDLK_RSHIFT => keyinput.select.set(),
else => {},
}
cpu.bus.io.keyinput.fetchAnd(~keyinput.raw, .Monotonic);
},
SDL.SDL_KEYUP => {
// TODO: Make use of compare_and_xor?
const key_code = event.key.keysym.sym;
var keyinput: KeyInput = .{ .raw = 0x0000 };
switch (key_code) {
SDL.SDLK_UP => keyinput.up.set(),
SDL.SDLK_DOWN => keyinput.down.set(),
SDL.SDLK_LEFT => keyinput.left.set(),
SDL.SDLK_RIGHT => keyinput.right.set(),
SDL.SDLK_x => keyinput.a.set(),
SDL.SDLK_z => keyinput.b.set(),
SDL.SDLK_a => keyinput.shoulder_l.set(),
SDL.SDLK_s => keyinput.shoulder_r.set(),
SDL.SDLK_RETURN => keyinput.start.set(),
SDL.SDLK_RSHIFT => keyinput.select.set(),
else => {},
}
cpu.bus.io.keyinput.fetchOr(keyinput.raw, .Monotonic);
},
SDL.SDL_WINDOWEVENT => {
if (event.window.event == SDL.SDL_WINDOWEVENT_RESIZED) {
log.debug("window resized to: {}x{}", .{ event.window.data1, event.window.data2 });
win_dim.width = @intCast(u32, event.window.data1);
win_dim.height = @intCast(u32, event.window.data2);
}
},
else => {},
}
}
var zgui_redraw: bool = false;
switch (self.state.emulation) {
.Transition => |inner| switch (inner) {
.Active => {
ch.send(.Resume);
if (!config.config().host.mute) SDL.SDL_PauseAudioDevice(self.audio.device, 0);
self.state.emulation = .Active;
},
.Inactive => {
// Assert that double pausing is impossible
SDL.SDL_PauseAudioDevice(self.audio.device, 1);
ch.send(.Pause);
self.state.emulation = .Inactive;
},
},
.Active => {
const is_std = mode == .Standard;
if (is_std) ch.send(.Pause);
defer if (is_std) ch.send(.Resume);
// switch (mode) {
// .Standard => blk: {
// const limit = 15; // TODO: What should this be?
// // TODO: learn more about std.atomic.spinLoopHint();
// for (0..limit) |_| {
// const message = channel.gui.pop() orelse continue;
// switch (message) {
// .Paused => break :blk,
// .Quit => unreachable,
// }
// }
// log.info("timed out waiting for emu thread to pause (limit: {})", .{limit});
// break :skip_draw;
// },
// .Debug => blk: {
// switch (channel.gui.pop() orelse break :blk) {
// .Paused => unreachable, // only in standard mode
// .Quit => break :emu_loop, // FIXME: gdb side of emu is seriously out-of-date...
// }
// },
// }
// Add FPS count to the histogram
if (tracker) |t| self.state.fps_hist.push(t.value()) catch {};
// Draw GBA Screen to Texture
{
gl.bindFramebuffer(gl.FRAMEBUFFER, fbo_id);
defer gl.bindFramebuffer(gl.FRAMEBUFFER, 0);
const buf = cpu.bus.ppu.framebuf.get(.Renderer);
gl.viewport(0, 0, gba_width, gba_height);
opengl_impl.drawScreenTexture(emu_tex, prog_id, objects, buf);
}
// FIXME: We only really care about locking the audio device (and therefore writing silence)
// since if nfd-zig is used the emu may be paused for way too long. Perhaps we should try and limit
// spurious calls to SDL_LockAudioDevice?
SDL.SDL_LockAudioDevice(self.audio.device);
defer SDL.SDL_UnlockAudioDevice(self.audio.device);
zgui_redraw = imgui.draw(&self.state, win_dim, out_tex, cpu);
},
.Inactive => zgui_redraw = imgui.draw(&self.state, win_dim, out_tex, cpu),
}
if (zgui_redraw) {
// Background Colour
const size = zgui.io.getDisplaySize();
gl.viewport(0, 0, @floatToInt(GLsizei, size[0]), @floatToInt(GLsizei, size[1]));
gl.clearColor(0, 0, 0, 1.0);
gl.clear(gl.COLOR_BUFFER_BIT);
zgui.backend.draw();
}
SDL.SDL_GL_SwapWindow(self.window);
}
ch.send(.Quit);
}
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);
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 = sample_format;
want.channels = 2;
want.samples = 0x100;
want.callback = Self.callback;
want.userdata = apu;
std.debug.assert(sample_format == SDL.AUDIO_U16);
log.info("Host Sample Rate: {}Hz, Host Format: SDL.AUDIO_U16", .{sample_rate});
const device = SDL.SDL_OpenAudioDevice(null, 0, &want, &have, 0);
if (device == 0) panic();
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 T = *Apu;
const apu = @ptrCast(T, @alignCast(@alignOf(T), userdata));
_ = SDL.SDL_AudioStreamGet(apu.stream, stream, len);
}
};
fn panic() noreturn {
const str = @as(?[*:0]const u8, SDL.SDL_GetError()) orelse "unknown error";
@panic(std.mem.sliceTo(str, 0));
}
const opengl_impl = struct {
// 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
const Objects = struct { vao: GLuint, vbo: GLuint, ebo: GLuint };
fn drawScreenTexture(tex_id: GLuint, prog_id: GLuint, ids: Objects, buf: []const u8) void {
gl.bindTexture(gl.TEXTURE_2D, tex_id);
defer gl.bindTexture(gl.TEXTURE_2D, 0);
gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, gba_width, gba_height, gl.RGBA, gl.UNSIGNED_INT_8_8_8_8, buf.ptr);
// Bind VAO, EBO. VBO not bound
gl.bindVertexArray(ids.vao); // VAO
defer gl.bindVertexArray(0);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, ids.ebo); // EBO
defer gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0);
// Use compiled frag + vertex shader
gl.useProgram(prog_id);
defer gl.useProgram(0);
gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_INT, null);
}
fn compileShaders() !GLuint {
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);
if (!shader.didCompile(vs)) return error.VertexCompileError;
const fs = gl.createShader(gl.FRAGMENT_SHADER);
defer gl.deleteShader(fs);
gl.shaderSource(fs, 1, &[_][*c]const u8{frag_shader}, 0);
gl.compileShader(fs);
if (!shader.didCompile(fs)) return error.FragmentCompileError;
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 createObjects() Objects {
var vao_id: GLuint = undefined;
var vbo_id: GLuint = undefined;
var ebo_id: GLuint = undefined;
gl.genVertexArrays(1, &vao_id);
gl.genBuffers(1, &vbo_id);
gl.genBuffers(1, &ebo_id);
gl.bindVertexArray(vao_id);
defer gl.bindVertexArray(0);
gl.bindBuffer(gl.ARRAY_BUFFER, vbo_id);
defer gl.bindBuffer(gl.ARRAY_BUFFER, 0);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, ebo_id);
defer gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0);
gl.bufferData(gl.ARRAY_BUFFER, @sizeOf(@TypeOf(vertices)), &vertices, gl.STATIC_DRAW);
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), null); // 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 = vao_id, .vbo = vbo_id, .ebo = ebo_id };
}
fn createScreenTexture(buf: []const u8) GLuint {
var tex_id: GLuint = undefined;
gl.genTextures(1, &tex_id);
gl.bindTexture(gl.TEXTURE_2D, tex_id);
defer gl.bindTexture(gl.TEXTURE_2D, 0);
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);
return tex_id;
}
fn createOutputTexture() GLuint {
var tex_id: GLuint = undefined;
gl.genTextures(1, &tex_id);
gl.bindTexture(gl.TEXTURE_2D, tex_id);
defer gl.bindTexture(gl.TEXTURE_2D, 0);
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, null);
return tex_id;
}
fn createFrameBuffer(tex_id: GLuint) !GLuint {
var fbo_id: GLuint = undefined;
gl.genFramebuffers(1, &fbo_id);
gl.bindFramebuffer(gl.FRAMEBUFFER, fbo_id);
defer gl.bindFramebuffer(gl.FRAMEBUFFER, 0);
gl.framebufferTexture(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, tex_id, 0);
const draw_buffers: [1]GLuint = .{gl.COLOR_ATTACHMENT0};
gl.drawBuffers(1, &draw_buffers);
if (gl.checkFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE)
return error.FrameBufferObejctInitFailed;
return fbo_id;
}
const shader = struct {
const Kind = enum { vertex, fragment };
const log = std.log.scoped(.Shader);
fn didCompile(id: gl.GLuint) bool {
var success: gl.GLint = undefined;
gl.getShaderiv(id, gl.COMPILE_STATUS, &success);
if (success == 0) err(id);
return success == 1;
}
fn err(id: gl.GLuint) void {
const buf_len = 512;
var error_msg: [buf_len]u8 = undefined;
gl.getShaderInfoLog(id, buf_len, 0, &error_msg);
log.err("{s}", .{std.mem.sliceTo(&error_msg, 0)});
}
};
};