feat: use opengl

TODO:
- Texture isn't scaling properly
- I need to reverse the colours in the frag shader
This commit is contained in:
Rekai Nyangadzayi Musuka 2022-09-22 12:23:16 -03:00
parent 26dba16789
commit 1575f517a9
5 changed files with 9418 additions and 21 deletions

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@ -31,6 +31,9 @@ pub fn build(b: *std.build.Builder) void {
// TOML Library
exe.addPackagePath("toml", "lib/zig-toml/src/toml.zig");
// OpenGL Bindings
exe.addPackagePath("gl", "lib/gl_4v5.zig");
// Zig SDL Bindings: https://github.com/MasterQ32/SDL.zig
const sdk = Sdk.init(b);
sdk.link(exe, .dynamic);

9263
lib/gl_4v5.zig Normal file

File diff suppressed because it is too large Load Diff

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@ -1,5 +1,6 @@
const std = @import("std");
const SDL = @import("sdl2");
const gl = @import("gl");
const emu = @import("core/emu.zig");
const config = @import("config.zig");
@ -11,21 +12,43 @@ 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,
renderer: *SDL.SDL_Renderer,
texture: *SDL.SDL_Texture,
audio: Audio,
program_id: gl.GLuint,
pub fn init(title: *const [12]u8, apu: *Apu, width: i32, height: i32) Self {
const ret = SDL.SDL_Init(SDL.SDL_INIT_VIDEO | SDL.SDL_INIT_EVENTS | SDL.SDL_INIT_AUDIO | SDL.SDL_INIT_GAMECONTROLLER);
if (ret < 0) panic();
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, 4) < 0) panic();
if (SDL.SDL_GL_SetAttribute(SDL.SDL_GL_CONTEXT_MAJOR_VERSION, 4) < 0) panic();
const win_scale = @intCast(c_int, config.config().host.win_scale);
@ -35,29 +58,98 @@ pub const Gui = struct {
SDL.SDL_WINDOWPOS_CENTERED,
@as(c_int, width * win_scale),
@as(c_int, height * win_scale),
SDL.SDL_WINDOW_SHOWN,
SDL.SDL_WINDOW_OPENGL | SDL.SDL_WINDOW_SHOWN,
) orelse panic();
const renderer_flags = SDL.SDL_RENDERER_ACCELERATED | if (config.config().host.vsync) SDL.SDL_RENDERER_PRESENTVSYNC else 0;
const renderer = SDL.SDL_CreateRenderer(window, -1, @bitCast(u32, renderer_flags)) orelse panic();
const ctx = SDL.SDL_GL_CreateContext(window) orelse panic();
if (SDL.SDL_GL_MakeCurrent(window, ctx) < 0) panic();
const texture = SDL.SDL_CreateTexture(
renderer,
SDL.SDL_PIXELFORMAT_RGBA8888,
SDL.SDL_TEXTUREACCESS_STREAMING,
@as(c_int, width),
@as(c_int, height),
) orelse panic();
gl.load(ctx, Self.glGetProcAddress) catch @panic("gl.load failed");
if (config.config().host.vsync) if (SDL.SDL_GL_SetSwapInterval(1) < 0) panic();
const program_id = compileShaders();
return Self{
.window = window,
.title = span(title),
.renderer = renderer,
.texture = texture,
.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), &0);
gl.enableVertexAttribArray(0);
// Colour
gl.vertexAttribPointer(1, 3, gl.FLOAT, gl.FALSE, 8 * @sizeOf(f32), &(3 * @sizeOf(f32)));
gl.enableVertexAttribArray(1);
// Texture Coord
gl.vertexAttribPointer(2, 3, gl.FLOAT, gl.FALSE, 8 * @sizeOf(f32), &(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_BYTE, 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();
@ -67,6 +159,9 @@ pub const Gui = struct {
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) {
@ -125,9 +220,12 @@ pub const Gui = struct {
// Emulator has an internal Double Buffer
const framebuf = cpu.bus.ppu.framebuf.get(.Renderer);
_ = SDL.SDL_UpdateTexture(self.texture, null, framebuf.ptr, pitch);
_ = SDL.SDL_RenderCopy(self.renderer, self.texture, null, null);
SDL.SDL_RenderPresent(self.renderer);
gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, gba_width, gba_height, gl.RGBA, gl.UNSIGNED_BYTE, 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);
@ -138,12 +236,17 @@ pub const Gui = struct {
pub fn deinit(self: *Self) void {
self.audio.deinit();
SDL.SDL_DestroyTexture(self.texture);
SDL.SDL_DestroyRenderer(self.renderer);
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(@ptrCast([*c]const u8, proc));
}
};
const Audio = struct {

14
src/shader/pixelbuf.frag Normal file
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@ -0,0 +1,14 @@
#version 450 core
out vec4 FragColor;
in vec3 ourColor;
in vec2 TexCoord;
// texture sampler
uniform sampler2D texture1;
void main()
{
FragColor = texture(texture1, TexCoord).wzyx;
}

14
src/shader/pixelbuf.vert Normal file
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@ -0,0 +1,14 @@
#version 450 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aColor;
layout (location = 2) in vec2 aTexCoord;
out vec3 ourColor;
out vec2 TexCoord;
void main()
{
gl_Position = vec4(aPos, 1.0);
ourColor = aColor;
TexCoord = vec2(aTexCoord.x, aTexCoord.y);
}