chore: add code for heap alloc of white texture

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "lib/SDL.zig"]
+	path = lib/SDL.zig
+	url = https://github.com/MasterQ32/SDL.zig

build.zig

@@ -1,4 +1,5 @@
 const std = @import("std");
+const Sdk = @import("lib/SDL.zig/Sdk.zig");
 
 pub fn build(b: *std.build.Builder) void {
     // Standard target options allows the person running `zig build` to choose
@@ -14,7 +15,13 @@ pub fn build(b: *std.build.Builder) void {
     const exe = b.addExecutable("zba", "src/main.zig");
 
     // Bitfield type from FlorenceOS: https://github.com/FlorenceOS/
-    exe.addPackage(.{ .name = "bitfield", .path = .{ .path = "./lib/util/bitfield.zig" } });
+    exe.addPackage(.{ .name = "bitfield", .path = .{ .path = "lib/util/bitfield.zig" } });
+
+    // Zig SDL Bindings: https://github.com/MasterQ32/SDL.zig
+    const sdk = Sdk.init(b);
+    sdk.link(exe, .dynamic);
+
+    exe.addPackage(sdk.getNativePackage("sdl2"));
 
     exe.setTarget(target);
     exe.setBuildMode(mode);

lib/SDL.zig

@@ -0,0 +1 @@
+Subproject commit d3a764869b31575d3d73cc874b1ff27879407b5a

src/main.zig

@@ -1,15 +1,18 @@
 const std = @import("std");
-const emu = @import("emu.zig");
+const SDL = @import("sdl2");
 
+const emu = @import("emu.zig");
 const Bus = @import("Bus.zig");
 const Arm7tdmi = @import("cpu.zig").Arm7tdmi;
 const Scheduler = @import("scheduler.zig").Scheduler;
 
 pub fn main() anyerror!void {
+    // Allocator for Emulator + CLI Aruments
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
     const alloc = gpa.allocator();
     defer std.debug.assert(!gpa.deinit());
 
+    // Handle CLI Arguments
     const args = try std.process.argsAlloc(alloc);
     defer std.process.argsFree(alloc, args);
 
@@ -23,6 +26,7 @@ pub fn main() anyerror!void {
         return;
     }
 
+    // Initialize Emulator
     var scheduler = Scheduler.init(alloc);
     defer scheduler.deinit();
 
@@ -30,14 +34,55 @@ pub fn main() anyerror!void {
     defer bus.deinit();
 
     var cpu = Arm7tdmi.init(&scheduler, &bus);
-
     cpu.skipBios();
 
-    while (true) {
+    // Initialize SDL
+    const status = SDL.SDL_Init(SDL.SDL_INIT_VIDEO | SDL.SDL_INIT_EVENTS | SDL.SDL_INIT_AUDIO);
+    if (status < 0) sdlPanic();
+    defer SDL.SDL_Quit();
+
+    var window = SDL.SDL_CreateWindow(
+        "Gameboy Advance Emulator",
+        SDL.SDL_WINDOWPOS_CENTERED,
+        SDL.SDL_WINDOWPOS_CENTERED,
+        240 * 3,
+        160 * 3,
+        SDL.SDL_WINDOW_SHOWN,
+    ) orelse sdlPanic();
+    defer SDL.SDL_DestroyWindow(window);
+
+    var renderer = SDL.SDL_CreateRenderer(window, -1, SDL.SDL_RENDERER_ACCELERATED) orelse sdlPanic();
+    defer SDL.SDL_DestroyRenderer(renderer);
+
+    const texture = SDL.SDL_CreateTexture(renderer, SDL.SDL_PIXELFORMAT_BGR555, SDL.SDL_TEXTUREACCESS_STREAMING, 240, 160) orelse sdlPanic();
+    defer SDL.SDL_DestroyTexture(texture);
+
+    const buf_pitch = 240 * @sizeOf(u16);
+    const buf_len = buf_pitch * 160;
+    var white: [buf_len]u8 = [_]u8{ 0xFF, 0x7F } ** (buf_len / 2);
+
+    var white_heap = try alloc.alloc(u8, buf_len);
+    for (white) |b, i| white_heap[i] = b;
+    defer alloc.free(white_heap);
+
+    emu_loop: while (true) {
         emu.runFrame(&scheduler, &cpu, &bus);
+
+        var event: SDL.SDL_Event = undefined;
+        _ = SDL.SDL_PollEvent(&event);
+
+        switch (event.type) {
+            SDL.SDL_QUIT => break :emu_loop,
+            else => {},
+        }
+
+        _ = SDL.SDL_UpdateTexture(texture, null, &white_heap, buf_pitch);
+        _ = SDL.SDL_RenderCopy(renderer, texture, null, null);
+        SDL.SDL_RenderPresent(renderer);
     }
 }
 
-test "basic test" {
-    try std.testing.expectEqual(10, 3 + 7);
+fn sdlPanic() noreturn {
+    const str = @as(?[*:0]const u8, SDL.SDL_GetError()) orelse "unknown error";
+    @panic(std.mem.sliceTo(str, 0));
 }

src/ppu.zig

@@ -23,6 +23,7 @@ pub const Ppu = struct {
 
     pub fn deinit(self: @This()) void {
         self.vram.deinit();
+        self.palette.deinit();
     }
 };