From 71bfdf18c08e04fed139cdfaea4c8e81fecc7a27 Mon Sep 17 00:00:00 2001
From: Michael Zhang <mail@mzhang.io>
Date: Tue, 4 Jan 2022 02:23:21 -0600
Subject: [PATCH] initial

---
 .gitignore    |  4 ++++
 build.zig     | 27 +++++++++++++++++++++++++++
 src/main.zig  | 32 ++++++++++++++++++++++++++++++++
 src/point.zig | 15 +++++++++++++++
 4 files changed, 78 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 build.zig
 create mode 100644 src/main.zig
 create mode 100644 src/point.zig

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..7ffeddf
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+zig-cache
+zig-out
+
+out.*
diff --git a/build.zig b/build.zig
new file mode 100644
index 0000000..7b00ca5
--- /dev/null
+++ b/build.zig
@@ -0,0 +1,27 @@
+const std = @import("std");
+
+pub fn build(b: *std.build.Builder) void {
+    // Standard target options allows the person running `zig build` to choose
+    // what target to build for. Here we do not override the defaults, which
+    // means any target is allowed, and the default is native. Other options
+    // for restricting supported target set are available.
+    const target = b.standardTargetOptions(.{});
+
+    // Standard release options allow the person running `zig build` to select
+    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall.
+    const mode = b.standardReleaseOptions();
+
+    const exe = b.addExecutable("zigtracer", "src/main.zig");
+    exe.setTarget(target);
+    exe.setBuildMode(mode);
+    exe.install();
+
+    const run_cmd = exe.run();
+    run_cmd.step.dependOn(b.getInstallStep());
+    if (b.args) |args| {
+        run_cmd.addArgs(args);
+    }
+
+    const run_step = b.step("run", "Run the app");
+    run_step.dependOn(&run_cmd.step);
+}
diff --git a/src/main.zig b/src/main.zig
new file mode 100644
index 0000000..6531f74
--- /dev/null
+++ b/src/main.zig
@@ -0,0 +1,32 @@
+const std = @import("std");
+
+pub fn main() anyerror!void {
+    const stdout = std.io.getStdOut().writer();
+    const image_width = 256;
+    const image_height = 256;
+
+    std.log.info("All your codebase are belong to us.", .{});
+
+    // PPM header
+    try stdout.print("P3\n{d} {d}\n255\n", .{ image_width, image_height });
+
+    // this is a REALLY awkward way of writing a for-loop
+    var j: u32 = 0;
+    while (j < image_height) : (j += 1) {
+        var i: u32 = 0;
+        while (i < image_width) : (i += 1) {
+            // doing this makes the loop bounds a bit cleaner
+            const j_ = image_height - 1 - j;
+
+            const r = @intToFloat(f64, i) / (image_width - 1);
+            const g = @intToFloat(f64, j_) / (image_width - 1);
+            const b = 0.25;
+
+            const ir = @floatToInt(u32, 255.999 * r);
+            const ig = @floatToInt(u32, 255.999 * g);
+            const ib = @floatToInt(u32, 255.999 * b);
+
+            try stdout.print("{d} {d} {d}\n", .{ ir, ig, ib });
+        }
+    }
+}
diff --git a/src/point.zig b/src/point.zig
new file mode 100644
index 0000000..10f8f12
--- /dev/null
+++ b/src/point.zig
@@ -0,0 +1,15 @@
+const vec3 = struct {
+    x: f64,
+    y: f64,
+    z: f64,
+
+    pub fn plus(self: vec3, other: vec3) vec3 {
+        return vec3{
+            self.x + other.x,
+            self.y + other.y,
+            self.z + other.z,
+        };
+    }
+};
+
+const color = vec3;