changed main.rs to be a lot cleaner

Cargo.lock

@@ -74,6 +74,7 @@ dependencies = [
  "ceres-sys 0.1.0",
  "offbrand 0.1.0",
  "structopt 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thiserror 1.0.20 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]

Cargo.toml

@@ -10,9 +10,10 @@ offbrand = { path = "../offbrand" }
 structopt = "0.3.14"
 ceres-sys = { path = "ceres-sys" }
 ceres-asm = { path = "ceres-asm" }
+thiserror = "1.0.20"
 
 [workspace]
 members = [
     "ceres-sys",
     "ceres-asm",
-]
+]

src/main.rs

@@ -1,58 +1,90 @@
 use offbrand::prelude::*;
+use std::path::PathBuf;
 use structopt::StructOpt;
 
+// result type
+pub type Result<T> = std::result::Result<T, CeresError>;
+
+#[derive(Debug, thiserror::Error)]
+pub enum CeresError {
+    #[error(transparent)]
+    CeresAsm(#[from] ceres_asm::CeresAsmError),
+    #[error(transparent)]
+    StdIo(#[from] std::io::Error),
+    #[error(transparent)]
+    Offbrand(#[from] offbrand::Error),
+}
+
 #[derive(StructOpt)]
 #[structopt(name = "CERES-16", about = "16bit fantasy console")]
 struct Opt {
-    /// times the screen should be scaled by
+    /// how much the screen should be scaled by
     #[structopt(short = "s", long = "scale", default_value = "4")]
-    _scale_factor: usize,
+    scale_factor: usize,
+
+    /// assemble some source
+    #[structopt(short = "a", long = "assemble")]
+    source_path: Option<PathBuf>,
+
+    /// output file for assembly
+    #[structopt(short = "o", long = "output")]
+    output_path: Option<PathBuf>,
 }
 
 fn wrapper() -> Result<()> {
     // load options
-    let _opt = Opt::from_args();
-
-    // initialize the system
-    let _sys = ceres_sys::System::init();
-
-    let data = std::fs::read_to_string("test.asm").unwrap();
-    let mut assembler = ceres_asm::Assembler::new(&data);
-    let asm = assembler.assemble().unwrap();
-    asm.0.iter().for_each(|instruction| println!("0b{:032b}", instruction));
-    asm.write_to_file(None).unwrap();
-
-    /*
-    // create a new graphics context
-    let mut ctx = offbrand::Context::new(
-        ceres_sys::SCREEN_WIDTH,
-        ceres_sys::SCREEN_HEIGHT,
-        "CERES-16".to_owned(),
-        Some(opt.scale_factor),
-    )?;
-
-    // loop while the context window is open
-    while ctx.is_open() {
-        // clear the context
-        ctx.clear(None);
-
-        // print a pixel for ever word in the video memory buffer
-        for x in 0..ceres_sys::SCREEN_WIDTH {
-            for y in 0..ceres_sys::SCREEN_HEIGHT {
-                let color =
-                    color_from_u16(sys.video_memory[(y * ceres_sys::SCREEN_WIDTH + x) as u16]);
-                ctx.insert_pixel(x, y, color);
+    let opt = Opt::from_args();
+
+    if let Some(path) = opt.source_path {
+        // if assmebly flag provided assemble the code
+        let data = std::fs::read_to_string(path)?;
+        let mut assembler = ceres_asm::Assembler::new(&data);
+        let asm = assembler.assemble()?;
+        asm.write_to_file(opt.output_path)?;
+    } else {
+        // otherwise start the console
+
+        // initialize the system
+        let sys = ceres_sys::System::init();
+
+        // create a new graphics context
+        let mut ctx = offbrand::Context::new(
+            ceres_sys::SCREEN_WIDTH,
+            ceres_sys::SCREEN_HEIGHT,
+            "CERES-16".to_owned(),
+            Some(opt.scale_factor),
+        )?;
+
+        // loop while the context window is open
+        while ctx.is_open() {
+            // clear the context
+            ctx.clear(None);
+
+            // print a pixel for ever word in the video memory buffer
+            for x in 0..ceres_sys::SCREEN_WIDTH {
+                for y in 0..ceres_sys::SCREEN_HEIGHT {
+                    let color =
+                        color_from_u16(sys.video_memory[(y * ceres_sys::SCREEN_WIDTH + x) as u16]);
+                    ctx.insert_pixel(x, y, color);
+                }
             }
-        }
 
-        // render the context
-        ctx.present()?;
+            // render the context
+            ctx.present()?;
+        }
     }
-    */
 
     Ok(())
 }
 
+// convert a color from u16
+fn color_from_u16(color: u16) -> Color {
+    let r = (((color >> 8) & 0x000f) as u8) * 17;
+    let g = (((color >> 4) & 0x000f) as u8) * 17;
+    let b = ((color & 0x000f) as u8) * 17;
+    Color { r, g, b }
+}
+
 fn main() {
     if let Err(err) = wrapper() {
         eprintln!("error: {:?}", err);