From 12d4439037a55c13b9e5202b2cc7890e6b748a20 Mon Sep 17 00:00:00 2001
From: Michael Zhang <mail@mzhang.io>
Date: Fri, 8 Jan 2021 20:18:09 -0600
Subject: [PATCH] draw the grid

---
 src/game/grid.rs | 62 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/game/mod.rs  | 20 ++++++----------
 todo.txt         |  1 -
 3 files changed, 69 insertions(+), 14 deletions(-)
 create mode 100644 src/game/grid.rs

diff --git a/src/game/grid.rs b/src/game/grid.rs
new file mode 100644
index 0000000..d7dd8ea
--- /dev/null
+++ b/src/game/grid.rs
@@ -0,0 +1,62 @@
+use anyhow::Result;
+use ggez::{
+    graphics::{self, Color, DrawMode, DrawParam, Mesh, StrokeOptions},
+    nalgebra::Point2,
+    Context,
+};
+
+use super::{Game, PLAYFIELD_BOUNDS as BOUNDS};
+
+pub const GRID_HEAVY: Color = Color::new(1.0, 1.0, 1.0, 0.25);
+pub const GRID_LIGHT: Color = Color::new(1.0, 1.0, 1.0, 0.05);
+
+impl Game {
+    pub(super) fn draw_grid(&self, ctx: &mut Context) -> Result<()> {
+        let playfield = Mesh::new_rectangle(
+            ctx,
+            DrawMode::Stroke(StrokeOptions::default()),
+            BOUNDS,
+            Color::new(1.0, 1.0, 1.0, 0.5),
+        )?;
+        graphics::draw(ctx, &playfield, DrawParam::default())?;
+
+        let min_x = BOUNDS.x;
+        let min_y = BOUNDS.y;
+        let max_x = min_x + BOUNDS.w;
+        let max_y = min_y + BOUNDS.h;
+
+        let grid_size = self.beatmap.inner.grid_size;
+
+        for x in (0..512).step_by(grid_size as usize) {
+            let (weight, color) = match x {
+                x if x == 0 || x == 256 || x == 512 => (2.0, GRID_HEAVY),
+                _ => (1.0, GRID_LIGHT),
+            };
+            let x = BOUNDS.x + x as f32 * BOUNDS.w / 512.0;
+            let line = Mesh::new_line(
+                ctx,
+                &[Point2::new(x, min_y), Point2::new(x, max_y)],
+                weight,
+                color,
+            )?;
+            graphics::draw(ctx, &line, DrawParam::default())?;
+        }
+
+        for y in (0..384).step_by(grid_size as usize) {
+            let (weight, color) = match y {
+                y if y == 0 || y == 192 || y == 384 => (2.0, GRID_HEAVY),
+                _ => (1.0, GRID_LIGHT),
+            };
+            let y = BOUNDS.y + y as f32 * BOUNDS.h / 384.0;
+            let line = Mesh::new_line(
+                ctx,
+                &[Point2::new(min_x, y), Point2::new(max_x, y)],
+                weight,
+                color,
+            )?;
+            graphics::draw(ctx, &line, DrawParam::default())?;
+        }
+
+        Ok(())
+    }
+}
diff --git a/src/game/mod.rs b/src/game/mod.rs
index 8d6c81d..17ae341 100644
--- a/src/game/mod.rs
+++ b/src/game/mod.rs
@@ -1,3 +1,4 @@
+mod grid;
 mod sliders;
 mod timeline;
 
@@ -10,13 +11,11 @@ use anyhow::Result;
 use ggez::{
     event::{EventHandler, KeyCode, KeyMods},
     graphics::{
-        self, Color, DrawMode, DrawParam, FillOptions, FilterMode, Mesh, Rect, StrokeOptions, Text,
-        WHITE,
+        self, Color, DrawMode, DrawParam, FilterMode, Mesh, Rect, StrokeOptions, Text, WHITE,
     },
-    nalgebra::Point2,
     Context, GameError, GameResult,
 };
-use libosu::{Beatmap, HitObject, HitObjectKind, Point, SpinnerInfo, Spline};
+use libosu::{Beatmap, HitObjectKind, Point, SpinnerInfo, Spline};
 
 use crate::audio::{AudioEngine, Sound};
 use crate::beatmap::{BeatmapExt, STACK_DISTANCE};
@@ -25,6 +24,9 @@ use crate::skin::Skin;
 
 use self::sliders::render_slider;
 
+pub const PLAYFIELD_BOUNDS: Rect = Rect::new(112.0, 112.0, 800.0, 600.0);
+pub const SEEKER_BOUNDS: Rect = Rect::new(46.0, 722.0, 932.0, 36.0);
+
 pub type SliderCache = HashMap<Vec<Point<i32>>, Spline>;
 
 pub struct Game {
@@ -89,18 +91,10 @@ impl Game {
 
     fn priv_draw(&mut self, ctx: &mut Context) -> Result<()> {
         // TODO: lol
-        const PLAYFIELD_BOUNDS: Rect = Rect::new(112.0, 112.0, 800.0, 600.0);
-        const SEEKER_BOUNDS: Rect = Rect::new(46.0, 722.0, 932.0, 36.0);
 
         graphics::clear(ctx, [0.0, 0.0, 0.0, 1.0].into());
 
-        let playfield = Mesh::new_rectangle(
-            ctx,
-            DrawMode::Stroke(StrokeOptions::default()),
-            PLAYFIELD_BOUNDS,
-            Color::new(1.0, 1.0, 1.0, 0.5),
-        )?;
-        graphics::draw(ctx, &playfield, DrawParam::default())?;
+        self.draw_grid(ctx)?;
 
         let time = self.song.as_ref().unwrap().position()?;
         let text = Text::new(format!("time: {}", time).as_ref());
diff --git a/todo.txt b/todo.txt
index 4c77ee7..1f185ab 100644
--- a/todo.txt
+++ b/todo.txt
@@ -1,4 +1,3 @@
 - stacking
 - don't draw overlaps between slider segments
-- use skin components
 - timeline