From 04adcd4532160f2fed0ca51b41c0d30f424a71be Mon Sep 17 00:00:00 2001
From: Joseph Ferano <joseph@ferano.io>
Date: Fri, 27 Sep 2024 10:55:59 +0700
Subject: [PATCH] Boids

---
 .gitignore |   3 ++
 boids.odin | 115 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 118 insertions(+)
 create mode 100644 boids.odin

diff --git a/.gitignore b/.gitignore
index 8e5dba4..1f1de7e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,4 @@
 /org-roam.db
+/boids
+/floodfill
+/p5/
diff --git a/boids.odin b/boids.odin
new file mode 100644
index 0000000..9e869e2
--- /dev/null
+++ b/boids.odin
@@ -0,0 +1,115 @@
+package boids
+
+import rl "vendor:raylib"
+import "core:math"
+import "core:math/rand"
+import "core:fmt"
+
+Vec2  :: [2]f32
+Rect  :: rl.Rectangle
+Img   :: rl.Image
+Tex   :: rl.Texture
+Key   :: rl.KeyboardKey
+Color :: rl.Color
+
+SCREEN_WIDTH : i32 = 1600
+SCREEN_HEIGHT : i32 = 1000
+BW := f32(SCREEN_WIDTH)
+BH := f32(SCREEN_HEIGHT)
+
+Boid :: struct {
+    pos: Vec2,
+    angle: f32,
+    accel: Vec2,
+    vel: Vec2
+}
+
+GameState :: struct {
+    dt:      f32,
+    keymap:  map[string]Key,
+    follow_point: Maybe(Vec2),
+    boids: [dynamic]Boid,
+} 
+
+init_state :: proc() -> ^GameState {
+    keymap := make(map[string]Key)
+    keymap["Left"] = .A
+    keymap["Right"] = .D
+    keymap["Up"] = .W
+    keymap["Down"] = .S
+
+    state := GameState {
+        keymap = keymap,
+    }
+
+    boid := Boid {
+        pos = {100, 100},
+    }
+    append(&state.boids, boid)
+
+    cloned := new_clone(state)
+    return cloned
+}
+
+get_rand_angle :: proc(min: i32, max: i32) -> f32 { return f32(rl.GetRandomValue(min, max)) * rl.DEG2RAD }
+
+player_input :: proc(using s: ^GameState) {
+    horizontal: f32
+    vertical: f32
+    if rl.IsKeyDown(s.keymap["Right"]) { horizontal =  1 }
+    if rl.IsKeyDown(s.keymap["Left"]) { horizontal = -1 }
+    if rl.IsKeyDown(s.keymap["Up"]) { vertical   = -1 }
+    if rl.IsKeyDown(s.keymap["Down"]) { vertical   =  1 }
+    if rl.IsMouseButtonPressed(rl.MouseButton.LEFT) {
+        follow_point = rl.GetMousePosition()
+    }
+}
+
+update :: proc(using s: ^GameState) {
+    if fpoint, ok := follow_point.?; ok {
+        for &boid in boids {
+            desired := fpoint - boid.pos
+            desired = rl.Vector2ClampValue(desired, 10, 10)
+            steer := desired - boid.vel
+            steer = rl.Vector2ClampValue(steer, 0, 0.3)
+            boid.vel += steer
+            boid.pos += boid.vel
+        }
+    }
+}
+
+draw :: proc(using s: ^GameState) {
+    for boid in boids {
+        rl.DrawCircleV(boid.pos, 15, rl.RED)
+    }
+}
+
+main :: proc() {
+    rl.SetTraceLogLevel(.ERROR)
+    rl.InitWindow(SCREEN_WIDTH, SCREEN_HEIGHT, "Boids")
+    rl.SetTargetFPS(60)
+    // rl.DisableCursor()
+
+    state := init_state()
+    defer {
+        delete(state.boids)
+        free(state)   
+    }
+
+    for !rl.WindowShouldClose() {
+        state.dt = rl.GetFrameTime()
+
+        player_input(state)
+
+        update(state)
+
+        rl.BeginDrawing()
+        rl.ClearBackground(rl.WHITE)
+
+        draw(state)
+
+        rl.EndDrawing()
+    }
+
+    rl.CloseWindow()
+}