Assign entities random RGB colors

src/sandbox.zig

@@ -104,12 +104,18 @@ pub fn spawnAtEdge(rng: *std.Random) Entity {
     const vx = (dx / dist) * ENTITY_SPEED;
     const vy = (dy / dist) * ENTITY_SPEED;
 
+    // random RGB color
+    const r = rng.int(u8);
+    const g = rng.int(u8);
+    const b = rng.int(u8);
+    const color: u32 = (@as(u32, r) << 16) | (@as(u32, g) << 8) | @as(u32, b);
+
     return .{
         .x = x,
         .y = y,
         .vx = vx,
         .vy = vy,
-        .color = 0x00FFFF, // cyan
+        .color = color,
     };
 }
 

src/sandbox_main.zig

@@ -117,7 +117,7 @@ fn createCircleTexture() ?rl.Texture2D {
         @divTrunc(TEXTURE_SIZE, 2),
         @divTrunc(TEXTURE_SIZE, 2),
         ENTITY_RADIUS,
-        CYAN,
+        rl.Color{ .r = 255, .g = 255, .b = 255, .a = 255 }, // white, tinted per-entity
     );
     rl.endTextureMode();
 
@@ -183,9 +183,14 @@ pub fn main() !void {
 
         rl.gl.rlSetTexture(circle_texture.id);
         rl.gl.rlBegin(rl.gl.rl_quads);
-        rl.gl.rlColor4ub(255, 255, 255, 255); // white tint
 
         for (entities.items[0..entities.count]) |entity| {
+            // extract RGB from entity color (0xRRGGBB)
+            const r: u8 = @truncate(entity.color >> 16);
+            const g: u8 = @truncate(entity.color >> 8);
+            const b: u8 = @truncate(entity.color);
+            rl.gl.rlColor4ub(r, g, b, 255);
+
             const x1 = entity.x - half;
             const y1 = entity.y - half;
             const x2 = entity.x + half;

src/ui.zig

@@ -8,8 +8,8 @@ const sandbox = @import("sandbox.zig");
 // config - tweak these
 // =============================================================================
 
-pub const font_size: f32 = 14;
-pub const small_font_size: f32 = 12;
+pub const font_size: f32 = 16;
+pub const small_font_size: f32 = 16;
 pub const line_height: f32 = 20;
 pub const small_line_height: f32 = 18;
 pub const padding: f32 = 10;