From c5fe725b1b8086366537a6983f36de1e13dcb5c5 Mon Sep 17 00:00:00 2001
From: Aaron Fenyes <aaron.fenyes@fareycircles.ooo>
Date: Sun, 25 Aug 2024 22:22:14 -0700
Subject: [PATCH] Ray-caster: automate getting uniform array locations

---
 app-proto/inversive-display/src/main.rs | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/app-proto/inversive-display/src/main.rs b/app-proto/inversive-display/src/main.rs
index 83e05c0..e2097e7 100644
--- a/app-proto/inversive-display/src/main.rs
+++ b/app-proto/inversive-display/src/main.rs
@@ -11,7 +11,7 @@ extern crate js_sys;
 use core::array;
 use nalgebra::DVector;
 use sycamore::{prelude::*, rt::{JsCast, JsValue}};
-use web_sys::{console, WebGl2RenderingContext, WebGlShader};
+use web_sys::{console, WebGl2RenderingContext, WebGlProgram, WebGlShader, WebGlUniformLocation};
 
 mod engine;
 
@@ -26,6 +26,18 @@ fn compile_shader(
     shader
 }
 
+fn get_uniform_array_locations<const N: usize>(
+    context: &WebGl2RenderingContext,
+    program: &WebGlProgram,
+    var_name: &str,
+    member_name: &str
+) -> [Option<WebGlUniformLocation>; N] {
+    array::from_fn(|n| {
+        let name = format!("{var_name}[{n}].{member_name}");
+        context.get_uniform_location(&program, name.as_str())
+    })
+}
+
 // load the given data into the vertex input of the given name
 fn bind_vertex_attrib(
     context: &WebGl2RenderingContext,
@@ -131,11 +143,11 @@ fn main() {
             ctx.use_program(Some(&program));
             
             // find indices of vertex attributes and uniforms
-            let sphere_sp_locs = array::from_fn::<_, SPHERE_MAX, _>(
-                |n| ctx.get_uniform_location(&program, format!("sphere_list[{}].sp", n).as_str())
+            let sphere_sp_locs = get_uniform_array_locations::<SPHERE_MAX>(
+                &ctx, &program, "sphere_list", "sp"
             );
-            let sphere_lt_locs = array::from_fn::<_, SPHERE_MAX, _>(
-                |n| ctx.get_uniform_location(&program, format!("sphere_list[{}].lt", n).as_str())
+            let sphere_lt_locs = get_uniform_array_locations::<SPHERE_MAX>(
+                &ctx, &program, "sphere_list", "lt"
             );
             let position_index = ctx.get_attrib_location(&program, "position") as u32;
             let resolution_loc = ctx.get_uniform_location(&program, "resolution");