Add more improvements

src/graphics/graphics-library/compiling/create-program.ts

@@ -7,11 +7,8 @@ export const createProgram = (
   fragmentShaderSource: string,
   substitutions: { [name: string]: string }
 ): WebGLProgram => {
-  const program = gl.createProgram();
-
-  if (!program) {
-    throw new Error('Could not create program');
-  }
+  // can only return null on lost context
+  const program = gl.createProgram()!;
 
   // const extension = tryEnableExtension(gl, 'KHR_parallel_shader_compile');
 
@@ -43,5 +40,8 @@ export const createProgram = (
 
   checkProgram(gl, program);
 
+  gl.deleteShader(vertexShader);
+  gl.deleteShader(fragmentShader);
+
   return program;
 };