calc normal mat on cpu. use blinn-phong lighting. adjust lighting intensities

shaders/vertex.glsl

@@ -9,11 +9,12 @@ out vec2 texCoords;
 uniform mat4 model;
 uniform mat4 view;
 uniform mat4 projection;
+uniform mat3 normalMatrix;
 
 void main()
 {
   gl_Position = projection * view * model * vec4(aPos, 1.0f);
-  fragNormals = mat3(transpose(inverse(model))) * aNormal;
+  fragNormals = normalMatrix * aNormal;
   fragPos = vec3(model * vec4(aPos, 1.0));
   texCoords = aTexCoords;
 }