Prepared better shaders.

assets/shaders/fragment_shader.glsl

@@ -1,7 +1,15 @@
 #version 330 core
+
+uniform vec3 light_dir;
 in vec3 frag_col;
+in vec3 frag_pos;
+in vec3 normal;
 out vec3 col;
 
 void main() {
-	col = frag_col;
+	vec3 norm = normalize(normal);
+	vec3 lightDir = normalize(-light_dir);
+	float diff = max(dot(norm, lightDir), 0.0);
+	vec3 diffuse = diff * frag_col;
+	col = diffuse;
 }

assets/shaders/vertex_shader.glsl

@@ -1,9 +1,20 @@
 #version 330 core
 layout(location = 0) in vec3 vert_pos;
+layout(location = 1) in vec3 vert_norm;
+
 uniform vec3 col;
-uniform mat4 mvp;
+uniform vec3 light_col;
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 proj;
+
+out vec3 frag_pos;
 out vec3 frag_col;
+out vec3 normal;
+
 void main() {
-	gl_Position = mvp * vec4(vert_pos, 1);
-	frag_col = col;
+	gl_Position = model * view * proj * vec4(vert_pos, 1);
+	frag_pos = vec3(model * vec4(vert_pos, 1.0));
+	frag_col = col * light_col;
+	normal = mat3(transpose(inverse(model))) * vert_norm;
 }