adjust light functionality,

bugs:
- background cannot be changed during runtime

QtMeshViewer/Resources/fshader.glsl

@@ -15,40 +15,41 @@ uniform struct Light {
 uniform bool b_transparent;
 uniform bool b_light;
 
-varying vec2 v_texcoord;
-varying vec3 v_position;
-varying vec3 v_normal;
+varying vec2 v_surfaceUV;
+varying vec3 v_surfacePosition;
+varying vec3 v_surfaceNormal;
 
 void main()
 {
 	// variables
-	float brightness;
-
-	if(b_light == true)
-	{
-		// calculate normals in worldspace
-		vec3 normal = normalize(n_matrix * v_normal);
-
-		//get the surface - light vector (cause this is a candel)
-		vec3 surfaceToLight = light.position - v_position;
-
-		// calculate the brightness depending on the angle
-		brightness = dot(normal, surfaceToLight) / (length(surfaceToLight) * length(normal));
-		brightness = clamp(brightness, 0, 1);
-	}
-	else
-	{
-		brightness = 1;
-		light.intensities = vec3(1,1,1);
-	}
+	vec3 diffuse;
 
 	// get fragment color from texture
-	vec4 surfaceColor = vec4(texture2D(texture, v_texcoord));
+	vec4 surfaceColor = vec4(texture2D(texture, v_surfaceUV));
 
 	// if not transparent, ignore alpha value and set it to 1
 	if(!b_transparent)
 		surfaceColor.a = 1.0f;
 
-	// pass the data to ogl
-	gl_FragColor = vec4(brightness * light.intensities * surfaceColor.rgb, surfaceColor.a);
+	if(b_light)
+	{
+		// calculate normals in worldspace
+		vec3 normalWorld = normalize(n_matrix * v_surfaceNormal);
+
+		//get the surface - light vector (cause this is a point light)
+		vec3 surfaceToLight = normalize(light.position - v_surfacePosition);
+
+		// calculate the brightness depending on the angle
+		float diffuseCoefficient = max(0.0, dot(normalWorld, surfaceToLight));
+
+		// result diffuse color
+		diffuse = diffuseCoefficient * surfaceColor.rgb * light.intensities;
+	}
+	else
+	{
+		diffuse = surfaceColor.rgb;
+	}
+
+	// put all together
+	gl_FragColor = vec4(diffuse, surfaceColor.a);
 }