Standard Lighting (3/3)

- Added normal and specular maps to standard shader.
- Added full tint attribute to standard shader and material data type.
- Changed point light attenuation to radius.

examples/resources/shaders/standard.fs

@@ -8,12 +8,18 @@ in vec3 fragNormal;
 out vec4 finalColor;
 
 uniform sampler2D texture0;
+uniform sampler2D texture1;
+uniform sampler2D texture2;
 
+uniform vec4 colTint;
 uniform vec4 colAmbient;
 uniform vec4 colDiffuse;
 uniform vec4 colSpecular;
 uniform float glossiness;
 
+uniform int useNormal;
+uniform int useSpecular;
+
 uniform mat4 modelMatrix;
 uniform vec3 viewDir;
 
@@ -24,7 +30,7 @@ struct Light {
     vec3 direction;
     vec4 diffuse;
     float intensity;
-    float attenuation;
+    float radius;
     float coneAngle;
 };
 
@@ -32,27 +38,27 @@ const int maxLights = 8;
 uniform int lightsCount;
 uniform Light lights[maxLights];
 
-vec3 CalcPointLight(Light l, vec3 n, vec3 v)
+vec3 CalcPointLight(Light l, vec3 n, vec3 v, float s)
 {
     vec3 surfacePos = vec3(modelMatrix*vec4(fragPosition, 1));
     vec3 surfaceToLight = l.position - surfacePos;
     
     // Diffuse shading
     float brightness = clamp(dot(n, surfaceToLight)/(length(surfaceToLight)*length(n)), 0, 1);
-    float diff = 1.0/dot(surfaceToLight/l.attenuation, surfaceToLight/l.attenuation)*brightness*l.intensity;
+    float diff = 1.0/dot(surfaceToLight/l.radius, surfaceToLight/l.radius)*brightness*l.intensity;
     
     // Specular shading
     float spec = 0.0;
     if (diff > 0.0)
     {
         vec3 h = normalize(-l.direction + v);
-        spec = pow(dot(n, h), 3 + glossiness);
+        spec = pow(dot(n, h), 3 + glossiness)*s;
     }
     
     return (diff*l.diffuse.rgb*colDiffuse.rgb + spec*colSpecular.rgb);
 }
 
-vec3 CalcDirectionalLight(Light l, vec3 n, vec3 v)
+vec3 CalcDirectionalLight(Light l, vec3 n, vec3 v, float s)
 {
     vec3 lightDir = normalize(-l.direction);
     
@@ -64,14 +70,14 @@ vec3 CalcDirectionalLight(Light l, vec3 n, vec3 v)
     if (diff > 0.0)
     {
         vec3 h = normalize(lightDir + v);
-        spec = pow(dot(n, h), 3 + glossiness);
+        spec = pow(dot(n, h), 3 + glossiness)*s;
     }
     
     // Combine results
     return (diff*l.intensity*l.diffuse.rgb*colDiffuse.rgb + spec*colSpecular.rgb);
 }
 
-vec3 CalcSpotLight(Light l, vec3 n, vec3 v)
+vec3 CalcSpotLight(Light l, vec3 n, vec3 v, float s)
 {
     vec3 surfacePos = vec3(modelMatrix*vec4(fragPosition, 1));
     vec3 lightToSurface = normalize(surfacePos - l.position);
@@ -95,7 +101,7 @@ vec3 CalcSpotLight(Light l, vec3 n, vec3 v)
     if (diffAttenuation > 0.0)
     {
         vec3 h = normalize(lightDir + v);
-        spec = pow(dot(n, h), 3 + glossiness);
+        spec = pow(dot(n, h), 3 + glossiness)*s;
     }
     
     return falloff*(diffAttenuation*l.diffuse.rgb + spec*colSpecular.rgb);
@@ -104,9 +110,10 @@ vec3 CalcSpotLight(Light l, vec3 n, vec3 v)
 void main()
 {
     // Calculate fragment normal in screen space
+    // NOTE: important to multiply model matrix by fragment normal to apply model transformation (rotation and scale)
     mat3 normalMatrix = transpose(inverse(mat3(modelMatrix)));
     vec3 normal = normalize(normalMatrix*fragNormal);
-   
+
     // Normalize normal and view direction vectors
     vec3 n = normalize(normal);
     vec3 v = normalize(viewDir);
@@ -115,6 +122,17 @@ void main()
     vec4 texelColor = texture(texture0, fragTexCoord);
     vec3 lighting = colAmbient.rgb;
     
+    // Calculate normal texture color fetching or set to maximum normal value by default
+    if(useNormal == 1)
+    {
+        n *= texture(texture1, fragTexCoord).rgb;
+        n = normalize(n);
+    }
+    
+    // Calculate specular texture color fetching or set to maximum specular value by default
+    float spec = 1.0;
+    if(useSpecular == 1) spec *= normalize(texture(texture2, fragTexCoord).r);
+    
     for (int i = 0; i < lightsCount; i++)
     {
         // Check if light is enabled
@@ -123,14 +141,14 @@ void main()
             // Calculate lighting based on light type
             switch (lights[i].type)
             {
-                case 0: lighting += CalcPointLight(lights[i], n, v); break;
-                case 1: lighting += CalcDirectionalLight(lights[i], n, v); break;
-                case 2: lighting += CalcSpotLight(lights[i], n, v); break;
+                case 0: lighting += CalcPointLight(lights[i], n, v, spec); break;
+                case 1: lighting += CalcDirectionalLight(lights[i], n, v, spec); break;
+                case 2: lighting += CalcSpotLight(lights[i], n, v, spec); break;
                 default: break;
             }
         }
     }
     
     // Calculate final fragment color
-    finalColor = vec4(texelColor.rgb*lighting, texelColor.a);
+    finalColor = vec4(texelColor.rgb*lighting*colTint.rgb, texelColor.a*colTint.a);
 }