Add point lights

shaders/flat.vert

@@ -27,6 +27,17 @@ struct DirectionalLight {
   float specular;
 };
 
+struct PointLight {
+  vec3 pos;
+  float radius;
+  vec3 color;
+  float ambient;
+  float diffuse;
+  float specular;
+};
+#define NUM_POINT_LIGHTS 4
+uniform PointLight pointLights[NUM_POINT_LIGHTS];
+
 struct Material {
   sampler2D tex;
   bool usesTex;
@@ -44,6 +55,29 @@ struct Material {
 uniform DirectionalLight directionalLight;
 uniform Material material;
 
+void calcDirectionalLight(in vec3 normal) {
+  AMBIENT += directionalLight.ambient * directionalLight.color * material.ambient;
+
+  vec3 direction = -(VIEW * vec4(directionalLight.direction, 0.0)).xyz;
+  float diff = dot(normalize(direction), normalize(normal));
+  diff = max(diff, 0.0);
+  DIFFUSE += directionalLight.diffuse * diff * directionalLight.color * material.diffuse;
+
+  vec3 viewDir = normalize((VIEW * MODEL * vec4(pos, 1.0)).xyz);
+  vec3 reflectionDir = reflect(normalize(direction), normalize(normal));
+  float spec = dot(viewDir, reflectionDir);
+  spec = max(spec, 0.0);
+  spec = pow(spec, material.shininess);
+  SPECULAR += directionalLight.color * (spec * material.specular);
+}
+
+void calcPointLight(in vec3 normal, in PointLight pointLight) {
+  vec4 ray = VIEW * MODEL * vec4(pos, 1.0) - VIEW * vec4(pointLight.pos, 1.0);
+  float dist = length(ray);
+  float attenuation = max(1.0 - dist * dist / pointLight.radius / pointLight.radius, 0.0);
+  AMBIENT += pointLight.color * material.ambient * pointLight.ambient * attenuation;
+}
+
 void main() {
   vec4 vertex = PROJECTION * VIEW * MODEL * vec4(pos, 1.0);
   gl_Position = vertex;
@@ -58,17 +92,14 @@ void main() {
   vec3 my_normal = (VIEW * mat4(NORMAL) * vec4(normal, 0.0)).xyz;
 
   // Flat shading, we compute light per vertex
-  AMBIENT = directionalLight.ambient * directionalLight.color * material.ambient;
+  AMBIENT = vec3(0.0);
+  DIFFUSE = vec3(0.0);
+  SPECULAR = vec3(0.0);
 
-  vec3 direction = -(VIEW * vec4(directionalLight.direction, 0.0)).xyz;
-  float diff = dot(normalize(direction), normalize(my_normal));
-  diff = max(diff, 0.0);
-  DIFFUSE = directionalLight.diffuse * diff * directionalLight.color * material.diffuse;
+  calcDirectionalLight(my_normal);
 
-  vec3 viewDir = normalize((VIEW * MODEL * vec4(pos, 1.0)).xyz);
-  vec3 reflectionDir = reflect(normalize(direction), normalize(my_normal));
-  float spec = dot(viewDir, reflectionDir);
-  spec = max(spec, 0.0);
-  spec = pow(spec, material.shininess);
-  SPECULAR = directionalLight.color * (spec * material.specular);
+  // PointLights
+  for(int i = 0; i < NUM_POINT_LIGHTS; i++) {
+    calcPointLight(my_normal, pointLights[i]);
+  }
 }