[Shaders] add explicit lights

shaders/fs_default.sc

@@ -2,26 +2,103 @@ $input v_position, v_normal, v_texcoord0
 
 #include <bgfx_shader.sh>
 
-SAMPLER2D(u_tex_color, 0);
+uniform sampler2D material_texture_diffuse;
+uniform sampler2D material_texture_specular;
+uniform sampler2D material_emission;
+uniform vec4      material_shininess; // float
+uniform vec4      material_color;
+uniform vec4      material_specular; // float
 
-uniform vec4 u_seg_color;
+uniform vec4 dir_light_direction; // vec3
+uniform vec4 dir_light_ambient;
+uniform vec4 dir_light_diffuse;
+uniform vec4 dir_light_specular;
 
-void main() {
-    vec3 lightColor = vec3(1, 1, 1);
-    vec3 lightPos = vec3(0, 0, 100);
+#define MAX_NB_POINT_LIGHTS 20 
+uniform vec4 point_light_position[MAX_NB_POINT_LIGHTS]; // vec3
+uniform vec4 point_light_ambient[MAX_NB_POINT_LIGHTS];
+uniform vec4 point_light_diffuse[MAX_NB_POINT_LIGHTS];
+uniform vec4 point_light_specular[MAX_NB_POINT_LIGHTS];
+uniform vec4 point_light_attenuation[MAX_NB_POINT_LIGHTS]; // vec3
+uniform vec4 nb_point_light; // float
 
-    // ambient
-    float ambientStrength = 0.1;
-    vec3 ambient = ambientStrength * lightColor;
+uniform vec4 view_position; // vec3
 
-    // Diffuse
-    vec3 norm = normalize(v_normal);
-    vec3 lightDir = normalize(lightPos - v_position);
+vec4 CalcDirLight(vec3 light_direction, vec4 light_ambient,
+                  vec4 light_diffuse, vec4 light_specular,
+                  vec3 normal, vec3 view_dir, vec2 texcoord0);
+vec4 CalcPointLight(vec3 light_position, vec4 light_ambient,
+                    vec4 light_diffuse, vec4 light_specular,
+                    vec3 light_attenuation,
+                    vec3 frag_pose, vec3 normal, vec3 view_dir, vec2 texcoord0);
 
-    float diff = max(dot(norm, lightDir), 0.0);
-    vec3 diffuse = diff * lightColor;
+void main()
+{
+  // properties
+  vec3 norm = normalize(v_normal);
+  vec3 view_dir = normalize(view_position.xyz - v_position);
 
-    vec4 result = vec4(ambient + diffuse, 1) * texture2D(u_tex_color, v_texcoord0) * u_seg_color;
+  // phase 1: Directional lighting
+  vec4 result = CalcDirLight(dir_light_direction.xyz, dir_light_ambient,
+                             dir_light_diffuse, dir_light_specular,
+                             norm, view_dir, v_texcoord0);
+  // phase 2: Point lights
+  for(int i = 0; i < int(nb_point_light.x); i++)
+      result += CalcPointLight(point_light_position[i].xyz, point_light_ambient[i],
+                               point_light_diffuse[i], point_light_specular[i],
+                               point_light_attenuation[i].xyz,
+                               v_position, norm, view_dir, v_texcoord0);  
 
-	gl_FragColor = result;
+  gl_FragColor = result;
+}
+
+vec4 CalcDirLight(vec3 light_direction, vec4 light_ambient,
+                  vec4 light_diffuse, vec4 light_specular,
+                  vec3 normal, vec3 view_dir, vec2 texcoord0)
+{
+  vec3 light_dir = normalize(-light_direction.xyz);
+  // diffuse shading
+  float diff = max(dot(normal, light_dir), 0.0);
+  // specular shading
+  vec3 reflect_dir = reflect(-light_dir, normal);
+  float spec = pow(max(dot(view_dir, reflect_dir), 0.0), material_shininess.x);
+  // combine results
+  vec4 ambient  = light_ambient * texture2D(material_texture_diffuse, texcoord0) * material_color;
+  vec4 diffuse  = light_diffuse  * diff * texture2D(material_texture_diffuse, texcoord0);
+  vec4 specular = vec4(0.f);
+  if(material_specular.x >= 0.f)
+    specular = light_specular * spec * vec4(material_specular.x);
+  else
+    specular = light_specular * spec * vec4(texture2D(material_texture_specular, texcoord0).r);
+  return (ambient + diffuse + specular);
+}
+
+vec4 CalcPointLight(vec3 light_position, vec4 light_ambient,
+                    vec4 light_diffuse, vec4 light_specular,
+                    vec3 light_attenuation,
+                    vec3 frag_pose, vec3 normal, vec3 view_dir, vec2 texcoord0)
+{
+  vec3 light_dir = normalize(light_position - frag_pose);
+  // diffuse shading
+  float diff = max(dot(normal, light_dir), 0.0);
+  // specular shading
+  vec3 reflect_dir = reflect(-light_dir, normal);
+  float spec = pow(max(dot(view_dir, reflect_dir), 0.0), material_shininess.x);
+  // attenuation
+  float distance    = length(light_position - frag_pose);
+  float attenuation = 1.0 / (light_attenuation.x + light_attenuation.y * distance + 
+                      light_attenuation.z * (distance * distance));    
+  // combine results
+  vec4 ambient  = light_ambient  * texture2D(material_texture_diffuse, texcoord0);
+  vec4 diffuse  = light_diffuse  * diff * texture2D(material_texture_diffuse, texcoord0);
+  vec4 specular = vec4(0.f);
+  if(material_specular.x >= 0.f)
+    specular = light_specular * spec * vec4(material_specular.x);
+  else
+    specular = light_specular * spec * vec4(texture2D(material_texture_specular, texcoord0).r);
+
+  ambient  *= attenuation;
+  diffuse  *= attenuation;
+  specular *= attenuation;
+  return (ambient + diffuse + specular);
 }

shaders/vs_default.sc

@@ -3,11 +3,11 @@ $output v_position, v_normal, v_texcoord0
 
 #include <bgfx_shader.sh>
 
-void main() {
-    vec3 light_position = vec3(0, 0, 100);
-
-	gl_Position = mul(u_modelViewProj, vec4(a_position, 1.0));
+void main()
+{
 	v_position = vec3(u_model[0] * vec4(a_position, 1.0));
 	v_normal = a_normal;
 	v_texcoord0 = a_texcoord0;
+
+	gl_Position = mul(u_modelViewProj, vec4(a_position, 1.0));
 }