3DFileViewer: Replace lambertian lighting with GL Lighting

Userland/Applications/3DFileViewer/Mesh.cpp

@@ -33,13 +33,6 @@ Mesh::Mesh(Vector<Vertex> vertices, Vector<TexCoord> tex_coords, Vector<Vertex>
 
 void Mesh::draw(float uv_scale)
 {
-    // Light direction
-    const FloatVector3 light_direction(1.f, 1.f, 1.f);
-
-    // Mesh color
-    const FloatVector4 mesh_ambient_color(0.2f, 0.2f, 0.2f, 1.f);
-    const FloatVector4 mesh_diffuse_color(0.6f, 0.6f, 0.6f, 1.f);
-
     for (u32 i = 0; i < m_triangle_list.size(); i++) {
         const auto& triangle = m_triangle_list[i];
 
@@ -83,17 +76,14 @@ void Mesh::draw(float uv_scale)
             normal = vec_ab.cross(vec_ac).normalized();
         }
 
-        // Compute lighting with a Lambertian color model
-        const auto light_intensity = max(light_direction.dot(normal), 0.f);
-        const FloatVector4 color = mesh_ambient_color
-            + mesh_diffuse_color * light_intensity;
-
         glBegin(GL_TRIANGLES);
-        glColor4f(color.x(), color.y(), color.z(), color.w());
 
         if (is_textured())
             glTexCoord2f(m_tex_coords.at(triangle.tex_coord_index0).u * uv_scale, (1.0f - m_tex_coords.at(triangle.tex_coord_index0).v) * uv_scale);
 
+        // Upload the face normal
+        glNormal3f(normal.x(), normal.y(), normal.z());
+
         // Vertex 1
         glVertex3f(
             m_vertex_list.at(triangle.a).x,

Userland/Applications/3DFileViewer/main.cpp

@@ -69,6 +69,12 @@ private:
         glEnable(GL_CULL_FACE);
         glEnable(GL_DEPTH_TEST);
 
+        // Enable lighting
+        glEnable(GL_LIGHTING);
+        glEnable(GL_LIGHT0);
+        glEnable(GL_LIGHT1);
+        glEnable(GL_LIGHT2);
+
         // Set projection matrix
         glMatrixMode(GL_PROJECTION);
         glLoadIdentity();
@@ -159,6 +165,7 @@ void GLContextWidget::mousewheel_event(GUI::MouseEvent& event)
 void GLContextWidget::timer_event(Core::TimerEvent&)
 {
     auto timer = Core::ElapsedTimer::start_new();
+    static unsigned int light_counter = 0;
 
     glCallList(m_init_list);
 
@@ -175,6 +182,23 @@ void GLContextWidget::timer_event(Core::TimerEvent&)
     glRotatef(m_angle_y, 0, 1, 0);
     glRotatef(m_angle_z, 0, 0, 1);
 
+    glPushMatrix();
+    glLoadIdentity();
+    // Disco time ;)
+    GLfloat const light0_position[4] = { -4.0f, 0.0f, 0.0f, 0.0f };
+    GLfloat const light0_diffuse[4] = { 1.0f, 0.0f, 0.0f, 0.0f };
+    GLfloat const light1_position[4] = { 4.0f, 0.0f, 0.0f, 0.0f };
+    GLfloat const light1_diffuse[4] = { 0.0f, 1.0f, 0.0f, 0.0f };
+    GLfloat const light2_position[4] = { 0.0f, 5.0f, 0.0f, 0.0f };
+    GLfloat const light2_diffuse[4] = { 0.0f, 0.0f, 1.0f, 0.0f };
+    glLightfv(GL_LIGHT0, GL_POSITION, &light0_position[0]);
+    glLightfv(GL_LIGHT0, GL_DIFFUSE, &light0_diffuse[0]);
+    glLightfv(GL_LIGHT1, GL_POSITION, &light1_position[0]);
+    glLightfv(GL_LIGHT1, GL_DIFFUSE, &light1_diffuse[0]);
+    glLightfv(GL_LIGHT2, GL_POSITION, &light2_position[0]);
+    glLightfv(GL_LIGHT2, GL_DIFFUSE, &light2_diffuse[0]);
+    glPopMatrix();
+
     if (m_texture_enabled) {
         glEnable(GL_TEXTURE_2D);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, m_wrap_s_mode);
@@ -195,6 +219,18 @@ void GLContextWidget::timer_event(Core::TimerEvent&)
         auto frame_rate = render_time > 0 ? 1000 / render_time : 0;
         m_stats->set_text(String::formatted("{:.0f} fps, {:.1f} ms", frame_rate, render_time));
         m_accumulated_time = 0;
+
+        glEnable(GL_LIGHT0);
+        glEnable(GL_LIGHT1);
+        glEnable(GL_LIGHT2);
+        light_counter++;
+
+        if ((light_counter % 3) == 0)
+            glDisable(GL_LIGHT0);
+        else if ((light_counter % 3) == 1)
+            glDisable(GL_LIGHT1);
+        else
+            glDisable(GL_LIGHT2);
     }
 
     update();