flash screen whenever load_level is called

config.json

@@ -61,7 +61,9 @@
         "quest best foreground": [255.0, 255.0, 255.0, 255.0],
         "quest best background": [0.0, 0.0, 0.0, 60.0],
         "hue shift": 10.0,
-        "hue shift frequency": 0.025
+        "hue shift frequency": 0.025,
+        "flash length": 1.1,
+        "flash darken factor": 2.0
     },
 
     "configuration":

lib/sb

@@ -1 +1 @@
-Subproject commit a5f55be257eee0886c4fdd9287c9d91c9de22d8d
+Subproject commit 5750997d5c7ef0a4fd9b41e0e4ba566d3a3907d2

src/Cakefoot.cpp

@@ -1217,6 +1217,9 @@ void Cakefoot::load_level(int index)
                 world_color = world[ii].at("color").get<glm::fvec4>();
                 break;
             } } }
+
+    /* Flash the screen at the start of a level */
+    flash_animation.play_once(configuration()("display", "flash length"));
 }
 
 void Cakefoot::write_progress() const
@@ -1815,6 +1818,7 @@ void Cakefoot::update(float timestamp)
     game_over_animation.update(timestamp);
     submit_score_animation.update(timestamp);
     shift_hue_animation.update(timestamp);
+    flash_animation.update(timestamp);
 
     /* Transformation for looking at the center of the field of play from the camera position. */
     view = glm::lookAt(camera_position, {0.0f, 0.0f, 0.0f}, glm::vec3{0.0f, 1.0f, 0.0f});
@@ -2009,14 +2013,30 @@ void Cakefoot::update(float timestamp)
 
         /* Disable texture, set background color for the current world using the color addition uniform, and draw playing field (background) */
         glUniform1i(uniform["texture enabled"], false);
-        glUniform4fv(uniform["color addition"], 1, &world_color[0]);
+        if (flash_animation.playing())
+        {
+            sb::Color extra_shift = rotating_hue;
+            extra_shift.shift_hue(180.0f);
+            glUniform4fv(uniform.at("color addition"), 1, &(extra_shift.normal() / configuration()("display", "flash darken factor").get<float>() + world_color)[0]);
+        }
+        else
+        {
+            glUniform4fv(uniform.at("color addition"), 1, &world_color[0]);
+        }
         playing_field.attributes("color")->bind("vertex_color", shader_program);
         playing_field.attributes("color")->enable();
         playing_field.draw(uniform["mvp"], view * rotation_matrix, projection, uniform["texture enabled"]);
         playing_field.attributes("color")->disable();
 
         /* Reset color addition, and draw curve. */
-        glUniform4fv(uniform["color addition"], 1, &glm::vec4(0)[0]);
+        if (flash_animation.playing())
+        {
+            glUniform4fv(uniform.at("color addition"), 1, &rotating_hue.normal()[0]);
+        }
+        else
+        {
+            glUniform4fv(uniform.at("color addition"), 1, &glm::vec4(0)[0]);
+        }
         glm::mat4 vp = projection * view * rotation_matrix;
         glUniformMatrix4fv(uniform["mvp"], 1, GL_FALSE, &vp[0][0]);
         curve().color.bind("vertex_color", shader_program);
@@ -2058,6 +2078,10 @@ void Cakefoot::update(float timestamp)
         for (auto& enemy : enemies)
         {
             enemy->draw(uniform.at("mvp"), view * rotation_matrix, projection, uniform.at("texture enabled"), rotating_hue, uniform.at("color addition"));
+            if (!flash_animation.playing())
+            {
+                glUniform4fv(uniform.at("color addition"), 1, &glm::vec4(0)[0]);
+            }
         }
 
         /* Draw cake */
@@ -2069,6 +2093,10 @@ void Cakefoot::update(float timestamp)
             for (Flame& coin : ending_coins)
             {
                 coin.draw(uniform.at("mvp"), view * rotation_matrix, projection, uniform.at("texture enabled"), rotating_hue, uniform.at("color addition"));
+                if (!flash_animation.playing())
+                {
+                    glUniform4fv(uniform.at("color addition"), 1, &glm::vec4(0)[0]);
+                }
             }
         }
 

src/Cakefoot.hpp

@@ -429,6 +429,9 @@ private:
     /* Shift the hue by the configured amount once per configured amount of seconds */
     Animation shift_hue_animation {sb::Animation(std::bind(&Cakefoot::shift_hue, this))};
 
+    /* Flash the screen */
+    Animation flash_animation;
+
     /*!
      * Get the arcade time as the amount of time remaining before the limit is reached.
      *

src/Enemy.cpp

@@ -60,7 +60,6 @@ void Enemy::draw(GLuint transformation_uniform, const glm::mat4& view, const glm
     {
         glUniform4fv(color_addition_uniform, 1, &rotating_hue.normal()[0]);
         _coin->draw(transformation_uniform, view, projection, texture_flag_uniform);
-        glUniform4fv(color_addition_uniform, 1, &glm::vec4(0)[0]);
     }
 }
 
@@ -306,7 +305,6 @@ void Projectile::draw(GLuint transformation_uniform, const glm::mat4& view, cons
         {
             glUniform4fv(color_addition_uniform, 1, &rotating_hue.normal()[0]);
             _coin->draw(transformation_uniform, view, projection, texture_flag_uniform);
-            glUniform4fv(color_addition_uniform, 1, &glm::vec4(0)[0]);
         }
     }
     else